Pregnancy outcomes in patients with axial spondyloarthritis: a UK-based survey.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that commonly affects individuals during their reproductive years. As such, understanding the impact of axSpA on pregnancy outcomes is of considerable clinical importance. However, available data remain limited and somewhat conflicting. Earlier studies, conducted between 1998 and 2018, consistently reported an increased incidence of adverse outcomes, including higher rates of preterm birth [ 1 ], caesarean delivery [ 2 ] and pre-eclampsia [ 3 ] among patients with axSpA compared with the general population. These findings raised concerns regarding maternal and foetal risks and highlighted the need for close monitoring and multidisciplinary care for pregnant women living with axSpA. In more recent years, emerging data have suggested that pregnancy outcomes among patients with axSpA may have improved compared with historical cohorts. Improved disease management strategies, greater awareness of the importance of disease control prior to conception and the availability of safer treatment options during pregnancy may have contributed to these positive developments. Nevertheless, registry data from Ireland and health insurance data from Germany continue to report elevated rates of adverse pregnancy outcomes in women with axSpA [ 4 , 5 ]. It has been postulated that immunological changes during pregnancy, including a shift away from Th17-driven inflammation and endothelial dysfunction, may paradoxically increase susceptibility to complications such as pre-eclampsia [ 6 ]. Conversely, reports from combined European registries and a cohort from the Middle East have shown favourable pregnancy outcomes in women with axSpA, with high rates of successful pregnancies and low complication rates [ 7 , 8 ]. These positive outcomes have been attributed to proactive pre-pregnancy counselling, reported in up to 75% of cases, and effective disease control prior to conception [ 7 ]. Such findings underscore the potential benefits of comprehensive pre-conception planning and tailored multidisciplinary care. Despite these insights, there is a notable absence of data regarding pregnancy outcomes in women with axSpA within the UK. Given the potential regional variations in healthcare access, disease management strategies and patient support services, it is essential to characterise pregnancy outcomes in the UK population specifically. The objective of the present study was therefore to explore pregnancy experiences, outcomes and related clinical factors among women with axSpA in the UK using data collected through a national patient-reported survey.

The data were collected via a patient-reported questionnaire specifically designed to capture pregnancy-related information in individuals diagnosed with axSpA. The questionnaire was developed based on the EULAR core dataset for pregnancy registries in rheumatology [ 9 ] and structured into five key sections: general information about the respondent and their axSpA diagnosis, including symptom onset, age at diagnosis and HLA-B27 status; maternal health details, including comorbidities; pre-pregnancy information, covering conception planning, fertility treatments and medication use; pregnancy-specific data, including disease activity, medication adjustments, complications and delivery outcomes; and postpartum outcomes, including breastfeeding practices, postpartum flares and infant health. The questionnaire was tested with a small group of patients and representatives of the National Axial Spondyloarthritis Society (NASS) and amended following feedback. The survey was administered via the Research Electronic Data Capture (REDCap) platform hosted at University College London (UCL) and distributed in October 2022, with data included until October 2023. Respondents had to be ≥18 years of age, with a diagnosis of axSpA and are, or have been, pregnant. Ethical approval was obtained from the UCL Research and Ethics Committee (project ID: 22365/001) and the study received endorsement from the NASS and the British Society for Spondyloarthritis. Participant engagement in the survey was taken as implied consent. A comprehensive recruitment strategy was implemented utilising a range of digital and social media platforms, direct clinician communication, e-mail/SMS invitations and/or posters at rheumatology departments and patient advocacy networks such as the NASS. This strategy aimed to maximise visibility and participation. Given the retrospective nature of data collection, disease activity during pregnancy was assessed using spinal visual analogue scale (VAS) scores (range 0–10). The BASDAI was not incorporated into the survey due to concerns regarding the accuracy and reliability of patient recall over extended periods. The spinal VAS was selected as a pragmatic alternative, allowing participants to reflect on their perceived spinal symptoms during each trimester. The survey responses were summarised using descriptive statistics. Categorical variables were reported as frequencies and percentages while continuous variables were presented as means and S.D. Demographic and clinical characteristics were presented per respondent (mother). All other data (e.g. disease activity, pregnancy features, complications and outcomes) were presented per distinct pregnancy episode. To maximise the data, analysis was based on the number of complete responses per question. All analyses were performed using SPSS (version 28; IBM, Armonk, NY, USA). Given the exploratory nature of the study and the descriptive design, no formal hypothesis testing was conducted.

A total of 185 individuals completed the survey between October 2022 and October 2023; however, 14 did not report pregnancies and were excluded from the study. For this analysis, 71 responses were excluded, as they only reported pregnancies prior to a diagnosis of axSpA. A further 10 responses were excluded for missing or incomplete data and 1 was excluded due to diagnosis during pregnancy. A total of 89 women diagnosed with axSpA who subsequently experienced pregnancy were included in this analysis. Overall, 139 distinct pregnancy episodes occurring after a diagnosis of axSpA were available for analysis (see Fig. 1 ). Of these, 12 (8.6%) were ‘current pregnancies’ (i.e. no delivery/miscarriage/baby loss), with applicable data included. Flow chart of respondents diagnosed with axSpA and associated pregnancies Respondents were mainly white [93.2% (82/88)] and completed the survey at a mean age of 40.1 years ( s . d . 9.3). Only one respondent [1.1% (1/89)] was a current smoker. Regarding smoking history, 29.1% (25/86) previously smoked and 70.9% (61/86) never smoked. Most respondents [78.4% (58/74)] were HLA-B27 positive. Respondents had a mean age of axSpA symptom onset of 20.8 years ( s . d . 5.8) and a mean age at diagnosis of 27.6 years ( s . d . 5.1). The mean and median time to axSpA diagnosis from symptom onset was 7.5 and 7.0 years ( n  = 77), respectively. A self-reported history of IBD was reported by 15.7% (14/89), psoriasis by 24.7% (22/89) and uveitis by 39.8% (35/88) of respondents (see Table 1 ). Demographic and clinical characteristics of women diagnosed with axSpA prior to pregnancy ( N  = 89 women). COPD: chronic obstructive pulmonary disease; PCOS: polycystic ovary syndrome. Some women contributed more than one pregnancy. Respondents could select multiple options for some of these questions. ‘Other’ under ‘gynaecological conditions’ included prolapse, menorrhagia, hernia and other conditions. ‘Other conditions’ under ‘comorbidities’ are as reported by respondents and thus may include duplicates from other categories such as gynaecological conditions. Some examples of other conditions include rheumatoid arthritis, fibromyalgia, multiple sclerosis and epilepsy. At the time of survey completion. At the time of survey completion, the most frequently reported comorbid conditions were migraines [14.6% (13/98)], respiratory disease (e.g. asthma, chronic obstructive pulmonary disease or other) [11.2% (10/89)] and cardiovascular/heart conditions (e.g. hypertension or cardiovascular disease) [9.0% (8/89)]. One case of anti-phospholipid syndrome was reported. Furthermore, a range of gynaecological conditions were reported and included endometriosis, polycystic ovary syndrome, prolapse after pregnancy, menorrhagia (abnormally heavy menstrual bleeding), borderline ovarian tumour, pelvic hernia, placental abruption, heart-shaped uterus (patient reported) and a tilted uterus (see Table 1 ). Most pregnancies were planned [90.6% (126/139)]. The time to conceive was within 1 year for 68.3% (86/126) of planned pregnancies and >1 year for 31.7% (40/126) of planned pregnancies. Of those who took >1 year, 40.0% (16/40) were receiving NSAIDs before pregnancy. Natural conception occurred in 90.2% (111/123) of pregnancies. Assisted reproductive techniques were reported infrequently, with four patients undergoing in vitro fertilisation, three undergoing intrauterine insemination and five receiving medication-assisted conception. Respondents with axSpA had many concerns before becoming pregnant, with the most prominent being ‘will my pain levels increase’ [74.8% (104/139)] and ‘axSpA causing birth complications’ [62.6% (87/139)]. In only 9.4% (13/139) of pregnancies did respondents report ‘no concerns’ before becoming pregnant. For more than half of the pregnancies [54.7% (76/139)], respondents discussed plans to become pregnant with the rheumatologist/rheumatology team, with many receiving advice about ‘stopping medication’ [53.7% (36/67)] and ‘breastfeeding on medication’ [43.3% (29/67)]. For the pregnancies where the respondent did not discuss plans to become pregnant [45.3% (63/139)], the most common reason for this was ‘I didn’t know I could’ [36.5% (23/63)] (see Table 2 ). Pre-pregnancy details for pregnancies of women diagnosed with axSpA prior to pregnancy ( N  = 139 pregnancies). Some women contributed more than one pregnancy. Respondents could select multiple options for some of these questions. ‘Other’ details are as reported by respondents and thus may include specific or unspecific topics or potentially duplicated responses. For ‘Other’ in ‘Advice received before pregnancy’, 8/13 were related to medication. Many of the responses under ‘Other’ in ‘Reasons for not discussing plans’ were related to lack of regularity of appointment. Does not include data from current pregnancies. The mean maternal age at pregnancy was 32.1 years [ s . d . 4.3; range 20–44 years; n  = 111 (not including current pregnancies)]. Regarding pregnancy-related complications, the self-reported rate of pre-eclampsia was 5.4% (6/111), while 4.5% (5/111) ‘developed diabetes during pregnancy’. Infections during pregnancy included urinary tract infections, respiratory tract infections (chest and throat) and sinus infections (see Table 3 ). Pregnancy features, postpartum features and complications of pregnancies in women diagnosed with axSpA prior to pregnancy ( N  = 139 pregnancies). HELLP: haemolysis, elevated liver enzymes and low platelet count. Some patients contributed more than one pregnancy. Respondents may have reported several pregnancy complications, infections during pregnancy or indications for C-section. ‘Other’ details are as reported by respondents and thus may include specific or unspecific topics or potentially duplicated responses. Does not include data from current pregnancies. Outcome: eight live births and one medical termination at 15 weeks. The rate of self-reported congenital malformations (any) was 9.5% (9/95). Reported congenital anomalies included one case of triploidy, one case of unspecified chromosomal anomaly, one case of ventricular septal defect, one case of atrial septal defect and pulmonary valve stenosis, one unspecific cardiovascular defect, one case of horseshoe kidney, one case of mild talipes and two cases of craniosynostosis. In this study, the live birth rate was 76.4% (97/127) and the baby loss rate was 23.6% (30/127). The latter includes pregnancy loss/miscarriage (baby loss before 24 weeks of pregnancy; 28/30), termination of pregnancy (medical reasons; 1/30) and stillbirth (baby loss after 24 weeks of pregnancy; 1/30). The mode of delivery was reported as 46.2% (43/93) for vaginal births and 53.8% (50/93) for caesarean section (C-section). Indications for C-sections included active axSpA symptoms [34.0% (17/50)], patient choice [24.0% (12/50)], foetal distress [20.0% (10/50)], obstetric complications [20.0% (10/50)] or other reasons [30.0% (15/40)]. Prior to pregnancy, the mean spinal pain score, as measured using the VAS, was 4.9 ( s . d . 2.7). Notably, spinal pain scores decreased to a mean of 3.9 ( s . d . 2.6) in the first trimester, increased to 4.9 ( s . d . 3.3) in the second trimester and peaked at 5.4 ( s . d . 3.5) in the third trimester ( n  = 34). The mean spinal pain score during pregnancy was 4.7 ( s . d . 3.2) ( n  = 34; not including current pregnancies). For current pregnancies, the mean spinal pain was 3.9 ( s . d . 2.7; n  = 11). Flare rates were reported as 33.6% (40/119) during pregnancy (intrapartum) and were managed by contacting the rheumatology team [42.5% (17/40)], contacting the obstetric team [35.0% (14/40)] or through self-management strategies [37.5% (15/40)]. The most frequently used medications to manage flare during pregnancy were paracetamol [67.5% (27/40)] and codeine [15.0% (6/40)]. Some report having undergone combinations of treatments. Flare rates were reported as 55.6% (55/99) following delivery/miscarriage/baby loss and were managed by contacting the rheumatology team [47.3% (26/55)], contacting the obstetric team [10.9% (6/55)] or through self-management strategies [43.6% (24/55)]. The most frequently used medications to manage flare after delivery/miscarriage/baby loss were NSAIDs [50.9% (28/55)] and paracetamol [36.4% (20/55) (see Table 4 ). Flare management during and after pregnancies in women diagnosed with axSpA prior to pregnancy ( N  = 139 pregnancies). Some women contributed more than one pregnancy. Respondents could select multiple options for most of these questions. Does not include current pregnancies ( n  = 12). Total possible pregnancies N  = 129. Biologic therapies (TNF inhibitors) were taken by respondents before 33.3% (4/12) of current pregnancies. Biologic therapies were not discontinued during any of these pregnancies and one intrapartum flare was reported. Biologic therapies were taken by respondents before 33.1% (42/127; 38 TNF inhibitors and 4 IL-17 inhibitors) of all other pregnancies with a delivery, miscarriage or baby loss. Biologic therapies were discontinued during or just before 40.5% of these pregnancies (17/42; two stopped before conception/pregnancy). For pregnancies where respondent biologic therapies were discontinued, eight flares during pregnancy and eight flares after delivery/miscarriage/baby loss were reported. In those who discontinued biologic therapy during (or before) pregnancy, a different biologic therapy was started during two pregnancies (one restarted for intrapartum flare management) and biologic therapy was restarted for flare management after five deliveries/miscarriages/baby losses. Neonates were vaccinated according to the immunisation schedule for most pregnancies [93.5% (72/77)]. Delay in any vaccine was reported in 13.0% (10/77) of pregnancy episodes and was most frequently attributed to medical advice from an obstetrician [50.0% (5/10)] or rheumatologist [40.0% (4/10)] (see Table 5 ). Vaccination and breastfeeding details for pregnancies with live births in women diagnosed with axSpA prior to pregnancy ( n  = 97 live births in 127 pregnancies). BCG: Bacillus Calmette-Guérin vaccine. Some women contributed more than one pregnancy. Some respondents gave multiple answers for reasons for vaccination delay. For many women experiencing a pregnancy episode, a diagnosis of axSpA did not impact the decision to breastfeed [82.5% (66/80)]. A diagnosis of axSpA influenced the breastfeeding decision in 17.5% (14/80) of pregnancies, with drug transmission in the breastmilk [57.1% (8/14)] and conflicting healthcare advice [28.6% (4/14)] being core reasons for this decision. Breastfeeding advice was given to the respondent by an obstetrician/midwife in 68.8% (55/80) of pregnancies and by a rheumatologist in 23.1% (18/78) of pregnancies. For 61.3% (49/80) of pregnancies respondents expressed concern that their axSpA symptoms negatively affected their ability to care for a newborn in the first 6 months. Of these, 81.6% (40/49) adapted to this concern using family support.

This retrospective survey is the first to explore pregnancy outcomes in women with axSpA in the UK. We found patterns of disease activity (greater in the second and third trimesters) comparable to those of other axSpA studies and some reports of flare during and following pregnancy. The rate of pregnancy complications such as pre-eclampsia were generally within the normal range; however, the prevalence of congenital malformations was slightly elevated. Pre-pregnancy discussions and opportunistic postpartum monitoring may be particularly important to support women with axSpA before, during and after pregnancy. These data may inform pre-pregnancy counselling and physician education. Prospective data collection via a pregnancy registry in the UK is needed.

Our study is the first to investigate pregnancy outcomes in women with axSpA in the UK. Most pregnancies were planned. Concerns were prominent prior to pregnancy, yet discussing plans to become pregnant with the rheumatologist or rheumatology team was reported for only 54.7% of pregnancies. Natural conception occurred for most pregnancies, with 31.7% taking >1 year to conceive. The pre-eclampsia rate was 5.4%, the infection rate was 17.0% and the congenital malformation rate was 9.5%. The rate of C-section was 53.8% and the live birth rate was 76.4%. Flares related to axSpA were reported during one-third of pregnancies, while flares after delivery/miscarriage/baby loss were reported for more than half of pregnancies. Neonates were largely vaccinated as per the immunisation schedule and without delay. For more than half of pregnancies, respondents expressed concern that their axSpA symptoms affected their ability to care for a newborn in the first 6 months. In this study, only two-thirds of pregnancies were achieved within 12 months of actively trying to conceive. As such, one-third of pregnancies exceeded a time to pregnancy (TTP) of 12 months, which is greater than that estimated in the general population based on population surveys from 25 countries (9%; clinically relevant range of 5–15%) [ 10 ]. More recently, one nationwide study in France, utilising a current-duration approach, found that 24% of women 18–44 years of age and trying to conceive did not achieve a TTP within 12 months [ 11 ]. For women with axSpA and SpA, the proportion of women exceeding a TTP of 12 months has been reported as 21.1% in a Norwegian registry-based multicentre study [ 12 ] and 45.4% in a French multicentre prospective observational study [ 13 ]. It appears that a TTP >12 months is common in women with axSpA; however, a complex range of factors (such as age, lifestyle, gynaecological conditions and medication use) likely contribute to this delay. For example, longer TTP has been associated with older age, longer disease activity, nulliparity [ 12 ] and NSAID use during preconception [ 13 ]. In the current study, NSAID use during the preconception period was reported for 40.0% of pregnancies with a TTP >12 months. NSAID use may interfere with ovulation and reduce fecundability [ 14 ]. As such, EULAR recommends the discontinuation of NSAIDs preconceptionally for women having difficulty conceiving [ 15 ]. Pre-eclampsia was the most frequently reported pregnancy complication (5.4%) in women diagnosed with axSpA, which is slightly higher than is estimated for the general population (4.6%; 95% uncertainty range 2.7–8.2) [ 16 ]. More recent findings from the European Network of Pregnancy Registries in Rheumatology found a pre-eclampsia rate of 2.2% (0–3.8% depending on the country) [ 7 ], while retrospective data from the Middle East found a pre-eclampsia rate of 14% in axSpA (6% for axSpA and peripheral SpA) [ 8 ]. Although our finding is encouraging, studies pertaining to the risk of pre-eclampsia among women with axSpA are not concordant [ 7 , 17 , 18 ]. Reassuring trends in pregnancy outcomes (i.e. preterm birth, infant infection and caesarean deliver) have been observed concurrently with increased biologic DMARD use over time; however, this was not found for pre-eclampsia [ 19 ]. Low-dose aspirin is used for the prevention of pre-eclampsia in those with autoimmune conditions, thereby reducing the risk of low birth weight (LBW; <2.5 kg) and small-for-gestational-age infants. The National Institute for Health and Care Excellence recommend the commencement of aspirin by 16 weeks’ gestation [ 20 ]. In our study, aspirin was initiated in 20.7% (25/121) of pregnancies, with most commencing by week 13 and stopping between week 16 and delivery. Studies have shown an increased prevalence of LBW in axSpA pregnancies [ 4 ], but our cohort demonstrated a mean birth weight of 3.3 kg, with 12.0% (10/83) weighing 4 kg) was akin to UK estimates (12.7%) [ 22 ]. The use of aspirin may be considered controversial, but it is unlikely to cause harm and may be beneficial in optimising placental function and reducing the risk of pre-eclampsia [ 23 ]. In this study, vaginal delivery and delivery by C-section was reported for 46.2% and 53.8% of pregnancies, respectively. This rate of C-section is greater than the worldwide average of 21.1% (range 5.0–42.8%) [ 24 ], but within the range found in other axSpA populations (24.2–59%) [ 3 , 5 , 7 , 8 , 19 , 25 , 26 ]. Two meta-analyses have found an increased risk of C-section in women with axSpA [ 17 , 27 ]. The reasons for C-section are likely to be multifaceted; in our cohort, the most common were active axSpA (34.0%) and patient choice (24.0%). Other indications may include treatment modalities and foetal distress; however, country-specific (and/or hospital differences) or cultural differences are likely to play a significant role in C-section rates. For example, Meissner et al. [ 7 ] found C-section rates ranging from 16.7% in France to 56.5% in Switzerland. For pregnancy outcome, the live birth rate was reported as 76.4%, which is lower than previously reported in axSpA populations [ 4 , 5 , 7 , 8 ]. The baby loss rate of 23.6% seems high. Differences in live birth/baby loss rates may partially be due to differing exclusion criteria between studies. For example, one study excluded pregnancies with early pregnancy loss ≤12 weeks’ gestation [ 7 ]. Regarding neonatal outcomes, this study found a congenital anomaly [ 28 ] rate of 9.5%, which is slightly higher than worldwide estimates (6%) [ 29 ] and previous findings in axSpA populations from health insurance data (8.5% for the axSpA population, 9.0% for infants of matched controls) [ 5 ] and a French prospective multicentre cohort (4.4%) [ 30 ]. This higher rate should be interpreted with caution and may be due to self-reported data, inclusion of all pregnancies and the lack of differentiation between anomalies identified before delivery, loss or termination. The average self-reported spinal pain VAS (indicating disease activity) during pregnancy was 4.7, with increasing pain scores in each trimester (from 3.9 to 4.9 to 5.4). This trend aligns with existing data suggesting that disease activity tends to worsen during the second and third trimesters of pregnancy [ 31 ]. Flare rates during and following pregnancy were reported as 33.6% and 55.6%, respectively. To date, the literature suggests that disease flare during pregnancy may be common, while data on postpartum flare are heterogeneous [ 32 , 33 ]. One meta-analysis suggests axSpA tends to flare in the postpartum period [ 17 ]. The increase in disease activity and prevalence of flare during and after pregnancy underscores the importance of proactive management and monitoring throughout pregnancy to mitigate adverse outcomes. However, data on disease activity should be interpretated with caution considering the multitude of factors influencing disease activity (such as treatment modalities and regulatory T cells during pregnancy [ 6 ]) and that mechanical loading during pregnancy may increase back pain. Further, we found an average time to flare following pregnancy of 5.6 weeks, and thus patients may also need access to healthcare professionals (HCPs) sooner than 3-months postpartum. The use of biologic therapy in pregnancy has gained more traction as clinical confidence has improved and recommendations have been updated [ 15 , 34 ]. In our survey, 33.1% reported treatment with a biologic prior to pregnancy (not including current pregnancies), of which 40.5% stopped during (or just before) pregnancy. The proportion of patients prescribed biologics may be up to 60% in the general (non-pregnant) axSpA population [ 35 ]. Certain centres encourage continuous use of biologic therapy in pregnancy to reduce the risk of flare and, in turn, the risk of adverse pregnancy outcomes. This may also be due to the US Food and Drug Administration recommendations against using NSAIDs after 20 weeks’ gestation due to the risk of premature closure of the ductus arteriosus and foetal kidney injury [ 36 ]. Further, steroid use can cause pregnancy complications and are not necessarily effective, leading to biologic therapy as a clinically relevant choice in the treatment of axSpA and pregnancy. The relatively low use of biologics reported in this study may be explained by the time frame of survey completion (and included pregnancies), self-reported information, recall bias and geographical differences in prescribing practices. More data are needed to determine the effects of stopping or continuing biologics during pregnancy. Most neonates received vaccinations as per the immunisation schedule and with limited delay. In those with vaccination delay, the most frequent reasons were rheumatologist advice or obstetrician advice. For the majority of respondents, a diagnosis of axSpA did not influence their decision to breastfeed. However, for those where an axSpA diagnosis did affect their decision to breastfeed (17.5%), concern of drug transmission and conflicting healthcare advice were prominent reasons. For women with chronic inflammatory disease, inconsistent advice from various HCPs regarding family planning and pregnancy has been a long-term issue [ 37 ]. In this study, breastfeeding advice was provided by the obstetrician/midwife for almost 70% of pregnancies and by the rheumatologist for almost 25% of pregnancies. Breastfeeding may not always be possible, but it is recommended by the World Health Organization [ 38 ] and remains an important personal choice for many women. Cross-speciality education is needed to empower clinicians to support women at the appropriate time. Many women had concerns before becoming pregnant, with increasing pain levels, genetic transmission of axSpA and birth complications the most frequent. Despite these worries, many women did not discuss family planning with their rheumatology team prior to their pregnancies (45.3%) and many of those did not know they could. When discussions did occur, advice largely focused on medication cessation (53.7%), breastfeeding (43.3%) and proactive flare management (37.3%), while vital topics such as infant vaccinations (16.4%) were less frequently discussed. Respondents also reported that axSpA affected the ability to care for the infant(s) in the first 6 months after birth in almost two-thirds of pregnancies. Together, these findings highlight the critical need for rheumatologists to proactively initiate family planning conversations with female patients of childbearing age and provide opportunistic postpartum support, ensuring comprehensive guidance that addresses both maternal anxieties and practical disease management. In previous studies of axSpA populations, favourable pregnancy outcomes have been partially attributed to pre-conception counselling and effective disease control [ 7 ]. A recent retrospective multicentric study demonstrated that pre-conception counselling in women with SpA can increase the likelihood of pre-pregnancy medical adjustments and decrease the occurrence of postpartum flares [ 39 ]. Early and regular counselling and personalised planning is recommended and should be offered (females and males) to ensure the best outcomes for patients and infants [ 15 ]. This study has numerous strengths and limitations. To the authors knowledge, this is the first study exploring pregnancy outcomes in women with axSpA in the UK. Outreach was maximised due to the easily accessible online survey format and leveraging of social networks. The online survey was informed by the EULAR recommendations for a core dataset for pregnancy registries in rheumatology [ 9 ] and contributes to the existing literature by providing valuable insights into TTP, flare rates, vaccination practices and breastfeeding behaviours in women with axSpA. The main limitation of this study is the retrospective design and risk for recall bias. Participant outcomes were self-reported and comprehension could not be verified via medical records. Indeed, previous research has indicated discrepancies between self-reported pregnancy data and chart review [ 40 ]. We acknowledge that prospective data collection would have been ideal, however, resources were restricted and study conceptualisation was during the COVID-19 pandemic and national lockdowns, limiting interaction and face-to-face clinics. Selection bias may have also been an issue, as women with pregnancies from a long time ago may have been less likely to participate and women with worse pregnancy outcomes may have been more likely to participate. The retrospective design, survey length, incomplete data and selection bias may have hindered the findings and the ability to generalise to all women with axSpA in the UK with current or previous pregnancies. There is a clear need to develop a pregnancy registry in the UK to allow for prospective data collection.