Table 1.

Comparability of the intervention and control groups, % if not otherwise indicated¹⁾

	Intervention	Control
	(n = 845)	(n = 723)
Age at birth, mean (SD)	30.6 (5.5)	30.6 (5.4)
< 25 yr	14	13
25–29	28	30
30–34	30	31
35 +	27	27
Marital status
Married	52	59
Common law	38	35
Other + NG	10	6
Social class
Upper white collar	27	29
Lower white collar	31	29
Worker	10	9
Student	13	12
Other + NG	20	20
Previous births2), mean (SD)	0.67 (0.97)	0.70 (0.98)
0	57	55
Previous pregnancies2), mean (SD)	1.07 (1.27)	1.16 (1.32)
Smoking2)
No	84	85
Current	14	13
Quitted (during pregnancy)	2	2
Timing of 1st prenatal visit, mean (SD)	9.0 (3.1)	9.0 (3.1)
< 10 gest. weeks	69	68
Boy	53	52
Twin	1	1
Pregnancy length, mean weeks (SD)	40.1 (1.6)	40.0 (1.6)
< 37	3	3
37–41.9	89	91
42+	8	6
Birth weight, mean g (SD)	3521 (487)	3522 (537)
< 2500	3	4
2500–2999	9	9
3000–3499	35	33
3500–3999	40	36
4000+	13	18

¹⁾ NG = no information

²⁾ Missing information 0–4 women in each group