Prospective Pregnancy Preferences and Adverse Birth Outcomes in the United States: A Population-Based Study

Adverse birth outcomes have been linked to "unintended" pregnancy; however, research that relies on retrospective measurement of "intentions" is vulnerable to differential recall bias. This study estimates associations between prospectively measured pregnancy preferences and preterm birth (<37 weeks) and low birthweight (<5.5 pounds). We analyzed longitudinal, population-based data from the Surveys of Women, conducted in nine US states (2016-2023), linking births reported across annual waves with pregnancy preferences measured before pregnancy using the 14-item Desire to Avoid Pregnancy (DAP) scale. We fit weighted logistic regression models to estimate associations between DAP categories (lower DAP: more open to pregnancy; higher DAP: stronger preference to avoid pregnancy) and outcomes using multiple imputation (primary analysis) and complete case analysis excluding participants whose DAP scores were imputed (sensitivity analysis). Although the adjusted association between DAP grouping and low birthweight was not statistically significant in analyses using imputation (15% high vs. 7% low DAP), it was significant treating DAP scores continuously (aOR=1.56 [1.01-2.43]) and in complete case analysis (20% vs. 6%, p=0.01). DAP scores were not associated with preterm birth in imputation analyses (18% high vs. 14% low DAP) or using continuous scores but were in complete case analysis (25% vs. 12%, p=0.02). While the magnitudes of associations were suggestive of a relationship between a strong prospective preference to avoid pregnancy and low birthweight, analyses were limited by low precision. Supporting individuals in achieving their reproductive preferences may have child health benefits.