Relationship Between Prepregnancy Overweight, Obesity, and Preterm Birth in Puerto Rico.

Objectives We examined the association between prepregnancy body mass index (PP-BMI) and preterm birth (PTB) among women in Puerto Rico (PR) as a potentially modifiable risk factor. Methods We conducted a retrospective study using the birth certificate data files from 2005 to 2012 developed by the PR Department of Health to examine the relationship between PP-BMI and PTB. Logistic regression was used to determine crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) for the categories of PP-BMI of overweight (25-29.9 kg/m), obesity (≥ 30 kg/m), and overweight and obesity together (≥ 25 kg/m) and PTB. Stratified analysis explored the associations between PP-BMI and PTB by region within PR and year. Results Following exclusions of birth records with missing data, 343,508 births were included in our analysis. The percentage of PTB decreased from 18.6 to 15.2 during our study period. Statistically significant differences were observed between preterm and full term births across all covariates. Overweight (OR 1.08, 95% CI 1.06, 1.11), obesity (OR 1.17, 95% CI 1.14, 1.20), and overweight and obesity together (OR 1.11, 95% CI 1.09, 1.14) were significantly associated with increased odds of PTB after adjusting for confounders. The associations between PP-BMI and PTB persisted across all regions and years. Conclusions for Practice PP-BMI is associated with increased odds of PTB among women in PR and the associations were consistent in exploratory analyses. Future research should examine the relationship between PP-BMI and PTB among other Hispanic subgroups and among Puerto Ricans in the mainland United States.