Perinatal and psychosocial circumstances associated with risk of attempted suicide, non-suicidal self-injury and psychiatric service use. A longitudinal study of young people

Table 1 Descriptive statistics for perinatal covariates

Perinatal covariates ^{all @11p}	N	(%)
Maternal parity
0 first born	989	45.9
*1 second born	784	36.3
*2+ third or later	384	17.8
Family size (total at age 11) +Twins
2	247	11.5
*3	1001	46.4
*4+	909	42.1
Birth size [MV = 20]
Small	293	13.7
Average	1458	68.2
Large	386	18.1
Birth weight (g) [MV = 96]
<2500	133	6.5
2500-3249	719	34.9
3250-3749	801	38.9
3750+	408	19.8
Birth complications [MV = 15]
0	1499	70.0
1	360	16.8
*2	189	8.8
*3 or more	94	4.4
Birth spacing - Prior birth
Under 2 years	346	16.0
2-5 years	502	23.3
6+ years or singleton	1309	60.7
Birth spacing - Next birth
Under 2 years	429	19.9
2-5 years	510	23.6
6+ years or singleton	1218	56.5
Maternal age (years) [MV = 79]
15-19	139	6.7
20-24	626	30.1
25-29	764	36.8
30-34	421	20.3
35-46	128	6.2
Breastfeeding [MV = 12]
None	1333	62.1
Less than 6 months	463	21.6
6 months or more	349	16.3

Baseline N = 2157, final sample excludes adopted children i.e. only natural mother.
MV = missing values; * Adjacent category collapsed for analysis; +Twins = includes 16 twin births.
^@11p = parental figure provided information when participants age 11.

ISSN: 1471-2458