Temporal
trends of preterm birth subtypes and neonatal outcomes - Obstetrics and
Gynecology , vol 107, no 5, May 2006, pp 1035-1041 Barros FC; del Pilar Velez
M - (2006) OBJECTIVE: To describe
temporal trends of preterm birth subtypes, neonatal morbidity, and hospital
neonatal mortality. METHODS: A database of 1.7 million births that occurred in
51 maternity hospitals in Latin America from
1985 to 2003 was studied. Subgroups of preterm births were classified according
to the presence or absence of maternal medical or obstetric complications,
spontaneous labor, preterm labor after premature rupture of membranes,
induction of labor, or elective cesarean. Outcomes studied, for different
periods, were prevalence of small for gestational age, neonatal morbidity, and
neonatal mortality. RESULTS: Spontaneous preterm labor without maternal
complications was the most frequent subtype of preterm birth (60%), followed by
premature rupture of membranes without maternal complications. Preterm births
due to elective induction and delivery by elective cesarean increased markedly
in the last 20 years, from 10% in 1985-1990 to 18.5% in recent years. Neonates
born after spontaneous labor without maternal complications had the lowest
mortality rate, but their large numbers made them responsible for one half of
the preterm mortality. The induction followed by elective cesarean subgroups
accounted for 13.4% of the preterm deaths between 1985 and 1990 and increased
to 21.2% between 1996 and 2003. CONCLUSION: Spontaneous labor in mothers
without maternal complications is the most frequent cause of preterm births and
is also the most important subgroup related to neonatal mortality. However,
preterm births due to induction of labor or elective cesarean are increasing in
Latin America and are becoming important
contributors to neonatal mortality. (22 references) (Author)
