Table 3 Pooled and site-wise univariate analysis for adverse birth outcomes according to Hba1c levels

Pregnancy ended in stillbirth (Gestational Age > 22 Weeks)

N = 124

N = 91

N = 124

N = 339

 HbA1c < 5.7

Ref

Ref

Ref

Ref

 HbA1c 5.7–6.4

1.6 (1.0–2.2)

1.5(0.6–3.6)

0.8(0.5–1.5)

1.2(0.9–1.7)

 HbA1c ≥ 6.5

3.7 (1.6–13.4)

6.5(2.9–14.6)

6.5(3.4–12.5)

5.7(3.6–9.1)

Preterm birth

(< 37 weeks of Gestation)

N = 331

N = 351

N = 210

N = 892

 HbA1c < 5.7

Ref

Ref

Ref

Ref

 HbA1c 5.7–6.4

1.1 (0.8–1.5)

1.4 (0.9–2.1)

1.1 (0.8–1.6)

1.0 (0.8–1.2)

 HbA1c ≥ 6.5

3.6 (1.8–7.1)

2.1 (1.0–4.4)

3.4 (1.6–7.1)

2.6 (1.7–4.1)

Large for gestational age

(> 10th centile)

N = 30

N = 32

N = 470

N = 532

 HbA1c < 5.7

Ref

Ref

Ref

Ref

 HbA1c 5.7–6.4

0.7 (0.2–2.8)

1.8 (0.4–7.5)

1.3 (1.0–1.6)

1.6 (1.3–2.0)

 HbA1c ≥ 6.5

23.1 (8.2–65.6)

16.1 (5.6–46.5)

3.7 (2.5–5.5)

6.0 (4.2–8.6)

Caesarean section delivery

N = 385

N = 375

N = 132

N = 892

 HbA1c < 5.7

Ref

Ref

Ref

Ref

 HbA1c 5.7–6.4

1.0 (0.8–1.4)

1.5 (1.0–2.2)

1.4 (0.9–2.2)

1.0 (0.8–1.2)

 HbA1c ≥ 6.5

1.8 (0.7–5.0)

3.2 (1.9–5.3)

1.9 (0.5–7.4)

2.1 (1.3–5.3)