Introduction
Obstructive sleep apnea (OSA) is a high-prevalence disease, sometimes
exceeding 50% in the general population.1–4 The
intermittent hypoxia and fragmentation of sleep it engenders are risk
factors for cardiovascular diseases, especially for chronic
hypertension, metabolic syndrome, and diabetes.2–5Clinically, this disorder is manifested principally by two symptoms:
daytime somnolence and nocturnal snoring. Polysomnography in a sleep
laboratory is the reference examination for this diagnosis, defined by
calculating the apnea-hypopnea index (AHI). In Western countries, the
prevalence of mild OSA (AHI ≥ 5) has been estimated at 9–38% and that
of moderate to severe OSA (AHI ≥ 15) at 6–17%.2These variations are explained by differences in the diagnostic
criteria, but also by the heterogeneity of study populations; prevalence
is higher among men, the elderly, and obese women. Obesity is its
principal risk factor.
Obesity in pregnant women is accompanied by an increase in
pregnancy-related vascular complications such as preeclampsia,
pregnancy-related hypertension, and gestational
diabetes.6,7 Other obstetric complications are
associated with an impaired quality of labor (higher rate of post-term
pregnancies, prolonged labor, and cesareans for cervical
dystocia) 8-13 and a higher risk of postpartum
hemorrhage in vaginal deliveries.9 Obesity in pregnant
women may also be a risk factor for the development of sleep apnea,
which may further increase the risk of pregnancy complications.
OSA during pregnancy has been studied often. Depending on the definition
used and the study, its prevalence among women of child-bearing age has
been estimated at 1.4–16.9%.2,14,15 But the exact
prevalence among pregnant women remains unknown, especially because it
is underestimated and underdiagnosed in this population because of its
nonspecific clinical symptoms during pregnancy (asthenia, nonrestorative
sleep, snoring in the third trimester) that may thus be trivialized by
both women and clinicians.16,17 Moreover, because many
of the studies about OSA and pregnancy have not used polysomnography, it
may well have been either under- or overdiagnosed.
Substantially less is known about the effects of OSA in pregnant women
than in nonpregnant populations. Recent data indicate it is associated
with higher risks of gestational diabetes, preeclampsia, and fetal
growth restriction (FGR). A meta-analysis published in 2018 showed that
women with OSA are also at higher risk of preterm, cesarean, and
operative vaginal deliveries, as well as of postoperative
complications.18 Nonetheless, most of the data
currently available is limited to case reports or studies without either
or both of an appropriate, objective test to diagnosis OSA and
adjustment for obesity, an obvious confounding
factor.19,20
Few studies have specifically explored OSA in pregnant women with
obesity. We therefore chose to conduct a study in this population: its
principal objective was to define their prevalence of OSA. Our
hypothesis was that its prevalence would be higher among them than among
non-obese women. Our secondary objectives were to compare the women with
and without OSA for the course and outcomes of their pregnancy and to
identify some of its predictive factors.