Increased risk of severe maternal morbidity among infertile women: analysis of US claims data

Abstract

Background: Severe maternal morbidity continues to be an issue of national and global concern and is increasing in incidence. The incidence of infertility is also on the rise, and infertile women experience a higher risk of incident chronic medical disease and cancer, suggesting that fertility may serve as a window to a woman's overall health.

Objective: To investigate the risk of severe maternal morbidity by maternal fertility status.

Materials and methods: This was a retrospective cohort analysis using Optum's de-identifed Clinformatics Data Mart Database between 2003 and 2015. Infertile women stratified by infertility diagnosis, testing, or treatment were compared to fertile women seeking routine gynecologic care. In both groups, only women who underwent pregnancy and delivery of a singleton during the follow-up period were included. Main outcomes were severe maternal morbidity indicators, defined by the Centers for Disease Control and Prevention and identified by International Classification of Diseases 10^th Revision and Common Procedural Technology codes within 6 weeks of each delivery. Results were adjusted for maternal age, race, education, nulliparity, smoking, obesity, delivery mode, preterm birth, number of prenatal visits, and year of delivery.

Results: A total of 19,658 women comprised the infertile group and 525,695 women comprised the fertile group. The overall incidence of any severe maternal morbidity indicator was 7.0% among women receiving fertility treatment, 6.4% among women receiving a fertility diagnosis, 5.5% among women receiving fertility testing, and 4.3% among fertile women. Overall, infertile women had a significantly higher risk of developing any severe maternal morbidity indicator (adjusted odds ratio, 1.22; confidence interval, 1.14-1.31, P < .01) as well as a significantly higher risk of disseminated intravascular coagulation (adjusted odds ratio, 1.48; confidence interval, 1.26-1.73, P < .01), eclampsia (adjusted odds ratio, 1.37; confidence interval, 1.05-1.79, P < .01), heart failure during procedure or surgery (adjusted odds ratio, 1.54; confidence interval, 1.21-1.97, P < .01), internal injuries of the thorax, abdomen, or pelvis (adjusted odds ratio, 1.59; confidence interval, 1.12-2.26, P < .01), intracranial injuries (adjusted odds ratio, 1.77; confidence interval, 1.20-2.61, P < .01), pulmonary edema (adjusted odds ratio, 2.18; confidence interval, 1.54-3.10, P < .01), thrombotic embolism (adjusted odds ratio, 1.58; confidence interval, 1.14-2.17, P < .01), and blood transfusion (adjusted odds ratio, 1.50; confidence interval, 1.30-1.72, P < .01) compared to fertile women. Fertile women did not face a significantly higher risk of any maternal morbidity indicator compared to infertile women. In subgroup analysis by maternal race/ethnicity, the likelihood of severe morbidity was significantly higher among fertile black women compared to fertile white women. There was no difference between infertile black women and infertile white women after multivariable adjustment.

Conclusion: Using an insurance claims database, we report that women diagnosed with infertility and women receiving fertility treatment experience a significantly higher risk of multiple indicators of severe maternal morbidity compared to fertile women. The increased risk of severe maternal morbidity noted among fertile black women compared to fertile white women is attenuated among infertile black women, who face risks similar to those of infertile white women.

Keywords: female infertility; fertility treatment; maternal mortality; racial disparities; severe maternal morbidity.