Results
In all, 86 pregnant women with a BMI >35 met the inclusion criteria; 19 were finally excluded because they had not undergone polysomnography (Figure 1). This statistical analysis included 67 patients. The characteristics of the excluded women did not differ significantly from those of the others. Table 1 presents the 67 women’s characteristics: their mean age was 30.5 years ± 4.9, and their mean BMI 42.4 ± 6.2. Fourteen (20.90%) had a history of chronic hypertension or diabetes.
Our principal objective was to assess the prevalence of OSA in our population. Among these 67 pregnant women, 29 (43.3%, 95% CI, 31.4–55.2) had OSA, 25 of them mild or moderate and 4 severe (Figure 1). These women’s median AHI was 10.9 (9.15-19.7) and their median time with oxygen saturation <90% 4 minutes (1-13 minutes). Of the four women with severe OSA, only three agreed to start CPAP treatment and only one continued it to the end of her pregnancy.
The first of our secondary objectives was to compare the OSA and non-OSA populations for several criteria (Table 2). During pregnancy, women with OSA developed gestational diabetes more often: 48.3% (n=14) compared with 23.7% in the non-OSA group (n=9) (P =0.04). There were no significant differences for weight gain, hospitalization during pregnancy, or the vascular disease composite criterion, although we note there was a trend toward more complications in the OSA group (n=10 vs n=6, 34.5% vs 16.2%, P =0.086). Among the characteristics of delivery, the groups did not differ significantly for rates of vaginal delivery, cesarean delivery, or labor induction (P >0.05). Similarly, there were no significant differences for neonatal characteristics: birth weight was 3165 g ± 937.5 in the OSA group and 3292 g ± 644.7 in the non-OSA group (P =0.98) with respectively, a pH of 7.24 ± 0.10 and 7.24 ± 0.09 (P =0.99) and 4 (13.79%) and 3 (8.33%) NICU admissions (P =0.69).
The second of our secondary objectives was to study whether various criteria, including age, parity, BMI, history of chronic hypertension, history of diabetes, family history of OSA, weight gain during pregnancy, and gestational diabetes, might be risk factors for developing OSA in this population. A significant difference was observed between the groups for women’s age, prepregnancy history of hypertension, gestational diabetes, and mean BMI (Table 3). The mean age of the women in the OSA group was 31.9 ± 4.7 years vs 29.5 ± 4.8 years (P =0.045) in the women with this sleep problem, and their mean BMI respectively 43.8 ± 6.2 kg/m2 and 41.2 ± 6 kg/m2 (P =0.045). Prepregnancy hypertension was found in 11 women with OSA (37.9%) and only 3 without it (7.9%) (P =0.0027). Gestational diabetes occurred among 48.3% of the women with OSA (n=14) and 23.7% in those without it (n=9,P =0.036). We observed no significant differences between the groups (P >0.05) for the other criteria studied: parity, prepregnancy diabetes, family history of OAS, and weight gain during pregnancy.