Sleep‐disordered breathing in hypertensive disorders of pregnancy: a BMI‐matched study

Abstract

Sleep-disordered breathing is more common in hypertensive disorders during pregnancy; however, most studies have not adequately accounted for the potential confounding impact of obesity. This study evaluated the frequency of sleep-disordered breathing in women with gestational hypertension and pre-eclampsia compared with body mass index- and gestation-matched normotensive pregnant women. Women diagnosed with gestational hypertension or pre-eclampsia underwent polysomnography shortly after diagnosis. Normotensive controls body mass index-matched within ±4 kg m underwent polysomnography within ±4 weeks of gestational age of their matched case. The mean body mass index and gestational age at polysomnography were successfully matched for 40 women with gestational hypertension/pre-eclampsia and 40 controls. The frequency of sleep-disordered breathing in the cases was 52.5% compared with 37.5% in the control group (P = 0.18), and the respiratory disturbance index overall did not differ (P = 0.20). However, more severe sleep-disordered breathing was more than twice as common in women with gestational hypertension or pre-eclampsia (35% versus 15%, P = 0.039). While more than half of women with a hypertensive disorder of pregnancy meet the clinical criteria for sleep-disordered breathing, it is also very common in normotensive women of similar body mass index. This underscores the importance of adjusting for obesity when exploring the relationship between sleep-disordered breathing and hypertension in pregnancy. More severe degrees of sleep-disordered breathing are significantly associated with gestational hypertension and pre-eclampsia, and sleep-disordered breathing may plausibly play a role in the pathophysiology of pregnancy hypertension in these women. This suggests that more severe sleep-disordered breathing is a potential therapeutic target for reducing the prevalence or severity of hypertensive disorders in pregnancy.

Sleep-disordered breathing does not impact maternal outcomes in women with hypertensive disorders of pregnancy

“…All subjects gave written informed consent to participate in the study. The data presented here is a secondary analysis of Wilson et al [10] which was a matched case-control study comparing the prevalence of SDB in women diagnosed with PE and GH to women with normotensive pregnancies.…”

“…As per our initial study, [10] women diagnosed with GH or PE between 26 and 37 weeks gestation were considered as cases. Control participants were normotensive women with an uncomplicated pregnancy and were one-to-one matched by BMI to each of the hypertensive cases (within ±4kg/m 2 , measured at the first antenatal appointment).…”

“…[8,9] Given that obesity is a well-recognised risk factor for both hypertension and SDB, our recent work highlighted the importance of adjusting for BMI. [10] What remains unknown however, is how the relationship between SDB and hypertension in pregnancy manifests, and whether there is an independent effect of co-existing SDB on pregnancy outcomes among women with GH or PE. If so, screening and treatment of SDB might have potential as an intervention to prevent or attenuate the severity of HDP, and thus improve perinatal outcomes.…”

The presence of coexisting sleep-disordered breathing among women with hypertensive disorders of pregnancy does not worsen perinatal outcome

“…[8] Accumulating evidence suggests this relationship may also exist in pregnancy with several studies reporting an association between SDB and gestational hypertensive disorders, [3,9,10] although obesity can act as a confounder to this relationship. [11] Hypertensive disorders of pregnancy (HDP), particularly preeclampsia, are associated with placental dysfunction resulting in impaired fetal growth and increased risks of acute compromise. [12][13][14][15] Whether co-existing SDB may increase these risks is currently unknown.…”

Sleep Apnoea and Early Antecedents of Adult Disease

“…Pregnancy, and particularly late gestation, has been associated with a relatively high prevalence of altered sleep patterns including restricted sleep duration, fragmented sleep, snoring, and especially OSA [55][56][57][58][59][60][61][62][63][64][65][66][67] . Experimental evidence in murine models has conclusively demonstrated that OSA can induce changes in insulin sensitivity and promote obesogenic behaviours as well as hypertension, i.e., correlates of pre-eclampsia [68][69][70][71][72][73][74] .…”