A Meta-Analysis of Depression During Pregnancy and the Risk of Preterm Birth, Low Birth Weight, and Intrauterine Growth Restriction

Background and Purpose: Maternal depressive symptoms during pregnancy have been reported in some, but not all, studies to be associated with an increased risk of preterm birth (PTB), low birth weight (LBW), and intrauterine growth restriction (IUGR). PTB, LBW, and IUGR are the leading causes of neonatal, infant, and childhood morbidity, mortality, and neurodevelopmental impairments and disabilities worldwide. The aim of the meta-analysis was to estimate the risk of PTB, LBW, and IUGR associated with antenatal depression and to examine potential moderators of negative birth outcomes, such as categorical versus continuous measurement of antenatal depression, race or socio-economic status of the sample, or country location of the study. We expected that women with antenatal depression who lived in developing countries, relative to their peers in the US or social democracies, and that socio-economically disadvantaged, depressed, pregnant women in the US compared to their middle- or upper-class counterparts, would show greater disparities in the likelihood of PTB, LBW, and IUGR because of their more limited access to adequate prenatal, health, and mental health care. Finally, given that categorical measures of antenatal depression more closely approximate clinical diagnoses of major depression than do continuous measures, we hypothesized that the former would show a stronger association with adverse birth outcomes than the latter.

Methods: Search for English- and non-English language articles via MEDLINE, PsycINFO, CINAHL, and Social Work Abstracts (1980 to December 2009). We aimed to include prospective studies reporting data on antenatal depression and at least one adverse birth outcome: PTB(<37 weeks gestation), LBW(<2500 grams), and IUGR(<10th percentile for gestational age). From 862 reviewed studies, 29 US and non-US published studies met selection criteria. Information was extracted on study characteristics, antenatal depression measurement, and other biopsychosocial risk factors and reviewed twice to minimize error.

Results: In studies of PTB, LBW, and IUGR that used a categorical depression measure, pooled effect sizes were significantly larger (pooled RR [95% CI]:1.39[1.19-1.61],1.49[1.25-1.77],1.45[1.05-2.02],respectively) compared with studies that used a continuous depression measure (1.03[1.00-1.06],1.04 [0.99-1.09],1.02[1.00-1.04],respectively). The estimates of risk for categorical-defined antenatal depression and PTB and LBW remained significant when the trim-and-fill procedure was used to correct for publication bias. The risk of LBW associated with antenatal depression was significantly larger in developing countries(RR, 2.05;95%CI,1.43-2.93) compared to the US(RR,1.10;95%CI,1.01-1.21) or European social democracies(RR,1.16; 95% CI,0.92-1.47). Categorical-defined antenatal depression also tended to be associated with an increased risk of PTB among women of lower socioeconomic status in the US.

Conclusions and Implications: Women with depression during pregnancy are at increased risk for PTB and LBW, although the magnitude of the effect varies as a function of depression measurement, country location, and socioeconomic status within the US. An important implication of these findings is that antenatal depression should be identified through universal screening and treated.