Table 4 Model results (odds ratios) for neonatal outcomes by category of pre-pregnancy body mass index and gestational weight gain (GWG)

Gestational weight gain

<  5 kg

5–9 kg

>  9 kg

<  5 kg

5–9 kg

>  9 kg

<  5 kg

5–9 kg

>  9 kg

Extremely low birth weight

4.4 (4.2, 4.6) ^a

2.4 (2.2, 2.5) ^a

2.5 (2.4, 2.6) ^a

4.3 (4.1, 4.6) ^a

2.6 (2.4, 2.8) ^a

3.2 (3.1, 3.4) ^a

4.5 (4.2, 4.7) ^a

2.8 (2.6, 3.1) ^a

4.0 (3.8, 4.3) ^a

Very low birth weight

3.2 (3.1, 3.3) ^a

2.0 (1.9, 2.1) ^a

2.1 (2, 2.1) ^a

3.1 (2.9, 3.2) ^a

2.1 (2.0, 2.2) ^a

2.6 (2.5, 2.7) ^a

3.2 (3.1, 3.4) ^a

2.3 (2.2, 2.5) ^a

3.2 (3.1, 3.3) ^a

Low birth weight

1.6 (1.5, 1.6) ^a

1.2 (1.2, 1.3) ^a

1.0 (1.0, 1.1) ^a

1.4 (1.4, 1.4) ^a

1.1 (1.1, 1.2) ^a

1.1 (1.1, 1.2) ^a

1.3 (1.3, 1.4) ^a

1.2 (1.2, 1.2) ^a

1.3 (1.3, 1.3) ^a

Macrosomia

1.1 (1.1, 1.1) ^a

1.5 (1.5, 1.5) ^a

2.6 (2.5, 2.6) ^a

1.5 (1.5, 1.5) ^a

2.0 (2.0, 2.0) ^a

3.1 (3.1, 3.1) ^a

1.9 (1.9, 2.0) ^a

2.6 (2.5, 2.6) ^a

3.6 (3.6, 3.6) ^a

Very pre-term birth

3.0 (2.9, 3.1) ^a

1.9 (1.8, 2.0) ^a

2.0 (1.9, 2.0) ^a

2.9 (2.8, 3.0) ^a

2.0 (1.9, 2.1) ^a

2.4 (2.3, 2.5) ^a

3.0 (2.9, 3.1) ^a

2.2 (2.0, 2.3) ^a

3.0 (2.9, 3.1) ^a

Pre-term birth

1.6 (1.6, 1.7) ^a

1.5 (1.5, 1.5) ^a

1.5 (1.4, 1.5) ^a

1.6 (1.6, 1.6) ^a

1.6 (1.5, 1.6) ^a

1.7 (1.7, 1.7) ^a

1.7 (1.7, 1.8) ^a

1.7 (1.7, 1.8) ^a

2.0 (2.0, 2.1) ^a

Low APGAR score

2.2 (2.1, 2.3) ^a

1.6 (1.5, 1.7) ^a

1.7 (1.6, 1.8) ^a

2.3 (2.2, 2.5) ^a

1.6 (1.5, 1.8) ^a

2.1 (2.0, 2.2) ^a

2.5 (2.4, 2.7) ^a

2.2 (2.0, 2.4) ^a

2.8 (2.7, 3.0) ^a

Admission to neonatal ICU

1.4 (1.4, 1.5) ^a

1.3 (1.3, 1.4) ^a

1.5 (1.5, 1.5) ^a

1.4 (1.4, 1.5) ^a

1.4 (1.4, 1.5) ^a

1.7 (1.7, 1.7) ^a

1.6 (1.6, 1.7) ^a

1.7 (1.7, 1.8) ^a

2.1 (2.1, 2.2) ^a

Ventilated for > 6 min

1.8 (1.7, 1.9) ^a

1.4 (1.3, 1.5) ^a

1.7 (1.6, 1.7) ^a

1.9 (1.8, 2.0) ^a

1.7 (1.6, 1.8) ^a

2.0 (1.9, 2.1) ^a

2.2 (2.1, 2.3) ^a

2.2 (2.1, 2.3) ^a

2.7 (2.6, 2.8) ^a

Neonatal mortality

2.5 (2.3, 2.7) ^a

1.6 (1.5, 1.7) ^a

1.6 (1.5, 1.6) ^a

2.4 (2.2, 2.6) ^a

1.6 (1.4, 1.7) ^a

1.8 (1.7, 1.9) ^a

2.5 (2.3, 2.7) ^a

1.9 (1.7, 2.1) ^a

2.2 (2, 2.3) ^a