Table 2 Risk factors for unplanned pregnancy among Japanese mothers

  + 1 year

0.95 (0.93–0.97)

<  0.001

0.94 (0.92–0.97)

<  0.001

  + 1 year

0.96 (0.94–0.98)

<  0.001

–

–

 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

 1–2

Ref

–

Ref

–

  ≥ 3

1.71 (1.29–2.25)

<  0.001

2.26 (1.66–3.08)

<  0.001

 Employed

Ref

–

–

–

 Unemployed

1.08 (0.82–1.43)

0.58

 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

 Never drank

Ref

–

–

–

 Ex-drinker

0.82 (0.62–1.07)

0.14

 Current drinker

1.14 (0.6–2.17)

0.68

 No

Ref

–

Ref

–

 Yes

0.55 (0.42–0.72)

<  0.001

0.62 (0.47–0.83)

<  0.001

 No

Ref

–

Ref

–

 Yes

1.74 (1.34–2.26)

<  0.001

1.63 (1.24–2.16)

<  0.001