Fasting in labor: relic or requirement

Abstract

Objective: To evaluate the scientific literature on restrictions of eating and drinking during labor.

Data sources: Computerized searches in MEDLINE and CINAHL, as well as historical articles, texts, and references cited in published works. Key words used in the searches included anesthesia in labor, childbirth, eating and drinking, epidural, fasting, fasting in labor, fasting and pregnancy, gastric aspiration, gastric emptying, intrapartum, intravenous fluids, i.v.s in labor, ketonuria, ketonuria in labor, parturition, pregnancy, and stomach contents in labor.

Study selection: Articles from indexed journals, excluding single-person case studies.

Data extraction: Data were extracted and organized under the following headings: historical review, effects of fasting on labor, research on maternal mortality/morbidity from aspiration, research on gastric emptying in labor, intravenous hydration in labor, and implications for nursing research.

Data synthesis: Research does not support restricting food and fluids in labor to prevent gastric aspiration. Restricting oral intake during labor has unexpected negative outcomes.

Conclusions: Little is known about the differences in labor progress, birth outcomes, and neonatal status between mothers who consume food and/or fluids during labor and women who fast during labor. Research also is needed on the effects of epidural opioids on gastric emptying, nutritional requirements during labor, and the physiologic implications of fasting during labor. Fasting during labor is a tradition that continues with no evidence of improved outcomes for mother or newborn. Many facilities (especially birth centers) do not restrict eating and drinking. Across the United States, most hospitals restrict intake, usually to ice chips and sips of clear liquids. Anesthesia studies have focused on gastric emptying, measured by various techniques, presuming that delayed gastric emptying predisposes women to aspiration. Narcotic analgesia delays gastric emptying, but results are conflicting on the effect of normal labor and of epidural anesthesia on gastric emptying. The effect of fasting in labor on the fetus and newborn and on the course of labor has not been studied adequately. Only one study evaluated the probable risk of maternal aspiration mortality, which is approximately 7 in 10 million births.