Confounder-adjusted associations between sleep in late pregnancy and customised infant birthweight centile (N=633)
| Measure of sleep | Birth size using customised birthweight centiles for the NZ population | ||
|---|---|---|---|
| Small for gestational age (<10th centile) | Appropriate for gestational age | Large for gestational age (>90th centile) | |
| N=56 | N=490 | N=87 | |
| Poor sleep quality | |||
| 3 or more nights poor sleep | 1.0 (0.4 to 2.0) p=0.89 | 1 (ref) | 0.9 (0.5 to 1.6) p=0.61 |
| GSDS total | 1.1 (0.5 to 2.7) p=0.77 | 1 (ref) | 1.0 (0.5 to 2.0) p=0.99 |
| GSDS quality subscale | 1.0 (0.4 to 2.1) p=0.90 | 1 (ref) | 0.7 (0.4 to 1.3) p=0.23 |
| GSDS daytime sleepiness subscale | 1.3 (0.7 to 2.3) p=0.45 | 1 (ref) | 1.2 (0.7 to 1.9) p=0.52 |
| Sleep disturbances on three or more nights per week | |||
| Going to the bathroom | 1.1 (0.4 to 3.0) p=0.82 | 1 (ref) | 1.5 (0.6 to 3.6) p=0.39 |
| Pain in back/neck/joints | 1.1 (0.6 to 2.0) p=0.81 | 1 (ref) | 1.0 (0.6 to 1.6) p=0.87 |
| Dreams | 0.8 (0.4 to 1.5) p=0.46 | 1 (ref) | 1.5 (0.9 to 2.4) p=0.10 |
| Nightmares | 0.7 (0.2 to 2.4) p=0.57 | 1 (ref) | 0.5 (0.2 to 1.5) p=0.21 |
| Heartburn | 0.6 (0.3 to 1.1) p=0.09 | 1 (ref) | 0.8 (0.5 to 1.3) p=0.29 |
| Nasal congestion | 1.8 (1.0 to 3.2) p=0.06 | 1 (ref) | 1.0 (0.6 to 1.7) p=0.95 |
| Leg cramps | 0.6 (0.3 to 1.2) p=0.14 | 1 (ref) | 1.2 (0.7 to 2.0) p=0.55 |
| Contractions | 1.0 (0.4 to 2.6) p=0.96 | 1 (ref) | 1.3 (0.6 to 2.6) p=0.48 |
| Feeling too hot or too cold | 0.9 (0.5 to 1.6) p=0.81 | 1 (ref) | 1.2 (0.8 to 2.0) p=0.40 |
| Thinking or worrying about things | 1.1 (0.6 to 1.9) p=0.85 | 1 (ref) | 1.6 (1.0 to 2.6) p=0.08 |
| Baby moving about | 1.3 (0.7 to 2.4) p=0.34 | 1 (ref) | 1.3 (0.8 to 2.1) p=0.29 |
| Other children | 1.1 (0.5 to 2.3) p=0.76 | 1 (ref) | 1.1 (0.6 to 2.1) p=0.79 |
| Just cannot get comfortable | 1.2 (0.7 to 2.3) p=0.48 | 1 (ref) | 1.2 (0.7 to 2.0) p=0.53 |
| Just cannot get to sleep | 0.7 (0.4 to 1.3) p=0.27 | 1 (ref) | 1.4 (0.9 to 2.2) p=0.19 |
| Disturbed by partner | 0.2 (0.1 to 0.7) p=0.01 | 1 (ref) | 1.4 (0.8 to 2.3) p=0.26 |
| Sleep duration | |||
| Short sleep (≤6 h) | 0.9 (0.4 to 1.8) p=0.72 | 1 (ref) | 1.1 (0.6 to 1.9) p=0.76 |
| Average sleep (>6 to <9 h) | 1 (ref) | 1 (ref) | 1 (ref) |
| Long sleep (≥9 h) | 1.6 (0.8 to 3.2) p=0.19 | 1 (ref) | 1.1 (0.6 to 2.0) p=0.83 |
| Change in sleep duration between pre-pregnancy and late pregnancy* | |||
| Increased | 1.4 (0.6 to 3.2) p=0.47 | 1 (ref) | 1.4 (0.7 to 2.9) p=0.29 |
| No change | 1 (ref) | 1 (ref) | 1 (ref) |
| Decreased | 0.8 (0.4 to 1.5) p=0.50 | 1 (ref) | 1.3 (0.7 to 2.2) p=0.37 |
| Sleep disorders | |||
| Snoring | 1.2 (0.6 to 2.4) p=0.52 | 1 (ref) | 1.2 (0.7 to 2.0) p=0.58 |
| Chronic snoring | 1.6 (0.6 to 4.0) p=0.32 | 1 (ref) | 1.7 (0.8 to 3.7) p=0.14 |
| Pregnancy-onset snoring | 0.8 (0.4 to 1.8) p=0.58 | 1 (ref) | 1.1 (0.6 to 2.1) p=0.75 |
| Breathing pauses | 2.8 (0.9 to 9.0) p=0.08 | 1 (ref) | 2.0 (0.7 to 5.7) p=0.21 |
| Pregnancy-onset breathing pauses | 1.7 (0.4 to 7.9) p=0.52 | 1 (ref) | 3.5 (1.3 to 9.6) p=0.01 |
| Les twitching | 1.4 (0.6 to 3.5) p=0.45 | 1 (ref) | 1.0 (0.5 to 2.2) p=0.99 |
| Pregnancy-onset leg twitching | 0.2 (0.0 to 1.9) p=0.18 | 1 (ref) | 0.6 (0.2 to 2.1) p=0.42 |
| Restless legs | 0.9 (0.4 to 2.0) p=0.86 | 1 (ref) | 1.5 (0.8 to 2.6) p=0.19 |
| Excessive daytime sleepiness (ESS≥10) | 0.8 (0.4 to 1.6) p=0.52 | 1 (ref) | 1.4 (0.8 to 2.4) p=0.19 |
Coefficients are ORs with 95% CIs from logistic regressions, adjusted for infant gender, ethnicity (Māori or non-Māori), NZ Deprivation Index, maternal age, parity, BMI, EPDS score, smoking (any vs none), pre-pregnancy sleep duration and number of poor nights’ sleep.
*Defined as movement between 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.