Table 4

Associations between sleep in late pregnancy and fetal distress (N=633)

Measure of sleepOR and 95% CI for fetal distress
Minimally adjusted association*Adjusted association†
Poor sleep quality
 3 or more nights poor sleep0.8 (0.4 to 1.9) p=0.650.8 (0.3 to 1.9) p=0.61
 GSDS total0.7 (0.3 to 1.7) p=0.480.7 (0.3 to 1.8) p=0.45
 GSDS quality subscale1.4 (0.5 to 3.7) p=0.501.4 (0.5 to 3.9) p=0.52
 GSDS daytime sleepiness subscale1.3 (0.7 to 2.5) p=0.381.0 (0.5 to 2.2) p=0.92
Sleep disturbances on three or more nights per week
 Going to the bathroom0.6 (0.2 to 1.4) p=0.220.6 (0.2 to 1.5) p=0.25
 Pain in back/neck/joints1.4 (0.7 to 2.9) p=0.311.0 (0.5 to 2.2) p=0.93
 Dreams1.5 (0.8 to 2.8) p=0.241.2 (0.6 to 2.4) p=0.62
 Nightmares1.3 (0.4 to 3.8) p=0.640.9 (0.3 to 2.9) p=0.87
 Heartburn1.0 (0.5 to 1.9) p=0.981.1 (0.5 to 2.1) p=0.88
 Nasal congestion1.0 (0.5 to 2.1) p=0.980.9 (0.4 to 2.0) p=0.86
 Leg cramps0.7 (0.3 to 1.6) p=0.420.6 (0.2 to 1.3) p=0.17
 Contractions0.4 (0.1 to 1.6) p=0.190.3 (0.1 to 1.4) p=0.14
 Feeling too hot or too cold2.0 (1.0 to 3.9) p=0.041.7 (0.9 to 3.6) p=0.13
 Thinking or worrying about things1.2 (0.6 to 2.2) p=0.661.0 (0.5 to 2.0) p=0.90
 Baby moving about1.1 (0.6 to 2.1) p=0.761.0 (0.5 to 2.1) p=0.96
 Other children0.7 (0.3 to 1.5) p=0.371.4 (0.5 to 3.7) p=0.56
 Just cannot get comfortable0.7 (0.4 to 1.3) p=0.290.5 (0.2 to 1.0) p=0.04
 Just cannot get to sleep1.2 (0.6 to 2.2) p=0.620.9 (0.4 to 1.8) p=0.68
 Disturbed by partner0.9 (0.4 to 2.0) p=0.850.8 (0.4 to 1.8) p=0.63
Sleep duration1 (ref)1 (ref)
 Short sleep (≤6 h)1.4 (0.7 to 2.8) p=0.421.6 (0.7 to 3.5) p=0.26
 Average sleep (>6 to <9 h)1 (ref)1 (ref)
 Long sleep (≥9 h)1.4 (0.6 to 3.1) p=0.471.2 (0.5 to 3.0) p=0.66
Change in sleep duration between pre-pregnancy and late pregnancy‡
 Increased1.4 (0.5 to 3.9) p=0.471.4 (0.5 to 4.1) p=0.55
 No change1 (ref)1 (ref)
 Decreased1.8 (0.9 to 3.7) p=0.091.5 (0.7 to 3.4) p=0.28
Sleep disorders1 (ref)1 (ref)
 Snoring1.2 (0.6 to 2.4) p=0.651.1 (0.5 to 2.4) p=0.79
 Chronic snoring1.7 (0.6 to 4.5) p=0.301.5 (0.5 to 4.2) p=0.48
 Pregnancy-onset snoring0.2 (0.1 to 1.0) p=0.060.3 (0.1 to 1.2) p=0.09
 Breathing pauses0.6 (0.1 to 4.8) p=0.650.5 (0.1 to 4.0) p=0.50
 Pregnancy-onset breathing pauses0.8 (0.1 to 6.0) p=0.810.8 (0.1 to 6.7) p=0.86
 Leg twitching1.1 (0.4 to 3.0) p=0.790.5 (0.2 to 1.6) p=0.28
 Pregnancy-onset leg twitching2.6 (0.9 to 7.0) p=0.073.3 (1.1 to 10.0) p=0.03
 Restless legs1.2 (0.5 to 2.6) p=0.711.1 (0.5 to 2.5) p=0.89
Excessive daytime sleepiness (ESS≥10)1.1 (0.5 to 2.3) p=0.751.0 (0.5 to 2.2) p=0.93
  • Coefficients are ORs and 95% CIs for fetal distress (n=41) compared with no fetal distress.

  • *Adjusted for infant gender.

  • †Adjusted for infant gender, ethnicity (Māori or non-Māori), NZ Deprivation Index, maternal age, parity, BMI, EPDS score, gestational age at delivery, smoking (any vs none), pre-pregnancy sleep duration and number of poor nights’ sleep.

  • ‡Defined as movement between the defined categories of short sleep (≤6 h), average sleep (>6 and <9 h) and long sleep (≥9 h).

  • BMI, body mass index; EPDS, Edinburgh Postnatal Depression Scale; ESS, Epworth Sleepiness Scale; GSDS, General Sleep Disturbance Scale; NZ, New Zealand.