Table 1 Descriptive characteristics of mothers: Cohort Norway and. Medical Birth Registry of Norway (N = 13,227)

Age (years)

27.9 (4.5)

BMI (kg/m²)

23.9 (3.8)

Obese (> 30 kg/m²), %

6.7

Height (cm)

166.3 (6.5)

High blood pressure, %

4.6

Smoking cigarettes daily, %

26.9

Light physical activity, > 3 h/wk., %

48.9

Vigorous physical activity, > 3 h/wk., %

16.9

Region, Oslo

25.0

Any college/university, %

24.3

Time to delivery (years)

5.6 (3.5)

Medical Birth Registry of Norway Characteristics

Nulliparous, %

29.9

Preeclampsia or gestational hypertension, %

5.3

Diabetes mellitus (pregestational, gestational, type unspecified)^b

1.7

Preterm (< 37 weeks of gestation), %

5.4

Prior preterm, %

1.8