Addressing Sleep-disordered Breathing in Preeclampsia for Better Fetal Outcomes

Treatment of women who have preeclampsia with continuous positive airway pressure (CPAP) therapy for mild sleep-disordered breathing reverses low fetal activity levels and may improve fetal outcomes, according to the results of a new study.

The 3-part study appears in the January issue of the journal SLEEP.

The researchers validated a method of fetal movement recording against ultrasonography in 20 normal third trimester pregnancies. Then, they measured fetal movement overnight with concurrent polysomnography in 20 patients with preeclampsia and 20 controls during third trimester. Then, they conducted simultaneous polysomnography and fetal monitoring in 10 additional patients with preeclampsia during a control night and during a night of nasal CPAP.

Women with preeclampsia had inspiratory flow limitation and an increased number of oxygen desaturations during sleep, particularly during REM sleep. Preeclampsia was associated with reduced total fetal movements overnight versus controls and a change in fetal movement patterns. The number of fetal hiccups also was substantially reduced in patients with preeclampsia. CPAP treatment increased the number of fetal movements and hiccups.

The average number of fetal movements increased from 319 during a night without CPAP treatment to 592 during the subsequent night with treatment. The number of fetal movements decreased steadily by 7.4 movements per hour during the course of the night without CPAP treatment and increased by 12.6 movements per hour during the night with CPAP therapy.

What might be considered clinically unimportant or minor “snoring” probably has major effects on the blood supply to the fetus, and the fetus in turn protects itself by reducing movements, it was suggested. Therefore, measurement of fetal activity during a mother’s sleep may be an important method of assessing fetal well-being.

Preeclampsia affects 5% to 7% of pregnancies, is strongly associated with low birth weight and fetal death, and is accompanied by sleep-disordered breathing, the authors stated, concluding that the effectiveness of CPAP therapy in improving fetal movements suggests a pathogenetic role for sleep-disordered breathing in the reduced fetal activity and possibly in the poorer fetal outcomes associated with preeclampsia.