Table 3

Adjusted odds ratios and corresponding 95% confidence intervals* for NICU admissions
1997-2000 2001-2003 2004-2006 2007-2010
All births 1 (Ref) 1.06 (0.94, 1.19) 0.81 (0.71, 0.92) 0.84 (0.75, 0.95)
PTB
Separated by type
  Medically indicated PTB 37 wk 1 (Ref) 1.12 (0.67, 1.87) 0.47 (0.30, 0.72) 0.44 (0.29, 0.68)
  Spontaneous PTB 37 wk 1 (Ref) 0.80 (0.49, 1.29) 0.64 (0.39, 1.05) 1.05 (0.66, 1.65)
Separated by gestational week
  PTB 34–36 wk 1 (Ref) 1.02 (0.70, 1.47) 0.67 (0.47, 0.96) 0.77 (0.54, 1.09)
  PTB 28–33 wk 1 (Ref) 0.57 (0.12, 2.67) 0.07 (0.02, 0.26) 0.14 (0.04, 0.50)
  PTB 22–27 wk 1 (Ref) 0.77 (0.09, 6.56) 1.57 (0.21, 11.48) 5.22 (0.38, 71.55)
LBW 1 (Ref) 1.24 (0.98, 1.56) 0.84 (0.67, 1.05) 0.97 (0.78, 1.20)

*Adjusted for maternal age, parity, maternal body mass index, maternal smoking, maternal occupation, maternal alcohol, and paternal smoking.

LBW, low birth weight; PTB, preterm birth.

Yorifuji et al.

Yorifuji et al. BMC Pregnancy and Childbirth 2012 12:162   doi:10.1186/1471-2393-12-162

Open Data