The term cotwin with special pulmonary lesions and elevated maternal-neonatal D- dimer levels following single intrauterine fetal death in a monochorionic-monoamniotic twin pregnancy: a case report and literature review

The term cotwin with special pulmonary lesions and elevated maternal-neonatal D- dimer levels following single intrauterine fetal death in a monochorionic-monoamniotic twin pregnancy: a case report and literature review | 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 Case Report The term cotwin with special pulmonary lesions and elevated maternal-neonatal D- dimer levels following single intrauterine fetal death in a monochorionic-monoamniotic twin pregnancy: a case report and literature review Haiyan Liu, Xiaoyue Zhang, Zhenzhen Liu, Yi Yu, Weirong Gu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4700216/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 May, 2025 Read the published version in BMC Pediatrics → Version 1 posted 15 You are reading this latest preprint version Abstract Background Complications such as cerebral impairment, preterm delivery, and even intrauterine death can occur in monochorionic twins with singleton fetal death. The coagulation functions of the surviving fetus and mother are controversial. Case presentation We reported a case of spontaneous single intrauterine fetal death at 17 weeks of gestation in a monochorionic monoamniotic twin pregnancy followed by increased maternal-neonatal D-dimer levels and special pulmonary lesions in the surviving term cotwin without cerebral impairment. The mother was complicated with massive pelvic hematomas postpartum and recovered after conservative treatment. Conclusions Maternal-neonatal follow-up of D-dimer and detailed examination of the respiratory system as well as brain impairment of the surviving cotwin and newborn are recommended, especially in monochorionic monoamniotic twin pregnancies with placental arterio-arterial or veno-venous anastomoses and elevated maternal D-dimer. monochorionic monoamniotic twin pregnancy spontaneous single intrauterine fetal death D-dimer pulmonary lesion placental anastomoses Figures Figure 1 Figure 2 Introduction Single intrauterine fetal death (sIUFD) occurs in 3.7–6.8% of all twin pregnancies [ 1 – 3 ], with the majority of fetal deaths occurring in the first trimester and posing a low risk to the surviving cotwin [ 4 ]. However, in monochorionic twin pregnancies, sIUFD in the second or third trimester poses a significant risk to the survival of the cotwin, with approximately 30–50% of surviving cotwins at risk of death or severe neurological injury [ 5 – 6 ]. Monochorionic monoamniotic (MCMA) twins constitute only 5% of all monochorionic pregnancies and less than 1% of all twins [ 7 ], with high rates of stillbirth and perinatal mortality reported in the literature [ 8 ]. Here, we present a novel case of a surviving term cotwin with special pulmonary injury and transient elevated D-dimer but without brain impairment in an MCMA twin pregnancy with spontaneous sIUFD at 17 weeks of gestation. To allow comprehensive recognition of this rare complication, we also conducted a review of monochorionic twin pregnancies complicated with sIUFD in the second or third trimester, excluding cases due to twin-twin transfusion syndrome (TTTS) or selected fetal growth restriction (sFGR). Case report A 39-year-old woman, gravida 3, para 2, underwent in vitro fertilization and embryo transfer, resulting in an MCMA twin pregnancy, a rare occurrence accounting for less than 1% of all twin pregnancies. Noninvasive DNA testing suggested low risk. At 17 weeks of gestation, the heart sounds of one fetus disappeared, and the maternal serum D-dimer level increased to 9.2 mg/L. The mother had been asymptomatic since her last normal scan at 15 weeks, and no discordance in fetal growth was noted. Nadroparin calcium was administered subcutaneously at a dose of 4,200 U once a day until 38 weeks and 2 days of gestation, while the maternal D-dimer level fluctuated between 4 mg/L and 20.4 mg/L. During pregnancy, the mother was asymptomatic, and compression venous ultrasonography revealed no abnormalities. The surviving fetus had normal cranial imaging by magnetic resonance imaging (MRI) and peak systolic velocity (PSV) of the middle cerebral artery (MCA) throughout the pregnancy. Due to a previous cesarean section (CS), the patient delivered via the CS at 39 weeks, and the surgery was successful. A routine blood test before surgery revealed a hemoglobin level of 128 g/L, a D-dimer level of 20.40 mg/L, and normal results for other blood tests. Two days after the CS, the patient had an anemic appearance and a pulse rate of 120 bpm. Physical examination revealed that she had good uterine contraction and less lochia, without obvious abdominal tenderness or rebound tenderness. Blood tests revealed a decrease in hemoglobin to 60 g/L, D-dimer to 4.96 mg/L, and creatinine to 106 µmol/L. A pelvic ultrasound revealed a massive hematoma measuring 8 cm ×7 cm × 5 cm in the right lower abdomen. After supportive and symptomatic treatments, the patient’s hemoglobin level and hematoma size were stable 4 days after the CS, with a maximum hematoma size measuring 14 cm × 10.5 cm × 7.5 cm in the right lower abdomen. The Chinese medicine hemostatic prescription was applied externally to the right lower abdomen, and nadroparin calcium and medical compression stockings were administered to prevent deep venous thrombosis (DVT). The patient was discharged 10 days after the CS, and her hemoglobin level returned to 92 g/L. Eight weeks after the CS, transvaginal ultrasound revealed a shrunken hematoma measuring 9.2 cm × 8.7 cm × 7.8 cm, and the D-dimer level returned to 2.24 mg/L. The fluctuations in D-dimer levels are shown in Fig. 1 . Following birth, the infant showed no obvious clinical signs of neurological problems, and subsequent brain MRI showed normal imaging. However, the term infant exhibited dyspnea 2 hours after birth, and a chest X-ray revealed exudation of both lungs, suggesting special inflammation (Fig. 2 A). After intubation and mechanical ventilation, the patient’s dyspnea improved. On the fourth day after birth, the newborn was removed from ventilation. Interestingly, routine blood tests of neutrophil and leukocyte counts and infection indicators such as C-reactive protein and serum amyloid A were within normal ranges. Furthermore, negative blood, sputum, chlamydia, and mycoplasma culture results suggested the absence of any infections. The bilateral exudation revealed by chest radiography improved 10 days after birth (Fig. 2 B). The first blood coagulation test on the 6th day after birth showed that the D-dimer level increased to 29.88 mg/L. However, no other abnormal coagulation indicators or thromboembolic complications were noted. The D-dimer level returned to normal 8 days after birth. The infant was discharged 10 days after birth. No neurological delays were observed in the neonate. Written informed consent was obtained from the patients who consented to the publication of all images, clinical data and other data included in the manuscript. Discussion The occurrence of surviving cotwins born at term without brain injury subsequent to sIUFD in the second trimester within an MCMA twin pregnancy is exceedingly rare. Following sIUFD, maternal D-dimer levels significantly increased throughout the entire gestational period. Upon birth, the surviving full-term newborn experienced a transient elevation in D-dimer levels within 8 days, concomitant with unexplained noninflammatory exudative lesions observed in the bilateral pulmonary region. However, the coagulation status of the mother, surviving fetus, and newborn following sIUFD remains uncertain in the literature. To comprehensively understand this uncommon complication, a thorough literature review was conducted encompassing cases of monochorionic pregnancies complicated by spontaneous sIUFD in the second or third trimester, excluding those attributed to TTTS or sFGR. This review aimed to elucidate the clinical characteristics of such cases, identify potential risk factors contributing to neonatal pulmonary lesions, and underscore the heightened importance of prenatal assessments encompassing maternal-neonatal D-dimer levels and potential end-organ damage in surviving cotwins, particularly concerning the respiratory system, in the context of pregnancies with MCMA pregnancies with elevated maternal D-dimer levels. The cause of the single fetal death in this patient remains unknown. An examination at delivery revealed that the dead fetus was a fetal papyraceus with an atrophic umbilical cord and that the insertion points of the two umbilical cords were 1 cm apart without velamentous insertion. A large portion of fetal deaths observed in monoamniotic twin pregnancies are caused by fetal defects, while in structurally normal monoamniotic twin pregnancies, fetal deaths are often explained by tight cord entanglement [ 9 ]. All these factors may have contributed to the single fetal death in this patient. In our review (Table 1), five surviving cotwins (7.6%, 5/66) experienced intrauterine death, 50 cotwins (82%, 50/61) were born prematurely, 14 neonates (23.0%, 14/61) died after birth, 26 neonates (44.1%, 26/59) suffered from intracranial lesions, and 7 preterm newborns developed other organ impairments, such as lung damage, kidney abnormalities, intestinal injury and cardiac failure, which may be mainly due to complications of prematurity. Additionally, brain MRI showed that the surviving fetus had normal cranial imaging in this patient, even as a term newborn. In fact, the surviving twin is at a high risk of abnormal postnatal brain imaging in cases of single fetal death, especially in monochorionic pregnancies, with an incidence of approximately 43% [ 10 ], which was similar to our reviewed case series. There are two main theories to explain the increased risk of morbidity and mortality of the surviving cotwin in monochorionic pregnancies: “twin embolization syndrome” and “hemodynamic imbalance.” The latter theory, which states that placental intertwin anastomoses allow the transfer of blood from the surviving cotwin to the dead twin, resulting in periods of hypoperfusion and adverse outcomes such as neurological changes, is widely accepted. This theory was based on the finding that fetal anemia was clearly documented in fetal blood sampling of the surviving cotwin [ 11 – 13 ]. Sonographic measurement of the MCA PSV is a reliable and noninvasive way to detect fetal anemia. Bajoria et al. established that superficial intertwin arterio-arterial or veno-venous anastomoses increase the incidence of intrauterine death, fetal anemia, and neurological handicap [ 14 ]. As shown in Table 1, of the 17 surviving fetuses with placental intertwin arterio-arterial or veno-venous anastomoses, 11 (64.7%, 11/17) developed anemia, and 10 of the 11 anemic fetuses (90.9%, 10/11) developed brain damage. In contrast, of the nine surviving fetuses with placental intertwin arterio-venous or veno-arterial vascular shunts, two (22.2%, 2/9) developed anemia followed by neurological impairment. The risk to the surviving monochorionic cotwin may depend upon the type and size of the placental anastomoses. Cotwin anemia and even death can be explained by acute hemodynamic imbalances caused by large placental anastomoses, such as arterio-arterial and veno-venous anastomoses. Fortunately, the MCA PSV of the surviving cotwin in our patient was normal, indicating that our patient did not have large arterio-arterial or veno-venous anastomoses. Since delineation of superficial placental anastomoses by power Doppler ultrasound or MRI has now become possible in the field of research, we may use this indicator to predict the prognosis of the surviving fetus and guide clinical management. Furthermore, the neonate in our case had transient D-dimer elevation with a maximum of 29.88 mg/L, which was extremely high. Nonetheless, it was reported that the results of coagulation screening tests on the surviving infant twin at delivery were almost always normal when the complications of prematurity were excluded [ 26 ]. Khalilov et al. reported that the mean D-dimer level measured in healthy term neonates at one week (2.44 ± 2.45 mg/L) was greater than that reported in the literature for adults (< 0.5 mg/L) and that D-dimer levels gradually decreased over time in the first month [ 27 ]. The high D-dimer levels in the neonatal period might be due to diminished renal clearance of D-dimer, birth stress, circulatory adaptation, short-term hypoxia, or intrauterine activation [ 27 ]. The transient elevation of D-dimer in the newborn patient in our case might be attributed to intrauterine activation derived from the mother. The gradient is such that thromboembolic material cannot flow from the dead fetus to the circulation of the survivor. In our patient, after 3 days of intubation and mechanical ventilation and 10 days of anti-inflammatory treatment with ampicillin sulbactam sodium and ceftazidime, the neonatal exudative lesions in both lungs, as well as other clinical symptoms, improved significantly. It is well known that neonatal wet lung disease is usually self-limiting, with complete remission within 2–3 days. Respiratory distress syndrome is a progressive disease commonly encountered in premature infants and mothers with diabetes. The characteristics of respiratory distress syndrome include reduced transparency, a ground-glass opacities, and even white lungs on chest radiographs. Our case was not very similar to either of these two diseases. The fetus lacks pulmonary circulation during the intrauterine period. Once the fetus is born, thrombotic material may flow into the neonate’s pulmonary circulation, resulting in pulmonary damage. However, this kind of lung damage is usually mild, which is not consistent with our case. In this case, the two fetuses shared a single amniotic sac. When sIUFD occurs, the necrotic material from the deceased fetus is released into the shared amniotic cavity. The surviving fetus might have inhaled some amniotic fluid containing necrotic material via breath-like movements. The inhaled necrotic material might have blocked the fetal lung, resulting in obvious exudative changes in both lungs. However, it is important to note that this is a speculative interpretation, and further research is warranted to confirm this hypothesis. Szymonowicz W et al. reported three cases of pulmonary complications in monochorionic diamniotic twin pregnancies, of which two were pulmonary infarction and one was pulmonary artery embolism [ 16 ]. The gestational ages at delivery were 28, 31, and 32 weeks, respectively. Therefore, lung damage due to complications of prematurity cannot be excluded. Notably, the surviving term twin in this patient did not develop brain damage; however, special pulmonary lesions were present postnatally. The possible risk factors contributing to the special pulmonary lesions in our patient were elevated maternal D-dimer and MCMA. When sIUFD occurs, maternal disseminated intravascular coagulation (DIC) is extremely rare in multiple pregnancies [ 28 – 29 ], although the reason remains unclear. Maternal coagulation function results were available for eight patients, of whom two had decreased fibrinogen and five had normal fibrinogen. Only our patient showed increased maternal D-dimer levels from 1.18 mg/L to 9.21 mg/L following single fetal demise at 17 weeks of gestation, which indicated the activation of maternal fibrinolysis following fibrin formation. Moreover, the D-dimer concentration tended to decrease to 4.05 mg/L at 20 weeks of gestation, possibly due to self-regulation of the maternal coagulation-fibrinolysis system and the effect of low-molecular-weight heparin (LMWH). D-dimer levels are useful markers for the early diagnosis of DIC and thromboembolism [ 30 – 31 ]. Nevertheless, there were no complaints or clinical manifestations of thromboembolic complications in this mother. Of course, the formation of small emboli in deep pelvic veins cannot be ruled out because imaging is less sensitive for diagnosing pelvic DVT during pregnancy. Even if there was a pelvic DVT, it was estimated to only consist of small emboli and had little impact. Similarly, Daniilidis and his colleagues [ 32 ] also reported elevated D-dimer levels, with a maximum of approximately 10 mg/L at 33 weeks of gestation following a single twin death, without the occurrence of DIC or thromboembolism in the mother. Hence, a baseline coagulation profile, including D-dimer levels, needs to be followed up with serial coagulation studies. D-dimer, a fibrinolytic-specific degradation product, is a highly sensitive marker of fibrin formation. A high D-dimer concentration indicates activation of both the coagulation and fibrinolytic systems. During normal pregnancy, it increases gradually, reaches its peak in the third trimester and is maintained until 48 hours postpartum in response to the increased demand for fibrin formation and fibrinolysis to maintain proper blood flow to the placenta and fetus and reduce the risk of postpartum bleeding [ 33 – 37 ]. Previous research has demonstrated that elevated maternal D-dimer levels are independent risk factors for postpartum hemorrhage [ 34 , 38 ]. Severe pelvic bleeding occurred two days postpartum in our patient. This may be attributed to the delivery process as well as an increase in fibrinolysis indicated by elevated D-dimer levels, i.e., the consumption of fibrinogen results in relatively low levels of fibrinogen, and a low antenatal fibrinogen level increases the risk of postpartum hemorrhage. The pathological mechanism of D-dimer elevation and the effects of continuous D-dimer elevation on maternal and fetal prognosis, especially its relationships with maternal pelvic hemorrhage and neonatal pulmonary lesions, require further clinical and laboratory studies for verification. In this case, following a single fetal death and an increase in maternal D-dimer, LMWH was administered until 38 weeks and 2 days of gestation. During this time, the D-dimer levels fluctuated at relatively high levels. Fortunately, there was no cerebral impairment in the neonate. However, pelvic hemorrhage occurred two days postpartum, and the newborn was complicated with unexplained pulmonary lesions with transient elevated D-dimer. It was unclear whether these complications were related to the use of LMWH, although LMWH administration during the prenatal period is safe. Since MCMA twins are always accompanied by multiple complications, the diagnosis of chorionicity and amnionicity in the first trimester is needed for further pregnancy follow-up [ 39 ]. After the first trimester, we typically perform ultrasounds every 2 weeks to check fetal viability and screen for growth restriction, TTTS, and twin anemia-polycythemia sequences. When an intrauterine single fetal death was detected, the MCA PSV of the surviving cotwin was detected immediately, maternal coagulation function, including D-dimer levels, was examined every week for the following month, and LMWH was administered when necessary. Cranial images of the cotwin were obtained 3 weeks later by MRI, and the patient was followed up throughout the pregnancy. It would be even better if the type and size of placental intertwin anastomoses could be examined by MRI or ultrasound. Conclusions In addition to assessing the brain impairment of the surviving cotwin when sIUFD occurs, careful evaluation of damage to other end-organs, such as the respiratory system, is necessary, especially in MCMA pregnancies with elevated maternal D-dimer levels. Moreover, maternal and neonatal coagulation profiles, including D-dimer levels, are recommended for follow-up. Abbreviations sIUFD single intrauterine fetal death MCMA monochorionic monoamniotic TTTS twin-twin transfusion syndrome sFGR selected fetal growth restriction CS cesarean section CRP C-reactive protein WBC white blood cell FDP fibrinogen degradation products MCA the middle cerebral artery PSV peak systolic velocity DVT deep venous thrombosis DIC disseminated intravascular coagulation LMWH low molecular weight heparin MRI magnetic resonance imaging Declarations Ethics approval and consent to participate The study was approved by the Institutional Ethics Committee of our hospital, and written informed consent was obtained from the patients. Consent for publication Written informed consent for publication of their clinical details and clinical images was obtained from the patient and guardian of the patient. A copy of the consent form is available for review by the Editor of this journal. Availability of data and materials Data included in the article. Competing interests The authors declare no conflicts of interest. Funding This study was supported by the National Natural Science Foundation of China (No. 81801469). Authors' contributions Haiyan Liu participated in patient management, conceived and designed the study and was a major contributor to the writing of the manuscript. Xiaoyue Zhang acquired, analyzed and interpreted the data and revised the manuscript. Zhenzhen Liu and Yi Yu participated in patient management and analyzed and interpreted the patient data. Weirong Gu participated in patient management, conceived and designed the study and was a major contributor to revising the manuscript. All the authors have read and approved the final manuscript. Acknowledgments We thank the staff of the ultrasound department in our hospital for performing ultrasound to detect postpartum pelvic hematomas. References Enbom JA. Twin pregnancy with intrauterine death of one twin. Am J Obstet Gynecol, 1985; 152(4): 424-9. 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Supplementary Files table1.pdf table2.pdf Cite Share Download PDF Status: Published Journal Publication published 27 May, 2025 Read the published version in BMC Pediatrics → Version 1 posted Editorial decision: Revision requested 21 Feb, 2025 Reviews received at journal 20 Feb, 2025 Reviewers agreed at journal 18 Feb, 2025 Reviews received at journal 17 Feb, 2025 Reviewers agreed at journal 17 Feb, 2025 Reviewers agreed at journal 16 Feb, 2025 Reviewers agreed at journal 15 Feb, 2025 Reviewers agreed at journal 15 Feb, 2025 Reviewers agreed at journal 14 Feb, 2025 Reviewers agreed at journal 14 Feb, 2025 Reviewers invited by journal 22 Aug, 2024 Editor invited by journal 18 Jul, 2024 Editor assigned by journal 15 Jul, 2024 Submission checks completed at journal 15 Jul, 2024 First submitted to journal 07 Jul, 2024 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. 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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-4700216","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":336829504,"identity":"6ea56121-97a6-4d15-9b5a-09d32e7b32ab","order_by":0,"name":"Haiyan Liu","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Haiyan","middleName":"","lastName":"Liu","suffix":""},{"id":336829505,"identity":"d561ba1a-cc94-4566-b552-2e2a3c3d0e60","order_by":1,"name":"Xiaoyue Zhang","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Xiaoyue","middleName":"","lastName":"Zhang","suffix":""},{"id":336829506,"identity":"9b2fd489-048c-4a5d-a662-29318548212d","order_by":2,"name":"Zhenzhen Liu","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Zhenzhen","middleName":"","lastName":"Liu","suffix":""},{"id":336829507,"identity":"d44805b9-ef89-4c8f-b7b1-e3fc05ac93fc","order_by":3,"name":"Yi Yu","email":"","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Yi","middleName":"","lastName":"Yu","suffix":""},{"id":336829508,"identity":"d1dacacc-3afc-4f8d-8b79-e2e520e2fb7b","order_by":4,"name":"Weirong Gu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA60lEQVRIiWNgGAWjYLCCBBDB3viAgQfBJUYLz2EDErSAgUQykVrkI3IMHzzcY5MnH/mYTeJNzR0GfvYcA4afO3BrMbyRY2yQ8Cyt2PB2MpvknGPPGCR73hgw9p7Bo2VG7jaJhAOHEzfOzj8mzcN2mMHgRo4BM2MbXi3bf4C1zDzMJs3z7zCDPSEt8hK52xhAWuZLMLNJ87YBbZEgoMWA5/1noMPSEjfwJDNbzu07zCNx5lnBwV58trSnJX78ccAmcX77YcYbb74dluNvT9744Cc+Ww6gMcBRcwCbUrgtDeiMUTAKRsEoGAXoAACg+VSKav3bFQAAAABJRU5ErkJggg==","orcid":"","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":true,"prefix":"","firstName":"Weirong","middleName":"","lastName":"Gu","suffix":""}],"badges":[],"createdAt":"2024-07-07 12:38:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4700216/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4700216/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12887-025-05777-4","type":"published","date":"2025-05-27T15:57:36+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":62222465,"identity":"fec1cf13-67dd-42ef-94d2-d0378fa7d29d","added_by":"auto","created_at":"2024-08-11 12:38:02","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":411158,"visible":true,"origin":"","legend":"\u003cp\u003eChanges in D-dimer levels during pregnancy and puerperium. The maternal D-dimer level significantly increased to 9.2 mg/Lfollowing single fetal death in a monochorionic-monoamniotic twinpregnancy at 17 weeks of gestation anddecreased to 4 mg/L at 20 weeks of gestation after the administration of nadroparin calcium. Then, the D-dimer level continuously increased to a maximum of 20.4 mg/L at 38 weeks of gestation and returned to 2.24 mg/L at 8 weeks postpartum. 13 w, 13 weeks of gestation, and so on. d1, one day postpartum, and so on. LMWH, low molecular weight heparin.\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4700216/v1/51d62dd3f43c7cb675a9b165.jpg"},{"id":62222466,"identity":"40fa1f72-a991-45b3-9d63-3d87466a7b2f","added_by":"auto","created_at":"2024-08-11 12:38:02","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1734788,"visible":true,"origin":"","legend":"\u003cp\u003eChest radiographs of the neonate. The exudative lesions in both lungs improved 10 days later. A, Chest radiograph on the first day after birth. B, Chest radiograph on the 10\u003csup\u003eth\u003c/sup\u003e day after birth.\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4700216/v1/d754eb78bec4cc063b953f45.jpg"},{"id":83782892,"identity":"1cd09cab-e259-4719-bce6-922cb478cada","added_by":"auto","created_at":"2025-06-02 16:08:09","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2619097,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4700216/v1/48e43e4b-3f4a-4dfe-9768-7303970a9532.pdf"},{"id":62222463,"identity":"0ca3d9f0-24f0-466a-abcd-4638150dce80","added_by":"auto","created_at":"2024-08-11 12:38:02","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":40146,"visible":true,"origin":"","legend":"","description":"","filename":"table1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4700216/v1/306c94fa3bd4c0a80245f5a7.pdf"},{"id":62222464,"identity":"f4dcb446-4723-4ef7-9cf0-dac349ecc291","added_by":"auto","created_at":"2024-08-11 12:38:02","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":30636,"visible":true,"origin":"","legend":"","description":"","filename":"table2.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4700216/v1/52f73838620aeb240f89ff86.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The term cotwin with special pulmonary lesions and elevated maternal-neonatal D- dimer levels following single intrauterine fetal death in a monochorionic-monoamniotic twin pregnancy: a case report and literature review","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSingle intrauterine fetal death (sIUFD) occurs in 3.7\u0026ndash;6.8% of all twin pregnancies [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], with the majority of fetal deaths occurring in the first trimester and posing a low risk to the surviving cotwin [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. However, in monochorionic twin pregnancies, sIUFD in the second or third trimester poses a significant risk to the survival of the cotwin, with approximately 30\u0026ndash;50% of surviving cotwins at risk of death or severe neurological injury [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Monochorionic monoamniotic (MCMA) twins constitute only 5% of all monochorionic pregnancies and less than 1% of all twins [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], with high rates of stillbirth and perinatal mortality reported in the literature [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Here, we present a novel case of a surviving term cotwin with special pulmonary injury and transient elevated D-dimer but without brain impairment in an MCMA twin pregnancy with spontaneous sIUFD at 17 weeks of gestation. To allow comprehensive recognition of this rare complication, we also conducted a review of monochorionic twin pregnancies complicated with sIUFD in the second or third trimester, excluding cases due to twin-twin transfusion syndrome (TTTS) or selected fetal growth restriction (sFGR).\u003c/p\u003e"},{"header":"Case report","content":"\u003cp\u003eA 39-year-old woman, gravida 3, para 2, underwent \u003cem\u003ein vitro\u003c/em\u003e fertilization and embryo transfer, resulting in an MCMA twin pregnancy, a rare occurrence accounting for less than 1% of all twin pregnancies. Noninvasive DNA testing suggested low risk. At 17 weeks of gestation, the heart sounds of one fetus disappeared, and the maternal serum D-dimer level increased to 9.2 mg/L. The mother had been asymptomatic since her last normal scan at 15 weeks, and no discordance in fetal growth was noted. Nadroparin calcium was administered subcutaneously at a dose of 4,200 U once a day until 38 weeks and 2 days of gestation, while the maternal D-dimer level fluctuated between 4 mg/L and 20.4 mg/L. During pregnancy, the mother was asymptomatic, and compression venous ultrasonography revealed no abnormalities. The surviving fetus had normal cranial imaging by magnetic resonance imaging (MRI) and peak systolic velocity (PSV) of the middle cerebral artery (MCA) throughout the pregnancy. Due to a previous cesarean section (CS), the patient delivered via the CS at 39 weeks, and the surgery was successful. A routine blood test before surgery revealed a hemoglobin level of 128 g/L, a D-dimer level of 20.40 mg/L, and normal results for other blood tests.\u003c/p\u003e \u003cp\u003eTwo days after the CS, the patient had an anemic appearance and a pulse rate of 120 bpm. Physical examination revealed that she had good uterine contraction and less lochia, without obvious abdominal tenderness or rebound tenderness. Blood tests revealed a decrease in hemoglobin to 60 g/L, D-dimer to 4.96 mg/L, and creatinine to 106 \u0026micro;mol/L. A pelvic ultrasound revealed a massive hematoma measuring 8 cm \u0026times;7 cm \u0026times; 5 cm in the right lower abdomen. After supportive and symptomatic treatments, the patient\u0026rsquo;s hemoglobin level and hematoma size were stable 4 days after the CS, with a maximum hematoma size measuring 14 cm \u0026times; 10.5 cm \u0026times; 7.5 cm in the right lower abdomen.\u003c/p\u003e \u003cp\u003eThe Chinese medicine hemostatic prescription was applied externally to the right lower abdomen, and nadroparin calcium and medical compression stockings were administered to prevent deep venous thrombosis (DVT). The patient was discharged 10 days after the CS, and her hemoglobin level returned to 92 g/L. Eight weeks after the CS, transvaginal ultrasound revealed a shrunken hematoma measuring 9.2 cm \u0026times; 8.7 cm \u0026times; 7.8 cm, and the D-dimer level returned to 2.24 mg/L. The fluctuations in D-dimer levels are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFollowing birth, the infant showed no obvious clinical signs of neurological problems, and subsequent brain MRI showed normal imaging. However, the term infant exhibited dyspnea 2 hours after birth, and a chest X-ray revealed exudation of both lungs, suggesting special inflammation (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA). After intubation and mechanical ventilation, the patient\u0026rsquo;s dyspnea improved. On the fourth day after birth, the newborn was removed from ventilation. Interestingly, routine blood tests of neutrophil and leukocyte counts and infection indicators such as C-reactive protein and serum amyloid A were within normal ranges. Furthermore, negative blood, sputum, chlamydia, and mycoplasma culture results suggested the absence of any infections. The bilateral exudation revealed by chest radiography improved 10 days after birth (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB). The first blood coagulation test on the 6th day after birth showed that the D-dimer level increased to 29.88 mg/L. However, no other abnormal coagulation indicators or thromboembolic complications were noted. The D-dimer level returned to normal 8 days after birth. The infant was discharged 10 days after birth. No neurological delays were observed in the neonate.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e Written informed consent was obtained from the patients who consented to the publication of all images, clinical data and other data included in the manuscript.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe occurrence of surviving cotwins born at term without brain injury subsequent to sIUFD in the second trimester within an MCMA twin pregnancy is exceedingly rare. Following sIUFD, maternal D-dimer levels significantly increased throughout the entire gestational period. Upon birth, the surviving full-term newborn experienced a transient elevation in D-dimer levels within 8 days, concomitant with unexplained noninflammatory exudative lesions observed in the bilateral pulmonary region. However, the coagulation status of the mother, surviving fetus, and newborn following sIUFD remains uncertain in the literature. To comprehensively understand this uncommon complication, a thorough literature review was conducted encompassing cases of monochorionic pregnancies complicated by spontaneous sIUFD in the second or third trimester, excluding those attributed to TTTS or sFGR. This review aimed to elucidate the clinical characteristics of such cases, identify potential risk factors contributing to neonatal pulmonary lesions, and underscore the heightened importance of prenatal assessments encompassing maternal-neonatal D-dimer levels and potential end-organ damage in surviving cotwins, particularly concerning the respiratory system, in the context of pregnancies with MCMA pregnancies with elevated maternal D-dimer levels.\u003c/p\u003e \u003cp\u003eThe cause of the single fetal death in this patient remains unknown. An examination at delivery revealed that the dead fetus was a fetal papyraceus with an atrophic umbilical cord and that the insertion points of the two umbilical cords were 1 cm apart without velamentous insertion. A large portion of fetal deaths observed in monoamniotic twin pregnancies are caused by fetal defects, while in structurally normal monoamniotic twin pregnancies, fetal deaths are often explained by tight cord entanglement [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. All these factors may have contributed to the single fetal death in this patient.\u003c/p\u003e \u003cp\u003eIn our review (Table\u0026nbsp;1), five surviving cotwins (7.6%, 5/66) experienced intrauterine death, 50 cotwins (82%, 50/61) were born prematurely, 14 neonates (23.0%, 14/61) died after birth, 26 neonates (44.1%, 26/59) suffered from intracranial lesions, and 7 preterm newborns developed other organ impairments, such as lung damage, kidney abnormalities, intestinal injury and cardiac failure, which may be mainly due to complications of prematurity. Additionally, brain MRI showed that the surviving fetus had normal cranial imaging in this patient, even as a term newborn. In fact, the surviving twin is at a high risk of abnormal postnatal brain imaging in cases of single fetal death, especially in monochorionic pregnancies, with an incidence of approximately 43% [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], which was similar to our reviewed case series.\u003c/p\u003e \u003cp\u003eThere are two main theories to explain the increased risk of morbidity and mortality of the surviving cotwin in monochorionic pregnancies: \u0026ldquo;twin embolization syndrome\u0026rdquo; and \u0026ldquo;hemodynamic imbalance.\u0026rdquo; The latter theory, which states that placental intertwin anastomoses allow the transfer of blood from the surviving cotwin to the dead twin, resulting in periods of hypoperfusion and adverse outcomes such as neurological changes, is widely accepted. This theory was based on the finding that fetal anemia was clearly documented in fetal blood sampling of the surviving cotwin [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Sonographic measurement of the MCA PSV is a reliable and noninvasive way to detect fetal anemia. Bajoria et al. established that superficial intertwin arterio-arterial or veno-venous anastomoses increase the incidence of intrauterine death, fetal anemia, and neurological handicap [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. As shown in Table\u0026nbsp;1, of the 17 surviving fetuses with placental intertwin arterio-arterial or veno-venous anastomoses, 11 (64.7%, 11/17) developed anemia, and 10 of the 11 anemic fetuses (90.9%, 10/11) developed brain damage. In contrast, of the nine surviving fetuses with placental intertwin arterio-venous or veno-arterial vascular shunts, two (22.2%, 2/9) developed anemia followed by neurological impairment. The risk to the surviving monochorionic cotwin may depend upon the type and size of the placental anastomoses. Cotwin anemia and even death can be explained by acute hemodynamic imbalances caused by large placental anastomoses, such as arterio-arterial and veno-venous anastomoses. Fortunately, the MCA PSV of the surviving cotwin in our patient was normal, indicating that our patient did not have large arterio-arterial or veno-venous anastomoses. Since delineation of superficial placental anastomoses by power Doppler ultrasound or MRI has now become possible in the field of research, we may use this indicator to predict the prognosis of the surviving fetus and guide clinical management.\u003c/p\u003e \u003cp\u003eFurthermore, the neonate in our case had transient D-dimer elevation with a maximum of 29.88 mg/L, which was extremely high. Nonetheless, it was reported that the results of coagulation screening tests on the surviving infant twin at delivery were almost always normal when the complications of prematurity were excluded [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Khalilov et al. reported that the mean D-dimer level measured in healthy term neonates at one week (2.44\u0026thinsp;\u0026plusmn;\u0026thinsp;2.45 mg/L) was greater than that reported in the literature for adults (\u0026lt;\u0026thinsp;0.5 mg/L) and that D-dimer levels gradually decreased over time in the first month [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The high D-dimer levels in the neonatal period might be due to diminished renal clearance of D-dimer, birth stress, circulatory adaptation, short-term hypoxia, or intrauterine activation [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The transient elevation of D-dimer in the newborn patient in our case might be attributed to intrauterine activation derived from the mother. The gradient is such that thromboembolic material cannot flow from the dead fetus to the circulation of the survivor.\u003c/p\u003e \u003cp\u003eIn our patient, after 3 days of intubation and mechanical ventilation and 10 days of anti-inflammatory treatment with ampicillin sulbactam sodium and ceftazidime, the neonatal exudative lesions in both lungs, as well as other clinical symptoms, improved significantly. It is well known that neonatal wet lung disease is usually self-limiting, with complete remission within 2\u0026ndash;3 days. Respiratory distress syndrome is a progressive disease commonly encountered in premature infants and mothers with diabetes. The characteristics of respiratory distress syndrome include reduced transparency, a ground-glass opacities, and even white lungs on chest radiographs. Our case was not very similar to either of these two diseases. The fetus lacks pulmonary circulation during the intrauterine period. Once the fetus is born, thrombotic material may flow into the neonate\u0026rsquo;s pulmonary circulation, resulting in pulmonary damage. However, this kind of lung damage is usually mild, which is not consistent with our case. In this case, the two fetuses shared a single amniotic sac. When sIUFD occurs, the necrotic material from the deceased fetus is released into the shared amniotic cavity. The surviving fetus might have inhaled some amniotic fluid containing necrotic material via breath-like movements. The inhaled necrotic material might have blocked the fetal lung, resulting in obvious exudative changes in both lungs. However, it is important to note that this is a speculative interpretation, and further research is warranted to confirm this hypothesis. Szymonowicz W et al. reported three cases of pulmonary complications in monochorionic diamniotic twin pregnancies, of which two were pulmonary infarction and one was pulmonary artery embolism [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The gestational ages at delivery were 28, 31, and 32 weeks, respectively. Therefore, lung damage due to complications of prematurity cannot be excluded. Notably, the surviving term twin in this patient did not develop brain damage; however, special pulmonary lesions were present postnatally. The possible risk factors contributing to the special pulmonary lesions in our patient were elevated maternal D-dimer and MCMA.\u003c/p\u003e \u003cp\u003eWhen sIUFD occurs, maternal disseminated intravascular coagulation (DIC) is extremely rare in multiple pregnancies [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], although the reason remains unclear. Maternal coagulation function results were available for eight patients, of whom two had decreased fibrinogen and five had normal fibrinogen. Only our patient showed increased maternal D-dimer levels from 1.18 mg/L to 9.21 mg/L following single fetal demise at 17 weeks of gestation, which indicated the activation of maternal fibrinolysis following fibrin formation. Moreover, the D-dimer concentration tended to decrease to 4.05 mg/L at 20 weeks of gestation, possibly due to self-regulation of the maternal coagulation-fibrinolysis system and the effect of low-molecular-weight heparin (LMWH). D-dimer levels are useful markers for the early diagnosis of DIC and thromboembolism [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Nevertheless, there were no complaints or clinical manifestations of thromboembolic complications in this mother. Of course, the formation of small emboli in deep pelvic veins cannot be ruled out because imaging is less sensitive for diagnosing pelvic DVT during pregnancy. Even if there was a pelvic DVT, it was estimated to only consist of small emboli and had little impact. Similarly, Daniilidis and his colleagues [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] also reported elevated D-dimer levels, with a maximum of approximately 10 mg/L at 33 weeks of gestation following a single twin death, without the occurrence of DIC or thromboembolism in the mother. Hence, a baseline coagulation profile, including D-dimer levels, needs to be followed up with serial coagulation studies.\u003c/p\u003e \u003cp\u003eD-dimer, a fibrinolytic-specific degradation product, is a highly sensitive marker of fibrin formation. A high D-dimer concentration indicates activation of both the coagulation and fibrinolytic systems. During normal pregnancy, it increases gradually, reaches its peak in the third trimester and is maintained until 48 hours postpartum in response to the increased demand for fibrin formation and fibrinolysis to maintain proper blood flow to the placenta and fetus and reduce the risk of postpartum bleeding [\u003cspan additionalcitationids=\"CR34 CR35 CR36\" citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Previous research has demonstrated that elevated maternal D-dimer levels are independent risk factors for postpartum hemorrhage [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. Severe pelvic bleeding occurred two days postpartum in our patient. This may be attributed to the delivery process as well as an increase in fibrinolysis indicated by elevated D-dimer levels, i.e., the consumption of fibrinogen results in relatively low levels of fibrinogen, and a low antenatal fibrinogen level increases the risk of postpartum hemorrhage. The pathological mechanism of D-dimer elevation and the effects of continuous D-dimer elevation on maternal and fetal prognosis, especially its relationships with maternal pelvic hemorrhage and neonatal pulmonary lesions, require further clinical and laboratory studies for verification.\u003c/p\u003e \u003cp\u003eIn this case, following a single fetal death and an increase in maternal D-dimer, LMWH was administered until 38 weeks and 2 days of gestation. During this time, the D-dimer levels fluctuated at relatively high levels. Fortunately, there was no cerebral impairment in the neonate. However, pelvic hemorrhage occurred two days postpartum, and the newborn was complicated with unexplained pulmonary lesions with transient elevated D-dimer. It was unclear whether these complications were related to the use of LMWH, although LMWH administration during the prenatal period is safe.\u003c/p\u003e \u003cp\u003eSince MCMA twins are always accompanied by multiple complications, the diagnosis of chorionicity and amnionicity in the first trimester is needed for further pregnancy follow-up [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. After the first trimester, we typically perform ultrasounds every 2 weeks to check fetal viability and screen for growth restriction, TTTS, and twin anemia-polycythemia sequences. When an intrauterine single fetal death was detected, the MCA PSV of the surviving cotwin was detected immediately, maternal coagulation function, including D-dimer levels, was examined every week for the following month, and LMWH was administered when necessary. Cranial images of the cotwin were obtained 3 weeks later by MRI, and the patient was followed up throughout the pregnancy. It would be even better if the type and size of placental intertwin anastomoses could be examined by MRI or ultrasound.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn addition to assessing the brain impairment of the surviving cotwin when sIUFD occurs, careful evaluation of damage to other end-organs, such as the respiratory system, is necessary, especially in MCMA pregnancies with elevated maternal D-dimer levels. Moreover, maternal and neonatal coagulation profiles, including D-dimer levels, are recommended for follow-up.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003esIUFD\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003esingle intrauterine fetal death\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eMCMA\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003emonochorionic monoamniotic\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eTTTS\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003etwin-twin transfusion syndrome\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003esFGR\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eselected fetal growth restriction\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eCS\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003ecesarean section\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eCRP\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eC-reactive protein\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eWBC\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003ewhite blood cell\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eFDP\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003efibrinogen degradation products\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eMCA\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003ethe middle cerebral artery\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003ePSV\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003epeak systolic velocity\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eDVT\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003edeep venous thrombosis\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eDIC\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003edisseminated intravascular coagulation\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eLMWH\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003elow molecular weight heparin\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003eMRI\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003emagnetic resonance imaging\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the Institutional Ethics Committee of our hospital, and written informed consent was\u0026nbsp;obtained\u0026nbsp;from the\u0026nbsp;patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent for publication of their clinical details and clinical images was obtained from the patient and guardian of the patient. A copy of the consent form is available for review by the Editor of this journal.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData included in\u0026nbsp;the\u0026nbsp;article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cpre\u003eThe authors declare no conflicts of interest.\u003c/pre\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by the National Natural Science Foundation of China (No. 81801469).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHaiyan Liu participated in patient management, conceived and designed the\u0026nbsp;study\u0026nbsp;and was a major contributor\u0026nbsp;to the\u0026nbsp;writing\u0026nbsp;of\u0026nbsp;the manuscript. Xiaoyue Zhang acquired,\u0026nbsp;analyzed and interpreted the data and revised the manuscript. Zhenzhen Liu and Yi Yu participated in patient management and analyzed and interpreted the patient data.\u0026nbsp;Weirong Gu participated in patient management, conceived and designed the\u0026nbsp;study\u0026nbsp;and was a major contributor\u0026nbsp;to\u0026nbsp;revising the manuscript.\u0026nbsp;All the authors have read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the staff of the ultrasound department in our hospital for performing ultrasound to detect postpartum pelvic hematomas.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEnbom JA. Twin pregnancy with intrauterine death of one twin. Am J Obstet Gynecol, 1985; 152(4): 424-9.\u003c/li\u003e\n\u003cli\u003eKilby MD, Govind A, O\u0026rsquo;Brien PM. Outcome of twin pregnancies complicated by a single intrauterine death: a comparison with viable twin pregnancies. Obstet Gynecol, 1994; 84: 107-9.\u003c/li\u003e\n\u003cli\u003eWoo HH, Sin SY, Tang LC. Single fetal death in twin pregnancies: review of the maternal and neonatal outcomes and management. Hong Kong Med J, 2000; 6: 293-300.\u003c/li\u003e\n\u003cli\u003eHealy EF and Khalil A. Single intrauterine death in twin pregnancy: Evidenced-based counseling and management. Best Pract Res Cl Ob, 2022, 84: 205-217\u003c/li\u003e\n\u003cli\u003eOng S, Zamora J, Khan K, Kilby M. Prognosis for the cotwin following single-twin death: a systematic review. BJOG, 2006; 113: 992-998.\u003c/li\u003e\n\u003cli\u003eO\u0026apos;DonoghueK, RutherfordM, EngineerN, WimalasunderaR, CowanF, FiskN. Transfusional fetal complications after single intrauterine death in monochorionic multiple pregnancy are reduced but not prevented by vascular occlusion. BJOG An Int J Obstet Gynecol 2009; 116(6): 804-12\u003c/li\u003e\n\u003cli\u003eGlinianaia SV, Rankin J, Khalil A, Binder J, Waring G, Sturgiss SN, et al. Prevalence, antenatal management and perinatal outcome of monochorionic monoamniotic twin pregnancy: a collaborative multicenter study in England, 2000-2013. Ultrasound Obstet Gynecol 2019; 53(2): 184-92.\u003c/li\u003e\n\u003cli\u003eHack K, van Gemert M, Lopriore E, Schaap A, Eggink A, Elias S, et al. Placental characteristics of monoamniotic twin pregnancies in relation to perinatal outcome. Placenta, 2009; 30(1): 62-5.\u003c/li\u003e\n\u003cli\u003eHeyborne KD, Porreco RP, Garite TJ, Phair K, Abril D, Obstetrix/Pediatrix Research Study G. Improved perinatal survival of monoamniotic twins with intensive inpatient monitoring. Am J Obstet Gynecol 2005; 192: 96-101.\u003c/li\u003e\n\u003cli\u003eMackie FL, Rigby A, Morris RK, Kilby MD. Prognosis of the cotwin following spontaneous single intrauterine fetal death in twin pregnancies: a systematic review and meta-analysis. BJOG 2019; 126: 569-578.\u003c/li\u003e\n\u003cli\u003eNicolini U, Pisoni MP, Cela E, Roberts A. Fetal blood sampling immediately before and within 24 hours of death in monochori- onic twin pregnancies complicated by single intrauterine death. Am J Obstet Gynecol. 1998; 179: 800-3.\u003c/li\u003e\n\u003cli\u003eOkamura K, Murotsuki J, Tanigawara S, Uehara S, Yajima A. Funipuncture for evaluation of hematologic and coagulation indices in the surviving twin following cotwin\u0026rsquo;s death. Obstet Gynecol, 1994; 83: 975-8.\u003c/li\u003e\n\u003cli\u003eSenat MV, Bernard JP, Loizeau S, Ville Y. Management of single fetal death in twin-to-twin transfusion syndrome: a role for fetal blood sampling. Ultrasound Obstet Gynecol, 2002; 20: 360-3.\u003c/li\u003e\n\u003cli\u003eBajoria R, Wee LY, Anwar S and Ward S. Outcome of twin pregnancies complicated by single intrauterine death in relation to vascular anatomy of the monochorionic placenta. Human Reproduction 1999, 14(8): 2124-2130\u003c/li\u003e\n\u003cli\u003eRomero R, Duffy T, Berkowitz RL, Chang E and Hobbins J. Prolongation of a preterm pregnancy complicated by death of a single twin in utero and disseminated intravascular coagulation. Effects of treatment with heparin. NEJM, 1984, 310(12): 772-774\u003c/li\u003e\n\u003cli\u003eSzymonowicz W, Preston H, Yu V. The surviving monozygotic twin. Arch Dis Child, 1986; 61: 454-8.\u003c/li\u003e\n\u003cli\u003eFusi L, Gordon H. Twin pregnancy complicated by single intrauterine death. Problems and outcome with conservative management. BJOG 1990; 97: 511-6\u003c/li\u003e\n\u003cli\u003eGaucherand P, Rudigoz R, Piacenza J. Monofetal death in multiple pregnancies: risks for the cotwin, risk factors and obstetrical management. Eur J Obstet Gynecol Reprod Biol ,1994; 55: 111-5.\u003c/li\u003e\n\u003cli\u003eNicolini U, Pisoni MP, Cela E and Roberts A. Fetal blood sampling immediately before and within 24 hours of death in monochorionic twin pregnancies complicated by single intrauterine death. AJOG, 1998, 179(3): 800-803\u003c/li\u003e\n\u003cli\u003ePetersen I, Nyholm H. Multiple pregnancies with single intrauterine demise. Description of twenty-eight pregnancies. Acta Obstet Gynecol Scand 1999; 78: 202-6.\u003c/li\u003e\n\u003cli\u003eSaito K, Ohtsu Y, Amano K, Nishijima M. Perinatal outcome and management of single fetal death in twin pregnancy: a case series and review. J Perinat Med 1999; 27: 473-7.\u003c/li\u003e\n\u003cli\u003eMiura N, Suzuki S. Fetal Asphyxia due to Cord Entanglement in a Monochorionic Diamniotic Twin Pregnancy Complicated by 2nd-Trimester Single Intrauterine Demise. Fetal Diagn Ther, 2008; 23: 69-71\u003c/li\u003e\n\u003cli\u003eMorokum S, Tsukimori K, Anami A, Fukushima K, Morioka T, Wake N. Brain Injury of the Survivor Diagnosed at 18 Weeks of Gestation after Intrauterine Demise of the Co-Twin: A Case Report. Fetal Diagn Ther 2008; 23: 146-148\u003c/li\u003e\n\u003cli\u003eMachino H, Iriyama T, Nakayama T, Komatsu A, Nagamatsu T, Osuga Y and Fujii T. A case of a surviving cotwin diagnosed with porencephaly and renal hypoplasia after a single intrauterine fetal death at 21 weeks of gestation in a monochorionic monoamniotic twin pregnancy. Oxford Medical Case Reports, 2017, 1: 7-9\u003c/li\u003e\n\u003cli\u003eHui PW, Seto M, Cheung KW. Combined interstitial laser cauterization of placental anastomosis and intrauterine intracardiac transfusion following monochorionic cotwin demise: a case report. Hong Kong Med J, 2021, 27(4): 293-6\u003c/li\u003e\n\u003cli\u003eBejar R, Vigliocco G, Gramajo H. Antenatal origin of neurologic damage in newborn infants. II. Multiple gestations. Am J Obstet Gynecol 1990; 162: 1230-6.\u003c/li\u003e\n\u003cli\u003eKhalilov Z, Ünsal A, Altuntas ̧ N. The D-dimer reference intervals in healthy term newborns. Transfus Apher Sci, 2022, 61:103493\u003c/li\u003e\n\u003cli\u003eSantema JG, Swaak AM, Wallenburg HC. Expectant management of twin pregnancy with single fetal death. BJOG An Int J Obstet Gynecol, 1995; 102(1): 26-30.\u003c/li\u003e\n\u003cli\u003eBlickstein I, Perlman S. Single fetal death in twin gestations. J Perinat Med, 2013;41(1): 65-9.\u003c/li\u003e\n\u003cli\u003eWeitz JI, Fredenburgh JC, Eikelboom JW. A Test in Context: D-Dimer. J Am Coll Cardiol, 2017; 70: 2411-20.\u003c/li\u003e\n\u003cli\u003eHellgren M. Hemostasis during normal pregnancy and puerperium. Semin Throm Hemost, 2003; 29: 125-30.\u003c/li\u003e\n\u003cli\u003eDaniilidis A, Sardeli C, Dinas K, Tantanasis T, Tzafettas J. D-dimer levels following single twin death: a case report and review of the literature. Eur J Obstet Gynecol Reprod Biol, 2010; 148: 96.\u003c/li\u003e\n\u003cli\u003eFavresse J, Lippi G, Roy RM, Chatelain B, Jacqmin H, Ten Cate H, et al. D- dimer: Preanalytical, analytical, postanalytical variables, and clinical applications. Crit Rev Clin Lab Sci, 2018, 55: 548\u0026ndash;577. https://doi.org/10.1080/10408363.2018.1529734.\u003c/li\u003e\n\u003cli\u003eZhu Y, Liu Z, Miao C, Wang X, Liu W, Chen S, Gao H, Li W, Wu Z, Cao H, Li H. Trajectories of maternal D-dimer are associated with the risk of developing adverse maternal and perinatal outcomes: A prospective birth cohort study. Clinica Chimica Acta, 2023, 543: 117324\u003c/li\u003e\n\u003cli\u003eYuan X, Gao Y, Zhang M, Long W, Liu J, Wang H, Yu B, Xu J. Association of maternal D-dimer level in late pregnancy with birth outcomes in a Chinese cohort. Clinica Chimica Acta, 2020, 501: 258-263.\u003c/li\u003e\n\u003cli\u003eCui C, Yang S, Zhang J, Wang G, Huang S, Li A, Zhang Y, Qiao R. Trimester-specific coagulation and anticoagulation reference intervals for healthy pregnancy. Thromb Res, 2017, 156: 82-86.\u003c/li\u003e\n\u003cli\u003eMurphy N, Broadhurst DI, Khashan AS, Gilligan O, Kenny LC, O\u0026rsquo;Donoghue K. Gestation-specific D-dimer reference ranges: a cross-sectional study. BJOG-Int J Obstet Gynecol, 2015; 122: 395-400.\u003c/li\u003e\n\u003cli\u003eShao H, Gao S, Dai D, Zhao X, Hua Y, Yu H. The association of antenatal D-dimer and fibrinogen with postpartum hemorrhage and intrauterine growth restriction in preeclampsia. BMC Pregnancy Childbirth,2021; 21: 605\u003c/li\u003e\n\u003cli\u003eVan Mieghem T, Abbasi N, Shinar S, Keunen J, Seaward G, Windrim R, Ryan G. Monochorionic monoamniotic twin pregnancies. Am J Obstet Gynecol MFM, 2022; 4: 100520\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 and 2 are available in the Supplementary Files section.\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"monochorionic monoamniotic twin pregnancy, spontaneous single intrauterine fetal death, D-dimer, pulmonary lesion, placental anastomoses","lastPublishedDoi":"10.21203/rs.3.rs-4700216/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4700216/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eComplications such as cerebral impairment, preterm delivery, and even intrauterine death can occur in monochorionic twins with singleton fetal death. The coagulation functions of the surviving fetus and mother are controversial.\u003c/p\u003e\u003ch2\u003eCase presentation\u003c/h2\u003e \u003cp\u003eWe reported a case of spontaneous single intrauterine fetal death at 17 weeks of gestation in a monochorionic monoamniotic twin pregnancy followed by increased maternal-neonatal D-dimer levels and special pulmonary lesions in the surviving term cotwin without cerebral impairment. The mother was complicated with massive pelvic hematomas postpartum and recovered after conservative treatment.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eMaternal-neonatal follow-up of D-dimer and detailed examination of the respiratory system as well as brain impairment of the surviving cotwin and newborn are recommended, especially in monochorionic monoamniotic twin pregnancies with placental arterio-arterial or veno-venous anastomoses and elevated maternal D-dimer.\u003c/p\u003e","manuscriptTitle":"The term cotwin with special pulmonary lesions and elevated maternal-neonatal D- dimer levels following single intrauterine fetal death in a monochorionic-monoamniotic twin pregnancy: a case report and literature review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-11 12:37:57","doi":"10.21203/rs.3.rs-4700216/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-02-21T11:50:12+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-20T18:31:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250281338193329706871082023638921951842","date":"2025-02-18T11:41:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-17T15:34:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"249023451294898008770427671243186749851","date":"2025-02-17T13:22:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"279459802147340639203131994481089905781","date":"2025-02-16T09:51:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"313662586725027768656467842179960692180","date":"2025-02-15T12:09:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"295128621047327891676266311049635785042","date":"2025-02-15T06:35:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243761255817049401322806052257634295792","date":"2025-02-14T17:18:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"135763182704475960968369408354779864079","date":"2025-02-14T15:56:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-08-23T03:07:34+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-07-18T05:06:11+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-15T07:56:01+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-15T07:53:39+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pediatrics","date":"2024-07-07T12:36:49+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"770c9728-42d2-4b1d-a3fe-52d0c43c9bb6","owner":[],"postedDate":"August 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-06-02T16:01:56+00:00","versionOfRecord":{"articleIdentity":"rs-4700216","link":"https://doi.org/10.1186/s12887-025-05777-4","journal":{"identity":"bmc-pediatrics","isVorOnly":false,"title":"BMC Pediatrics"},"publishedOn":"2025-05-27 15:57:36","publishedOnDateReadable":"May 27th, 2025"},"versionCreatedAt":"2024-08-11 12:37:57","video":"","vorDoi":"10.1186/s12887-025-05777-4","vorDoiUrl":"https://doi.org/10.1186/s12887-025-05777-4","workflowStages":[]},"version":"v1","identity":"rs-4700216","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4700216","identity":"rs-4700216","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}