Risk factors for neonatal mortality among extremely-low-birth-weight infants.
OBJECTIVE
The purpose of this study was to examine characteristics associated with neonatal mortality among extremely low-birth-weight infants (< or = 1000 g).


METHODS
A population-based, case-control study using linked Missouri birth and death certificates from 1989 to 1997 was conducted. Cases (n = 835) were defined as extremely low-birth-weight infants that died within 28 days of birth. Controls (n = 907) were randomly selected from extremely low-birth-weight infants that were alive at 1 year and were frequency matched to subjects by birth year and birth weight.


RESULTS
Infants born with severe congenital anomalies and at the youngest gestational ages were at greatest risk for neonatal mortality. Other significant risk factors included maternal age (< 18 and > 34 years), vaginal delivery, nontertiary hospital care, malpresentation, male gender, and small for gestational age. Black race and preeclampsia were protective against early death.


CONCLUSIONS
The risk of neonatal mortality among extremely low-birth-weight infants was associated with several maternal, infant, and obstetric factors, some of which may be preventable.
Bacak
Stephen J
SJ
Department of Community Health, Saint Louis University School of Public Health, St. Louis, MO, USA.
Baptiste-Roberts
Kesha
K
Amon
Erol
E
Ireland
Belinda
B
Leet
Terry
T
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D000013:Congenital Abnormalities / Q000401:mortality; D005260:Female; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007746:Labor Presentation; D008297:Male; D008423:Maternal Age; D011225:Pre-Eclampsia; D011247:Pregnancy; D044469:Racial Groups; D012307:Risk Factors; D012737:Sex Factors