Table 3 Multivariable logistic regression analysis of obstetric outcomes and age for main confounding factors (obesity, use of ART, smoking, chronic hypertension, previous c-section and parity)

< 30

- Ref group -

1

1

1

1

1

1

1

30–34

1.47 (1.21–1.80)

0.91 (0.62–1.34)

1.01 (0.65–1.56)

1.52 (0.86–2.67)

1.20 (1.06–1.33)

1.29 (1.09–1.53)

1.01 (0.95–1.24)

35–39

2.07 (1.70–2.52)

1.03 (0.71–1.51)

1.06 (0.68–1.64)

1.58 (0.90–2.77)

1.49 (1.33–1.66)

1.82 (1.54–2.15)

1.15 (1.01–1.31)

40–44

3.18 (2.56–3.95)

1.12 (0.71–1.77)

1.18 (0.70–1.99)

2.54 (1.40–4.63)

2.46 (2.15–2.82)

3.17 (2.63–3.82)

1.38 (1.18–1.61)

≥45

3.25 (2.21–4.78)

1.75 (0.83–3.68)

1.28 (0.50–3.30)

3.80 (1.70–8.50)

7.80 (5.79–10.50)

8.09 (5.99–10.92)

2.03 (1.50–2.74)