Depression during pregnancy and birth complications.

By Nestor Lopez-Duran PhD

Editors note: Due to the yesterday especial editorial on bullying and suicide, Mondays brief comes to you a date late. Wednesdays post will be published tomorrow as expected. We will review the latest study on vaccines and autism.

The leading causes of childhood disabilities are prenatal and neonatal complications, such as preterm birth, low birth weight, and intrauterine growth restriction. There are multiple factors that can lead to these complications, such as smoking, drinking, and experiencing some medical conditions.  Some studies have suggested that maternal depression can increase the risk for these complications but other studies have found that depression has no impact on these complications. Why the discrepancy? The latest issue of the prestigious journal Archives of General Psychiatry included a comprehensive meta-analysis of the association between depression during pregnancy and birth complications. In the meta-analysis, the authors merged the results previous studies on this topic in order to examine factors that could explain the differences between the studies.

Among the many factors that the authors examined, I want to focus on a specific issue: whether the previous studies measured depression as a categorical construct (e.g., comparing mothers who met diagnostic criteria for a depressive disorder against those who didnt meet criteria) or as a continuous construct (comparing those with more symptoms of depression to those with less symptoms of depression). Overall, the authors found the following:

Effects of Depression on Pre-Term Birth:

Depression during pregnancy, when measured as a categorical construct, increased the risk for pre-term birth by 39%. In contrast, depression symptoms increased the risk by only 3%.

Effects of Depression Low Birth Weight:

Depression during pregnancy, when measured as a categorical construct, increased the risk for low birth weight by 49%. In contrast, depression symptoms did not impact the risk for low birth weight.

Effects of Depression on Intrauterine Growth Restriction:

Depression during pregnancy, when measured as a categorical construct, increased the risk for intrauterine growth restriction by 45%. In contrast, depression symptoms did not impact the risk for intrauterine growth restriction.

These results suggest that having some symptoms of depression may not increase the risk of birth complications. However, having clinical depression significantly increases the risk for complications. This is not entirely surprising since there are significant differences between experiencing symptoms of depression, many of which are common and normative, and having a diagnosed depressive disorder. In this case, it seems that having a depressive disorder is a risk factor for prenatal and neonatal complications. This highlights the need to screen for depression during pregnancy so that those affected can receive treatment.

The authors concluded:

Clearly, pregnancy is an important time to universally screen women for depression, especially those who are socioeconomically disadvantaged, and to improve their timely access to evidence-based prenatal and mental health services. Improved accuracy of diagnosis and treatment of antenatal depression combined with education about harmful but potentially modifiable lifestyle practices could lead to decreased rates of PTB and LBW.

The reference:

Grote, N., Bridge, J., Gavin, A., Melville, J., Iyengar, S., & Katon, W. (2010). A Meta-analysis of Depression During Pregnancy and the Risk of Preterm Birth, Low Birth Weight, and Intrauterine Growth Restriction Archives of General Psychiatry, 67 (10), 1012-1024 DOI: 10.1001/archgenpsychiatry.2010.111