TABLE 1

Maternal Characteristics

NAS (n = 3803)No NAS (n = 1 003 012)OR (95% CI)P
Mean maternal age, y29.1 (5.8)30.4 (5.6)<.001
Young mother (<20 y at delivery)174 (4.5)37 714 (3.8)1.23 (1.05–1.43).008
Older mother (>35 y at delivery)646 (17.0)214 280 (21.4)0.75 (0.69–0.82)<.001
Indigenous Australian595 (15.6)28 108 (2.8)6.43 (6.00–7.03)<.001
Primiparous1043 (27.4)420 839 (42.0)0.52 (0.49–0.56)<.001
Cigarette smoking2926 (76.9)124 431 (12.4)23.56 (21.84–25.41)<.001
No antenatal care321 (8.4)13 816 (1.4)6.60 (5.88–7.41)<.001
Mean gestation at first antenatal visit, wk16.7 (9.1)11.7 (6.1)<.001
Caesarean delivery844 (22.2)253 217 (25.2)0.85 (0.72–0.91)<.001
Instrumental delivery215 (5.7)97 533 (9.7)0.56 (0.49–0.64)<.001
Private hospital birth12 (0.3)240 991 (24.0)0.01 (0.01–0.02)<.001
Pregnancy complications
 Preeclampsia71 (1.9)29 484 (2.9)0.63 (0.50–0.79)<.001
 Gestational diabetes56 (1.5)48 395 (4.8)0.30 (0.23–0.38)<.001
Maternal discharge status
 Discharged alive3730 (98.1)973 599 (97.1)1.54 (1.22–1.95)<.001
 Transferred70 (1.8)29144 (2.9)0.63 (0.50–0.79)<.001
 Died in hospital12410.99 (1.49–81.27).09
SEIFA Quintile
 First (lowest)503 (13.3)88 763 (8.9)1.57 (1.43–1.73)<.001
 Fifth (highest)852 (22.5)328 695 (33.0)0.59 (0.55–0.64)<.001
  • Data expressed as n (%) or mean (SD) unless otherwise stated. SEIFA, Socioeconomic Indexes for Area; —, analysis not applicable, not conducted, or data not available.