Preeclampsia affects 5% to 7% of pregnancies, is strongly associated with low birth weight and fetal death, and is accompanied by sleep disordered breathing. We hypothesized that sleep disordered ...breathing may link preeclampsia with reduced fetal movements (a marker of fetal health), and that treatment of sleep disordered breathing might improve fetal activity during sleep.
First, a method of fetal movement recording was validated against ultrasound in 20 normal third trimester pregnancies. Second, fetal movement was measured overnight with concurrent polysomnography in 20 patients with preeclampsia and 20 control subjects during third trimester. Third, simultaneous polysomnography and fetal monitoring was done in 10 additional patients with preeclampsia during a control night and during a night of nasal CPAP.
Overnight continuous positive airway pressure.
Women with preeclampsia had inspiratory flow limitation and an increased number of oxygen desaturations during sleep (P = 0.008), particularly during REM sleep. Preeclampsia was associated with reduced total fetal movements overnight (319 SD 32) versus controls (689 SD 160, P < 0.0001) and a change in fetal movement patterns. The number of fetal hiccups was also substantially reduced in preeclampsia subjects (P < 0.0001). Continuous positive airway pressure treatment increased the number of fetal movements and hiccups (P < 0.0001 and P = 0.0002, respectively).
The effectiveness of continuous positive airway pressure 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.
Recent studies suggest a specific association between intrauterine growth restriction that commonly occurs in preeclampsia and decreased maternal cardiac output. Sleep is associated with marked ...hypertension in preeclampsia. We therefore aimed to determine how sleep influences other hemodynamic parameters in preeclampsia, specifically to determine if sleep-induced exacerbation of hypertension was associated with reductions in cardiac output.
Randomized controlled trial of nasal continuous positive airway pressure.
King George V, Royal Prince Alfred Hospital.
Twenty-four women with severe preeclampsia and 15 control nulliparous subjects.
Full polysomnography including beat-to-beat blood-pressure recording. Stroke volume, heart rate, cardiac output, total peripheral resistance, and ejection duration were derived from the blood pressure waveform. Half of the 24 preeclamptic subjects were randomly assigned to receive treatment with nasal continuous positive airway pressure and the other half to receive no treatment.
Heart rate, stroke volume, and cardiac output were similar in controls and patients with preeclampsia during wakefulness, while total peripheral resistance was significantly elevated. Sleep induced marked decrements in heart rate, stroke volume, and cardiac output in preeclamptic subjects and resulted in further increments in total peripheral resistance. Cardiac output during sleep was correlated with fetal birth weight (r2 = 0.64, P < .001). When preeclamptic subjects were treated with continuous positive airway pressure, reductions in cardiac output were minimized, while increments in total peripheral resistance were also reduced.
These data indicate that sleep is associated with adverse hemodynamic changes in women with preeclampsia. These changes are minimized with the use of continuous positive airway pressure. Reduced cardiac output during sleep may have an adverse effect on fetal development.
Changes in sleep-disordered breathing associated with late pregnancy have not previously been systematically investigated; however, a number of case reports indicate exacerbation of obstructive sleep ...apnea in late pregnancy, often in association with maternal hypertension. We aimed to compare the severity of sleep-disordered breathing and associated maternal blood-pressure responses in late pregnancy with the nonpregnant state.
Case-controlled, longitudinal study of sleep-disordered breathing during late pregnancy and postpartum.
Ten women referred for suspected sleep-disordered breathing during the third trimester of pregnancy.
None.
Full overnight polysomnography and continuous systemic blood pressure were measured during the third trimester of pregnancy and 3 months following delivery. Parameters of sleep-disordered breathing, including apnea hypopnea index and minimum overnight arterial oxyhemoglobin saturation, were compared between antenatal and postnatal studies. An improvement in both apnea-hypopnea index and minimum arterial oxyhemoglobin saturation occurred consistently in all subjects postnatally. In non-rapid eye movement sleep, mean apnea-hypopnea index was reduced from 63 +/- 15 per hour antenatally to 18 +/- 4 per hour postnatally (P = .03), and in rapid eye movement sleep, from 64 +/- 11 per hour to 22 +/- 4 per hour (P = .002). Minimum arterial oxyhemoglobin saturation was increased from 86% +/- 2% antenatally to 91% +/- 1% postnatally (P = .01). Arterial blood-pressure responses to apnea peaked at 170 to 180 mm Hg antenatally, while they only peaked at 130 to 140 mm Hg postnatally.
This study indicates that late pregnancy may be associated with increased severity of sleep-disordered breathing and associated blood-pressure responses.
Preeclampsia is the most common disease of pregnancy, occurring in up to 10% of the pregnant population. The cause of the disease is as yet undetermined; however, most of the clinical effects are ...commonly attributed to damage to the endothelial layer, leading to increased pressor activity of all the maternal blood vessels. Therefore, we suspected that if obstructive sleep apnea (OSA) coexisted with preeclampsia in pregnancy, the hemodynamic effects of the OSA would be markedly potentiated. To test this hypothesis, we performed full sleep studies and overnight beat-to-beat blood pressure (BP) monitoring. The control patient group included 10 pregnant women with OSA and no evidence of hypertensive disease either before or during their current pregnancy. The test group included 10 women with preeclampsia and coexisting OSA. The pressor responses to obstructive respiratory events during sleep were enhanced in preeclamptic patients compared with control OSA patients (21 ± 2/12 ± 1 mm Hg and 38 ± 5/25 ± 4 mm Hg above baseline in control OSA and preeclamptic OSA patients, respectively, P = .005/.005). In contrast, there was no difference in heart rate responses between the two groups of subjects (34 ± 5 beats/min and 49 ± 13 beats/min above baseline in control and preeclamptic patient groups, respectively, P = .326). We suggest that the augmented pressor responses in preeclamptic women occur as a result of maternal endothelial damage induced by the preeclampsia disease process. These findings may have important implications in the management of preeclamptic patients.
SUMMARY
Major physiological changes occur following parturition and the onset of lactation, including the withdrawal of oestrogen and progesterone, with a consequent increase in circulating prolactin ...(PRL). Changes in other circulating hormones are well known to alter sleep architecture in other circumstances. We therefore aimed to assess whether sleep architecture is altered in fully lactating women as a result of hormonal changes associated with lactation. A descriptive comparison study was undertaken on 12 fully breastfeeding women (B/F), 12 age‐matched control women (CTRL), and seven postnatal women who had chosen to bottle‐feed their infants (BOTTLE). Maternal age, infant age and body mass index (BMI) were similar between all three groups. We performed overnight polysomnography utilizing the Portable Compumedics P‐series. The total sleep time (TST) and rapid eye movement (REM) sleep time were similar in the three groups of women. However, B/F women demonstrated a marked increase in slow wave sleep (SWS), 182 ± 41 min compared with CTRL (86 ± 22 min, P < 0.001 compared with B/F) and BOTTLE subjects (63 ± 29 min, P < 0.001 compared with B/F). There was a compensatory reduction in light non‐rapid eye movement (NREM) sleep in B/F when compared with CTRL and BOTTLE. The most likely explanation for the altered sleep architecture noted to occur in women who are fully breastfeeding their infants is an increase in circulating PRL, which occurs in lactating women. Enhanced SWS may be another important factor to support breastfeeding in the postnatal period.
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