Association between Pregnancy Intention and Post-partum Depression in a Multi-state US Population

Background: Unintended pregnancies are pregnancies that are either unwanted or mistimed. In the US, about 45% of all pregnancies were unintended in 2011. Various unfavourable health consequences follow unintended pregnancies, including postpartum depression (PPD). Reports from CDC indicate that in 2018, nationally, about 1 in 8 women experienced symptoms of PPD. Few studies have investigated associations of unintended pregnancy with PPD, particularly in the US. Despite potential race-specific differences in associations, no prior study has examined the association across more than two racial/ethnic groups. The objective of the study was to investigate the association of unintended pregnancy with PPD and potential differences in associations across different racial/ethnic groups.
Methods: This study used data collected from 40 states as part of the Pregnancy Risk Assessment and Monitoring System from 2016-2018. After exclusions that include still births, multiple (nonsingleton) pregnancies and missing values for exposure, outcome, and survey weight variables, 78,204 participants comprised the analytic population. Exposures were defined as “mistimed” and “unwanted” pregnancy. Outcome was defined as PPD (yes/no). Multivariate logistic regression models were used to calculate adjusted odds ratios (Adj. ORs) and corresponding 95% Confidence Intervals (CIs), adjusted for maternal age, marital status, education, income, race/ethnicity, parity, prenatal depression, physical abuse, and pre-pregnancy body mass index. Models with interaction terms and stratified analyses were used to examine potential effect modification by race/ethnicity.
Results: About 28% women reported mistimed pregnancies and 8% reported unwanted pregnancies. Among women with intended pregnancies 12% reported PPD whereas among women who reported mistimed and unwanted pregnancies the prevalence of PPD was 20% and 29% respectively. Women with mistimed and unwanted pregnancies had higher odds of developing PPD compared to women with intended pregnancies. (Adj. ORs 1.24 [95% CI: 1.12-1.37] and 1.73 [95% CI: 1.50-1.98], respectively). Associations were stronger among non-Hispanic Blacks (OR = 1.54 [95% CI 1.38-1.71] for mistimed and OR = 2.48 [95% CI 2.13-2.89] for unwanted pregnancies) and Hispanic (OR = 1.85 [95% CI 1.71-1.99] for mistimed and OR = 2.69 [95% CI 2.41-3.02] for unwanted pregnancies) women compared to associations among non-Hispanic White women (OR = 1.19 [95% CI 1.08-1.32] for mistimed and OR = 1.52 [95% CI 1.34-1.73] for unwanted pregnancies).
Conclusion: Both mistimed and unwanted pregnancies are associated with higher risk of PPD. These associations may differ by race/ethnicity. Findings support importance of assessing pregnancy intention in routine prenatal care.