Consumption of solid food while in labor is safe for most women, according to the results of a large randomized trial.
It's been common practice to deny food to women in labor. Clinicians have worried that if general anesthesia were to be required for an emergency cesarean section, a woman might aspirate food into her lungs. As a result, even as recently as 2007, the American Society of Anesthesiologists recommended that laboring patients not be allowed solid food.
But in a study of 2,426 women, Dr. Geraldine O'Sullivan, consultant anesthetist at St. Thomas's Hospital, London, and her colleagues found that eating a low-fat, low-residue diet had no effect on the rate of spontaneous vaginal delivery, the duration of labor, the cesarean delivery rate, or the incidence of vomiting. In addition, the babies born to women permitted to eat solid foods were just as healthy as the babies born to women who were restricted to consuming water and ice (BMJ 2009;338:b784).
A total of 2,426 women with a mean age of 29 years were studied. All women in the study were giving birth for the first time, all pregnancies were uncomplicated, and all babies were singletons. The study was large enough to detect a difference as small as 6.7% in the rate of spontaneous vaginal delivery. The investigators agreed that a difference of this magnitude would be clinically as well as statistically significant.
Instead, they found no statistically significant differences on any measure. The rate of normal vaginal delivery was 44% in both groups. Instrumental delivery was 27% in the eating group and 26% in the water-only group. Cesarean sections were necessary in 30% of the women in the eating group and 30% of the women in the water-only group. A total of 35% of the women in the eating group vomited, compared with 34% of the women in the water-only group. And the mean length of labor was 597 minutes in the eating group, compared with 612 minutes in the water-only group.
Dr. William Camann, director of obstetric anesthesiology at Brigham andWomen's Hospital in Boston and past president of the Society for Obstetric Anesthesia and Perinatology, pointed out that the findings of this study didn't answer the question posed in regard to obstetric anesthesia safety concerns. The investigators didn't report whether any of the cesarean section patients received general anesthesia.
“The reason that pulmonary aspiration is so low is probably because the majority of obstetric patients nowadays have regional anesthesia during elective or emergent cesarean sections instead of general anesthesia, rather than [because] oral intake is restricted during labor, although we don't know this for sure. At our hospital only about 2%–3% of cesarean sections are done under general anesthesia.
“We don't really know whether liberalization of oral intake during labor will have adverse consequences or not. And we probably never will because the incidence of pulmonary aspiration is so low that it would take a study enrolling a huge number of women to achieve the statistical power necessary to get that evidence,” he said in an interview.
“Labor is not scheduled and predictable, like elective surgery. Although inevitably some women will end up having cesarean deliveries, this is highly likely to be done under regional anesthesia. There has to be a balance between patient comfort and patient safety, but with regard to oral intake in labor, this balance is hard to define,” Dr. Camann noted.
Not all of the women in the eating group actually ate solid food, and not all of the women in the water-only group avoided eating. Among the 1,219 women in the eating group, 71% actually ate, and the remainder either drank only water or had no oral intake. Among the 1,207 women in the water-only group, 20% failed to adhere to the protocol and ate some solid food.
The women ate a variety of foods, including fruit juice, soup, cereal, biscuits, fruits, chocolate, toast, vegetable stew, Danish pastry, sandwiches, hamburgers, chicken, and rice.
Denying solid food to women in labor became common after a 1946 study showing pulmonary acid aspiration, called Mendelson's syndrome, in some women who had eaten. But the risk of this has decreased in recent years. Anesthesiologists are more likely to use regional than general anesthesia for cesarean deliveries. In addition, it's common to prescribe proton pump inhibitors or H2 receptor blockers for women undergoing operative births.
Dr. Camann noted that there have been changes to the guidelines over the years, allowing for clear liquid intake of beverages such as juices, tea, and sports drinks during labor. “In fact, obstetric patients should drink something with electrolytes in it rather than just water to avoid water intoxication, which has been known to occur.”