Study objectives: This study was designed to evaluate
sleep-related disordered breathing in obese women during pregnancy.
Obesity is known to predispose to sleep-related breathing disorders.
During pregnancy, obese mothers gain additional weight, but other
mechanisms may counteract this effect.
case-control study to compare sleep-related breathing in obese pregnant
women (mean prepregnancy body mass index [BMI] > 30
kg/m2) with pregnant women of normal weight (mean BMI, 20
to 25 kg/m2).
Setting: University teaching
hospital with a sleep laboratory.
recruited 11 obese women (BMI, 34 kg/m2; mean age 31 years)
and 11 control women (BMI, 23 kg/m2; mean age 32
Interventions: Overnight polysomnography was
performed during early (after 12 weeks) and late (after 30 weeks)
Measurements and results: During pregnancy,
obese mothers gained 13 kg and control women gained 16 kg. Sleep
characteristics did not differ between the groups. During late
pregnancy, the women in both groups slept more poorly and slept in
supine position less. During early pregnancy, their apnea-hypopnea
indexes (1.7 events per hour vs 0.2 events per hour; p < 0.05), 4%
oxygen desaturations (5.3 events per hour vs 0.3 events per hour;
p < 0.005), and snoring times (32% vs 1%, p < 0.001) differed
significantly. These differences between the groups persisted in the
second polysomnography, with snoring time further increasing in the
obese. Preeclampsia and mild obstructive sleep apnea were diagnosed in
one obese mother. One obese mother delivered a baby showing growth
retardation (weight − 3 SD).
have shown significantly more sleep-related disordered breathing
occurring in obese mothers than in subjects of normal weight, despite
similar sleeping characteristics.