Protein Shake During Labor Does Not Delay Stomach Emptying

Kathleen Louden

October 29, 2013

SAN FRANCISCO — Consuming a high-protein shake during labor has no effect on rates of nausea, vomiting, or gastric emptying, new research shows.

In this randomized controlled trial, patient satisfaction with oral intake after epidural anesthesia was significantly higher in women who received the protein shake, the researchers report.

"Physicians should feel comfortable replacing ice chips or water with a high-protein liquid supplement" when vaginal delivery is expected, said Manuel Vallejo Jr, MD, an obstetric anesthesiologist at West Virginia University Health Sciences Center in Morgantown.

Healthcare providers can consider a more liberal oral intake policy in laboring patients who are at low risk for complications and who have no comorbid conditions that can delay gastric emptying, such as diabetes, gastroparesis, or intravenous narcotics, Dr. Vallejo told Medscape Medical News.

The study findings were released here at the American Society of Anesthesiologists (ASA) 2013 Annual Meeting.

Change in Oral Intake Policy Needed?

Physicians have restricted oral intake during labor since the 1940s, when doctors recognized that labor delays gastric emptying and when women routinely gave birth under general anesthesia.

The practice of restricting eating and drinking has continued because of the risk for aspiration with general anesthesia if a woman needs emergency cesarean delivery, Dr. Vallejo explained. However, he noted that improved technology that secures the airway has helped make the incidence of aspiration in this setting rare.

In 2009, the American Congress of Obstetricians and Gynecologists (ACOG) relaxed the oral intake standard of allowing only minimal amounts of water and ice chips, and said that women in uncomplicated labor can drink clear liquids, including black coffee, fruit juices without pulp, clear tea, carbonated beverages, and sports drinks.

However, many facilities still allow only ice chips and water, which can lead to dehydration, hypoglycemia, and anxiety, Dr. Vallejo said.

In this study, conducted at the University of Pittsburgh Medical Center, Dr. Vallejo and his colleagues evaluated 150 women who received epidural anesthesia.

All the women received ice chips and water as needed. Half of the women drank a 325-mL protein shake (Premier Nutrition) in the 15 minutes after the epidural block. The shake contained 30 g protein, 1 g sugar, and 160 kcal.

The researchers measured the incidence of nausea and vomiting during labor and 1 hour after delivery. They had hoped the protein shake would reduce nausea and vomiting, according to Dr. Vallejo, but that was not the case.

Multivariate analysis of variance revealed no significant difference in nausea or vomiting between the 2 groups, overall or at any time point (P > .05).

The next day, study participants rated satisfaction with their oral intake during labor on a scale from 0 to 100, with 0 indicating "not satisfied" and 100 indicating "very satisfied." The difference between the 2 groups was statistically significant.

Table. Effect of Drinking a High-Protein Shake During Labor

Outcome Shake Group Control Group P Value
Median oral intake satisfaction (from 0 to 100) 100 95 .03
Mean gastric emptying rate (min) 25.6 20.0 .19


In a separate study, the researchers used ultrasonography to determine whether the low-particulate shake would interfere with gastric emptying in the event that a woman had to undergo urgent cesarean delivery.

They determined gastric emptying rates in 18 women who ingested ice chips and water after epidural anesthesia, 9 of whom also drank the protein shake.

The mean rate of gastric emptying was slightly longer for women who consumed the shake, but the difference was not statistically significant.

"Anything we can do to increase patient satisfaction during labor without increasing adverse events is a major positive," Dr. Vallejo said in a press release.

The Debate Continues

Moving toward a low-particulate maternal intake during labor would be difficult for most anesthesiologists to accept. Dr. Ted Yaghmour

However, not everyone agrees.

The safety of the mother and baby is even more important than patient satisfaction, said Ted Yaghmour, MD, an anesthesiologist at Northwestern Memorial Hospital in Chicago, Illinois.

"I suspect that moving toward a low-particulate maternal intake during labor would be difficult for most anesthesiologists to accept. We're concerned about the airway," he told Medscape Medical News.

Dr. Yaghmour noted that the study did not directly address whether laboring patients who drank the shake and later needed general anesthesia were at increased risk for aspiration.

He said he hopes the study findings will stimulate others to perform research on whether the risk/benefit ratio of a protein shake during labor is acceptable.

Currently, the ACOG recommends that women avoid particulate-containing fluids and solid food during labor.

This study received no funding. Dr. Vallejo and Dr. Yaghmour have disclosed no relevant financial relationships.

American Society of Anesthesiologists (ASA) 2013 Annual Meeting. Abstract #1066. Presented October 12, 2013.


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