Poor sleep in pregnancy can disrupt immune system
"Our results highlight the importance of identifying sleep problems in early pregnancy, especially in women experiencing depression, since sleep is a modifiable behaviour," said Michele Okun, from University of Pittsburgh School of Medicine, and lead author of the report.
"The earlier that sleep problems are identified, the sooner physicians can work with pregnant women to implement solutions," Okun said.
Pregnancy often is associated with changes in sleep patterns, including shortened sleep, insomnia symptoms and poor sleep quality.
These disturbances can exacerbate the body's inflammatory responses and cause an overproduction of cytokines, which act as signal molecules that communicate among immune cells.
While cytokines are important for numerous pregnancy-related processes, excess cytokines can attack and destroy healthy cells and cause destruction of tissue in pregnant women, thereby inhibiting the ability to ward off disease.
For expectant mothers, excess cytokines also can disrupt spinal arteries leading to the placenta, cause vascular disease, lead to depression and cause pre-term birth.
The study is the first to evaluate all factors - inflammatory cytokines, depression and insomnia - and their possible combined effect on pregnant women.
The study examined nearly 170 women, both depressed and not depressed, at 20 weeks of pregnancy and analysed their sleep patterns and cytokine production levels over the course of 10 weeks (pregnancy-related physiological adaptations are in flux prior to 20 weeks).
Researchers found women with depression and poor sleep are at greatest risk for adverse birth-related outcomes. Cytokine levels may be one biological pathway through which this is accomplished, particularly with regard to preterm birth.
Any shift in immunity, such as poor sleep and/or depression, could set the stage for increased risk for adverse outcomes, they said.
The study found that at 20 weeks, depressed pregnant women have higher levels of inflammatory cytokines compared to non-depressed women.
However, at 30 weeks of pregnancy, differences in cytokines among depressed and non-depressed women were negligible, likely because as pregnancy progresses, levels of cytokines normally increase.
The study was published in the journal Psychosomatic Medicine.