Skip to main content

Table 1 Maternal medical background and obstetric outcomes of participants according to maternal sleep duration status

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

  1. Abbreviations: MSD maternal sleep duration, SD standard deviation, BMI body mass index, GWG gestational weight gain, PTB preterm births, LBW low birth weight, VLBW very low birth weight, SGA small for gestational age