Table 1. Characteristics of cases with schizophrenia and controls.

Characteristic	Cases	Controls	p-value
	n=963	n=963
Maternal age, mean (SD)	28.3 (5.5)	28.0 (5.1)	0.20
Paternal age, mean (SD)	31.0 (6.1)	30.4 (5.7)	0.03
Male, %	58.1%	58.1%	1.00
>=1 previous birth (versus 0), %	62.1%	62.0%	0.96
Maternal education, % *
Secondary school only	25.5%	22.5%	0.27
Vocational degree/secondary school graduate	57.5%	57.7%
College degree/bachelor university degree	11.8%	13.9%
Master degree/licenciate degree/PhD	5.2%	5.9%
Paternal education, % *
Secondary school only	31.1%	26.3%	0.03
Vocational degree/secondary school graduate	51.1%	57.3%
College degree/bachelor university degree	7.8%	8.1%
Master degree/licenciate degree/PhD	10.0%	8.3%
Maternal psychiatric disorders
Schizophrenia/non-affective psychosis	10.2%	1.8%	<0.0001
Affective disorders	20.9%	8.4%	<0.0001
Any psychiatric disorder	32.2%	13.8%	<0.0001
Parental psychiatric disorders
Schizophrenia/non-affective psychosis	16.4%	3.1%	<0.0001
Affective disorders	30.5%	13.3%	<0.0001
Any psychiatric disorder	49.6%	23.3%	<0.0001
Gestational age <37 weeks (versus >=37 weeks) *	7.3%	5.0%	0.08
Gestational week of blood draw *
Observed completed with estimated, mean (SD)	11.0 (3.9)	10.8 (3.9)	0.38
Twin birth (versus singleton) *	1.9%	4.4%	0.002
Municipality of birth
Rural	24.5%	30.0%	0.005
Semi-urban	12.1%	13.7%
Urban	63.5%	56.3%
Province of birth
Eastern Finland	11.9%	15.1%	<0.0001
Northern Finland	12.6%	14.1%
Southern Finland	48.6%	35.9%
Western Finland	26.9%	34.9%

^*Missing observations: maternal education, n=6; paternal education, n=35; gestational age, n=565; gestational week of blood draw, n=271; plurality, n=6.