Spontaneous fertility and pregnancy outcomes amongst 480 women with Turner syndrome.

STUDY QUESTION: What are the prevalence and the outcomes of spontaneous pregnancies (SP) in a large cohort of French women with Turner syndrome (TS)?

SUMMARY ANSWER: Amongst 480 women with TS, 27 women (5.6%) had a total of 52 SP, with 30 full-term deliveries for 18 women.

WHAT IS KNOWN ALREADY: Primary ovarian insufficiency is a classic feature of TS. So far, few studies have evaluated the rate of SP in these patients.

STUDY DESIGN, SIZE, DURATION: The French Ministry of Health set up a National Reference Centre for Rare Growth Disorders (CRMERC), including TS. We studied a cohort of adult TS patients from seven endocrine units (Saint-Antoine, Pitié-Salpêtrière, Bicêtre, Lyon, Marseille, Brest, Reims Hospitals) belonging to this centre, between January 1999 and January 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 480 adult patients with TS were included. The patients' clinical characteristics, karyotypes and reproductive histories had been collected, after informed consent, in a web database called CEMARA. Our reference population was issued from a database belonging to the French Health Ministry, collecting pregnancy outcomes in the French general population. In order to find predictive characteristics of SP, TS with spontaneous pregnancies were compared with non-pregnant TS patients from our cohort.

MAIN RESULTS AND THE ROLE OF CHANCE: There were 27 patients (5.6%) who had a total of 52 SP. The two predictive factors which correlated with occurrence of a SP were spontaneous menarche and mosaic karyotype. The median delay to conception was 6 months (range 0-84). Miscarriage occurred in 16 pregnancies, 30.8% versus 15% in the general French population (P < 0.01). The remaining pregnancy outcomes were legal abortion (n = 2), medical interruption (n = 3), intrauterine fetal death (n = 1) and delivery at term (n = 30). Caesarean section rates were higher than in the general population, respectively 46.7% versus 21% (P < 0.001). Pregnancy-induced hypertensive disorders (PHDs) occurred in four cases (13.3%), including two cases of mild pre-eclampsia (6.7%). Neither aortic root dilatation nor aortic dissection were observed. The median birthweight was 3030 g (range 2020-3460). Two cases of TS were identified in the 17 daughters issued from this cohort.

LIMITATIONS, REASONS FOR CAUTION: It would have been interesting to evaluate AMH levels and SP occurrence, as a predictive factor. Unfortunately, hormonal measurements were missing for some patients. Prospective studies are necessary to display prognostic values of AMH for SP and thus better target fertility preservation programmes in TS patients.

WIDER IMPLICATIONS OF THE FINDINGS: This study suggests that pregnancy outcomes in SPs are more favourable than those after oocyte donation in TS patients. However, the risk of fetal chromosomal abnormalities remains high. Our study will be useful in order to give patients with TS, their families, paediatricians and physicians involved in reproduction, better counselling concerning their fertility.

STUDY FUNDING/COMPETING INTERESTS: Funding was provided by the Association pour la recherche Claude Bernard, Paris France All authors claim no competing interests.

TRIAL REGISTRATION NUMBER: NA.