It followed 720 pregnant women during their pregnancies and the months after they gave birth. The catch, though, is that all the mothers were from Bangladesh, and rural Bangladesh at that. I'd love to see the same study repeated in the United States or in Europe, so that we can compare the results and see whether they are indeed the same. The study's lead researcher, Hashima Nasreen, reported: "Eighteen per cent of the women we studied in two rural areas of Bangladesh were diagnosed as having depression and one-quarter as having anxiety during pregnancy, and these women were much more likely to give birth to very small babies. This is a worrying problem, since low birth weight is strongly associated with infant death, which may in turn perpetuate the cycle of mental health problems and underdevelopment."
The researchers were not sure whether the low birth weights were due to a bigger likelihood that depressed women would have unhealthy habits in pregnancy, and might not seek prenatal care, or whether the depression itself had physical consequences for the babies. Perhaps the most fascinating thing about this study is the finding that depression was as likely to strike women living in poverty as those from higher socio-economic backgrounds, and that depression is a contributor to fetal death alongside malnutrition and other factors.