Survival Rate of Extremely Low Birth Weight Infants and Its Risk Factors: Case-Control Study in Japan
Table 2
Comparison of clinical characteristics in the death and survival groups.
Putative risk factors
Death ()
Survival (n = 1,347)
Clinical chorioamnionitis
47 (12.8%)
217 (16.1%)
Premature rupture of the membranes
78 (21.3%)*
412 (30.6%)
Placenta previa
10 (2.7%)
40 (3%)
Fetal growth restriction
122 (33.3%)
448 (33.3%)
Oligohydramnios
43 (11.7%)
186 (13.8%)
Placental abruption
37 (10.1%)†
58 (4.3%)
Antenatal steroid
26 (7.1%)†
333 (24.7%)
Nonvertex presentation
176 (48.1%)†
465 (34.5%)
Nonreassuring fetal status
113 (30.9%)*
550 (40.8%)
Gestational week at delivery
Vaginal delivery
234 (63.9%)
403 (29.9%)
Male
169 (46.2%)
684 (50.8%)
Birth weight (gram)
Apgar score at 5 minutes
Data are presented as number (%) or mean ± SD. *Significant decrease according to chi-square test. †Significant increase according to chi-square test. ‡Significant decrease according to Wilcoxon signed-rank test.
