Health Letter, December 2013
Deliveries by cesarean section, a surgical procedure in which incisions are made through a women’s abdomen and uterus to deliver a baby, have risen dramatically over the past 15 years. In 1996, roughly 1 in 5 deliveries was done by cesarean section. By 2010, the number had climbed to close to 1 in 3 live births.
In 2010, Public Citizen’s Health Research Group published a study of New York hospitals that revealed that cesarean rates varied widely depending on the hospital, suggesting that choice of hospital and provider may have an impact on a patient’s chances of undergoing this procedure.
Cesarean sections are sometimes necessary as a response to complications identified before and during delivery, but the procedure also involves a number of risks to the mother, the newborn and future children the mother might have. For this reason, it is important that cesarean sections be carried out only when medically necessary.
Two recent studies, published in 2012 and 2013, have shed new light on how a physician’s decisions and preferences influence the chances that a patient will receive a cesarean section. Learn how your choice of doctor may affect your risk of undergoing a cesarean section, and learn how to select a physician who will keep your risk low.
Physician’s influence in planning ahead for a cesarean
The decision to consent to a cesarean section lies with the woman giving birth. Yet physicians have a strong influence over the decision, both because the physician is often the primary source of information about risks and benefits of a procedure, and because patients often defer to the medical opinion of their doctors. A study published in 2012 in the American Journal of Obstetrics & Gynecology (AJOG) documented this influence by interviewing 155 women who were pregnant again after undergoing a cesarean section in one previous birth. These women were asked to choose between attempting to give birth vaginally or scheduling a second cesarean section.
It is extremely common for women who have undergone one cesarean section to schedule another one for any subsequent children. This is an issue because the risk of complications with the procedure tends to increase with every subsequent cesarean delivery. In the mid-1990s, the American College of Obstetricians and Gynecologists recommended that vaginal delivery after cesarean section be counseled and encouraged in women who do not have any contraindications to vaginal delivery. Yet the group backed off of this recommendation in 1999, advising instead that attempts at vaginal delivery after a cesarean section should only be undertaken at “… institutions equipped to respond to emergencies with physicians immediately available to provide emergency care.” One of the main reasons for this shift was evidence from an observational study published in 1996 indicating that the risk of major complications is greater among women who attempt vaginal delivery after one prior cesarean, compared to women who plan a second cesarean. Most of the injuries to the women who attempted vaginal delivery occurred among those who tried and failed to deliver vaginally and needed an emergency, or “unplanned” cesarean section during their second delivery.
The AJOG study found that women deciding between vaginal and cesarean delivery after a prior cesarean section were generally poorly informed about the risks and benefits of both procedures. Most women did not know that the likelihood of a vaginal delivery being successful (in other words, the chance that an unplanned cesarean would not be needed during labor) is 60 to 80 percent. Most women also did not know that the risk of uterine rupture during an attempted vaginal delivery in these circumstances is just 0.5 to 1 percent. Women who attempted vaginal labor were much more likely to know this information than women who planned to have a cesarean section. Shockingly, more than half the women in the group who planned to undergo a second cesarean section were not aware that the risk of complications increases each time a woman has a cesarean section.
Perhaps the most interesting finding of the study was that women were extremely likely to follow the perceived preferences of their doctors. Of the patients who believed that their doctors preferred to plan a cesarean section, 86 percent chose to have one. On the other hand, of the patients who believed that their doctors preferred a trial of vaginal delivery, 78 percent chose to attempt vaginal delivery. When patients did not know their doctor’s preference or thought their doctors had no preference, about 50 percent opted for a planned cesarean section and 50 percent opted for a planned vaginal delivery.
Physician’s influence in the delivery room
Another recent study, published in 2013 in the journal Obstetrics & Gynecology, looked at medical records from more than 38,000 first-time cesarean deliveries to try to evaluate the clinical decision-making that occurs in the delivery room and identify opportunities to lower the cesarean section rate for women who have never had a cesarean delivery. Unplanned cesarean deliveries are even more likely to result in complications than planned cesarean deliveries, making it especially important for doctors not to carry out this procedure unless it is truly medically required.
The study found that many first-time cesarean sections that were described as medically “indicated” (in other words, medically required) were not based on objective criteria, but instead depended on the physician’s own personal assessment of the situation. For example, two of the most common indications were failure to progress (often because dilation did not occur fast enough) and unusual fetal heart rate, both of which are decided through a judgment call made by the physician.
Without objective criteria, some physicians may become concerned and recommend a cesarean section too soon. In fact, the researchers found that when they applied strict objective criteria to define “active labor,” between 33 and 43 percent of all women underwent a cesarean section before “active labor” had even started.
The researchers also found that a whopping 97 percent of the infants delivered by cesarean section because of suspected “macrosomia” (doctors expecting the fetus to be too big to deliver vaginally) were actually smaller than the size at which the American College of Obstetricians and Gynecologists recommends cesarean delivery in non-diabetic women. Part of the reason for this high mistake rate is that fetal size is difficult to determine prior to delivery.
Advice for patients
Regardless of whether you deliver vaginally or by cesarean section, the overall risks to you and the newborn are low, and the vast majority of deliveries result in good outcomes for both mother and newborn.
Nevertheless, the choice of whether to give birth by cesarean section has important health consequences, especially when a woman is considering having additional children. When choosing a health care provider for your delivery, ask about the provider’s rate of cesarean sections. A number below the national average of 30 percent is a good sign that the practice is taking steps to avoid unnecessary cesarean sections.
However, it is important to be cautious when assessing these numbers: sometimes high or low cesarean rates can be attributed to the underlying patient population, which may be at higher risk for cesarean depending on factors like age and pregnancy complications. This means you should not select a provider just because they provide the lowest cesarean rates, but you should think critically about the quality of care being provided. For example, if you are trying to choose between two providers, and one has a lower cesarean rate, ask questions to find out if the provider with the lower rate also screens out more high-risk patients. It is possible that the provider’s cesarean rates were low because the patients were already low-risk, not because the care they received was better. In such cases, the cesarean rate does not offer a reliable way to compare the quality of care between two providers.
Another way to help decide between various health care providers is to talk to each provider about how they make decisions with patients. What are the circumstances under which the doctor would recommend a planned cesarean section? If you have special circumstances, such as a history of prior cesarean section or pregnancy with twins, ask how these will affect the risks and likelihood of having a cesarean delivery. These conversations can help you better understand how the doctor makes medical decisions and will help you find a doctor you can trust to ensure you receive a cesarean section only when medically necessary.
Signing up for delivery at a hospital that uses a midwife service may help reduce the chances of undergoing an unnecessary cesarean delivery. Public Citizen found that one hospital in the Bronx, which had midwives attend most of the births, had been able to achieve relatively low cesarean section rates (less than 20 percent). Public Citizen has recommended that all hospitals offer the option of licensed midwife delivery as a way of reducing the rate of unnecessary cesarean sections.