Monday, April 16, 2007

Are there benefits to eating in labor?

The current issue of International Anesthesiology Clinics has a review article on Oral Intake During Labor. The article reviews the scientific literature for data about maternal aspiration in labor and for data about the purported benefits of eating in labor. On eating in labor:
... Many professionals argue that starvation in labor is both physiologically and psychologically detrimental for women. It is not surprising that prolonged fasting in labor is associated with an increased production of ketones ...

... It is not clear whether ketosis is as detrimental as initially thought and now it has been demonstrated that ketones can be utilized by both the mother and fetus.
Indeed, this may be a normal physiologic response in labor, which should not be tampered with.
What does the existing scientific evidence show about the benefits of eating in labor?
A key question in labor outcome is whether there are significant improvements in women who take either calories or light diet in labor. There is a scarcity of good controlled data looking specifically at delivery outcome, but there are some randomized control trials that have evaluated obstetric end points... In 1999, Scrutton et al investigated whether a light diet would affect a woman’s metabolic profile and increase her residual gastric volume. Labor outcome was also evaluated... Glucose levels were higher in the eating group, whereas eating prevented the rise in hydroxybutyrate and fatty acids. With these numbers, there were no significant differences in other labor end points. Mothers in the eating group, however, did have significantly larger gastric volumes at the time of delivery and these women vomited larger volumes, which contained a considerable amount of solid residue.

A further study from the same unit randomized 60 women comparing the metabolic effects of isotonic sports drink to water only during labor... [I]t was shown that these drinks prevented the rise in b-hydroxybutyrate and nonesterified fatty acids seen in the starved group. Once again, there was no change in any outcome of labor, but in contrast to the light diet allowed in the original study, there was no increase in residual gastric volume in the isotonic sport drink group...

... Scheepers et al performed a randomized controlled trial in 200 women who received either carbohydrate solutions or placebo... The main outcomes were operative deliveries, labor duration, and need for analgesia. Again, envelopes were used for randomization and the trial was blinded. They found a 3-fold increase in cesarean section in women who received calories.

Tranmer et al conducted a randomized trial to determine if unrestricted oral carbohydrate intake during labor reduced the incidence of dystocia ... There was no significant difference in the incidence of dystocia between intervention and control group ... Moreover, induction of labor, types of uterine stimulants administrated, delivery method, and indication of cesarean section were also evaluated and there were no significant difference between groups...
The authors summarize:
... Although a policy of ‘‘nil per os’’ may be responsible for unnecessary discomfort, there is very little evidence that it causes other harm. Current available studies suggest there is no change in the length of labor, the obstetrical outcome or neonatal outcome when parturients are fasted intrapartum compared with those who are fed.


0 Old Comments: