Sleep disturbance and cardiometabolic risk factors in early pregnancy: a preliminary study

Cardiometabolic (CM) risk factors are linked to increased morbidity. Disturbed sleep is associated with CM risk factors in late pregnancy, but little is known about sleep in early pregnancy and CM risk factors.

Diary and actigraphy-assessed sleep information, as well as CM outcomes (blood pressure (BP) and body mass index (BMI)), were collected thrice from pregnant women (N=161) in early pregnancy: T1 (10-12 weeks), T2 (14-16 weeks) and T3 (18-20 weeks). The sleep variables evaluated included sleep onset latency (SOL), wake after sleep onset (WASO) and total sleep time (TST). Sleep variables were dichotomised using established clinical cut-offs.

BMI and BP significantly changed across time. Women with persistent SOL≥20 min had greater BMI than women without persistent SOL≥20 min prior to covariate adjustment at T1 and T2, but at T3 the BMI values converged. Similar results were observed for persistent WASO≥30 min. Persistently long WASO, as measured by actigraphy, was associated with elevated SBP, after controlling for covariates.

Consistent with anecdotal evidence, it appears as if a subset of women report substantial difficulty initiating and maintaining sleep during early pregnancy and this may augment the risk of higher BP and BMI. Understanding these relationships is important as CM risk factors are linked to maternal and infant morbidity. Assessing sleep in early pregnancy may bestow time necessary for appropriate intervention.