ST. LOUIS — Normal labor is substantially longer than what doctors have long thought. Be patient, much more patient, say new guidelines released Thursday and aimed at reducing the spiraling cesarean delivery rate in the U.S.
The guidelines challenge many maternity care practices that have become common. In addition to allowing women to labor longer, recommendations in the report include:
• Restricting labor induction before 41 weeks to cases where there’s a danger to mother or baby.
• Letting more mothers of twins try to deliver vaginally.
• Allowing first-time mothers to push for at least three hours.
The guidelines were released jointly by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine.
“We have to look at the data we have now and the new research into what is normal. This is an attempt to put all those things together for providers to look at and think of potential ways they can alter their behavior and care to positively impact the C-section rate,” said Dr. Alison Cahill, chief of the division of maternal-fetal medicine at Washington University School of Medicine.
Approximately one in three women in the U.S. give birth by cesarean delivery, a 60 percent increase since 1996. The rapid increase, however, along with no improvements in health outcomes for mothers or babies has raised major concerns that the surgery is overused.
“Physicians do need to balance risk and benefits, and for some clinical conditions, cesarean is definitely the best mode of delivery,” said Dr. Vincenzo Berghella, SMFM president.
“But for most pregnancies that are low-risk, cesarean delivery may pose greater risk that vaginal delivery, especially risks related to future pregnancies.”
About 60 percent of all C-sections are among first-time mothers. While initial cesarean deliveries are associated with increases in maternal mortality and morbidity, those risks significantly increase with subsequent C-sections. Death and intensive-care stays also become more likely for babies.
Great variations in the rate of C-sections across states — from 23 percent in Utah to a high of nearly 40 percent in Kentucky — indicate that how clinicians practice can affect the number. Among hospitals, the rate has been shown to vary from 7 percent to 70 percent.
Because most women end up having repeat C-sections in subsequent pregnancies, the guidelines focus on practices that could prevent them in healthy first-time mothers.
“If we go back and look at the root of the problem – women who have never had a C-section before and why do they end up with one – we have more options to prevent and reduce some of those indications,” Cahill said.
The two biggest reasons – accounting for 57 percent of primary C-sections – are stalled labor and abnormal electronic fetal heart rate readings.
And according to the latest research, both are being called into question.
“We are learning how much we, in fact, don’t know about fetal heart rate monitoring; and it turns out, we are not correct in what is normal labor progress either,” Cahill said.
Labor has historically been divided into the latent phase of labor and the active phase — when a woman’s cervix begins to dilate rapidly. The latent phase has been considered stalled when it exceeds 20 hours for first-time mothers and 14 for others. With few exceptions, women will progress beyond the latent phase if allowed to do so, the guidelines state. A stalled latent phase should not be an indication for cesarean.
And while the turning point to the active phase has for decades been considered when the cervix has dilated to 4 cm, current research shows that 6 cm is more accurate. Women also dilate much more slowly than previously thought in the active phase — about .6 cm per hour instead of 1.2 cm for first-time moms.
The guidelines also call for allowing women to push for two hours if they have delivered before, and three hours if it’s their first delivery. In some situations, such as with an epidural, pushing may take even longer.
“Evidence now shows that labor actually progresses slower than we thought in the past, so many women might just need a little more time to labor and deliver vaginally instead of moving to a cesarean delivery,” said Dr. Aaron Caughney, a member of ACOG’s committee on obstetric practice.
The guidelines point to a standardized approach in interpreting electronic fetal heart-rate monitoring as key in helping reduce the
C-section rate. Introduced in the 1970s, electronic fetal heart-rate monitoring is now used in 85 percent of births. Despite its widespread use, the rate of stillbirth has not changed and the rate of cerebral palsy has increased.
While some heart rate readings are clearly normal and others are clearly abnormal, the most common are “indeterminate,” and little information exists on the meanings of those patterns. Yet, given that abnormal fetal heart rates are the second most common reason for C-sections in first-time mothers, these readings likely account for a large number of cesareans.
Other ways to decrease the rate include having continuous labor support and not performing cesareans because of the size of the baby, unless the baby is suspected to weigh over 11.2 pounds.
The report acknowledges that the systematic changes can be slow to implement, which is why it is critical for women and their families to be educated about what is safest.
“While it’s important to provide provider and physician education, I also hope this document educates patients,” Cahill said. “I’m not always sure that patients themselves are aware of the risks of having a C-section, that the long-term or downstream consequences can be significant.”