Introduction Black individuals experience a higher prevalence of sleep disruption, including obstructive sleep apnoea (OSA), compared to Whites, which is believed to contribute to a higher incidence of cardiovascular disease. Among pregnant women, Blacks experience a higher burden of poor pregnancy outcomes such as gestational hypertension, pre-eclampsia, gestational diabetes, foetal growth restriction, and premature birth. In pregnancy, OSA has been associated with the latter adverse outcomes. Nonetheless, it is currently unknown whether differences exist in the presence and severity of OSA between Black and White pregnant women

Methods Pregnant women in mid-to-late pregnancy were recruited from a large academic medical centre and invited to undergo home sleep testing using the WatchPAT device. OSA was defined as an apnoea-hypopnoea index (AHI) ≥5 events/hour. The frequency and severity of OSA was compared between Black and White pregnant women.

Results 191 women enrolled (42 Black). Demographic information is shown in table 1. Sleep duration was shorter in Blacks compared to Whites (350 minutes vs 375 minutes, p=0.02). A similar proportion of Black compared to White women had OSA (33% vs. 31%). Although severity of OSA was non-significantly elevated in Blacks (AHI 9.2 vs 6.3, p=0.07), minimum oxygen saturation was significantly lower in Black women (89% vs 91%, p=0.04) and the oxygen desaturation index was higher in Blacks compared to Whites (4.9 vs 2.5, p=0.03) after accounting for differences in demographics.

Discussion The incidence of OSA in pregnancy was high with approximately one-third of all women having OSA. Nonetheless, despite being younger and earlier in gestation, Black women had greater severity of oxygen desaturation compared to Whites; this is likely attributed to the higher BMI observed in Black women. These findings have implications for OSA screening in pregnancy.