Sleep complaints: snoring and daytime sleepiness in pregnant and pre-eclamptic women

Abstract

Background and purpose

To examine whether snoring and sleepiness are linked in pregnancy and pre-eclampsia.

Patients and methods

We recruited 167 healthy and 82 pre-eclamptic women in the third trimester of pregnancy and 160 non-pregnant women. Subjects and their partners completed a sleep questionnaire. Height, weight, neck circumferences and blood pressure were recorded for all.

Results

Pregnant and pre-eclamptic women were (mean ±SD) 36±3.6 and 36±3 weeks pregnant, respectively. Age and height did not differ significantly between groups (P>0.2), but pre-eclamptic women were heavier than pregnant and non-pregnant women and had higher BMI than pregnant women before pregnancy (all P<0.05). Thirty-two percent of control, 55% of pregnant and 85% of pre-eclamptic women snored (P<0.001), but pre-pregnancy snoring rates (pre-eclamptic=36%, healthy pregnant women=27%) were similar to those in non-pregnant women (32%) (P>0.7). Sleepiness was reported by 12% of non-pregnant, 23% of pregnant and 15% of pre-eclamptic women (P<0.04), but non-pregnant women had lower mean Epworth Sleepiness scores than both pregnant and pre-eclamptic groups (P<0.001). Snoring was correlated with (P=0.002), but explained only <2%, of the variance in sleepiness.

Conclusion

Snoring and sleepiness increased in the third trimester of pregnancy, particularly in patients with pre-eclampsia. However, the study suggests that sleepiness in pregnancy is largely due to factors other than snoring or breathing pauses.

Introduction

The third trimester of pregnancy is characterised by increased snoring frequency, nocturnal awakenings and daytime sleepiness as well as decreased daytime alertness and sleep quality [1], [2], [3], [4]. The most frequent reasons reported for these symptoms are weight gain, fragmented sleep, and loss of deep sleep stages [1], [5], [6], [7], [8], [9].

In the third trimester of pregnancy, around 14–28% of pregnant and 75% of pre-eclamptic women snore compared to 4–14% of non-pregnant women [1], [2], [3]. Snoring is associated with hypertension and is a risk factor for pre-eclampsia and intra-uterine growth retardation in pregnancy [1], [2], [7], [10], [11].

Daytime sleepiness increases in up to 65% of pregnant women by the end of pregnancy [2]. Polysomnographic studies show that total sleep time and sleep efficiency significantly decrease and that sleep stages three and four are shortened after the first trimester of pregnancy [5], [6], [7], [8], [9].

The American Sleep Disorders Association has asserted the existence of ‘pregnancy-associated sleep disorder’. It is generally agreed that this disorder begins with excessive sleepiness and progresses to severe insomnia [12]. The most common reason given for sleep alterations was pregnancy-associated physiological changes, including high concentration of sex steroids and sleep complaints. These include snoring, insomnia, nocturnal awakenings, parasomnias and daytime sleepiness [5], [7], [11], [13], [14], [15].

Thus, both snoring [1], [2], [3], [7] and sleepiness [2], [11], [13] are common in pregnancy, but it is not clear whether these features are associated. We have examined the association of snoring and sleepiness across groups of non-pregnant and pregnant women. The pregnant group was supplemented with women with pre-eclampsia as they have a higher rate of snoring [1], [2].