Women who became pregnant from infertility treatment, specifically in vitro fertilization, had a higher risk for severe morbidity and mortality, according to a study published in the Canadian Medical Association Journal.
A Canadian research team analyzed a population of women aged 18 to 60 years with a hospital delivery between April 2006 and March 2012. After propensity score matching, 11,546 pregnancies achieved with infertility treatment including ovulation induction, intrauterine insemination, or in vitro fertilization were compared with 47,553 unassisted pregnancies to assess the association of each to severe maternal morbidity and mortality. Infertility treatment was further categorized into invasive (in vitro fertilization with or without intracytoplasmic sperm injection) or noninvasive (intrauterine insemination or ovulation induction alone) to determine the relationship of treatment type to maternal morbidity indicators only.
Severe maternal morbidity or death that occurred between 20 weeks’ gestation and 42 days after hospital discharge after delivery was the primary outcome measure. Secondary outcomes included the most common individual indicators of severe maternal morbidity (severe postpartum hemorrhage, maternal admission to an intensive care unit, puerperal sepsis, hysterectomy, and cardiac conditions) and all-cause maternal mortality between 42 and 365 days postpartum.
Severe maternal morbidity or death occurred in 356 treated pregnancies (30.8 per 1000) and in 1054 untreated pregnancies (22.2 per 1000). This outcome measure occurred in 121 pregnancies achieved through noninvasive treatment (21.7 per 1000) and in 235 achieved through invasive treatment (39.3 per 1000). The absolute risk for severe maternal morbidity or death in relation to the use of infertility treatment was more pronounced in those ≥40 years of age and in those with a multiple gestation.
Maternal death from 20 weeks’ gestation to 42 days postpartum occurred in <6 women who used infertility treatment (≤0.5 per 1000) and in <6 women who did not (≤0.1 per 1000), and death from 42 to 365 days postpartum occurred in <6 women who received infertility treatment (≤0.5 per 1000) and in 11 women who did not (0.2 per 1000).
Indicators of severe maternal morbidity were more common in pregnancies achieved through infertility treatment than in untreated pregnancies. Significant associations were found among severe postpartum hemorrhage, maternal admission to an intensive care unit, puerperal sepsis, and invasive infertility treatment, whereas no statistically significant associations were observed for noninvasive treatment.
“Women whose pregnancy was achieved by infertility treatment, especially in vitro fertilization, are at a somewhat higher risk of severe maternal morbidity or death,” the authors concluded. “Further research should identify patient- and treatment-specific factors that might be modified to mitigate excess maternal risks.”
Dayan N, Joseph KS, Fell DB, et al. Infertility treatment and risk of severe maternal morbidity: a propensity score–matched cohort study. CMAJ. 2019;191:E118-E127.