No Ill Effects From Low-Carb Sports Drinks During Labor


CHICAGO — Laboring women can rely on sports drinks for hydration and sustenance without increasing their risk for cesarean section or instrumental vaginal delivery and without affecting the metabolic profiles of their newborns, according to a study of 198 women.

Sports drink consumption alleviated maternal ketosis without affecting neonatal Apgar score, glycemia, or umbilical cord gas, Dr. Marie-Eve Perron reported in a poster presentation at the annual meeting of the Society for Obstetric Anesthesia and Perinatology.

The findings contradict previous research (BJOG 2002;109:178-81), which indicated a threefold increase in C-sections among women who drank isotonic fluids during labor.

“The dissimilar results may be explained by the difference in the population studied and by the use of a lower carbohydrate concentration sports drink [in this study],” Dr. Perron said.

The isotonic drink in the earlier study contained a 12.6% carbohydrate concentration, more than twice that in the present study. Most of the patients in the previous research had high-risk pregnancies, and some had also received opioids during the course of labor.

Dr. Perron and her associates at Laval University, Quebec City, reported on 198 consecutive women who requested epidural analgesia at cervical dilation of 5 cm or less and in whom labor had begun spontaneously.

All patients had a single fetus in cephalic presentation. Women with known obstetric or medical conditions such as diabetes or previous C-section were not included.

There were no significant differences in the incidence of C-sections or instrumental vaginal deliveries among the intervention patients, who were encouraged to drink 200 mL/hr of a clear isotonic liquid containing a 6% carbohydrate concentration, and the control patients, who were limited to 30 mL/hr of water (standard practice at the hospital). The two groups were similar demographically.

Patients' maternal ketone bodies and glycemia were measured immediately after randomization into the intervention or control group and at the end of the first stage of labor using the Precision Xtra system. Apgar scores, neonatal glycemias, and umbilical cord gases were measured as well.

C-section rates for the intervention and control groups were 12.2% and 15%, respectively. Instrumental vaginal delivery rates for the intervention and control groups were 14.3% and 13%, respectively.

Maternal ketone bodies (beta-oxybutyrate) were 0.23 and 0.22 in the intervention and control groups at baseline, but nearly four times greater in the control group (0.19) than in the intervention group (0.5) at the end of the first stage of labor.

Apgar scores were 8.9 and 8.7 in the intervention and control groups at 1 minute, and 9.9 and 9.8 at 5 minutes. Neonatal arterial pH, venous pH, and glucose in the two groups were almost identical.

“The possible risk of pulmonary aspiration led many hospitals to restrict oral intake during labor,” said Dr. Perron. “However, the metabolic demand of labor is high. As clear fluids are rapidly evacuated from the stomach, they could represent a suitable source of energy.”

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