Joint Effect of Body Mass Index and Obstructive Sleep Apnea on Preeclampsia Risk.

Abstract

Objective: Preeclampsia remains one of the leading causes of perinatal mortality worldwide. Little is known of the modifiable risk factors that can be identified and addressed early in pregnancy to reduce the risk of preeclampsia and its associated adverse outcomes. We sought to determine if there is a synergistic effect of pre-pregnancy body-mass index and obstructive sleep apnea on the risk of preeclampsia.

Study design: We conducted a retrospective cohort study of singleton pregnancies delivered in Kaiser Permanente Southern California hospitals between January 1, 2010, and December 31, 2020 (n=342,349). Preeclampsia and sleep apnea were ascertained using clinical diagnosis codes. Body-mass index in kg/m2 measured during prenatal care visits was categorized as normal (18.5 to 24.9), overweight (25 to 29.9), and obese (≥30). Multivariable logistic regression was used to estimate adjusted relative risks (adjusted RR) and 95% confidence intervals (CI).

Results: Compared to normal weight in a pregnancy, overweight (adjusted RR: 1.6; 95% CI: 1.5, 1.7) and obese body mass index (adjusted RR: 2.5; 95% CI: 2.4, 2.6) were associated with an increased risk of preeclampsia. Independent of pre-pregnancy body-mass index, a pregnancy with obstructive sleep apnea was associated with an increased risk of preeclampsia (adjusted RR: 2.2; 95% CI: 1.8, 2.6). Compared to normal weight without the diagnosis of obstructive sleep apnea in a pregnancy, overweight (adjusted RR: 4.6; 95% CI: 2.9, 7.4) and obese body mass index (adjusted RR: 3.8; 95% CI: 3.2, 4.6) with the diagnosis of obstructive sleep apnea were associated with an increased risk of preeclampsia.

Conclusions: Obstructive sleep apnea and elevated body-mass index have independent and additive relationship with preeclampsia. Overweight women at-risk of preeclampsia should be advised of a higher likelihood of developing preeclampsia when both conditions occur together and may benefit from close monitoring and early interventions for these modifiable risk factors.