The association between antenatal depression and adverse birth outcomes: A statistical analysis and systematic review

Statistical Analysis The first study statistically examined the direct association between antenatal depression and the adverse birth outcomes of preterm birth (PTB), low birth weight (LBW), and small-for-gestational age (SGA) in a middle-upper SES population while in the context of other potential predictors. For the statistical analysis, a retrospective sample of 10,189 women who were screened for antenatal depression and who gave birth through the Kelsey-Seybold Clinic system in Houston, Texas was examined. The birth outcomes of women with elevated depression scores measured in the first trimester of pregnancy were compared to those with low depression scores to evaluate the association of antenatal depression with PTB, LBW, and SGA while controlling for a robust set of covariates and interaction terms using logistic regression. When running an initial main effects model with eighteen potential predictors, antenatal depression was significantly associated with PTB (OR: 1.73, 95% CI 1.09-2.74) and LBW (OR: 1.88, 95% CI 1.24-2.85), but not SGA. After testing for significant interactions and running a model with the interactions, the main effects were reduced and no longer significant for either outcome. However, the interaction term of antenatal depression by short cervix was significantly associated with PTB (OR: 4.39, 95% CI 1.39-13.91) and LBW (OR: 3.13, 95%CI 1.05-9.35). The results suggest that among antenatally screened women, those with elevated depression scores and a short cervix are at increased risk of an adverse birth outcome compared to women with a short cervix who are not depressed. Systematic Review The second study was a systematic review that evaluated study approaches, methods and results in recent U.S. based antenatal depression/birth outcome studies. The systematic review examined U.S. based English language articles published from January 2010 to April 2015 that included an evaluation of depression during pregnancy and its association with PTB, LBW and SGA. It specifically evaluated the quality of study approaches and methodologies used in these studies in relationship to their reported results. Four electronic databases were searched: Medline (Ovid), PubMed (NLM), PsychINFO (Ovid) and EMBASE (Ovid). The search resulted in 16 studies that met the criteria for inclusion. Out of these studies, 13 measured PTB, 10 measured LBW, and five measured SGA. The studies were evaluated based on study design, sample size, SES measure, depression measure, maternal ages of the samples, screening trimester, and inclusion of covariates. There was no consistent pattern found between methodological practices. However, it did demonstrate potential weaknesses in current research methodology, and it emphasized that the link between antenatal depression and the outcomes of PTB, LBW and SGA is not consistently well-investigated in literature