Severe Maternal Morbidity and Maternal Mortality Associated with Assisted Reproductive Technology.

OBJECTIVE:To assess the association between use of assisted reproductive technologies (ART) and severe maternal morbidity and maternal mortality (SMM). METHODS:We carried out a cohort study that included all hospital deliveries at ≥20 weeks gestation in Canada (excluding Québec) between April 2009 and March 2018. Outcomes of interest included composite SMM and SMM types (e.g., severe preeclampsia, HELLP syndrome, and eclampsia; severe hemorrhage; acute renal failure). Multivariable regression was used to estimate crude and adjusted rate ratios (RR and aRR) and 95% confidence intervals (CI). RESULTS:The study included 2 535 056 women, of whom 72 023 (2.8%) delivered following the use of ART. The composite SMM rate for women who used ART was 34.7 per 1000 deliveries (95% CI 33.0-36.0) versus 11.5 per 1000 deliveries (95% CI 11.4-11.6) for women who did not use ART (RR 3.01; 95% CI 2.89-3.14). ART use was associated with SMM types such as severe preeclampsia, HELLP syndrome, and eclampsia (RR 3.50; 95% CI 3.27-3.73), severe hemorrhage (RR 3.58, 95% CI 3.27-3.92), and acute renal failure (RR 6.79; 95% CI 5.78-7.98). Associations between ART and composite SMM were attenuated but remained elevated after adjusting for maternal characteristics (aRR 2.34; 95% CI 2.24-2.45). Women who used ART and had a multi-fetal pregnancy had a 4.7 times higher rate of composite SMM compared with women who did not use ART and delivered singletons. CONCLUSION:Women who deliver following the use of ART have increased risks of SMM and require counselling that includes mention of the lower risks of SMM associated with ART-conceived singleton pregnancy.