An analysis of the data from the Epimoms study conducted in 6 French regions shows that the risk of severe maternal morbidity is higher in women with IVF pregnancies, after taking into account their other characteristics. This excess risk is significant regardless of the type of IVF but seems higher for IVF with oocyte donation than for autologous IVF. About half of this excess risk appears to be mediated by multiple pregnancy, which argues for single embryo transfer to reduce these induced multiple pregnancies.
Le Ray C, Pelage L, Seco A, Bouvier-Colle MH, Chantry AA, Deneux-Tharaux C; Epimoms study group. BJOG. 2019 Feb 24. doi: 10.1111/1471-0528.15668. [Epub ahead of print] PMID:30801948
OBJECTIVE: To investigate the association between IVF and severe maternal morbidity (SMM) and to explore the role of multiple pregnancy as an intermediate factor.
DESIGN: Population-based cohort-nested case-control study.
SETTING: 6 French regions in 2012-2013.
POPULATION: Cases were 2540 women with SMM according to the EPIMOMS definition; controls were 3651 randomly selected women who gave birth without SMM.
METHODS: Analysis of the associations between IVF and SMM with multivariable logistic regression models, differentiating IVF with autologous oocytes(IVF-AO) from IVF with oocyte donation(IVF-OD). The contribution of multiple pregnancy as an intermediate factor was assessed by path-analysis.
MAIN OUTCOME MEASURES: SMM overall and SMM according to its main underlying causal condition and by severity (near misses).
RESULTS: The risk of SMM was significantly higher in women with IVF (adjustedOR=2.5[1.8, 3.3]). The risk of SMM was significantly higher with IVF-AO, for all-cause SMM (aOR=2.0[1.5-2.7], for near misses (aOR=1.9[1.3-2.8]), and for intra/postpartum hemorrhages (aOR=2.3[1.6-3.2]). The risk of SMM was significantly higher with IVF-OD, for all-cause SMM (aOR=18.6[4.4-78.5]), for near misses (aOR=18.1[4.0-82.3]), for SMM due to hypertensive disorders (aOR=16.7[3.3- 85.4]) and due to intra/postpartum hemorrhages (aOR=18.0[4.2-77.8]). Path-analysis estimated that 21.6% (10.1-33.0) of the risk associated with IVF-OD was mediated by multiple pregnancy, and 49.6% (95% CI 24.0-75.1) of the SMM risk associated with IVF-AO.
CONCLUSION: The risk of SMM is higher in IVF pregnancies after adjustment for confounders. Exploratory results suggest higher risks among women with IVF-OD, however with wide confident intervals, thus needing to be confirmed. A large part of the association between IVF-AO and SMM appears mediated by multiple pregnancy.