Table 5 Multivariable analysis between maternal characteristics, educational variables and gestational age (week) (N = 763) ^†

Baseline age

0.19(0.10)

0.17(0.10)

0.03(0.10)

0.01(0.10)

Age at pregnancy

−0.13(0.12)

−0.11(0.12)

−0.11(0.10)

−0.09(0.10)

Baseline BMI category

Underweight

0.46(0.42)

0.36(0.41)

−0.05(0.29)

−0.08(0.30)

Normal weight

ref

ref

ref

ref

Over weight

0.06(0.44)

−0.01(0.46)

−0.01(0.44)

−0.12(0.47)

Obese

−1.46(2.09)

−1.57(2.13)

0.64(0.36)

0.62(0.37)

Parental education

≥HS

ref

ref

ref

ref

Less than HS

0.60(0.40)^§

0.64(0.45)^§

−0.43(0.28)^§

−0.40(0.28)^§

GPA

Below average

−0.33(0.48)

−0.31(0.46)

0.31(0.29)

0.35(0.30)

Above average

ref

ref

ref

ref

Ever skipped a grade

No

ref

ref

ref

ref

Yes

−0.28(0.87)

−0.18(0.88)

0.97(0.43)^*

1.11(0.43)^*

Ever repeated a grade

No

ref

ref

ref

ref

Yes

0.11(0.32)

0.01(0.34)

−0.31(0.34)

−0.33(0.35)

Educational aspiration

−0.09(0.22)

−0.08(0.22)

0.14(0.15)

0.14(0.15)

Smoking during pregnancy

No

ref

ref

Yes

1.14(0.53)*

0.18(0.23)

Initiation of prenatal care

1^st trimester

ref

ref

2^nd trimester

0.41(0.36)

0.57(0.25)

3^rd trimester or no prenatal care

−0.07(0.66)

0.30(0.43)