Table 4 Pooled and site-wise adjusted 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

 HbA1c 5.7–6.4

-

1.5 (0.6–3.9)

0.5 (0.2–1.2)

1.2 (0.9–1.7)

 HbA1c ≥ 6.5

-

10.1 (3.6–28.4)

8.3 (2.8–24.3)

6.3 (3.4–11.6)

Preterm birth

(< 37 weeks of Gestation)

N = 331

N = 351

N = 210

N = 892

 HbA1c < 5.7

Ref

-

-

Ref

 HbA1c 5.7–6.4

1.2 (0.8–1.9)

-

-

1.2 (0.9–1.6)

 HbA1c ≥ 6.5

6.8 (1.8–25.9)

-

-

3.5 (1.8–6.7)

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

0.5 (0.1–2.4)

1.4 (0.3–6.1)

1.1 (0.8–1.4)

1.2 (0.9–1.6)

 HbA1c ≥ 6.5

34.8 (8.8–139.6)

12.0 (2.8–52.0)

4.1 (1.9–8.4)

5.5 (2.9–10.6)

Caesarean section delivery

N = 385

N = 375

N = 132

N = 892

 HbA1c < 5.7

-

Ref

-

-

 HbA1c 5.7–6.4

-

1.3 (0.7–2.2)

-

-

 HbA1c ≥ 6.5

-

5.7 (1.8–18.3)

-

-