An international trial of antioxidants in the prevention of preeclampsia (INTAPP).

OBJECTIVE: We sought to investigate whether prenatal vitamin C and E supplementation reduces the incidence of gestational hypertension (GH) and its adverse conditions among high- and low-risk women. STUDY DESIGN: In a multicenter randomized controlled trial, women were stratified by the risk status and assigned to daily treatment (1 g vitamin C and 400 IU vitamin E) or placebo. The primary outcome was GH and its adverse conditions. RESULTS: Of the 2647 women randomized, 2363 were included in the analysis. There was no difference in the risk of GH and its adverse conditions between groups (relative risk, 0.99; 95% confidence interval, 0.78-1.26). However, vitamins C and E increased the risk of fetal loss or perinatal death (nonprespecified) as well as preterm prelabor rupture of membranes. CONCLUSION: Vitamin C and E supplementation did not reduce the rate of preeclampsia or GH, but increased the risk of fetal loss or perinatal death and preterm prelabor rupture of membranes.

Hemodynamic Response to Upper Airway Obstruction in Hypertensive and Normotensive Pregnant Women.

Background. Mild obstructive sleep apnea is common in pregnancy and may have an exacerbating role in gestational hypertension, although currently the interaction between these two diseases is uncertain. Methods. We analyzed 43 pregnant subjects, 28 with gestational hypertension (GH) and 15 with normal healthy pregnancy, by level I polysomnography. Additionally, diastolic and systolic blood pressure changes in response to obstructive respiratory events were measured by noninvasive beat-by-beat monitoring. We also assessed a subgroup (n = 27) of women with respiratory disturbance indexes <5, for blood pressure responses to very subtle obstructive respiratory disturbances ("airflow reductions"). Results. The mean ± standard deviation respiratory disturbance index of our 28 GH women and 15 healthy pregnant women was 10.1 ± 9.9 mmHg and 3.0 ± 3.8 mmHg, respectively. Systolic and diastolic pressure responses to these events were 30.1 ± 12.8 mmHg and 16.0 ± 6.1 mmHg for GH women and 29.1 ± 14.2 mmHg and 14.3 ± 7.7 mmHg for healthy women. For the 27 women in whom we assessed for airflow reduction events, the hemodynamic responses were 27.1 ± 12.3 mmHg systolic and 14.4 ± 6.7 mmHg diastolic. Interpretation. Upper airway obstructive events of any severity are associated with a substantial transient blood pressure response in both healthy pregnant and GH women. Whether or not these events have a clinically significant impact on women with GH remains uncertain.

Can gestational hypertension be modified by treating nocturnal airflow limitation?

OBJECTIVE: Recent evidence suggests that women with gestational hypertension (GH) have a high rate of sleep disordered breathing (SDB), and treatment for even marginal SDB may improve blood pressure control in women with GH. We assessed whether the application SDB treatment could improve blood pressure in women with GH. METHODS: This was a single-center randomized study. Subjects underwent an unattended home-based diagnostic sleep study. The study was then repeated with subjects wearing one of two randomly assigned treatments: auto-titrating continuous positive airway pressure (auto-CPAP) or mandibular advancement device (MAD) + nasal strip. First morning blood pressure and blood for standard GH measures plus inflammatory markers were taken after each study. Subjects completed a series of questionnaires addressing sleep quality and tolerance of assigned therapy. RESULTS: Twenty-four women completed the protocol-13 in the MAD group and 11 in auto-CPAP. The overall rate of SDB was 38%. Auto-CPAP was more effective at treating SDB than MAD + nasal strip, although the women randomized to MAD + nasal strip reported the greater comfort with therapy. First morning blood pressure was not consistently improved with either therapy. When subjects were stratified according to those whose blood pressure increased or decreased with therapy, an association was suggested between blood pressure improvement and reduced levels of tumour necrosis factor-α. CONCLUSION: We demonstrated that 38% of women with GH had concurrent SDB. We did not find an improvement in blood pressure or inflammatory markers with a single night of either the auto-CPAP or MAD + nasal strip interventions. However important lessons from this study may guide future investigations in this area.

Sleep disordered breathing and gestational hypertension: postpartum follow-up study.

BACKGROUND: Gestational hypertension (GH) is a newly recognized risk factor for adverse cardiovascular events later in life. Sleep disordered breathing (SDB) is an established risk factor for adverse cardiovascular events. Recent research has suggested that women with GH may have an increased rate of SDB during pregnancy, but it is not known if this higher rate of SDB persists into the postpartum state. OBJECTIVE: To assess whether women with GH continue to have an increased rate of SDB compared to healthy pregnant women, after the physiologic changes of pregnancy resolve. METHODS: We previously studied women with GH and uncomplicated pregnancies with sleep questionnaires and level 1 polysomnography. Participants were invited to participate in repeat testing 1-2 years postpartum. Respiratory disturbance index (RDI) differences were assessed. RESULTS: Eighteen subjects (11 GH and 7 healthy) had complete follow-up data available for comparison with antepartum data. This group was representative of the initial antepartum cohort. Women with GH experienced a decrease in mean RDI from antepartum to postpartum (12.0 ± 12.3 vs. 2.9 ± 2.9; P = 0.02). Healthy women did not experience the same change (2.8 ± 5.3 vs. 2.1 ± 3.2; P = 0.81). Postpartum comparisons showed the mean RDI of women with GH had decreased to be similar to that of healthy women (P = 0.75). CONCLUSIONS: SDB in women with gestational hypertension improved in the postpartum state to levels indistinguishable from our healthy subjects. This suggests that the physiologic effects of pregnancy may have had a pathologic role in the development of antepartum SDB in women with GH.

Pregnant women with gestational hypertension may have a high frequency of sleep disordered breathing.

BACKGROUND: Gestational hypertension is a common complication of pregnancy. Recent evidence suggests that women with gestational hypertension have a high rate of sleep disordered breathing (SDB). Using laboratory-based polysomnography, we evaluated for the frequency of SDB in women with gestational hypertension compared to healthy women with uncomplicated pregnancies. METHODS: In this single-center cross-sectional study, women with the diagnosis of gestational hypertension were screened in the Fetal Assessment Unit and Antepartum ward. Healthy subjects were recruited by local advertising. Subjects completed a series of questionnaires addressing sleep quality and daytime sleepiness, followed by full night polysomnography. The primary outcome was frequency of SDB (defined as a respiratory disturbance index ≥ 5) in the gestational hypertension and healthy groups. RESULTS: A total of 34 women with gestational hypertension and singleton pregnancies and 26 healthy women with uncomplicated singleton pregnancies consented to participate in the study. The mean ages and gestational ages, but not the body mass indices, of the 2 groups were similar. The frequencies of SDB in the more obese gestational hypertension group and the healthy group were 53% and 12%, respectively (P < 0.001). INTERPRETATION: Women with gestational hypertension may have a significantly higher frequency of SDB than do healthy women with uncomplicated pregnancies of similar gestational age. The relative causal contributions, if any, of SDB and obesity remain to be determined.