P-310 Impact of adenomyosis on the live birth rate during management by in vitro fertilization : a French study

Abstract Study question Evaluate the impact of adenomyosis on the likelihood of live birth after a fresh embryo transfer. Summary answer Adenomyosis reduces the live-birth rate. The location of adenomyosis and the type of protocol appears to have no impact on the live birth rates. What is known already The prevalence of adenomyosis varies between 7 and 27%, and affects 25% of infertile women. Its impact on fertility remains debated. According to some studies, it leads to a lower pregnancy rate, a doubling of the spontaneous miscarriage rate and a lower live birth rate as compared to non-adenomyosis women. However according to some authors adenomyosis does not reduce the live birth rate. Similarly, the impact of the location of adenomyosis remains debated. On the impact of the stimulation protocol, several studies have shown that the use of GnRH agonist improves the live birth rate in patients with adenomyosis. Study design, size, duration This is a retrospective, descriptive and observational study, managed at the fertility department of Dijon University Hospital between January 2015 and March 2020. Systematically, the women infertility cause was assessed. We compared the group of patients with adenomyosis (i.e. symptomatic adenomyosis completed with a 3D ultrasound within a maximum of 1 year prior to management) with controls (i.e. patients treated for another cause of infertility). Ultrasound was performed by the same two experienced operators. Participants/materials, setting, methods We included 340 patients aged 18-41 years. Data concerning live births and type of stimulation protocol were collected from the patient’s electronic medical and therapeutic records. MUSA classification was used to determine whether the adenomyosis was localized or diffuse. The primary endpoint of this study was the live-birth rate (LBR) after fresh embryo transfer. The implantation and miscarriage rates were also compared. Main results and the role of chance We included 92 patients in adenomyosis group, and 248 patients in control group. Baseline characteristics of patients including women age, BMI and smoking habits were comparable in both groups. Moreover, no difference was found on the mean number of mature oocytes and embryos between the two groups. LBR after fresh embryo transfer was significantly lower in the adenomyosis group than in the control (34.8 % versus 41.5%, respectively, p = 0,02). There was no significant difference in implantation rate (35.7% versus 37,4%, p = 0.76). Early miscarriage rate (12 weeks of amenorrhea) was higher in the control group than the adenomyosis group (15.3 versus 7.5, p = 0.012). Concerning late miscarriage (12 weeks of amenorrhea), we observed 3 medical termination of pregnancy (all for fetal malformation) and 1 miscarriage (10%) in the adenomyosis group and 1 miscarriage (0.81%) in the control group (p = 0.02). Subgroup analyses showed no decrease in LBR according to adenomyosis location (32.7% versus 37.2% in the diffuse and localized groups, respectively, p = 0.46). Limitations, reasons for caution Even though our cohort is a good reflection of the all-French population of Burgundy since all patients are treated at the fertility center of Dijon. Despite its retrospective nature and the small number of included adenomyosis-patients, the ultrasound scans were performed by two experienced operators that reduced inter-observer variability. Wider implications of the findings It would be useful to carry out a prospective study including more patients to better assess the impact of location on implantation. It would also be interesting to evaluate neonatal and obstetrical complications, especially the late miscarriage issue requiring further investigation. Trial registration number non-clinical trials