A new study has found a
higher risk of infant deaths among infants born
by Caesarean section to mothers who have no medical
need for the procedure.
While
C-sections have saved the lives of "countless"
women and babies, and the risk of infant death
is still very low, it is crucial to determine
the reasons for the higher infant mortality seen
with C-section, because the rates of this surgery
are becoming increasingly common, Dr. Marian F.
MacDorman of the National Center for Health Statistics
at the Centers for Disease Control in Hyattsville,
Maryland and colleagues conclude.
Rates
of Caesarean have risen steadily in the U.S.,
from 14.6 percent of all first-time births in
1996, to 20.6 percent in 2004, MacDorman's group
notes in the September issue of Birth.
Since the U.S. began gathering
data on C-sections in 1989, MacDorman and her
team note, a greater risk of death has been seen
among infants born via the procedure, but researchers
have generally assumed that this was because these
infants were more likely to die due to other causes.
To
investigate whether the C-section itself might
somehow be a factor in infant deaths, the researchers
looked at data from more than 5.8 million births
to U.S. women between 1998 and 2001. All of the
women were at "no indicated risk" for a C-section,
meaning the infant was a singleton, full-term,
in a head-down position, and no other medical
risk factors or delivery complications were indicated
on the child's birth certificate.
Rising
number of elective C-sections
MacDorman and her colleagues had
previously identified a 49-percent increase in
C-section rates between 1996 and 2001 among women
in this "no risk" category.
he risk of death in the first 28 days of life
was 1.77 per 1,000 live births among women who
had C-sections, compared to 0.62 per 1,000 for
women who delivered vaginally. Even after analyzing
the various causes of infant death, the researchers
could find no clear explanation for the difference.
"Understanding
the causes of these differentials is important,
given the rapid growth in the number of primary
Caesareans without a reported medical indication,"
they conclude.
