(887) Moderate/severe insomnia and risk of ischemic placental disease and preterm delivery: a longitudinal evaluation

To assess whether persistent moderate/severe insomnia during pregnancy or its development in the third trimester is associated with ischemic placental disease (IPD)—including preeclampsia (PEC), abruption, and fetal growth restriction (FGR)—and with preterm delivery (PTD).


Study Design:

We conducted a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring New Mothers-to-be, a prospective cohort of nulliparous singletons. We included those who underwent insomnia screening with the Women’s Health Initiative Insomnia Rating Scale (WHIRS) in the first and second/third trimesters (visit 1: 6-14 weeks; visit 3: 22-30 weeks). We compared those with persistent insomnia, defined as moderate/severe insomnia (WHIRS scores of 15-28) at both visits 1 and 3 and those with incident insomnia, defined as none/mild insomnia at visit 1 and moderate/severe insomnia at visit 3. The primary outcome was IPD, defined as any PEC, abruption, or FGR. Secondary outcomes included individual IPD components and PTD < 37 weeks. Log-binomial regression models estimated the relative risk between groups and corresponding 95% confidence intervals (CI).


Results:

Among 7,273 individuals with WHIRS measured at both study visits, 1596 (22.0%) had persistent moderate/severe insomnia and 1240 (17%) had incident moderate/severe insomnia. Those with persistent moderate/severe insomnia had more gestational diabetes (6.5%) and pre-pregnancy depression (17.9%) (Table 1). Persistent moderate/severe insomnia was associated with 29% increased risk of PTD < 37 weeks (Table 2). Compared to those with none/mild insomnia at both visits, the adjusted risk of IPD was 1.02 (95% CI 0.83, 1.26) for the persistent moderate/severe insomnia group versus 0.85 (95% CI 0.66, 1.09) for the incident insomnia group.


Conclusion:

Persistent moderate/severe insomnia was associated with increased risk for PTD, while exposure to neither persistent nor incident insomnia was associated with IPD. These findings provide mechanistic insights that suggest the link between insomnia and pregnancy complications such as PTD are not driven by placental ischemia.