Table 1

Maternal and infant characteristics and adverse outcomes in the first pregnancy of 42 962 women who had a caesarean and 251 636 women who had a vaginal delivery (VD) during 1996–2015

CDVD
Age, mean (SD)27.8 (4.7)26.5 (4.5)
Smoking, N (%)
 Information about smoking in the MBRN29 229 (68.0)170 040 (67.6)
 Smoked during pregnancy4571 (15.6)*27 273 (16.0)*
Pre-eclampsia N (%)5348 (12.4)9346 (3.7)
Diabetes, N (%)1366 (3.2)2977 (1.2)
Placenta previa N (%)474 (1.1)52 (0.02)
Placenta abruption N (%)865 (2.0)258 (0.1)
Uterine rupture N (%)5 (0.01)5 (0.002)
Start of delivery, N (%)
 Spontaneous18 568 (43.2)215 243 (85.5)
 Induced10 626 (24.7)36 393 (14.5)
 Caesarean delivery (CD)13 768 (33.0)0
Gestational age at birth in weeks, mean (SD)39.0 (2.9)39.6 (1.9)
Birth weight in grams, mean (SD)3401 (810)3477 (524)
Sex, N (%)
 Female19 597 (46.0)123 230 (49.0)
SGA†, N (%)1995 (5.0)4823 (2.0)
Congenital anomalies, N (%)3004 (7.0)10 386 (4.1)
Total stillbirth, N (%)110 (0.3)1408 (0.6)
Antepartum stillbirth, N (%)55 (0.1)1039 (0.4)
Intrapartum stillbirth, N (%)28 (0.1)102 (0.04)
Perinatal mortality, N (%)301 (0.7)1714 (0.7)
Early neonatal mortality, N (%)191 (0.4)306 (0.1)
Neonatal mortality, N (%)262 (0.6)399 (0.2)
Cerebral palsy, N (%)189 (0.4)350 (0.1)
Apgar score after five min‡, N (%)
 0–3406 (0.9)1662 (0.7)
 4–62314 (5.4)5972 (2.3)
 7–1040 142 (93.7)243 221 (97.0)
Transferred NICU, N (%)
 Yes8965 (26.0)18 971 (10.0)
  • *Percentage of mothers with information on smoking (available in the MBRN since 1999).

  • †971 (2.3%) deliveries with missing information about SGA in the CD group and 5280 (2.1%) in the VD group.

  • ‡100 (0.2%) deliveries with missing information about Apgar score in the CD group and 781 (0.3%) in the VD group.

  • MBRN, Medical Birth Registry of Norway; NICU, neonatal intensive care unit; SGA, small for gestational age.