Table 2.

Risk factors for unplanned pregnancy among Japanese mothers

	Crude analysis OR (95% CI)	p-value	Multivariable analysis OR (95% CI)	p-value
Maternal age
+ 1 year	0.95 (0.93–0.97)	<  0.001	0.94 (0.92–0.97)	<  0.001
Paternal age
+ 1 year	0.96 (0.94–0.98)	<  0.001	–	–
Family structure
Nuclear family	Ref	–	Ref	–
Extended family	1.11 (0.84–1.48)	0.46	1.01 (0.75–1.37)	0.93
Other	3.47 (1.48–8.10)	0.004	2.76 (1.12–6.76)	0.027
Number of pregnancies
1–2	Ref	–	Ref	–
≥ 3	1.71 (1.29–2.25)	<  0.001	2.26 (1.66–3.08)	<  0.001
Employment status
Employed	Ref	–	–	–
Unemployed	1.08 (0.82–1.43)	0.58
Smoking status
Never smoked	Ref	–	Ref	–
Ex-smoker	1.13 (0.84–1.53)	0.41	1.06 (0.77–1.45)	0.72
Current smoker	3.81 (1.91–7.61)	<  0.001	2.60 (1.26–5.35)	0.01
Drinking status
Never drank	Ref	–	–	–
Ex-drinker	0.82 (0.62–1.07)	0.14
Current drinker	1.14 (0.6–2.17)	0.68
Balanced diet
No	Ref	–	Ref	–
Yes	0.55 (0.42–0.72)	<  0.001	0.62 (0.47–0.83)	<  0.001
Currently depressed
No	Ref	–	Ref	–
Yes	1.74 (1.34–2.26)	<  0.001	1.63 (1.24–2.16)	<  0.001

Multivariable model fitted using stepwise regression. OR odds ratio; CI confidence interval; Ref reference