Table 3 Bivariate analysis between maternal characteristics, education variables and gestational age (week) (N = 763)*

0.18(0.10)

0.08

0.01(0.08)

0.87

0.20

−0.05(0.10)

0.60

−0.07(0.09)

0.43

0.86

0.68

0.47

0.94

Underweight

0.31(0.36)

−0.09(0.27)

Normal weight

ref

ref

Over weight

0.18(0.43)

−0.03(0.46)

Obese

−1.60(2.10)

0.54(0.37)

Parental education

0.16

0.27

0.08

≥HS

ref

ref

Less than HS

0.54(0.38)

−0.35(0.32)

Educational aspiration standardized

−0.07(0.19)

0.71

0.09(0.11)

0.39

0.44

GPA

0.54

0.62

0.42

Below average

−0.25(0.41)

0.14(0.28)

Above average

ref

ref

Ever skipped a grade

0.95

<0.01

0.29

No

ref

ref

Yes

−0.06(0.88)

0.95(0.32)

Ever repeated a grade

0.29

0.38

0.18

No

ref

ref

Yes

0.36(0.33)

−0.28(0.32)

Smoking during pregnancy

0.01

0.53

0.08

No

ref

ref

Yes

0.92(0.36)

0.14(0.21)

Initiation of prenatal care

0.16

0.10

0.95

1^st trimester

ref

ref

2^nd trimester

0.66(0.38)

0.55(0.25)

3^rd trimester or no prenatal care

−0.01(0.61)

0.28(0.46)