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wait full term
Babies born before, after
9 months face higher risk
By Nathan Seppa
Babies delivered by cesarean section a
week or two before the full 39 weeks of
pregnancy face a heightened risk of respiratory problems and other complications,
researchers report in the Jan. 8 New
England Journal of Medicine. Being born
too late isn’t good either, the study finds.
Obstetric gynecologist Alan Tita of the
University of Alabama at Birmingham
and his colleagues identified more than
13,000 births in which a woman had delivered by nonemergency cesarean section at
37 weeks or later. All mothers had had a
previous C-section at some point.
The researchers found that 15 percent of babies delivered at 37 weeks had
a complication, compared with 8 percent
of those delivered at 39 weeks. Complications included respiratory problems,
low blood sugar and blood infection,
or the need to go to the intensive care
unit, get resuscitated, put on a ventilator or stay in the hospital more than five
days. Of babies born at 38 weeks, 11 percent had complications. Those born at
40 weeks were not more likely to have
problems, but babies born after 41 or
42 weeks faced risks similar to those
born at 38 and 37 weeks.
A closer look at these women reveals
that those delivering earlier were more
likely to be married, white and privately
insured than those delivering at 39 weeks
or later, says Michael Greene of Harvard
Medical School and Massachusetts General Hospital in Boston. The early deliverers may have placed a premium on
having their own doctors perform the
cesarean, requiring planning and scheduling, he says.
The risks of such early deliveries are
now clearer, Tita says. “This study brings
some of these problems to the fore. Hopefully, with this publication, some of these
practices will change,” he says.
But there remains at least one major
confounding factor in all this: The risk of
stillbirth is greatest at 39 weeks or more.
It remains unknown whether avoiding
the slight risk of stillbirth outweighs the
other risks shown in this study, Greene
says. “This is interesting and useful
information, but the stillbirth risk is not
accounted for,” he concludes.