. 2022 Jun 28;38(5):915–949. doi: 10.1007/s10680-022-09623-6

Table 2.

Descriptive statistics for covariates by type of conception, children born in Finland 1995–2000

	Between-family sample		Within-family sample
	Naturally conceived	MAR	Naturally conceived	MAR
Confounders
Child's sex (male, %)	51.11	51.07	50.80	51.08
Maternal age at birth (mean)	29.98^ac	32.38^bc	31.74^ad	30.85^bd
Birth order (%)
First-born	77.49^ac	89.36^bc	22.32^ad	75.82^bd
Second child	20.49^ac	10.43^bc	72.38^ad	23.45^bd
Third or higher	2.02^ac	0.21^bc	5.30^ad	0.72^bd
Maternal smoking (%)	14.83^ac	7.06^c	6.37^a	7.39
Family structure (%)
Married parents	63.72^ac	77.53^bc	80.76^a	79.80^b
Cohabiting parents	28.43^ac	18.74^c	16.03^a	17.27
One-parent family	7.85^ac	3.74^bc	3.21^a	2.93^b
Parental education (highest, %)
Higher tertiary	15.32^ac	22.95^c	22.73^a	21.69
Lower tertiary	37.23^ac	43.00^c	43.03^a	44.82
Secondary	40.22^ac	30.54^c	30.50^a	30.20
Basic	7.23^ac	3.50^c	3.70 ^a	3.29
Household income decile (mean)	5.52^ac	6.90^bc	6.27^ad	6.74^bd
Mediators
Type of Birth (%)
Singleton	97.8^ac	77.55^bc	98.44^ad	88.67^bd
Twins	2.17^ac	21.39^bc	1.44^ad	10.81^bd
Triplets	0.03^ac	1.05^bc	0.12^ad	0.48^bd
Low birth weight (%)	3.47^c	14.15^bc	2.88^d	8.39^bd
Gestational age (days, mean)	278.09^c	271.10^bc	277.62^d	274.55^bd

Figures in this table correspond to the mean of the analytical sample for the mental health outcomes (n = 280,682 in the overall population and 4,923 in the within-family sample). Covariates for birth year (1995–2000) and hospital district (n = 20) not shown

^a Statistically significant difference between naturally conceived adolescents in the between- and within-family samples at 95% confidence level. ^bStatistically significant difference between MAR adolescents in the between- and within-family samples at 95% confidence level. ^cStatistically significant difference between MAR- and naturally conceived adolescents in the between-family sample at 95% confidence level.^dStatistically significant difference between MAR- and naturally conceived adolescents in the within-family sample at 95% confidence level