In low-risk pregnant women, high
induction and first-cesarean delivery rates do not lead to improved
outcomes for newborns, according to new research published in the April
issue of The Journal of Maternal-Fetal and Neonatal Medicine.
The finding that rates of intervention at delivery – whether high,
low, or in the middle – had no bearing on the health of new babies
brings into question the skyrocketing number of both inductions and
cesarean deliveries in the United States.
“Like virtually all medical therapies and procedures, these
interventions entail some risk for the mother, and there is no evidence
in this study that they benefit the baby,” said Christopher
Glantz, M.D., M.P.H., study author and professor of Maternal
Fetal Medicine at the University
of Rochester Medical Center. “In my mind, if you are
getting the same outcome with high and low rates of intervention, I say
‘Do no harm’ and go with fewer interventions.”
Similar to other fields of medicine, great variation exists in
obstetric practices, particularly in rates of induction of labor and
cesarean delivery. A limited number of studies have examined if and how
these rates are associated with improvement in the health of newborns
and reported mixed results.
“‘More is better’ seems to be the epitome of U.S. healthcare
today, with doctors and patients often choosing to do more rather than
less, even when there is no evidence to support it,” noted Glantz.
“But, as our study suggests, more may not always be better.”
Glantz acknowledges that the optimal rate of any medical intervention
is difficult to define, and that larger studies are needed to better
understand the relationship between intervention and outcome. In the
meantime, he believes it’s hard to justify high rates of interventions
– especially elective – in low-risk pregnant women without any known
benefits to newborns, given that these interventions pose maternal
In the study, Glantz focused on pregnant women delivering in level I
hospitals – those lacking a Neonatal Intensive Care Unit or NICU –
because they care primarily for low-risk women who do not have major
complications, such as diabetes, high blood pressure or other severe
disease. The majority of women in the United States deliver in level I
Through a birth certificate database, Glantz obtained and analyzed
data from 10 level I hospitals in the Finger Lakes Region of upstate New
York and calculated the rates of induction and cesarean delivery at each
between 2004 and 2008. Not surprisingly, the rates varied widely.
To determine the health of newborns delivered at these hospitals, he
looked at three outcomes: transfer of the newborn to a hospital with a
NICU (signifying the presence of complications that required a higher
level of care); immediate ventilation or breathing assistance; and a low
score (a quick assessment of the overall wellbeing of a
Using statistical models, Glantz assessed the relationship between
rates of induction and cesarean delivery and rates of the three neonatal
outcomes. He found intervention rates had no consistent effect on
newborns: Whether a hospital did a lot or very few interventions, there
was no association with how sick or healthy the infants were.
Even after a second round of analysis that accounted for differences
among pregnant women that could potentially impact the results, the
finding was the same – hospitals with high intervention rates had
newborn outcomes indistinguishable from hospitals with low rates.
According to Glantz, “If higher intervention rates were preventing
negative outcomes that otherwise would have occurred, and lower
intervention rates led to negative outcomes that potentially could have
been avoided, the data would have revealed these relationships, but
there were no such trends.”
The study included a group of approximately 28,800 women who labored
(some naturally and some induced), followed by re-analysis of 29,700
women who had no history of previous cesarean section (some of whom
ultimately delivered vaginally and others by cesarean section). Many
women in the first group were also analyzed in the second group. Women
who had had a previous cesarean delivery were excluded from the second
analysis, because more than 90 percent of women with previous cesareans
deliver by repeat cesarean, and these are not necessarily being done to
benefit the newborns.
Glantz recognizes that some labor inductions and cesarean sections,
when done for specific, established medical reasons, are necessary and
lead to improved outcomes. But some interventions are elective or
marginally indicated, driven by social reasons such as convenience and
patient requests to deliver with “their” physician.
Labor induction is not always successful and is associated with an
increased likelihood of cesarean delivery. Cesarean delivery, while
common, is a major surgery and like all surgeries increases the risk of
infection, bleeding, the need for additional surgeries, and results in
longer recovery times.
“It is always important to try to find out when interventions will
do the most good, and this study is one more log on the fire for
researchers and physicians exploring these issues,” said Jennifer
Bailit, M.D., M.P.H, a maternal fetal medicine expert at the MetroHealth
Medical Center in Cleveland who conducts similar research.
“Understanding when and how an intervention can best improve outcomes
is important to physicians and patients.”
The study was funded by the University of Rochester Medical Center
and the New York State Department of Health. A major strength of the
study is its large size, while limitations include the inability to
assess and control for all possible factors influencing interventions
– a constraint of database research.