Risk factors for and outcomes after unintended pregnancy: Evaluation in a contemporary cohort

Prior research has demonstrated associations between unintended pregnancy and adverse birth outcomes. The recent restrictions on abortion access may result in a rise in unintended pregnancy. Our objective was to comprehensively evaluate risk factors for and outcomes after unintended pregnancy in a contemporary cohort.

Cross-sectional analysis of the Pregnancy Risk Assessment Monitoring System (2016-2020) respondents with singleton live births. The primary exposure was unintended pregnancy, including respondents who reported being unsure, had mistimed, or had undesired pregnancies. Models evaluated the association between unintended pregnancy and social determinants of health, selected using the US Department of Health and Human Services Healthy People 2030 conceptual framework. Multivariable regression models estimated the independent association between pregnancy intention and outcomes, including maternal healthcare utilization and maternal and neonatal outcomes. Secondary analyses evaluated the three subgroups of unintended pregnancies.

In this weighted population of 8.9 million respondents, 40.0% reported unintended pregnancy. Social determinants of health associated with unintended pregnancy included young age, non-Hispanic Black race, Hispanic ethnicity, being unmarried, more prior live births, more income dependents, and lower household income. Unintended pregnancy was associated with decreased healthcare utilization, including lower odds of prenatal care in the first trimester (aOR 0.60, 95% CI 0.57-0.63), adequate prenatal care (aOR 0.75, 95% CI 0.72-0.78), and postpartum visit attendance (aOR 0.88, 95% CI 0.83-0.94), but higher odds of using postpartum contraception (aOR 1.44, 95% CI 1.38-1.50). Unintended pregnancy was also associated with higher odds of adverse maternal outcomes including perinatal depression (during pregnancy, aOR 1.53, 95% CI 1.43-1.65; postpartum, aOR 1.29, 95% CI 1.22-1.37), and intimate partner violence (aOR 1.44, 95% CI 1.26-1.65), as well as lower odds of breastfeeding more than 3 months (aOR 0.90, 95% CI 0.86-0.94), but was not associated with neonatal outcomes. In secondary analyses, the three unintended pregnancy subgroups (mistimed, unsure, and undesired) were each individually associated with higher odds of adverse outcomes compared to intended pregnancy. Undesired pregnancy had the strongest associations with adverse outcomes, including higher odds of hypertensive disorders of pregnancy (aOR 1.26, 95% CI 1.14-1.40).

Unintended pregnancy is associated with adverse maternal outcomes in this contemporary cohort. Findings highlight populations that are vulnerable to the adverse consequences of unintended pregnancy, which is of particular importance in the era of restricted reproductive freedom.