Table 1.

Child and family characteristics by mode of conception

	Total	NC	MAR
Birth outcomes
LBW (%)	7	6.6	21.9
Child characteristics
Female (%)	49.8	49.7	51.6
Firstborn (%)	42.3	41.5	66.1
Twin (%)	2.7	2.1	23.2
Family characteristics
Maternal age at birth (mean/SE)	29.7 (0.13)	29.6 (0.12)	33.1 (0.34)
Mother is married or cohabiting at birth (%)	86.3	85.9	97.8
Mother of White ethnic origin (%)	90	89.9	94.5
Mother has a university degree (%)	33.5	33.1	45.5
Mother smoked during pregnancy (%)	21.4	21.8	9.3
Mother used antenatal care before 12th week (%)	43.3	42.9	55.4
N (%)	13716 (100)	13320 (97.1)	396 (2.9)

Descriptive statistics refer to the analytical sample at age 3.

SE, standard error.