A new study of kindergarten children revealed the influence of a mother's mood during the prenatal (before birth) and postnatal (after birth) stages. The findings from the longitudinal study suggested that maternal depressive mood was related to child sleep disturbances.

The research titled "Child Behavioral Problems Mediate The Relationship Between Maternal Emotions During The Prenatal And Postnatal Period And Kindergarten Children's Sleep Disturbances" was published recently in an online supplement of the journal Sleep.

As many as 833 kindergarteners with the mean age of six years were assessed for sleep problems and behavioral problems using the Child Behavior Checklist (CBCL). The emotional status of the mothers was recorded with a self-designed set of questions using a 5-point scale for happiness and a 3-point scale for depression. In addition to prenatal and postnatal depressive emotion, the data included perceived happiness levels throughout trimesters.

Women who expressed depressive emotion during the postnatal period or during both prenatal and postnatal periods were likely to have a child who exhibited sleep disturbances. On the flip side, increased happiness during pregnancy was linked to a decreased risk of poor sleep quality in children.

Lead author Jianghong Liu and co-authors Xiaopeng Ji, Guanghai Wang, Yuli Li and Jennifer Pinto-Martin found the new results to be noteworthy in highlighting the importance of prenatal maternal emotional health and its impact on child sleep outcomes. 

"[We] found that happiness increased across the trimesters and that happiness during the second and third trimester was protective against child sleep problems," explained Liu, an associate professor at the Schools of Nursing and Medicine at the University of Pennsylvania.

She added that the mediation role of child behavior in the relationship between maternal emotion and children's sleep quality was most surprising. It appeared to demonstrate that the emotion during pregnancy affects child behavior which is what, in turn, affects the sleep quality for the child. 

This is, of course, far from the first study to explore the link and its effects. Previous research which explored maternal depression during prenatal and postnatal periods found the children were 1.28 times more likely to have depression as adults. The physiological effects of depression were thought to have passed through the placenta, influencing the fetus' brain development.

Estimations suggest 10 to 20 percent of pregnant women may experience symptoms of depression.

"These results promote the caretaking of maternal health and happiness during pregnancy and encourage the roles of familial and community support in aiding expecting mothers. This will benefit not only maternal health but also the long-term behavioral and sleep health of their child," said Liu.

The research will be presented at the 32nd annual meeting of the Associated Professional Sleep Societies LLC (APSS) in Baltimore. Liu is set to conduct a poster presentation and an oral presentation on June 5 and 6 respectively.