From: Maternal sleep duration and neonatal birth weight: the Japan Environment and Children’s Study
MSD < 6.0 h | MSD 6.0–7.9 h | MSD 8.0–8.9 h | MSD 9.0–9.9 h | MSD 10.0–12.0 h | p-value | |
---|---|---|---|---|---|---|
Variable | n = 3958 | n = 37,944 | n = 23,769 | n = 11,976 | n = 4524 | |
Maternal medical background | ||||||
Maternal age (years), mean ± SD | 31.7 ± 5.5 | 31.7 ± 4.9 | 31.5 ± 4.7 | 30.9 ± 4.8 | 29.1 ± 5.2 | < 0.001 |
BMI (kg/m2) before pregnancy, mean ± SD | 21.4 ± 3.6 | 21.2 ± 3.3 | 21.3 ± 3.2 | 21.3 ± 3.4 | 21.3 ± 3.4 | < 0.001 |
Nulliparous, % (n) | 51.6 (2043) | 47.7 (18,096) | 32.7 (7761) | 25.0 (2992) | 37.1 (1679) | < 0.001 |
Smoking during pregnancy, % (n) | 8.9 (352) | 4.6 (1751) | 4.1 (971) | 4.0 (475) | 6.3 (284) | < 0.001 |
Alcohol consumption, % (n) | 3.8 (149) | 2.7 (1008) | 3.0 (707) | 3.2 (384) | 2.5 (114) | < 0.001 |
Maternal educational status, % (n) | ||||||
< 10 years | 7.3 (289) | 3.8 (1442) | 3.9 (929) | 4.9 (588) | 9.0 (406) | < 0.001 |
10–12 years | 35.1 (1390) | 29.8 (11,296) | 30.0 (7135) | 31.5 (3778) | 37.6 (1699) | < 0.001 |
13–16 years | 56.3 (2227) | 64.8 (24,599) | 64.6 (15,359) | 62.2 (7445) | 52.7 (2383) | < 0.001 |
≥ 17 years | 1.3 (52) | 1.6 (607) | 1.5 (346) | 1.4 (165) | 0.8 (36) | < 0.001 |
Annual household income, % (n) | ||||||
< 2,000,000 JPY | 7.6 (302) | 4.5 (1708) | 5.1 (1209) | 7.2 (862) | 11.8 (533) | < 0.001 |
2,000,000–5,999,999 JPY | 66.3 (2624) | 65.8 (24,986) | 68.1 (16,178) | 70.4 (8426) | 73.7 (3333) | < 0.001 |
6,000,000–9,999,999 JPY | 21.6 (856) | 25.1 (9524) | 22.5 (5354) | 18.7 (2244) | 12.0 (544) | < 0.001 |
≥ 10,000,000 JPY | 4.4 (176) | 4.5 (1726) | 4.3 (1028) | 3.7 (444) | 2.5 (114) | < 0.001 |
GWG (kg), mean ± SD | 10.3 ± 4.3 | 10.2 ± 4.8 | 10.3 ± 5.9 | 10.2 ± 4.1 | 10.6 ± 4.3 | < 0.001 |
Excessive GWG, ≥ 12 kg, % (n) | 33.6 (1331) | 30.8 (11,690) | 31.2 (7423) | 31.9 (3819) | 36.9 (1669) | < 0.001 |
Obstetric outcomes | ||||||
PTB, < 37 weeks, % (n) | 4.7 (185) | 4.4 (1660) | 4.5 (1058) | 4.3 (516) | 4.5 (205) | 0.86 |
Neonatal birth weight (g), mean ± SD | 3017 ± 419 | 3022 ± 412 | 3037 ± 410 | 3044 ± 406 | 3030 ± 410 | < 0.001 |
LBW infants < 2500 g, % (n) | 8.3 (330) | 8.2 (3101) | 7.6 (1803) | 7.0 (837) | 7.2 (327) | < 0.001 |
VLBW infants < 1500 g, % (n) | 0.5 (20) | 0.5 (177) | 0.4 (101) | 0.4 (51) | 0.6 (25) | 0.87 |
SGA infants, % (n) | 4.7 (187) | 5.1 (1951) | 4.9 (1173) | 4.7 (558) | 5.0 (224) | 0.25 |
Macrosomia, > 4000 g, % (n) | 1.0 (41) | 0.8 (318) | 0.9 (211) | 1.0 (119) | 0.8 (35) | 0.38 |