Pregnancy outcomes after in vitro fertilization for moderate and severe endometriosis. A case-control study.

Introduction: Previous international studies showed that endometriosis could have a link with obstetrical complications, as an increased risk of preterm birth, gestational diabetes mellitus, and cesarean section. However, the results are difficult to interpret because biases are common, such as heterogeneity in the severity of the endometriosis cases included. That's why some complications as risk of miscarriage and post-partum hemorrhage are still debated. Our objective was to study pregnancy outcome after In Vitro Fertilization (IVF) in women suffering from rAFS stage III and IV endometriosis.

Methods: We conducted a case-control study between 2009 and 2019. We compared pregnancy outcomes after IVF in two groups of women matched by age, body mass index and smoking in two hospital centers. Group A was constituted by singleton pregnancies following ART for moderate and severe endometriosis (rAFS stage III and IV endometriosis). Group B was composed of singleton pregnancies in women with no endometriosis following ART for another reproductive disease. All women achieved pregnancy after 22 weeks.

Results: A total of 240 pregnant women were included: 80 singleton IVF pregnancies (group A) were compared with 160 singleton IVF pregnancies (group B). We observed an increased risk of placenta previa (12.5% Vs 1.9%; p = 0,001), and cesarean section (49.4% (n = 39) Vs 29.6% (n = 47) p = 0,004). Rate of postpartum hemorrhage was not significantly different in endometriosis group (11.2% Vs 7.5% p = 0.47).

Conclusion: Despite conflicting results in literature due to a lot of confounding variables, the impact of endometriosis on pregnancy is still debated in women suffering from rAFS III and IV endometriosis. In our study, we observed statistically higher rates of placenta previa and cesarean section but not an increased risk of postpartum hemorrhage. Further larger series are needed to confirm our findings and a possible link with other obstetrical complications. However, we think that an ART pregnancy in a context of severe endometriosis should be considered at risk of adverse obstetrical outcomes.