About 15% of women suffer from depression during pregnancy, and many reports have suggested that depression during pregnancy may have negative effects on the fetus. A new study from researchers at the University of Michigan indicates a link between depression during pregnancy and infant sleep problems.
This study examined sleep patterns in 18 healthy, full-term infants (9 males and 9 females). Of the infants assessed, seven were born to women with no personal or family history of depression; the remaining 11 were born to women who had been diagnosed with depression or had experienced depressive symptoms during pregnancy.
Researchers observed that the infants of depressed mothers were more likely to exhibit disrupted sleep than the infants of non-depressed mothers. The infants of depressed mothers took longer to fall asleep, had lower sleep efficiencies, and had more nighttime awakenings than the infants of non-depressed mothers. These differences were observed 2 weeks after delivery and persisted at 6 months postpartum.
Although this study is small in size, these finding are consistent with those of an earlier study which demonstrated that depression and anxiety during pregnancy was associated with infant sleep problems at 18 and 30 months. Both of these studies add to the growing body of literature suggesting that maternal depression and/or anxiety during pregnancy, if left untreated, may be associated with longer term developmental and behavioral issues in the child.
Researchers hypothesize that stress hormones, like cortisol, circulate at higher levels in women who suffer from depression or anxiety and that these hormones may have an affect on the developing fetal brain. There is concern that this in utero exposure to high levels of these stress hormones may alter the development of the hypothalamic-pituitary-adrenal axis or HPA axis and may make these children more vulnerable to depression or anxiety later on in life.
Ruta Nonacs, MD PhD
Armitage R, Flynn H, Hoffmann R, Vazquez D, Lopez J, Marcus S. Early Developmental Changes in Sleep in Infants: The Impact of Maternal Depression. SLEEP 2009;32(5):693-696