Table 1 Factors associated with early teenage pregnancy: % or mean scores and unadjusted ORs (unweighted n = 809, weighted n = 764).

	Pregnant	Never pregnant	Unadjusted logistic regression
	%	%	OR (95% CI)	p Value
Live with both parents
Yes	43.2	58.2	1
No	56.8	41.8	1.83 (1.17 to 2.87)	0.008
Housing type
Privately owned	42.3	59.6	1
Council or rented accommodation	57.5	40.4	2 (1.25 to 3.22)	0.004
Parental monitoring
High	52.3	64.4	1
Low	47.7	35.6	1.66 (1.06 to 2.61)	0.027
Smoked cigarettes
Never tried	10.5	18.3	1
Tried	34.9	39	1.48 (0.69 to 3.18)	0.314
Use occasionally	8.1	15.4	0.95 (0.35 to 2.57)	0.918
Use regularly	46.5	27.3	2.85 (1.35 to 6.01)	0.006
Proportion of friends who smoke (cohort 2 only)
None/few	35	55.3	1
Half or more	65	44.7	2.27 (1.15 to 4.50)	0.018
Friends at other schools
None/a few	69.4	79.6	1
Half or more	30.6	20.4	1.69 (1.03 to 2.79)	0.039
Attitude to school (scale: positive–negative)*	3 (0.97)	2.6 (0.89)	1.5 (1.19–1.89)	0.001
Not likely to have a child in near future (scale: very likely–very unlikely)*	3.4 (1.18)	3.7 (1.13)	0.78 (0.65 to 0.94)	0.01
Using a condom properly would be
Difficult	27.6	39.5	1
Easy	72.4	60.5	1.72 (1.05 to 2.84)	0.032
Used contraception at first intercourse†
No	47.1	25.1	1
Yes	52.9	74.9	0.38 (0.24 to 0.59)	<0.001
Talked to partner about protection before first intercourse†
Yes	39	52	1
No	61	48	1.67 (1.03 to 2.72)	0.037
Age at first sex*†‡	13.5 (1.09)	14.5 (1.08)	0.49 (0.4 to 0.6)	<0.001
Partner's age at first sex*†‡	15 (1.68)	16 (1.66)	0.68 (0.59 to 0.79)	<0.001

Pregnant group (unweighted n = 76 and weighted n = 87); never‐pregnant group (unweighted n = 733 and weighted n = 677). Weighting was used to deal with the issue of attrition; original numbers and weighted percentages and p values are presented in the table.

*Mean scores (SD).

†Time two variable.

‡Age range at first sex—pregnant group 11–16 years, never pregnant group 8–16 years; partner's age range at first sex—pregnant group 10–20 years, never pregnant group 10–21 years.