Background The American Academy of Sleep Medicine include ‘pregnancy-associated sleep disorder’ (PASD) in its International Classification of Sleep Disorders. PASD is indicated by: either frequent arousals and reduced sleep efficiency or a prolonged habitual sleep duration; and habitual sleep latencies of <10 min. The present study aimed to assess whether pregnant women sleep differently to non-pregnant women, and if so whether any differences might reflect underlying PASD.

Methods Data on self-reported sleep characteristics (duration [hours]; latency, disturbance, coughing/snoring, medication and daytime sleepiness [frequency]; and quality [very good, fairly good, fairly bad, very bad]) from Waves 1 and 4 of the UK Household Longitudinal Study were available for n = 792 pregnant and n = 9,965 age-matched non-pregnant women with complete data on seven potential confounders (age, ethnicity, educational, marital status, employment, parity and household structure). Multinomial logistic regression analyses were conducted before and after adjustment for confounding using STATA IC14 using the least unfavourable response as the referent category.

Results Pregnant women were more likely to sleep both shorter and longer than 7–9 hrs (RRR = 1.22–1.45), and they were also more likely to struggle to get to sleep within 30 min on a regular basis (RRR = 1.07–1.28). Although pregnant women reported more frequent sleep disturbance than non-pregnant women (RRR = 1.35–3.72), they did not report coughing/snoring more frequently (RRR = 0.89–1.20). Likewise, despite reporting poorer sleep quality than non-pregnant women (RRR = 1.60–2.21), pregnant women were less likely to report using sleep medication on a regular basis (RRR = 0.44–0.55). Finally, pregnant women were more likely to report difficulty staying awake during the day than non-pregnant (RRR = 1.28–1.77).

Discussion The findings of the present study confirm that pregnant women sleep differently to non-pregnant women, although these differences may partly reflect the lower use of medication by pregnant women. In general, the differences observed indicate that pregnancy is associated with sleeping patterns that: have sub/superoptimal duration and extended latency; are more frequently disturbed with an overall quality described as less than ‘very good’; and lead to more frequent daytime sleepiness. But it is also clear that pregnant women cough/snore significantly less frequently than non-pregnant.