Table 2

Apgar scores, cord blood pHs (artery and vein), and percentages of NICU admission
1997-2000 2001-2003 2004-2006 2007-2010 p value*
All births
  Apgar score 1, mean (SD) 7.8 (1.4) 7.9 (1.3) 8 (1.2) 8 (1.2) <0.01
  Apgar score 5, mean (SD) 8.6 (0.9) 8.7 (0.9) 8.8 (0.8) 8.8 (0.7) <0.01
  Umbilical artery pH, mean (SD) 7.30 (0.07) 7.31 (0.07) 7.30 (0.07) 7.30 (0.07) <0.01
  Umbilical vein pH, mean (SD) 7.33 (0.07) 7.34 (0.08) 7.35 (0.07) 7.34 (0.07) <0.01
  NICU admission (%) 809 (15.2) 602 (15.8) 522 (13) 745 (12.9) <0.01
PTB
Separated by type
Medically indicated PTB, 37 wk
  Apgar score 1, mean (SD) 5.3 (2.8) 5.8 (2.7) 6.5 (2.4) 6.5 (2.4) <0.01
  Apgar score 5, mean (SD) 7.6 (1.8) 7.5 (2.1) 8.3 (1.7) 8.2 (1.6) <0.01
  Umbilical artery pH, mean (SD) 7.29 (0.11) 7.30 (0.09) 7.30 (0.10) 7.29 (0.09) 0.40
  Umbilical vein pH, mean (SD) 7.32 (0.10) 7.32 (0.09) 7.33 (0.1) 7.32 (0.10) 0.41
  NICU admission (%) 256 (84.5) 214 (85.3) 244 (72.8) 287 (72.1) <0.01
Spontaneous PTB, 37 wk
  Apgar score 1, mean (SD) 7.1 (1.9) 7.3 (2) 7.3 (1.8) 7.3 (2.1) 0.74
  Apgar score 5, mean (SD) 8.1 (1.5) 8.4 (1.2) 8.6 (1.1) 8.5 (1.4) <0.01
  Umbilical artery pH, mean (SD) 7.31 (0.08) 7.33 (0.08) 7.3 (0.10) 7.32 (0.08) 0.03
  Umbilical vein pH, mean (SD) 7.34 (0.09) 7.35 (0.09) 7.35 (0.13) 7.35 (0.10) 0.89
  NICU admission (%) 112 (62.6) 89 (59.7) 77 (54.6) 141 (66.5) 0.15
Separated by gestational week
PTB 34–36 wk
  Apgar score 1, mean (SD) 7.1 (1.9) 7.3 (1.9) 7.6 (1.6) 7.5 (1.7) <0.01
  Apgar score 5, mean (SD) 8.3 (1.2) 8.5 (1.1) 8.7 (1.1) 8.7 (1) <0.01
  Umbilical artery pH, mean (SD) 7.3 (0.1) 7.31 (0.08) 7.3 (0.08) 7.3 (0.07) 0.28
  Umbilical vein pH, mean (SD) 7.33 (0.09) 7.34 (0.09) 7.34 (0.1) 7.34 (0.08) 0.58
  NICU admission (%) 191 (63.2) 161 (63.6) 146 (53.7) 212 (57.8) 0.05
PTB 28–33 wk
  Apgar score 1, mean (SD) 4.6 (2.8) 5.4 (2.6) 6.6 (2) 6.3 (2.5) <0.01
  Apgar score 5, mean (SD) 7.4 (1.6) 7.4 (1.9) 8.5 (1.4) 8.2 (1.5) <0.01
  Umbilical artery pH, mean (SD) 7.31 (0.09) 7.32 (0.09) 7.31 (0.1) 7.3 (0.11) 0.52
  Umbilical vein pH, mean (SD) 7.33 (0.1) 7.33 (0.09) 7.34 (0.1) 7.33 (0.12) 0.95
  NICU admission (%) 142 (97.3) 117 (95.9) 112 (80) 157 (86.7) <0.01
PTB 22–27 wk
  Apgar score 1, mean (SD) 2.7 (1.9) 2.6 (2.1) 3.8 (2.3) 3.7 (2.5) <0.01
  Apgar score 5, mean (SD) 5.1 (2.4) 4.6 (2.5) 7.2 (2.6) 6.8 (2.4) <0.01
  Umbilical artery pH, mean (SD) 7.28 (0.12) 7.32 (0.07) 7.28 (0.14) 7.28 (0.12) 0.59
  Umbilical vein pH, mean (SD) 7.28 (0.11) 7.31 (0.08) 7.31 (0.15) 7.29 (0.14) 0.78
  NICU admission (%) 38 (90.5) 28 (90.3) 68 (94.4) 63 (95.5) 0.65
LBW
  Apgar score 1, mean (SD) 6.7 (2.4) 6.9 (2.3) 7.1 (2.1) 7.2 (2.1) <0.01
  Apgar score 5, mean (SD) 8.2 (1.5) 8.2 (1.6) 8.6 (1.4) 8.5 (1.3) <0.01
  Umbilical artery pH, mean (SD) 7.30 (0.09) 7.31 (0.08) 7.30 (0.09) 7.30 (0.08) <0.01
  Umbilical vein pH, mean (SD) 7.33 (0.09) 7.33 (0.09) 7.34 (0.10) 7.33 (0.09) 0.40
  NICU admission (%) 447 (59.4) 380 (64.3) 385 (55.7) 525 (57.8) 0.02

LBW low birth weight; NICU neonatal intensive care unit; PTB preterm birth; SD standard deviation.

*Obtained by the chi-square test or analysis of variance.

Yorifuji et al.

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

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