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, MD, 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,” he said in a statement.
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 US health care 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 risks.
In the study, Glantz focused on pregnant women delivering in level I hospitals 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 hospitals.
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, immediate ventilation or breathing assistance, and a low five-minute Apgar score.
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.
“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,” Glantz said.
The study included a group of approximately 28,800 women who labored (some naturally and some induced), followed by reanalysis of 29,700 women who had no history of previous cesarean section (some of whom ultimately delivered vaginally and others by cesarean section).