Revealing language development delays in preterm infants compared to full-term infants based on the CCDI

Revealing language development delays in preterm infants compared to full-term infants based on the CCDI | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Revealing language development delays in preterm infants compared to full-term infants based on the CCDI Feng Liu, Qu Xu, Yachun Xie, Jingyu Wang, Cai Wang, Mengmeng Yao, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8731965/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective This study aimed to investigate and compare language development in preterm and full-term infants at 12 and 24 months of age, utilizing the Chinese Communicative Development Inventory (CCDI) to identify distinct developmental features in preterm infants and inform timely language interventions. Methods A cross-sectional study was conducted, including 139 preterm infants (59 at 12 months, 80 at 24 months) and 235 full-term infants (123 at 12 months, 112 at 24 months). The CCDI "Words and Gestures" (8–16 months) and "Words and Sentences" (16–30 months) questionnaires were used to assess gestural communication, early comprehension, vocabulary breadth, and syntactic complexity. Statistical analyses, including t-tests and chi-square tests, were performed to compare groups. Results Preterm infants exhibited significantly lower scores than full-term infants at both 12 and 24 months in various language domains assessed by the CCDI. Specifically, at 12 months, preterm infants showed deficits in initial gestures, motion gestures, phrase comprehension, vocabulary comprehension, and vocabulary expression. At 24 months, preterm infants scored lower in vocabulary expression and sentence complexity. The incidence of language development delay was significantly higher in preterm infants at both 12 months (40.68% vs. 18.70%, P = 0.0028) and 24 months (26.25% vs. 5.35%, P < 0.0001). Gender also impacted language development, with boys often exhibiting lower language development levels than girls. Conclusion Preterm infants demonstrate significant delays in both pre-linguistic and linguistic stages of language development compared to full-term infants, highlighting the importance of early language development assessment and targeted interventions to mitigate long-term sequelae. The CCDI proves to be a valuable tool in identifying these differences and guiding early intervention efforts. preterm infants language development CCDI (Chinese Communicative Development Inventory) language delay Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Each year, approximately 15 million premature infants are born worldwide, representing about 10% of all live births [ 1 ] . While advancements in perinatal care have significantly improved the survival rates of preterm infants, they remain at a substantially higher risk of neurodevelopmental disorders [ 2 – 4 ] . Among these, language delay is a frequent early manifestation of neurodevelopmental impairment [ 5 – 8 ] . Beyond affecting basic language comprehension and expression, such delays can lead to cascading challenges, including reading and spelling difficulties, interpersonal struggles, emotional-behavioral disorders, and long-term impacts on academic achievement, career trajectories, and social integration [ 9 , 10 ] . Consequently, investigating the language development patterns of preterm infants has become a critical focus in child health and developmental-behavioral pediatrics. Children’s typical language development progresses through two sequential phases: the prelinguistic stage (nonverbal communication, including joint attention, gestures, babbling, and early comprehension) and the linguistic stage (spoken language, encompassing vocabulary expansion and syntactic complexity) [ 11 , 12 ] . However, preterm infants often exhibit atypical language trajectories due to the interplay of prematurity, neonatal complications, and socioenvironmental factors [ 13 ] . Research in this domain holds dual significance: It elucidates the pathways underlying language impairments in preterm infants, pinpointing developmental gaps and informing targeted remediation strategies. It enables clinicians to differentiate transient developmental delays from persistent high-risk profiles for language/learning disorders [ 14 , 15 ] . Systematic assessment across developmental stages is thus essential to characterize preterm infants language profiles and guide evidence-based interventions. The MacArthur Communicative Development Inventory (MCDI), developed by Fenson et al. (1994), is a globally utilized parent-report tool for evaluating early language and communication skills, with adaptations in over 100 languages [ 16 , 17 ] . Its Mandarin version, the Chinese Communicative Development Inventory (CCDI), was standardized by Liang Weilan’s team (2001) with culturally and linguistically appropriate modifications, demonstrating robust psychometric validity [ 18 ] . The CCDI comprises two age-specific questionnaires: "Words and Gestures" (8–16 months) assessing prelinguistic abilities, and "Words and Sentences" (16–30 months) evaluating expressive vocabulary and grammar. Its widespread adoption in clinical and research contexts underscores its utility in profiling infant language development [19.20] . This study employs the CCDI to compare language development in preterm and full-term infants at 12 and 24 months, examining gestural communication, early comprehension, vocabulary breadth, and syntactic maturation. By identifying distinct developmental features in preterm infants, the findings will inform timely, tailored language interventions to mitigate long-term sequelae. Method Preterm infant group In this study, the preterm infant group was recruited from the High-Risk Pediatric Outpatient Department of the Early Intervention and Rehabilitation Center at Nanjing Maternal and Child Health Hospital, between October 2021 and December 2022. This group included preterm infants who were either 1 year (± 1 month) or 2 years (± 1 month) old. Following the recommendations of the study [45], the corrected age up to 24 months was used to assess the growth and development of preterm infants. Consequently, for preterm infants younger than 24 months, the corrected age was used, while for those older than 24 months, their actual age was considered. Inclusion criteria: (1) Hearing assessment: Passed automated auditory brainstem response testing at birth or during the 42-day health check, and also passed screening otoacoustic emissions testing within the past six months; (2) Both parents are native Mandarin speakers; (3) No known history of psychiatric disorders in the family. Exclusion criteria: (1) Complications during the neonatal period that may cause severe brain damage, including hypoxic-ischemic encephalopathy, severe bronchopulmonary dysplasia, intraventricular hemorrhage grade III or IV, bilirubin encephalopathy, severe apnea, and meningitis; (2) Congenital malformations, genetic and metabolic disorders, sensory impairments, and cerebral palsy; (3) History of otitis media within the past six months. A total of 139 preterm infants were included in the preterm infant group, comprising 59 infants who were 1 year old and 80 infants who were 2 years old. Among them, there were 79 boys and 60 girls. Full-term infant group The full-term infant group was recruited from routine health check-ups at the pediatric outpatient department of Nanjing Maternal and Child Health Hospital during the same period. This group included full-term infants matched 1:2 by gender and age to the preterm infant group, comprising 1-year-old (± 1 month) and 2-year-old (± 1 month) full-term infants. The inclusion and exclusion criteria were the same as those applied to the preterm infant group. A total of 235 full-term infants were included in the full-term infant group, consisting of 123 infants who were 1 year old and 112 infants who were 2 years old. Among them, there were 116 boys and 119 girls. This study was approved by the Medical Ethics Committee of Nanjing Medical University Affiliated Obstetrics and Gynecology Hospital (Approval No. NFMU-2020-KY-058). Before initiating the study procedures, the parents or legal guardians of the participants were informed about the purpose and detailed process of the research. Informed consent was obtained from all guardians before conducting any tests. Collection of child data General Information: Gender, chronological age, vision, and hearing screening results. Birth Information: Date of birth, expected delivery date, gestational age at birth, birth weight, results of newborn disease screening, and hospitalization details during the neonatal period. Parental and Family Information: Parents' educational level and family annual income. Language development assessment the Chinese Communicative Development Inventory (CCDI) The MacArthur Communicative Development Inventory (MCDI), developed by Fenson et al. in 1994, is a widely used parent-report instrument designed to assess early language and communication skills. It has been adapted into more than 100 languages worldwide [16,17]. The Mandarin version, known as the Chinese Communicative Development Inventory (CCDI), was standardized by Liang Weilan’s team in 2001. This version incorporates culturally and linguistically appropriate modifications and has demonstrated strong psychometric properties [18]. The CCDI includes two age-specific questionnaires: “Words and Gestures” for infants aged 8–16 months, which assesses prelinguistic communication abilities, and “Words and Sentences” for toddlers aged 16–30 months, focusing on expressive vocabulary and early grammatical development. The tool’s extensive use in both clinical and research settings highlights its value in characterizing early language development in infants [19,20]. CCDI vocabulary and gestures (Applicable to 8–16 months of age) The questionnaire includes assessments of early gestures, later gestures, total gestures, phrase comprehension, vocabulary comprehension, and vocabulary production. The early gestures subscale comprises 11 initial communication gestures and 5 play and routine gestures, with a total score of 27 points. The later gestures subscale includes 15 interactive actions, 5 pretend play actions, and 7 imitation of adult actions, with a total score of 27 points. The total gestures score is the sum of the early and later gestures subscales, totaling 54 points. Phrase comprehension includes 27 short phrases, with a total score of 27 points. The vocabulary scale section consists of 411 words, divided into the following subscales: 214 nouns (across 10 categories, including 26 names, 29 eating and drinking items, 18 body parts, 33 animals, 35 household items, 8 toys and recreational items, 15 articles of clothing, 19 pieces of furniture/household items, 22 outdoor items and places, and 9 vehicles), 78 verbs, 11 onomatopoeic words, 22 game/routine words, 44 adjectives/adverbs, 11 directional words, 6 quantifiers, 6 interrogative words, 7 pronouns, 6 measure words, and 6 time-related words. Both vocabulary comprehension and vocabulary production are scored with a maximum of 411 points each. Percentile ranks corresponding to the raw scores can be obtained. A percentile rank of ≤ P10 in any of these measures indicates language development delays in the child. CCDI vocabulary and sentences (Applicable to 16–30 months of age) The questionnaire includes assessments of vocabulary production and sentence complexity. The vocabulary section comprises 799 words, with a total score of 799 points, while the sentence complexity score includes 27 items, with a total of 81 points. The vocabulary section is divided into 24 categories and contains 799 words, including 371 nouns (across 11 categories: 32 names, 69 eating and drinking items, 27 body parts, 49 animals, 56 household items, 18 toys and recreational items, 28 articles of clothing, 29 pieces of furniture and household items, 32 outdoor items, 14 vehicles, and 17 outdoor places), 194 verbs, 66 adjectives/adverbs, 28 game/routine words, 12 onomatopoeic words, 21 directional words, 9 numerals, 24 pronouns, 20 measure words, 12 interrogative words, 6 sentence-final particles, 15 time-related words, 12 auxiliary particles, and 9 conjunctions. The vocabulary production section is scored with a total of 799 points. The sentence complexity section includes 27 items, covering grammatical components such as morphemes indicating progressive and perfect aspects, possessive morphemes, time adverbs, auxiliary verbs, negation words, mood particles, and sentence-final particles. Each item consists of 2–5 sentence patterns, with more complex patterns earning higher scores, totaling 81 points. Percentile ranks corresponding to the raw scores can be obtained, with a percentile rank of ≤ P10 in any measure indicating language development delays in the child. Quality control Developmental assessment quality control All developmental assessments were conducted by qualified pediatricians to ensure standardization and accuracy. Data entry quality control Data entry was performed using Epidata 3.1, with processes in place for uniqueness checks, double-entry verification, and logical consistency checks. Data analysis quality control The statistical analysis of the data was supervised by specialized statisticians to ensure the correctness of the interpretation of results. Statistical analysis Statistical analyses were performed using R (version 4.4.2). Normally distributed continuous data are presented as mean ± standard deviation, while non-normally distributed continuous data are presented as median (interquartile range). Categorical data are presented as sample size (percentage). Independent sample t-tests were used to compare differences in continuous data between two groups. Pearson chi-square tests, Pearson chi-square tests with continuity correction, or Fisher's exact tests were used to compare differences in categorical data between two groups. Spearman correlation analysis was used to examine the relationship between gestational age and scores on various dimensions of language development. All tests were two-tailed, with a significance level of P < 0.05. Result 1. General clinical and sociodemographic characteristics A total of 374 children were ultimately included in the study, comprising 139 preterm infants (79 boys and 60 girls) and 235 full-term infants (116 boys and 119 girls). In the preterm infant group, there were 59 infants aged 1 year and 80 infants aged 2 years. In the full-term infant group, there were 123 infants aged 1 year and 112 infants aged 2 years. There were no statistically significant differences between the two groups in terms of age (1-year-old group: P = 0.474; 2-year-old group: P = 0.226) or gender (P = 0.197). The preterm infant group had significantly lower gestational age at birth (P < 0.001) and birth weight (P < 0.001) compared to the full-term infant group. The proportion of preterm infants delivered by cesarean section and suffocation was significantly higher than that of full-term infants (P < 0.001). There was no statistically significant difference between the two groups in the proportion of singleton births (P = 1.000) (Table 1). 2. Comparison of CCDI results between preterm infants and full-term infants in different age groups 2.1. Comparison of CCDI vocabulary and gestures score between preterm infants and full-term infants in one-year-old group The preterm infants exhibited significantly lower scores than the full-term infants in vocabulary and gestures score , including initial gestures score (P = 0.0180), motion gestures score (P = 0.0200), phrase comprehension scores (P = 0.0001), vocabulary comprehension score (P = 0.0013), and vocabulary expression scores (P = 0.0068), but there were no statistically significant differences between the groups in later gestures score (P = 0.0770) (Figure 1A). In the sub - test of “Gesture Types” in CCDI, the scores of early gesture communication in early gestures (P = 0.0110) and the scores of pretend play in later gestures (P = 0.0035) were significantly lower in preterm infants than in full - term infants (Figure 1B). In the sub - test of “Vocabulary Types” in CCDI, the scores of nouns (P = 0.0035), verbs (P = 0.001), onomatopoeia (P = 0.0022), game and routine vocabulary (P = 0.0002), as well as adjectives and adverbs (P = 0.0024) in the vocabulary comprehension items were significantly lower in preterm infants (Figure 1C). Similarly, the scores of nouns (P = 0.0088), onomatopoeia (P = 0.0028), game and routine vocabulary (P = 0.0230) and numeral - classifiers (P = 0.0490) in the vocabulary expression items were lower in preterm infants (Figure 1D). 2.2. Comparison of CCDI vocabulary and sentences results between preterm infants and full-term Infants in two-year-old group In the two - year - old group, the scores of vocabulary expression (P = 0.0005) and sentence complexity (P = 0.0014) of preterm infants were significantly lower than those of full - term infants (Figure 2A). In the sub - tests of vocabulary expression, the scores of nouns (P = 0.0003), verbs (P = 0.0001), adjectives and adverbs (P = 0.0006), game and routine vocabulary (P = 0.0003), onomatopoeia (P = 0.0006), directional words (P = 0.0099), interrogative words (P = 0.0200), modal particles at the end of sentences (P = 0.0140), and auxiliary words (P = 0.0058) in the preterm infant group were significantly lower than those in the full - term infant group (Figure 2B). 3. incidence of language development delay In the one - year - old group, the rate of language development delay in preterm infants was 40.68% (24/59), significantly higher than that in full - term infants (18.70%, 23/123) (P = 0.0028) (Figure 3A). The same result was observed in the two - year - old group. The rate in the preterm infant group (26.25%, 21/80) was significantly higher than that in the full - term infant group (5.35%, 6/112) (P = 1e - 04) (Figure 3B). 4. Impact of gender on language development 4.1. Comparison of CCDI results for one-year-old group In the boys' group, there were no statistically significant differences in the total scores of the "Vocabulary and Gestures" section of the CCDI between preterm infants and full - term infants (Figure 4A). In the sub - test of "Gesture Types" in the CCDI, there were no statistically significant differences in the early gesture scores (Figure 4B). In the sub - test of "Vocabulary Types" in the CCDI, the scores for verbs in the vocabulary comprehension items (P = 0.0260) were significantly lower in preterm infants (Figure 4C), while there were no statistically significant differences in the scores of each sub - test in the vocabulary expression items (Figure 4D). In the girls' group，The preterm infants exhibited significantly lower scores than the full-term infants in vocabulary and gestures score , including initial gestures score (P = 0.0004) ,later gestures(P=0.0220), motion gestures score (P = 0.0014), phrase comprehension scores (P < 0.0001), vocabulary comprehension score (P = 0.0130), and vocabulary expression scores (P = 0.0230) (Figure 4E)。In the sub - test of "Gesture Types" in the CCDI, the scores for early gesture communication in early gestures (P = 0.0006) and the scores for pretend play in later gestures (P = 0.0037) were significantly lower in preterm infants than in full - term infants (Figure 4F). In the sub - test of "Vocabulary Types" in the CCDI, the scores for nouns (P = 0.0250), verbs (P = 0.0047), onomatopoeia (P = 0.0038), game and routine vocabulary (P = 0.0022), adjectives and adverbs (P = 0.0220) in the vocabulary comprehension items, as well as numeral - classifiers (P = 0.0020) were significantly lower in preterm infants (Figure 4G). Similarly, the scores for nouns (P = 0.0330) and onomatopoeia (P = 0.0001) in the vocabulary expression items were lower in preterm infants (Figure 4H). 4.2. Comparison of CCDI results for two-year-old group In the boys' group, the scores of vocabulary expression (P = 0.0002) and sentence complexity (P = 0.0005) in preterm infants were significantly lower than those in full - term infants (Figure 5A). In the sub - test of vocabulary expression, the scores of nouns (P = 0.0003), verbs (P = 0.0001), adjectives and adverbs (P = 0.0002), game and routine vocabulary (P = 0.0001), onomatopoeia (P = 0.0001), directional words (P = 0.0008), numeral - classifiers (P = 0.0067), pronouns (P = 0.0220), interrogative words (P = 0.0040), modal particles at the end of sentences (P = 0.0037), time words (P = 0.0390) and auxiliary words (P = 0.0004) in the preterm infant group were significantly lower than those in the full - term infant group (Figure 5B). However, in the girls' group, there were no statistically significant differences in the total score and sub - test scores of vocabulary expression, as well as the score of sentence complexity between preterm infants and full - term infants (Figure 5C - 5D). Discussion Language developmental delays are a common manifestation of early neurodevelopmental disorders in preterm infants. Such delays can severely impact children's academic, professional, and social development. Typical language development in children is characterized by a continuous process, divided into pre-linguistic and linguistic stages. Due to the interplay of factors such as the degree of prematurity, associated complications, and environmental and social characteristics, preterm infants often exhibit atypical developmental features in their language abilities. This section uses the CCDI scale to evaluate and compare the language development characteristics of preterm and full-term infants across the pre-linguistic and linguistic stages. It also further analyzes the impact of gender and gestational age on language development, aiming to explore the language and communication development characteristics of preterm infants and provide a theoretical basis for early language interventions. 1. Analysis of CCDI results between preterm and full-term infants of different ages This study first compared various dimensions of language development in preterm and full-term infants, including early gestures, late gestures, total gestures, phrase comprehension, vocabulary comprehension, and vocabulary expression from the CCDI "Vocabulary and Gestures" subtest, as well as vocabulary expression and sentence complexity from the CCDI "Vocabulary and Sentences" subtest. The results indicated that one-year-old preterm infants had significantly lower scores than full-term infants in early gestures, total action gesture scores, phrase comprehension, total vocabulary comprehension, and total vocabulary expression on the CCDI "Vocabulary and Gestures" Similarly, two-year-old preterm infants scored significantly lower than full-term infants in vocabulary expression and sentence complexity on the CCDI "Vocabulary and Sentences" These findings suggest that preterm infants exhibit developmental delays at various stages of language development compared to full-term infants. Nguyen et al [ 21 ] conducted a follow-up study of 30 extremely preterm infants and 2 full-term infants, assessing their language skills at ages 5, 7, and 13, and found significant delays in phonology, grammar, and vocabulary in extremely preterm infants. Van Noort-van der Spek et al [ 22 ] reviewed and compared the language development of preterm and full-term children from ages 3 to 12, using the Peabody Picture Vocabulary Test (PPVT) and the Clinical Evaluation of Language Fundamentals (CELF) to assess simple language functions (e.g., vocabulary expression) and complex language functions (e.g., vocabulary and semantic knowledge, grammar, and phonological working memory). Their results showed that, even in the absence of major disabilities and independent of socioeconomic status, preterm infants scored significantly lower than full-term infants in both simple and complex language functions, with the gap widening in complex language functions as age increased. This indicates a general delay in language development among preterm infants. Additionally, a further comparison of the screening abnormality rates between preterm and full-term infants at different ages revealed that the screening abnormality rates for preterm infants were 40.7% at 1 year and 26.3% at 2 years, while for full-term infants, the rates were 18.7% at 1 year and 5.4% at 2 years. The CCDI screening abnormality rates were significantly higher in the preterm infants group at all age stages compared to the full-term infants group, although the rates of language developmental delays decreased with increasing age. Since the critical period for children's language development is between 18 and 36 months, some children with language developmental delays may catch up in their language development after age 2. However, this does not negate the importance of early intervention [ 23 ] . Longitudinal cohort studies have found that even if children with language developmental delays catch up with their typically developing peers later, they often face narrative and reading-related learning issues in upper elementary grades. In practice, some parents adopt a wait-and-see attitude when they first notice language developmental delays, believing that their child will eventually speak or influenced by comments such as "late talkers become great speakers" leading to delays in diagnosis, intervention, and treatment, which often misses the optimal window for language development intervention [ 24 ] .In summary, preterm infants lag significantly behind full-term infants in both the pre-linguistic and linguistic stages of language development. This underscores the importance of early language development assessment, which facilitates the early detection and intervention of language delays in preterm infants, ultimately improving the prognosis of adverse language outcomes. 2. Analysis of CCDI subtest results for preterm and full-term infants of different ages This study utilized the CCDI "Vocabulary and Gestures" to assess the pre-linguistic development stages in preterm infants, further analyzing various subtests within the gesture dimension, including early gesture communication and play, as well as later gestures such as interactive actions, pretend play, and imitation of adult actions. The results revealed that one-year-old preterm infants scored significantly lower in initial communication gestures and pretend play gestures compared to full-term infants, indicating delays in gesture development, particularly in initial communication gestures and pretend play. Development of communication skills begins before children can use language as their primary means of communication. Gestures are a crucial component of early communication skills. Research shows that the development from gestures to vocabulary expression is continuous, with a close developmental relationship between gestures and language. Gesture development plays a vital role in early language development [ 25 – 28 ] . Through gestures, children can attract and maintain adult attention, promote interactive communication with adults, and create new opportunities for language learning [ 29 ] . Previous studies have demonstrated that early communication gestures and pretend play development can predict language outcomes, indicating a higher risk of long-term language development abnormalities in preterm infants compared to full-term children [ 30 ] . Additionally, studies have shown that gesture development at 12 and 18 months can predict later vocabulary expression and sentence complexity [ 31 , 32 ] . A cohort study by Alessandra Sansavini et al. assessed language development in 20 extremely preterm infants at 18 months using the MCDI and found that preterm infants with delayed gesture development at 18 months were at a higher risk of language developmental delays at ages 2 and 3 [ 33 ] . Furthermore, research by Benassi et al. indicated that extremely low birth weight preterm infants at 12 months corrected age exhibited fewer gestures compared to full-term infants at 12 months [ 34 ] . These studies underscore the importance of research into gesture development in preterm infants. The delays observed in gesture development among preterm infants suggest that we should closely monitor gesture development and follow up on the language outcomes of preterm infants with delayed gesture development. This study used the CCDI "Vocabulary and Gestures" to compare the differences in vocabulary comprehension and vocabulary expression between one-year-old preterm and full-term infants. The vocabulary types included nouns, verbs, onomatopoeia, game/routine words, adjectives/adverbs, directional words, quantifiers, interrogative words, pronouns, measure words, and temporal words. The results showed that, in terms of vocabulary comprehension, preterm infants scored significantly lower than full-term infants in understanding nouns, verbs, onomatopoeia, game and routine words, and adjectives/adverbs. In terms of vocabulary expression, preterm infants significantly lagged behind full-term infants in expressing onomatopoeia, game and routine words, and quantifiers. This suggests a developmental mismatch between vocabulary comprehension and expression in preterm infants. Typically developing children exhibit a developmental trajectory where language comprehension precedes language expression; however, preterm infants did not show significant delays in the initial expression of nouns and verbs compared to full-term infants [ 35 ] . Research indicates that adaptations to biological and environmental changes can lead to atypical developmental trajectories, diverging from normal developmental paths [ 36 ] . Prematurity occurs during a critical period of rapid neural development [ 37 ] and the interplay of factors such as the degree of prematurity, associated complications, and environmental and social characteristics contributes to atypical development in preterm infants [ 38 , 39 ] . Therefore, the language development of preterm infants is not only delayed but also follows an atypical developmental trajectory. This study used the CCDI "Vocabulary and Sentences" to compare vocabulary expression between two-year-old preterm and full-term children, including vocabulary types such as nouns, verbs, adjectives/adverbs, game/routine words, onomatopoeia, directional words, quantifiers, pronouns, measure words, interrogative words, sentence-final particles, temporal words, particles, and conjunctions. The results indicated that preterm infants lagged behind full-term infants in expressing nouns, verbs, adjectives and adverbs, game and routine words, onomatopoeia, directional words, interrogative words, sentence-final particles, and particles. Following the first year of life, infants begin to attempt more verbal expressions based on their understanding of language. Research shows that early mastery of vocabulary has a high predictive value for later language skills development [ 40 ] . Suvi Stolt et al [ 41 ] used the MCDI to study vocabulary in two-year-old extremely low birth weight preterm infants and full-term infants, finding that the trajectories for major vocabulary categories were highly similar, with significant differences between the groups in nouns and grammatical function words. Bahra et al [ 42 ] compared the vocabulary size of extremely low birth weight preterm children aged 18–36 months with that of same-age full-term children, revealing that preterm infants had significantly lower vocabulary sizes and a notably slower rate of vocabulary growth compared to their full-term peers. These studies suggest that a reduction in vocabulary size due to prematurity may lead to subsequent deficits in syntactic development and lower levels of reading and writing skills upon school entry. This study used the CCDI "Vocabulary and Sentences" to assess the complexity of sentences in the language development of preterm infants. The results showed that two-year-old preterm infants had significantly lower sentence complexity scores compared to full-term infants, indicating delays in syntactic development in preterm infants. Around 18 months of age, toddlers begin to produce phrase expressions, and grammatical aspects of language start to develop, with simple sentences typically emerging by 24 months. Kunnari et al [ 43 ] found that, in their study of spontaneous speech samples from two-year-old preterm infants, there was no difference in vocabulary size between preterm and full-term infants. However, the maximum sentence length in preterm infants was significantly shorter, suggesting delays in grammatical development. Perez-Pereira et al [ 43 ] used the Trivandrum Language Evaluation Scale (LEST) to study preterm infants from 6 months to 3 years old and found that 32% of preterm infants exhibited language developmental delays. Additionally, preterm infants demonstrated lower grammatical skills compared to full-term controls. Van Noort-van der Spek et al [ 45 ] reviewed and compared language development from ages 3 to 12 in preterm and full-term children. They found that preterm infants exhibited increasing differences in complex language functions (such as vocabulary and semantic knowledge, grammar, and phonological working memory) with age, indicating a general delay in language development among preterm infants. Therefore, preterm infants not only face deficiencies in syntactic development but also often experience persistent issues, which have long-term impacts on their language and communication skills. 3. The impact of gender on language development This study compared the differences between preterm and full-term infants across different age groups in boys and girls. In the one-year-old boys' group, preterm infants scored significantly lower than full-term infants only in the verb comprehension item of the "vocabulary types" subtest of the CCDI. In the girls' group, preterm infants scored significantly lower than full-term infants in both total vocabulary and gesture scores, as well as in multiple subtests. In the two-year-old boys' group, preterm infants scored significantly lower than full-term infants in vocabulary expression, sentence complexity, and multiple vocabulary expression subtests, whereas no statistically significant differences were observed in the girls' group. The study suggests that gender influences language development, with boys often exhibiting lower language development levels than girls [ 46 – 48 ] . The lack of significant differences in screening abnormalities between preterm boys and girls may be attributed to the overall delayed language development in preterm infants, which masks gender differences. Sansavini et al [ 49 ] used the MCDI to assess language development in very preterm infants and found that being male increased the risk of language delay at 24 months. Margot Prior et al [ 50 ] used the Communication and Symbolic Behavior Scales (CSBS) and MCDI to evaluate the communication abilities of 24-month-old children and found that boys had lower language development scores than girls. Therefore, boys may require more attention to their language development to enable early detection and intervention for language development issues. Limitations of the study This study has several limitations: Cross sectional design : The study employed a cross-sectional design and did not include longitudinal follow-up of children with language development delays. Future research should include tracking the neurodevelopmental outcomes of children with language abnormalities through preschool and early school years. Behavioral assessment only : This study assessed language development in preterm infants solely from a behavioral perspective. It may be necessary to explore the "neural" mechanisms underlying cognitive processing in language development to better understand the brain functions associated with language delays in preterm infants. Such research could enhance our understanding of various aspects of language development delays and contribute to earlier diagnosis and intervention. Abbreviations CCDI, the Chinese Communicative Development Inventory; MCDI the MacArthur Communicative Development Inventory; PPVT, the Peabody Picture Vocabulary Test ; CELF, the Clinical Evaluation of Language Fundamentals; LEST, the Trivandrum Language Evaluation Scale; CSBS, the Communication and Symbolic Behavior Scales; Declarations Acknowledgments The authors would like to thank all individuals and research staff who participated in this study. Authors’ contributions Methodology, formal analysis, investigation, F.L. and Q.X.; resources, J.W., C.W., M.M.Y., Q.H., and X.C.; data curation, F.L. and Q.X.; writing – original draft, F.L. and Q.X.; writing – review & editing, F.L. and Q.X.; visualization, F.L. and Q.X. Funding This work was supported by Jiangsu Province Science and Technology Plan Project (BE2023666), Specialized disease cohort study of Nanjing Medical University (NMUC2018014A). Data availability statement The data that support the findings of this study are available from the corresponding author with reasonable request. Ethical Approval and Consent to participate This study was approved by the Medical Ethics Committee of the Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University (Approval No. Ning Fu Lun Zi [2020] KY-058). Before the trial procedures commenced, the purpose and detailed procedures of the study were explained to the parents or legal guardians of the subjects, and written informed consent was obtained from the guardians for all subjects' participation. Research conducted on humans and/or human data, or material is in compliance with the Helsinki Declaration. Consent for publication Not applicable. Competing interests All authors declare that there are no conflicts of interest. References Walani SR. Global burden of preterm birth. Int J Gynaecol Obstet. 2020;150(1):31–3. Chin WC, Wu WC, Hsu JF, Tang I, Yao TC, Huang YS. Correlation Analysis of Attention and Intelligence of Preterm Infants at Preschool Age: A Premature Cohort Study. Int J Environ Res Public Health, 2023. 20(4). Allotey J, Zamora J, Cheong-See F, Kalidindi M, Arroyo-Manzano D, Asztalos E, van der Post J, Mol BW, Moore D, Birtles D, Khan KS. 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Lewis V, Boucher J, Lupton L, Watson S. Relationships between symbolic play, functional play, verbal and non-verbal ability in young children. Int J Lang Commun Disord. 2000;35(1):117–27. McGillion M, Herbert JS, Pine J, Vihman M, dePaolis R, Keren-Portnoy T, Matthews D. What Paves the Way to Conventional Language? The Predictive Value of Babble, Pointing, and Socioeconomic Status. Child Dev. 2017;88(1):156–66. Kraljevic JK, Cepanec M, Simlesa S. Gestural development and its relation to a child's early vocabulary. Infant Behav Dev. 2014;37(2):192–202. Sansavini A, Guarini A, Zuccarini M, Lee JZ, Faldella G, Iverson JM. Low Rates of Pointing in 18-Month-Olds at Risk for Autism Spectrum Disorder and Extremely Preterm Infants: A Common Index of Language Delay? Front Psychol. 2019;10:2131. Benassi E, Savini S, Iverson JM, Guarini A, Caselli MC, Alessandroni R, Faldella G, Sansavini A. Early communicative behaviors and their relationship to motor skills in extremely preterm infants. Res Dev Disabil. 2016;48:132–44. Vandormael C, Schoenhals L, Huppi PS, Filippa M, Borradori Tolsa C. Language in Preterm Born Children: Atypical Development and Effects of Early Interventions on Neuroplasticity. Neural Plast, 2019. 2019: p. 6873270. Karmiloff-Smith A. Development itself is the key to understanding developmental disorders. Trends Cogn Sci. 1998;2(10):389–98. Volpe JJ. Brain injury in premature infants: a complex amalgam of destructive and developmental disturbances. Lancet Neurol. 2009;8(1):110–24. Vandormael C, Schoenhals L, Huppi PS, Filippa M, Borradori Tolsa C. Language in Preterm Born Children: Atypical Development and Effects of Early Interventions on Neuroplasticity. Neural Plast, 2019. 2019: p. 6873270. Sansavini A, Guarini A, Savini S, Broccoli S, Justice L, Alessandroni R, Faldella G. Longitudinal trajectories of gestural and linguistic abilities in very preterm infants in the second year of life. Neuropsychologia. 2011;49(13):3677–88. Suppanen E, Winkler I, Kujala T, Ylinen S. More efficient formation of longer-term representations for word forms at birth can be linked to better language skills at 2 years. Dev Cogn Neurosci. 2022;55:101113. Stolt S, Klippi A, Launonen K, Munck P, Lehtonen L, Lapinleimu H, Haataja L. Pipari Study G., Size and composition of the lexicon in prematurely born very-low-birth-weight and full-term Finnish children at two years of age. J Child Lang. 2007;34(2):283–310. Bahram Soleimani YK, Zohre Badiee BM, Bakhtiyari M, Soraya. A Comparative Study of Size of Expressive Lexicon in Prematurely Born Children with Full-Term 18–36 Month’s Children. Auditory Vestib Res. 2012;21:76–82. Kunnari S, Yliherva A, Paavola L, Peltoniemi OM. Expressive language skills in Finnish two-year-old extremely- and very-low-birth-weight preterm children. Folia Phoniatr Logop. 2012;64(1):5–11. Perez-Pereira M. Prevalence of Language Delay among Healthy Preterm Children, Language Outcomes and Predictive Factors. Child (Basel), 2021. 8(4). van Noort IL, Franken MC, Weisglas-Kuperus N. Language functions in preterm-born children: a systematic review and meta-analysis. Pediatrics. 2012;129(4):745–54. Stolt S, Klippi A, Launonen K, Munck P, Lehtonen L, Lapinleimu H, Haataja L. Pipari Study G., Size and composition of the lexicon in prematurely born very-low-birth-weight and full-term Finnish children at two years of age. J Child Lang. 2007;34(2):283–310. Zhang y, Wang JF. Ding Yh, clinical features and influencing factors of language developmental delay in children. Chin J Child Health. 2022;30(08):912–5. Zhang Ruifang L, Xinyan F, Guoye B, Hua. Wang Wenli, developmental characteristics and related factors of children with language developmental delay. Chin J Child Health. 2017;25(03):287–9. Sansavini A, Guarini A, Savini S, Broccoli S, Justice L, Alessandroni R, Faldella G. Longitudinal trajectories of gestural and linguistic abilities in very preterm infants in the second year of life. Neuropsychologia. 2011;49(13):3677–88. Prior M, Bavin EL, Cini E, Reilly S, Bretherton L, Wake M, Eadie P. Influences on communicative development at 24 months of age: child temperament, behaviour problems, and maternal factors. Infant Behav Dev. 2008;31(2):270–9. Tables Table 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1Generalclinicalcharacteristicsandsociodemographiccharacteristicsofchildren.xlsx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8731965","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":592012105,"identity":"03faa457-01ab-458c-9dbe-43a0c6dda23f","order_by":0,"name":"Feng Liu","email":"","orcid":"","institution":"Nanjing Women and Children's Healthcare Hospital","correspondingAuthor":false,"prefix":"","firstName":"Feng","middleName":"","lastName":"Liu","suffix":""},{"id":592012106,"identity":"b4b494e9-c276-4019-a555-a382ec2d6a6f","order_by":1,"name":"Qu Xu","email":"","orcid":"","institution":"Nanjing Women and Children's Healthcare 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05:41:56","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3609463,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8731965/v1/3dfbb9c2-c202-47a2-a46f-c97a9d3b021d.pdf"},{"id":102982138,"identity":"a47096cd-8fcf-4b09-b9c0-9ab5f32a5cb3","added_by":"auto","created_at":"2026-02-19 09:12:25","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":12144,"visible":true,"origin":"","legend":"","description":"","filename":"Table1Generalclinicalcharacteristicsandsociodemographiccharacteristicsofchildren.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-8731965/v1/0832b58a65576196abf0f36a.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Revealing language development delays in preterm infants compared to full-term infants based on the CCDI","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEach year, approximately 15\u0026nbsp;million premature infants are born worldwide, representing about 10% of all live births \u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. While advancements in perinatal care have significantly improved the survival rates of preterm infants, they remain at a substantially higher risk of neurodevelopmental disorders \u003csup\u003e[\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Among these, language delay is a frequent early manifestation of neurodevelopmental impairment \u003csup\u003e[\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Beyond affecting basic language comprehension and expression, such delays can lead to cascading challenges, including reading and spelling difficulties, interpersonal struggles, emotional-behavioral disorders, and long-term impacts on academic achievement, career trajectories, and social integration \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. Consequently, investigating the language development patterns of preterm infants has become a critical focus in child health and developmental-behavioral pediatrics.\u003c/p\u003e \u003cp\u003eChildren\u0026rsquo;s typical language development progresses through two sequential phases: the prelinguistic stage (nonverbal communication, including joint attention, gestures, babbling, and early comprehension) and the linguistic stage (spoken language, encompassing vocabulary expansion and syntactic complexity) \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. However, preterm infants often exhibit atypical language trajectories due to the interplay of prematurity, neonatal complications, and socioenvironmental factors \u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Research in this domain holds dual significance: It elucidates the pathways underlying language impairments in preterm infants, pinpointing developmental gaps and informing targeted remediation strategies. It enables clinicians to differentiate transient developmental delays from persistent high-risk profiles for language/learning disorders \u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. Systematic assessment across developmental stages is thus essential to characterize preterm infants language profiles and guide evidence-based interventions.\u003c/p\u003e \u003cp\u003eThe MacArthur Communicative Development Inventory (MCDI), developed by Fenson et al. (1994), is a globally utilized parent-report tool for evaluating early language and communication skills, with adaptations in over 100 languages \u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. Its Mandarin version, the Chinese Communicative Development Inventory (CCDI), was standardized by Liang Weilan\u0026rsquo;s team (2001) with culturally and linguistically appropriate modifications, demonstrating robust psychometric validity \u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. The CCDI comprises two age-specific questionnaires: \"Words and Gestures\" (8\u0026ndash;16 months) assessing prelinguistic abilities, and \"Words and Sentences\" (16\u0026ndash;30 months) evaluating expressive vocabulary and grammar. Its widespread adoption in clinical and research contexts underscores its utility in profiling infant language development \u003csup\u003e[19.20]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThis study employs the CCDI to compare language development in preterm and full-term infants at 12 and 24 months, examining gestural communication, early comprehension, vocabulary breadth, and syntactic maturation. By identifying distinct developmental features in preterm infants, the findings will inform timely, tailored language interventions to mitigate long-term sequelae.\u003c/p\u003e"},{"header":"Method","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePreterm infant group\u003c/h2\u003e \u003cp\u003eIn this study, the preterm infant group was recruited from the High-Risk Pediatric Outpatient Department of the Early Intervention and Rehabilitation Center at Nanjing Maternal and Child Health Hospital, between October 2021 and December 2022. This group included preterm infants who were either 1 year (± 1 month) or 2 years (± 1 month) old. Following the recommendations of the study [45], the corrected age up to 24 months was used to assess the growth and development of preterm infants. Consequently, for preterm infants younger than 24 months, the corrected age was used, while for those older than 24 months, their actual age was considered. Inclusion criteria: (1) Hearing assessment: Passed automated auditory brainstem response testing at birth or during the 42-day health check, and also passed screening otoacoustic emissions testing within the past six months; (2) Both parents are native Mandarin speakers; (3) No known history of psychiatric disorders in the family. Exclusion criteria: (1) Complications during the neonatal period that may cause severe brain damage, including hypoxic-ischemic encephalopathy, severe bronchopulmonary dysplasia, intraventricular hemorrhage grade III or IV, bilirubin encephalopathy, severe apnea, and meningitis; (2) Congenital malformations, genetic and metabolic disorders, sensory impairments, and cerebral palsy; (3) History of otitis media within the past six months. A total of 139 preterm infants were included in the preterm infant group, comprising 59 infants who were 1 year old and 80 infants who were 2 years old. Among them, there were 79 boys and 60 girls.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eFull-term infant group\u003c/h3\u003e\n\u003cp\u003eThe full-term infant group was recruited from routine health check-ups at the pediatric outpatient department of Nanjing Maternal and Child Health Hospital during the same period. This group included full-term infants matched 1:2 by gender and age to the preterm infant group, comprising 1-year-old (± 1 month) and 2-year-old (± 1 month) full-term infants. The inclusion and exclusion criteria were the same as those applied to the preterm infant group. A total of 235 full-term infants were included in the full-term infant group, consisting of 123 infants who were 1 year old and 112 infants who were 2 years old. Among them, there were 116 boys and 119 girls. This study was approved by the Medical Ethics Committee of Nanjing Medical University Affiliated Obstetrics and Gynecology Hospital (Approval No. NFMU-2020-KY-058). Before initiating the study procedures, the parents or legal guardians of the participants were informed about the purpose and detailed process of the research. Informed consent was obtained from all guardians before conducting any tests.\u003c/p\u003e\n\u003ch3\u003eCollection of child data\u003c/h3\u003e\n\u003cp\u003eGeneral Information: Gender, chronological age, vision, and hearing screening results. Birth Information: Date of birth, expected delivery date, gestational age at birth, birth weight, results of newborn disease screening, and hospitalization details during the neonatal period. Parental and Family Information: Parents' educational level and family annual income.\u003c/p\u003e\n\u003ch3\u003eLanguage development assessment\u003c/h3\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003ethe Chinese Communicative Development Inventory (CCDI)\u003c/h2\u003e \u003cp\u003eThe MacArthur Communicative Development Inventory (MCDI), developed by Fenson et al. in 1994, is a widely used parent-report instrument designed to assess early language and communication skills. It has been adapted into more than 100 languages worldwide [16,17]. The Mandarin version, known as the Chinese Communicative Development Inventory (CCDI), was standardized by Liang Weilan’s team in 2001. This version incorporates culturally and linguistically appropriate modifications and has demonstrated strong psychometric properties [18]. The CCDI includes two age-specific questionnaires: “Words and Gestures” for infants aged 8–16 months, which assesses prelinguistic communication abilities, and “Words and Sentences” for toddlers aged 16–30 months, focusing on expressive vocabulary and early grammatical development. The tool’s extensive use in both clinical and research settings highlights its value in characterizing early language development in infants [19,20].\u003c/p\u003e \u003cp\u003e \u003cb\u003eCCDI vocabulary and gestures\u003c/b\u003e (Applicable to 8–16 months of age)\u003c/p\u003e \u003cp\u003eThe questionnaire includes assessments of early gestures, later gestures, total gestures, phrase comprehension, vocabulary comprehension, and vocabulary production. The early gestures subscale comprises 11 initial communication gestures and 5 play and routine gestures, with a total score of 27 points. The later gestures subscale includes 15 interactive actions, 5 pretend play actions, and 7 imitation of adult actions, with a total score of 27 points. The total gestures score is the sum of the early and later gestures subscales, totaling 54 points. Phrase comprehension includes 27 short phrases, with a total score of 27 points. The vocabulary scale section consists of 411 words, divided into the following subscales: 214 nouns (across 10 categories, including 26 names, 29 eating and drinking items, 18 body parts, 33 animals, 35 household items, 8 toys and recreational items, 15 articles of clothing, 19 pieces of furniture/household items, 22 outdoor items and places, and 9 vehicles), 78 verbs, 11 onomatopoeic words, 22 game/routine words, 44 adjectives/adverbs, 11 directional words, 6 quantifiers, 6 interrogative words, 7 pronouns, 6 measure words, and 6 time-related words. Both vocabulary comprehension and vocabulary production are scored with a maximum of 411 points each. Percentile ranks corresponding to the raw scores can be obtained. A percentile rank of ≤ P10 in any of these measures indicates language development delays in the child.\u003c/p\u003e \u003cp\u003e \u003cb\u003eCCDI vocabulary and sentences\u003c/b\u003e (Applicable to 16–30 months of age)\u003c/p\u003e \u003cp\u003eThe questionnaire includes assessments of vocabulary production and sentence complexity. The vocabulary section comprises 799 words, with a total score of 799 points, while the sentence complexity score includes 27 items, with a total of 81 points. The vocabulary section is divided into 24 categories and contains 799 words, including 371 nouns (across 11 categories: 32 names, 69 eating and drinking items, 27 body parts, 49 animals, 56 household items, 18 toys and recreational items, 28 articles of clothing, 29 pieces of furniture and household items, 32 outdoor items, 14 vehicles, and 17 outdoor places), 194 verbs, 66 adjectives/adverbs, 28 game/routine words, 12 onomatopoeic words, 21 directional words, 9 numerals, 24 pronouns, 20 measure words, 12 interrogative words, 6 sentence-final particles, 15 time-related words, 12 auxiliary particles, and 9 conjunctions. The vocabulary production section is scored with a total of 799 points. The sentence complexity section includes 27 items, covering grammatical components such as morphemes indicating progressive and perfect aspects, possessive morphemes, time adverbs, auxiliary verbs, negation words, mood particles, and sentence-final particles. Each item consists of 2–5 sentence patterns, with more complex patterns earning higher scores, totaling 81 points. Percentile ranks corresponding to the raw scores can be obtained, with a percentile rank of ≤ P10 in any measure indicating language development delays in the child.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eQuality control\u003c/h2\u003e \u003cp\u003e \u003cstrong\u003eDevelopmental assessment quality control\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eAll developmental assessments were conducted by qualified pediatricians to ensure standardization and accuracy.\u003c/p\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eData entry quality control\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eData entry was performed using Epidata 3.1, with processes in place for uniqueness checks, double-entry verification, and logical consistency checks.\u003c/p\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eData analysis quality control\u003c/strong\u003e \u003c/p\u003e\u003cp\u003eThe statistical analysis of the data was supervised by specialized statisticians to ensure the correctness of the interpretation of results.\u003c/p\u003e \u003cp\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eStatistical analyses were performed using R (version 4.4.2). Normally distributed continuous data are presented as mean ± standard deviation, while non-normally distributed continuous data are presented as median (interquartile range). Categorical data are presented as sample size (percentage). Independent sample t-tests were used to compare differences in continuous data between two groups. Pearson chi-square tests, Pearson chi-square tests with continuity correction, or Fisher's exact tests were used to compare differences in categorical data between two groups. Spearman correlation analysis was used to examine the relationship between gestational age and scores on various dimensions of language development. All tests were two-tailed, with a significance level of \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Result","content":"\u003cp\u003e\u003cstrong\u003e1. General clinical and sociodemographic characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 374 children were ultimately included in the study, comprising 139 preterm infants (79 boys and 60 girls) and 235 full-term infants (116 boys and 119 girls). In the preterm infant group, there were 59 infants aged 1 year and 80 infants aged 2 years. In the full-term infant group, there were 123 infants aged 1 year and 112 infants aged 2 years. There were no statistically significant differences between the two groups in terms of age (1-year-old group: P = 0.474; 2-year-old group: P = 0.226) or gender (P = 0.197). The preterm infant group had significantly lower gestational age at birth (P \u0026lt; 0.001) and birth weight (P \u0026lt; 0.001) compared to the full-term infant group. The proportion of preterm infants delivered by cesarean section and suffocation was significantly higher than that of full-term infants (P \u0026lt; 0.001). There was no statistically significant difference between the two groups in the proportion of singleton births (P = 1.000) (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. Comparison of CCDI results between preterm infants and full-term infants in different age groups\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.1. Comparison of CCDI vocabulary and gestures score between preterm infants and full-term infants in one-year-old group\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe preterm infants exhibited significantly lower scores than the full-term infants in \u003cstrong\u003evocabulary and gestures score\u003c/strong\u003e, including initial gestures score (P = 0.0180), motion gestures score (P = 0.0200), phrase comprehension scores (P = 0.0001), vocabulary comprehension score (P = 0.0013), and vocabulary expression scores (P = 0.0068), but there were no statistically significant differences between the groups in later gestures score (P = 0.0770) (Figure 1A).\u003c/p\u003e\n\u003cp\u003eIn the sub - test of \u0026ldquo;Gesture Types\u0026rdquo; in CCDI, the scores of early gesture communication in early gestures (P = 0.0110) and the scores of pretend play in later gestures (P = 0.0035) were significantly lower in preterm infants than in full - term infants (Figure 1B). In the sub - test of \u0026ldquo;Vocabulary Types\u0026rdquo; in CCDI, the scores of nouns (P = 0.0035), verbs (P = 0.001), onomatopoeia (P = 0.0022), game and routine vocabulary (P = 0.0002), as well as adjectives and adverbs (P = 0.0024) in the vocabulary comprehension items were significantly lower in preterm infants (Figure 1C). Similarly, the scores of nouns (P = 0.0088), onomatopoeia (P = 0.0028), game and routine vocabulary (P = 0.0230) and numeral - classifiers (P = 0.0490) in the vocabulary expression items were lower in preterm infants (Figure 1D).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2. Comparison of CCDI vocabulary and sentences results between preterm infants and full-term Infants in two-year-old group\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the two - year - old group, the scores of vocabulary expression (P = 0.0005) and sentence complexity (P = 0.0014) of preterm infants were significantly lower than those of full - term infants (Figure 2A). In the sub - tests of vocabulary expression, the scores of nouns (P = 0.0003), verbs (P = 0.0001), adjectives and adverbs (P = 0.0006), game and routine vocabulary (P = 0.0003), onomatopoeia (P = 0.0006), directional words (P = 0.0099), interrogative words (P = 0.0200), modal particles at the end of sentences (P = 0.0140), and auxiliary words (P = 0.0058) in the preterm infant group were significantly lower than those in the full - term infant group (Figure 2B).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eincidence of language development delay\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the one - year - old group, the rate of language development delay in preterm infants was 40.68% (24/59), significantly higher than that in full - term infants (18.70%, 23/123) (P = 0.0028) (Figure 3A). The same result was observed in the two - year - old group. The rate in the preterm infant group (26.25%, 21/80) was significantly higher than that in the full - term infant group (5.35%, 6/112) (P = 1e - 04) (Figure 3B).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4. Impact of gender on language development\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.1. Comparison of CCDI results for one-year-old group\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the boys\u0026apos; group, there were no statistically significant differences in the total scores of the \u0026quot;Vocabulary and Gestures\u0026quot; section of the CCDI between preterm infants and full - term infants (Figure 4A). In the sub - test of \u0026quot;Gesture Types\u0026quot; in the CCDI, there were no statistically significant differences in the early gesture scores (Figure 4B). In the sub - test of \u0026quot;Vocabulary Types\u0026quot; in the CCDI, the scores for verbs in the vocabulary comprehension items (P = 0.0260) were significantly lower in preterm infants (Figure 4C), while there were no statistically significant differences in the scores of each sub - test in the vocabulary expression items (Figure 4D).\u003c/p\u003e\n\u003cp\u003eIn the girls\u0026apos; group，The preterm infants exhibited significantly lower scores than the full-term infants in \u003cstrong\u003evocabulary and gestures score\u003c/strong\u003e, including initial gestures score (P = 0.0004) ,later gestures(P=0.0220), motion gestures score (P = 0.0014), phrase comprehension scores (P \u0026lt; 0.0001), vocabulary comprehension score (P = 0.0130), and vocabulary expression scores (P = 0.0230) (Figure 4E)。In the sub - test of \u0026quot;Gesture Types\u0026quot; in the CCDI, the scores for early gesture communication in early gestures (P = 0.0006) and the scores for pretend play in later gestures (P = 0.0037) were significantly lower in preterm infants than in full - term infants (Figure 4F). In the sub - test of \u0026quot;Vocabulary Types\u0026quot; in the CCDI, the scores for nouns (P = 0.0250), verbs (P = 0.0047), onomatopoeia (P = 0.0038), game and routine vocabulary (P = 0.0022), adjectives and adverbs (P = 0.0220) in the vocabulary comprehension items, as well as numeral - classifiers (P = 0.0020) were significantly lower in preterm infants (Figure 4G). Similarly, the scores for nouns (P = 0.0330) and onomatopoeia (P = 0.0001) in the vocabulary expression items were lower in preterm infants (Figure 4H).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2. Comparison of CCDI results for two-year-old group\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the boys\u0026apos; group, the scores of vocabulary expression (P = 0.0002) and sentence complexity (P = 0.0005) in preterm infants were significantly lower than those in full - term infants (Figure 5A). In the sub - test of vocabulary expression, the scores of nouns (P = 0.0003), verbs (P = 0.0001), adjectives and adverbs (P = 0.0002), game and routine vocabulary (P = 0.0001), onomatopoeia (P = 0.0001), directional words (P = 0.0008), numeral - classifiers (P = 0.0067), pronouns (P = 0.0220), interrogative words (P = 0.0040), modal particles at the end of sentences (P = 0.0037), time words (P = 0.0390) and auxiliary words (P = 0.0004) in the preterm infant group were significantly lower than those in the full - term infant group (Figure 5B). However, in the girls\u0026apos; group, there were no statistically significant differences in the total score and sub - test scores of vocabulary expression, as well as the score of sentence complexity between preterm infants and full - term infants (Figure 5C - 5D).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eLanguage developmental delays are a common manifestation of early neurodevelopmental disorders in preterm infants. Such delays can severely impact children's academic, professional, and social development. Typical language development in children is characterized by a continuous process, divided into pre-linguistic and linguistic stages. Due to the interplay of factors such as the degree of prematurity, associated complications, and environmental and social characteristics, preterm infants often exhibit atypical developmental features in their language abilities. This section uses the CCDI scale to evaluate and compare the language development characteristics of preterm and full-term infants across the pre-linguistic and linguistic stages. It also further analyzes the impact of gender and gestational age on language development, aiming to explore the language and communication development characteristics of preterm infants and provide a theoretical basis for early language interventions.\u003c/p\u003e \u003cp\u003e \u003cb\u003e1. Analysis of CCDI results between preterm and full-term infants of different ages\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThis study first compared various dimensions of language development in preterm and full-term infants, including early gestures, late gestures, total gestures, phrase comprehension, vocabulary comprehension, and vocabulary expression from the CCDI \"Vocabulary and Gestures\" subtest, as well as vocabulary expression and sentence complexity from the CCDI \"Vocabulary and Sentences\" subtest. The results indicated that one-year-old preterm infants had significantly lower scores than full-term infants in early gestures, total action gesture scores, phrase comprehension, total vocabulary comprehension, and total vocabulary expression on the CCDI \"Vocabulary and Gestures\" Similarly, two-year-old preterm infants scored significantly lower than full-term infants in vocabulary expression and sentence complexity on the CCDI \"Vocabulary and Sentences\" These findings suggest that preterm infants exhibit developmental delays at various stages of language development compared to full-term infants. Nguyen et al \u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e conducted a follow-up study of 30 extremely preterm infants and 2 full-term infants, assessing their language skills at ages 5, 7, and 13, and found significant delays in phonology, grammar, and vocabulary in extremely preterm infants. Van Noort-van der Spek et al \u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e reviewed and compared the language development of preterm and full-term children from ages 3 to 12, using the Peabody Picture Vocabulary Test (PPVT) and the Clinical Evaluation of Language Fundamentals (CELF) to assess simple language functions (e.g., vocabulary expression) and complex language functions (e.g., vocabulary and semantic knowledge, grammar, and phonological working memory). Their results showed that, even in the absence of major disabilities and independent of socioeconomic status, preterm infants scored significantly lower than full-term infants in both simple and complex language functions, with the gap widening in complex language functions as age increased. This indicates a general delay in language development among preterm infants.\u003c/p\u003e \u003cp\u003eAdditionally, a further comparison of the screening abnormality rates between preterm and full-term infants at different ages revealed that the screening abnormality rates for preterm infants were 40.7% at 1 year and 26.3% at 2 years, while for full-term infants, the rates were 18.7% at 1 year and 5.4% at 2 years. The CCDI screening abnormality rates were significantly higher in the preterm infants group at all age stages compared to the full-term infants group, although the rates of language developmental delays decreased with increasing age. Since the critical period for children's language development is between 18 and 36 months, some children with language developmental delays may catch up in their language development after age 2. However, this does not negate the importance of early intervention \u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. Longitudinal cohort studies have found that even if children with language developmental delays catch up with their typically developing peers later, they often face narrative and reading-related learning issues in upper elementary grades. In practice, some parents adopt a wait-and-see attitude when they first notice language developmental delays, believing that their child will eventually speak or influenced by comments such as \"late talkers become great speakers\" leading to delays in diagnosis, intervention, and treatment, which often misses the optimal window for language development intervention \u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e.In summary, preterm infants lag significantly behind full-term infants in both the pre-linguistic and linguistic stages of language development. This underscores the importance of early language development assessment, which facilitates the early detection and intervention of language delays in preterm infants, ultimately improving the prognosis of adverse language outcomes.\u003c/p\u003e \u003cp\u003e \u003cb\u003e2. Analysis of CCDI subtest results for preterm and full-term infants of different ages\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThis study utilized the CCDI \"Vocabulary and Gestures\" to assess the pre-linguistic development stages in preterm infants, further analyzing various subtests within the gesture dimension, including early gesture communication and play, as well as later gestures such as interactive actions, pretend play, and imitation of adult actions. The results revealed that one-year-old preterm infants scored significantly lower in initial communication gestures and pretend play gestures compared to full-term infants, indicating delays in gesture development, particularly in initial communication gestures and pretend play.\u003c/p\u003e \u003cp\u003eDevelopment of communication skills begins before children can use language as their primary means of communication. Gestures are a crucial component of early communication skills. Research shows that the development from gestures to vocabulary expression is continuous, with a close developmental relationship between gestures and language. Gesture development plays a vital role in early language development \u003csup\u003e[\u003cspan additionalcitationids=\"CR26 CR27\" citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e. Through gestures, children can attract and maintain adult attention, promote interactive communication with adults, and create new opportunities for language learning \u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. Previous studies have demonstrated that early communication gestures and pretend play development can predict language outcomes, indicating a higher risk of long-term language development abnormalities in preterm infants compared to full-term children \u003csup\u003e[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eAdditionally, studies have shown that gesture development at 12 and 18 months can predict later vocabulary expression and sentence complexity \u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e. A cohort study by Alessandra Sansavini et al. assessed language development in 20 extremely preterm infants at 18 months using the MCDI and found that preterm infants with delayed gesture development at 18 months were at a higher risk of language developmental delays at ages 2 and 3 \u003csup\u003e[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/sup\u003e. Furthermore, research by Benassi et al. indicated that extremely low birth weight preterm infants at 12 months corrected age exhibited fewer gestures compared to full-term infants at 12 months \u003csup\u003e[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/sup\u003e. These studies underscore the importance of research into gesture development in preterm infants. The delays observed in gesture development among preterm infants suggest that we should closely monitor gesture development and follow up on the language outcomes of preterm infants with delayed gesture development.\u003c/p\u003e \u003cp\u003eThis study used the CCDI \"Vocabulary and Gestures\" to compare the differences in vocabulary comprehension and vocabulary expression between one-year-old preterm and full-term infants. The vocabulary types included nouns, verbs, onomatopoeia, game/routine words, adjectives/adverbs, directional words, quantifiers, interrogative words, pronouns, measure words, and temporal words. The results showed that, in terms of vocabulary comprehension, preterm infants scored significantly lower than full-term infants in understanding nouns, verbs, onomatopoeia, game and routine words, and adjectives/adverbs. In terms of vocabulary expression, preterm infants significantly lagged behind full-term infants in expressing onomatopoeia, game and routine words, and quantifiers. This suggests a developmental mismatch between vocabulary comprehension and expression in preterm infants.\u003c/p\u003e \u003cp\u003eTypically developing children exhibit a developmental trajectory where language comprehension precedes language expression; however, preterm infants did not show significant delays in the initial expression of nouns and verbs compared to full-term infants \u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/sup\u003e. Research indicates that adaptations to biological and environmental changes can lead to atypical developmental trajectories, diverging from normal developmental paths \u003csup\u003e[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u003c/sup\u003e. Prematurity occurs during a critical period of rapid neural development \u003csup\u003e[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/sup\u003e and the interplay of factors such as the degree of prematurity, associated complications, and environmental and social characteristics contributes to atypical development in preterm infants \u003csup\u003e[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]\u003c/sup\u003e. Therefore, the language development of preterm infants is not only delayed but also follows an atypical developmental trajectory.\u003c/p\u003e \u003cp\u003eThis study used the CCDI \"Vocabulary and Sentences\" to compare vocabulary expression between two-year-old preterm and full-term children, including vocabulary types such as nouns, verbs, adjectives/adverbs, game/routine words, onomatopoeia, directional words, quantifiers, pronouns, measure words, interrogative words, sentence-final particles, temporal words, particles, and conjunctions. The results indicated that preterm infants lagged behind full-term infants in expressing nouns, verbs, adjectives and adverbs, game and routine words, onomatopoeia, directional words, interrogative words, sentence-final particles, and particles.\u003c/p\u003e \u003cp\u003e Following the first year of life, infants begin to attempt more verbal expressions based on their understanding of language. Research shows that early mastery of vocabulary has a high predictive value for later language skills development \u003csup\u003e[\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]\u003c/sup\u003e. Suvi Stolt et al \u003csup\u003e[\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]\u003c/sup\u003e used the MCDI to study vocabulary in two-year-old extremely low birth weight preterm infants and full-term infants, finding that the trajectories for major vocabulary categories were highly similar, with significant differences between the groups in nouns and grammatical function words. Bahra et al \u003csup\u003e[\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]\u003c/sup\u003e compared the vocabulary size of extremely low birth weight preterm children aged 18\u0026ndash;36 months with that of same-age full-term children, revealing that preterm infants had significantly lower vocabulary sizes and a notably slower rate of vocabulary growth compared to their full-term peers. These studies suggest that a reduction in vocabulary size due to prematurity may lead to subsequent deficits in syntactic development and lower levels of reading and writing skills upon school entry.\u003c/p\u003e \u003cp\u003eThis study used the CCDI \"Vocabulary and Sentences\" to assess the complexity of sentences in the language development of preterm infants. The results showed that two-year-old preterm infants had significantly lower sentence complexity scores compared to full-term infants, indicating delays in syntactic development in preterm infants.\u003c/p\u003e \u003cp\u003eAround 18 months of age, toddlers begin to produce phrase expressions, and grammatical aspects of language start to develop, with simple sentences typically emerging by 24 months. Kunnari et al \u003csup\u003e[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]\u003c/sup\u003e found that, in their study of spontaneous speech samples from two-year-old preterm infants, there was no difference in vocabulary size between preterm and full-term infants. However, the maximum sentence length in preterm infants was significantly shorter, suggesting delays in grammatical development. Perez-Pereira et al \u003csup\u003e[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]\u003c/sup\u003e used the Trivandrum Language Evaluation Scale (LEST) to study preterm infants from 6 months to 3 years old and found that 32% of preterm infants exhibited language developmental delays. Additionally, preterm infants demonstrated lower grammatical skills compared to full-term controls.\u003c/p\u003e \u003cp\u003eVan Noort-van der Spek et al \u003csup\u003e[\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]\u003c/sup\u003e reviewed and compared language development from ages 3 to 12 in preterm and full-term children. They found that preterm infants exhibited increasing differences in complex language functions (such as vocabulary and semantic knowledge, grammar, and phonological working memory) with age, indicating a general delay in language development among preterm infants. Therefore, preterm infants not only face deficiencies in syntactic development but also often experience persistent issues, which have long-term impacts on their language and communication skills.\u003c/p\u003e \u003cp\u003e \u003cb\u003e3. The impact of gender on language development\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThis study compared the differences between preterm and full-term infants across different age groups in boys and girls. In the one-year-old boys' group, preterm infants scored significantly lower than full-term infants only in the verb comprehension item of the \"vocabulary types\" subtest of the CCDI. In the girls' group, preterm infants scored significantly lower than full-term infants in both total vocabulary and gesture scores, as well as in multiple subtests. In the two-year-old boys' group, preterm infants scored significantly lower than full-term infants in vocabulary expression, sentence complexity, and multiple vocabulary expression subtests, whereas no statistically significant differences were observed in the girls' group. The study suggests that gender influences language development, with boys often exhibiting lower language development levels than girls \u003csup\u003e[\u003cspan additionalcitationids=\"CR47\" citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]\u003c/sup\u003e. The lack of significant differences in screening abnormalities between preterm boys and girls may be attributed to the overall delayed language development in preterm infants, which masks gender differences. Sansavini et al \u003csup\u003e[\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]\u003c/sup\u003e used the MCDI to assess language development in very preterm infants and found that being male increased the risk of language delay at 24 months. Margot Prior et al \u003csup\u003e[\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]\u003c/sup\u003e used the Communication and Symbolic Behavior Scales (CSBS) and MCDI to evaluate the communication abilities of 24-month-old children and found that boys had lower language development scores than girls. Therefore, boys may require more attention to their language development to enable early detection and intervention for language development issues.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eLimitations of the study\u003c/h2\u003e \u003cp\u003eThis study has several limitations:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eCross sectional design\u003c/b\u003e: The study employed a cross-sectional design and did not include longitudinal follow-up of children with language development delays. Future research should include tracking the neurodevelopmental outcomes of children with language abnormalities through preschool and early school years.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eBehavioral assessment only\u003c/b\u003e: This study assessed language development in preterm infants solely from a behavioral perspective. It may be necessary to explore the \"neural\" mechanisms underlying cognitive processing in language development to better understand the brain functions associated with language delays in preterm infants. Such research could enhance our understanding of various aspects of language development delays and contribute to earlier diagnosis and intervention.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Abbreviations","content":" \u003cp\u003eCCDI, the Chinese Communicative Development Inventory; MCDI the MacArthur Communicative Development Inventory; PPVT, the Peabody Picture Vocabulary Test ; CELF, the Clinical Evaluation of Language Fundamentals; LEST, the Trivandrum Language Evaluation Scale; CSBS, the Communication and Symbolic Behavior Scales;\u003c/p\u003e\u003cp\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank all individuals and research staff who participated in this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMethodology, formal analysis, investigation, F.L. and Q.X.; resources, J.W., C.W., M.M.Y., Q.H., and X.C.; data curation, F.L. and Q.X.; writing \u0026ndash; original draft, F.L. and Q.X.; writing \u0026ndash; review \u0026amp; editing, F.L. and Q.X.; visualization, F.L. and Q.X.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Jiangsu Province Science and Technology Plan Project (BE2023666), Specialized disease cohort study of Nanjing Medical University (NMUC2018014A).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from the corresponding author with reasonable request.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval and Consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Medical Ethics Committee of the Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University (Approval No. Ning Fu Lun Zi [2020] KY-058). Before the trial procedures commenced, the purpose and detailed procedures of the study were explained to the parents or legal guardians of the subjects, and written informed consent was obtained from the guardians for all subjects\u0026apos; participation.\u0026nbsp;Research conducted on humans and/or human data, or material is in compliance with the Helsinki Declaration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors declare that there are no conflicts of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWalani SR. Global burden of preterm birth. Int J Gynaecol Obstet. 2020;150(1):31\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChin WC, Wu WC, Hsu JF, Tang I, Yao TC, Huang YS. 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Am J Speech Lang Pathol. 2021;30(5):2241\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarchman VA. The MacArthur-Bates Communicative Development Inventories: updates from the CDI Advisory Board. Front Psychol. 2023;14:1170303.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiang Weilan H, Bo W, Shuang J, Yuqing Y, Yanling Z, Zhixiang. Zuo qihua, a study on the development of Chinese language and vocabulary in young children. Chin J Pediatr, 2002(11): pp. 13\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRinaldi P, Bello A, Lasorsa FR, Caselli MC. Do Spoken Vocabulary and Gestural Production Distinguish Children with Transient Language Delay from Children Who Will Show Developmental Language Disorder? A Pilot Study. Int J Environ Res Public Health, 2022. 19(7).].\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNguyen TN, Spencer-Smith M, Zannino D, Burnett A, Scratch SE, Pascoe L, Ellis R, Cheong J, Thompson D, Inder T, Doyle L. W.,Anderson P.J.,Developmental Trajectory of Language From 2 to 13 Years in Children Born Very Preterm. Pediatrics, 2018. 141(5).].\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNguyen TN, Spencer-Smith M, Zannino D, Burnett A, Scratch SE, Pascoe L, Ellis R, Cheong J, Thompson D, Inder T, Doyle LW, Anderson PJ. Developmental Trajectory of Language From 2 to 13 Years in Children Born Very Preterm. Pediatrics, 2018. 141(5).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Noort-van der Spek IL, Franken MC, Weisglas-Kuperus N. Language functions in preterm-born children: a systematic review and meta-analysis. Pediatrics. 2012;129(4):745\u0026ndash;54.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, Xueman. language disorders and language assessment in children. Chin J Hear speech rehabilitation. 2019;17(03):161\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTong Zhang. Effect of early comprehensive language intervention on children with language developmental delay and its influence on social adaptation and language development. Med Innov China. 2022;19(09):34\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBates E, Dick F. Language, gesture, and the developing brain. Dev Psychobiol. 2002;40(3):293\u0026ndash;310.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDe Stefani E, De Marco D. Language, Gesture, and Emotional Communication: An Embodied View of Social Interaction. Front Psychol, 2019. 10: p. 2063.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVainio L. Connection between movements of mouth and hand: Perspectives on development and evolution of speech. Neurosci Biobehav Rev. 2019;100:211\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMendes JBA, Santos CCD, Soares AJC, Befi-Lopes DM. Simbolic play, vocabulary and intellectual performance of children with developmental language disorder. Codas. 2021;33(2):e20200068.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoldin-Meadow S, Goodrich W, Sauer E, Iverson J. Young children use their hands to tell their mothers what to say. Dev Sci. 2007;10(6):778\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLewis V, Boucher J, Lupton L, Watson S. Relationships between symbolic play, functional play, verbal and non-verbal ability in young children. Int J Lang Commun Disord. 2000;35(1):117\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcGillion M, Herbert JS, Pine J, Vihman M, dePaolis R, Keren-Portnoy T, Matthews D. What Paves the Way to Conventional Language? The Predictive Value of Babble, Pointing, and Socioeconomic Status. Child Dev. 2017;88(1):156\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKraljevic JK, Cepanec M, Simlesa S. Gestural development and its relation to a child's early vocabulary. Infant Behav Dev. 2014;37(2):192\u0026ndash;202.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSansavini A, Guarini A, Zuccarini M, Lee JZ, Faldella G, Iverson JM. Low Rates of Pointing in 18-Month-Olds at Risk for Autism Spectrum Disorder and Extremely Preterm Infants: A Common Index of Language Delay? Front Psychol. 2019;10:2131.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBenassi E, Savini S, Iverson JM, Guarini A, Caselli MC, Alessandroni R, Faldella G, Sansavini A. Early communicative behaviors and their relationship to motor skills in extremely preterm infants. Res Dev Disabil. 2016;48:132\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVandormael C, Schoenhals L, Huppi PS, Filippa M, Borradori Tolsa C. Language in Preterm Born Children: Atypical Development and Effects of Early Interventions on Neuroplasticity. Neural Plast, 2019. 2019: p. 6873270.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKarmiloff-Smith A. Development itself is the key to understanding developmental disorders. Trends Cogn Sci. 1998;2(10):389\u0026ndash;98.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVolpe JJ. Brain injury in premature infants: a complex amalgam of destructive and developmental disturbances. Lancet Neurol. 2009;8(1):110\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVandormael C, Schoenhals L, Huppi PS, Filippa M, Borradori Tolsa C. Language in Preterm Born Children: Atypical Development and Effects of Early Interventions on Neuroplasticity. Neural Plast, 2019. 2019: p. 6873270.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSansavini A, Guarini A, Savini S, Broccoli S, Justice L, Alessandroni R, Faldella G. Longitudinal trajectories of gestural and linguistic abilities in very preterm infants in the second year of life. Neuropsychologia. 2011;49(13):3677\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuppanen E, Winkler I, Kujala T, Ylinen S. More efficient formation of longer-term representations for word forms at birth can be linked to better language skills at 2 years. Dev Cogn Neurosci. 2022;55:101113.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStolt S, Klippi A, Launonen K, Munck P, Lehtonen L, Lapinleimu H, Haataja L. Pipari Study G., Size and composition of the lexicon in prematurely born very-low-birth-weight and full-term Finnish children at two years of age. J Child Lang. 2007;34(2):283\u0026ndash;310.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBahram Soleimani YK, Zohre Badiee BM, Bakhtiyari M, Soraya. A Comparative Study of Size of Expressive Lexicon in Prematurely Born Children with Full-Term 18\u0026ndash;36 Month\u0026rsquo;s Children. Auditory Vestib Res. 2012;21:76\u0026ndash;82.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKunnari S, Yliherva A, Paavola L, Peltoniemi OM. Expressive language skills in Finnish two-year-old extremely- and very-low-birth-weight preterm children. Folia Phoniatr Logop. 2012;64(1):5\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerez-Pereira M. Prevalence of Language Delay among Healthy Preterm Children, Language Outcomes and Predictive Factors. Child (Basel), 2021. 8(4).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evan Noort IL, Franken MC, Weisglas-Kuperus N. Language functions in preterm-born children: a systematic review and meta-analysis. Pediatrics. 2012;129(4):745\u0026ndash;54.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStolt S, Klippi A, Launonen K, Munck P, Lehtonen L, Lapinleimu H, Haataja L. Pipari Study G., Size and composition of the lexicon in prematurely born very-low-birth-weight and full-term Finnish children at two years of age. J Child Lang. 2007;34(2):283\u0026ndash;310.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang y, Wang JF. Ding Yh, clinical features and influencing factors of language developmental delay in children. Chin J Child Health. 2022;30(08):912\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang Ruifang L, Xinyan F, Guoye B, Hua. Wang Wenli, developmental characteristics and related factors of children with language developmental delay. Chin J Child Health. 2017;25(03):287\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSansavini A, Guarini A, Savini S, Broccoli S, Justice L, Alessandroni R, Faldella G. Longitudinal trajectories of gestural and linguistic abilities in very preterm infants in the second year of life. Neuropsychologia. 2011;49(13):3677\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrior M, Bavin EL, Cini E, Reilly S, Bretherton L, Wake M, Eadie P. Influences on communicative development at 24 months of age: child temperament, behaviour problems, and maternal factors. Infant Behav Dev. 2008;31(2):270\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"preterm infants, language development, CCDI (Chinese Communicative Development Inventory), language delay","lastPublishedDoi":"10.21203/rs.3.rs-8731965/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8731965/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eThis study aimed to investigate and compare language development in preterm and full-term infants at 12 and 24 months of age, utilizing the Chinese Communicative Development Inventory (CCDI) to identify distinct developmental features in preterm infants and inform timely language interventions.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA cross-sectional study was conducted, including 139 preterm infants (59 at 12 months, 80 at 24 months) and 235 full-term infants (123 at 12 months, 112 at 24 months). The CCDI \"Words and Gestures\" (8\u0026ndash;16 months) and \"Words and Sentences\" (16\u0026ndash;30 months) questionnaires were used to assess gestural communication, early comprehension, vocabulary breadth, and syntactic complexity. Statistical analyses, including t-tests and chi-square tests, were performed to compare groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003ePreterm infants exhibited significantly lower scores than full-term infants at both 12 and 24 months in various language domains assessed by the CCDI. Specifically, at 12 months, preterm infants showed deficits in initial gestures, motion gestures, phrase comprehension, vocabulary comprehension, and vocabulary expression. At 24 months, preterm infants scored lower in vocabulary expression and sentence complexity. The incidence of language development delay was significantly higher in preterm infants at both 12 months (40.68% vs. 18.70%, P\u0026thinsp;=\u0026thinsp;0.0028) and 24 months (26.25% vs. 5.35%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Gender also impacted language development, with boys often exhibiting lower language development levels than girls.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003ePreterm infants demonstrate significant delays in both pre-linguistic and linguistic stages of language development compared to full-term infants, highlighting the importance of early language development assessment and targeted interventions to mitigate long-term sequelae. The CCDI proves to be a valuable tool in identifying these differences and guiding early intervention efforts.\u003c/p\u003e","manuscriptTitle":"Revealing language development delays in preterm infants compared to full-term infants based on the CCDI","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-19 09:12:10","doi":"10.21203/rs.3.rs-8731965/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0f854143-5e5e-4890-af99-42d66acb31a7","owner":[],"postedDate":"February 19th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-13T05:41:15+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-19 09:12:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8731965","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8731965","identity":"rs-8731965","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}