Sleep problems implicated in female fertility
Fecundability may be lower in women who have trouble sleeping at night or have shorter sleep duration, as suggested in a recent study.
The study population comprised 6,873 women aged 21–45 years attempting pregnancy for ≤6 months at enrolment. All of them completed follow-up questionnaires every 8 weeks for up to 12 months to report their pregnancy status.
Researchers analysed the women’s average sleep duration per 24-hour period in the previous month, frequency of trouble sleeping within the last 2 weeks (as measured by the Major Depression Inventory) and shift work patterns in relation to fertility. They used proportional probabilities regression to estimate fecundability.
Compared with women sleeping 8 hours per day, those who slept for <6, 6, 7 and ≥9 hours per day had fecundability ratios (FRs) of 0.89 (95 percent CI, 0.75–1.06), 0.95 (0.86–1.04), 0.99 (0.92–1.06) and 0.96 (0.84–1.10), respectively.
Meanwhile, relative to women who had no trouble sleeping, those who reported having difficulty sleeping <50 percent of the time and >50 percent of the time had FRs of 0.93 (0.88–1.00) and 0.87 (0.79–0.95), respectively.
The associations were slightly stronger among women with higher depressive symptoms and perceived stress levels. Shift work showed no association with fecundability.
Researchers explained that the interaction between stress and sleep may explain the slightly pronounced association between trouble sleeping and fecundability among women with higher depressive symptoms and perceived stress levels.
Stress may temporarily raise the concentration of melatonin. This important sleep-regulating hormone has been reported to have mixed effects on fertility, affecting reproductive hormones differently depending on the cycle phase in which sleep disruption occurs.