The effects of intravenous hydration regimens in nulliparous women undergoing induction of labor: A systematic review and meta-analysis

Introduction: Labor is both a physiological and physical activity that requires energy expenditure by the woman. Despite this, women are often fasted in labor, with hydration requirements addressed predominantly by intravenous therapy. Little is known about how best to manage this in nulliparous women undergoing induction of labor, who can be prone to lengthy labors. Therefore, we undertook a systematic review and meta-analysis to determine the effects of intravenous hydration regimens on nulliparous women undergoing induction of labor. Material and methods: A systematic review and meta-analysis were conducted. Databases searched were PubMed, CINAHL, Embase, Cochrane, Scopus, and Web of Science using the search strategy combination of associated key concepts for intravenous therapy and nulliparous laboring women. The primary outcome was excessive neonatal weight loss. Meta-analyses for categorical outcomes included estimates of odds ratio (OR) and their 95% confidence intervals (CI) calculated; and for continuous outcomes the standardized mean difference, each with its 95% CI. Heterogeneity was assessed visually and by using the χ² statistic and I² with significance being set at p < 0.10. Results: A total of 1512 studies were located and following screening, three studies met the eligibility criteria. No studies reported excessive neonatal weight loss. Increased rates of intravenous therapy (250 mL/h vs. 125 mL/h) during labor were not found to reduce the overall length of labor (mean difference −0.07 h, 95% CI −0.27 to 0.13 h) or reduce cesarean sections (OR 0.74, 95% CI 0.45–1.23), when women were not routinely fasted. Conclusions: Our review found no significant improvements for nulliparous women who received higher intravenous fluid volumes when undergoing induction of labor and were not routinely fasted. However, data are limited, and further research is needed.