Table 1—

Obstetric complications and fetal characteristics for type 1 diabetic pregnancies and the background population

Type 1 diabetic pregnancyBackground populationRR (95% CI) or P
n1,21570,089
Pre-eclampsia*220 (18.1%)*<0.001
Caesarean section680 (55.9%)8,831 (12.6%)4.4 (4.1–4.8)
Preterm delivery507 (41.7%)4,205 (6.0%)7.0 (6.3–7.6)
Gestational age at delivery (days)256 ± 16280<0.0001
Birth weight (g)3,487 ± 8173,4780.71
Birth weight ≥4,500 g97 (8.0%)2,383 (3.4%)2.3 (1.9–2.9)
Large for gestational age infant761 (62.5%)<0.001
Stillbirth26 (2.1%)318 (0.45%)4.7 (3.2–7.0)
Perinatal mortality38 (3.1%)525 (0.75%)4.1 (2.9–5.6)
Congenital malformations61 (5.0%)1,987 (2.8%)1.7 (1.3–2.2)
Respiratory distress syndrome§202 (17.1%)ND
Jaundice215 (18.1%)ND
  • Data are means ± SD or n (%).

  • *

    * Blood pressure ≥140/90 mmHg and proteinuria. The frequency in the background population is 2.6% (other data source, see text);

  • before 37 completed weeks of gestation;

  • birth weight ≥90th centile. The expected frequency in the background population is 10%, but exact numbers are not available;

  • §

    § use of continuous positive airway pressure for >1 h postpartum;

  • use of phototherapy. ND, no data.