Table 1. Maternal characteristics and rates of low Apgar scores (0–6), meconium aspiration, and neonatal seizures: live-born singleton second term infants of women in Sweden 1992–2012.

Category	Characteristic	Number of Births	Outcome Rate/1,000
			Apgar Score 0–6 at 5 min (n = 2,824)	Neonatal Seizures (n = 658)	Meconium Aspiration (n = 372)
Total		532,858	5.36	1.23	0.70
Maternal factors	BMI at first pregnancy (kg/m 2 )
	<18.5	14,467	3.50	1.04	0.69
	18.5–24.9	326,207	4.66	1.04	0.60
	25–29.9	95,773	6.45	1.59	0.75
	30–34.9	24,233	9.38	1.86	1.16
	≥35	8,127	11.20	2.70	1.97
	Data missing	64,051	5.50	1.30	0.78
	Maternal age at second delivery (years)
	≤24	58,932	4.09	1.04	0.68
	25–29	173,609	4.67	1.08	0.62
	30–34	207,307	5.46	1.29	0.67
	≥35	93,010	7.23	1.53	0.94
	Maternal height (cm)
	<155	13,695	8.81	1.53	0.58
	155–164.9	180,958	6.58	1.45	0.85
	165–174.9	278,325	4.68	1.16	0.61
	≥175	52,782	3.80	0.85	0.64
	Data missing	7,098	6.06	0.84	0.70
	Smoking in second pregnancy
	No	469,399	5.29	1.22	0.67
	Yes	41,048	5.95	1.46	0.95
	Data missing	22,411	5.92	1.20	0.80
	Inter-pregnancy interval (years)
	<1	94,653	4.56	1.09	0.61
	1 to <3	318,314	5.22	1.17	0.65
	3 to <5	78,566	5.82	1.37	0.75
	≥5	41,325	7.49	1.81	1.19
	Education (years)
	≤11	122,582	5.88	1.42	0.96
	12–14	218,822	5.42	1.24	0.64
	≥15	186,945	4.94	1.10	0.58
	Data missing	4,509	6.30	1.55	1.11
	Mother’s country of birth
	Nordic	460,920	5.35	1.26	0.67
	Non-Nordic	71,938	5.44	1.10	0.90
	Chronic hypertension
	No	530,249	5.34	1.23	0.70
	Yes	2,609	10.10	3.07	1.15
	Preeclampsia
	No	526,702	5.29	1.21	0.70
	Yes	6,165	11.32	3.57	0.49
	Diabetes
	No	526,995	5.29	1.21	0.69
	Gestational diabetes	4,079	11.67	2.45	1.23
	Pregestational diabetes	1,784	11.97	5.04	1.68
Offspring in second pregnancy	Birth weight (grams)
	<2,500	2,809	16.99	3.20	1.78
	2,500–2,999	32,346	6.47	1.79	0.74
	3,000–3,999	364,216	4.42	1.01	0.57
	4,000–4,499	105,070	5.91	1.24	0.82
	≥4,500	27,232	10.63	2.57	1.40
	Data missing	1,185	91.20	18.56	10.13
	Gestational age (weeks)
	37–38	96,571	6.09	1.30	0.27
	39–40	304,114	4.45	1.10	0.57
	41	99,113	6.44	1.35	1.22
	≥42	33,060	8.40	1.94	1.54
	Birth weight for gestational age (percentile)
	<3	3,611	16.10	3.05	2.49
	3 to <10	15,247	7.51	1.77	1.44
	10 to 90	430,198	4.64	1.05	0.61
	90 to 97	57,952	6.05	1.48	0.69
	≥97	24,514	10.42	2.37	1.02
	Data missing	1,336	83.50	17.22	8.98

Rates for low Apgar score are based on offspring with data on Apgar score at 1 and 5 min, n = 526,435.