Differences in mortality between late-preterm and term singleton infants in the United States, 1995-2002.
OBJECTIVE
To assess differences in mortality between late-preterm (34-36 weeks) and term (37-41 weeks) infants.


METHODS
We used US period-linked birth/infant death files for 1995 to 2002 to compare overall and cause-specific early-neonatal, late-neonatal, postneonatal, and infant mortality rates between singleton late-preterm infants and term infants.


RESULTS
Significant declines in mortality rates were observed for late-preterm and term infants at all age-at-death categories, except the late-neonatal period. Despite the decline in rates since 1995, infant mortality rates in 2002 were 3 times higher in late-preterm infants than term infants (7.9 versus 2.4 deaths per 1000 live births); early, late, and postneonatal rates were 6, 3, and 2 times higher, respectively. During infancy, late-preterm infants were approximately 4 times more likely than term infants to die of congenital malformations (leading cause), newborn bacterial sepsis, and complications of placenta, cord, and membranes. Early-neonatal cause-specific mortality rates were most disparate, especially deaths caused by atelectasis, maternal complications of pregnancy, and congenital malformations.


CONCLUSIONS
Late-preterm infants have higher mortality rates than term infants throughout infancy. Our findings may be used to guide obstetrical and pediatric decision-making.
Tomashek
Kay M
KM
Maternal and Infant Health Branch, Division of Reproductive Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. kct9@cdc.gov
Shapiro-Mendoza
Carrie K
CK
Davidoff
Michael J
MJ
Petrini
Joann R
JR
D001238:Asphyxia Neonatorum / Q000401:mortality; D001719:Birth Certificates; D002423:Cause of Death / Q000639:trends; D000013:Congenital Abnormalities / Q000401:mortality; D003644:Death Certificates; D020345:Enterocolitis, Necrotizing / Q000401:mortality; D005260:Female; D005865:Gestational Age; D006801:Humans; D015160:Hydrops Fetalis / Q000401:mortality; D000860:Hypoxia / Q000401:mortality; D007223:Infant; D007226:Infant Mortality / Q000639:trends*; D007231:Infant, Newborn; D007234:Infant, Premature; D007251:Influenza, Human / Q000401:mortality; D011014:Pneumonia / Q000401:mortality; D011247:Pregnancy; D011248:Pregnancy Complications / Q000401:mortality; D001261:Pulmonary Atelectasis / Q000401:mortality; D012127:Respiratory Distress Syndrome, Newborn / Q000401:mortality; D018805:Sepsis / Q000401:mortality; D013398:Sudden Infant Death / Q000453:epidemiology; D013997:Time Factors; D014481:United States / Q000453:epidemiology