Increased Intravenous Hydration of Nulliparas in Labor

Abstract

Maternal hydration can affect labor progression and is critical for fetal well-being. When women have restricted oral fluid intake during labor, the rates of dysfunctional labor and cesarean delivery increase. However, studies have reported conflicting results regarding hydration and its effects on labor duration, incidence of labor dystocia, and adverse maternal and neonatal outcomes. Maternal exhaustion and dehydration from prolonged labor have been linked to a more frequent need for epidural analgesia, cesarean delivery, greater occurrence of maternal or fetal infection, adverse birth outcomes, and postpartum hemorrhage. This randomized clinical trial was designed to compare the effects of oral hydration alone with those of oral and intravenous (IV) hydration on duration of labor, need for oxytocin, and incidence of adverse outcomes due to prolonged labor. Eligible patients, aged 18 to 35 years, were nulliparous, with a singleton pregnancy, in spontaneous active labor, with cervical dilation at 4 to 5 cm, gestational age 38 to 40 weeks, normal fetal heart rate tracings, intact membranes, and cephalic presentation. Labor analgesia was not used. Women were randomly assigned to 1 of 4 groups, with control women in group 1 receiving usual care that did not involve an IV infusion of Ringer’s lactate solution. Patients in groups 2, 3, and 4 received an infusion of Ringer’s lactate solution at the respective rates of 60, 120, and 240 mL/h. All participants were allowed to drink water or soft beverages at will. Infusion pumps controlled the flow of Ringer’s lactate solution allotted to the participants in groups 2, 3, and 4. Total fluid volumes were recorded. Main outcome data were duration of the active phase of the first stage of labor, durations of the second and third stages of labor, need for oxytocin, mode of delivery, Apgar scores at 1 and 5 minutes, and volumes of IV and oral fluids. All collected data were analyzed using SPSS. Means were compared using analysis of variance and proportions by the χ2 test. P < 0.05 was considered significant. Of 120 women recruited, 20 had cesarean deliveries, and 100 delivered vaginally. Maternal age and weight, cervical dilation, and station of the fetus were similar in all 4 groups as were neonatal gestational age at birth, birth weight, Apgar scores at 1 and 5 minutes, and presence of meconium in the amniotic fluid. For women who delivered vaginally, the differences in the duration of the active phase of the first stage of labor were significant (252.3 ± 40.9, 237.8 ± 36.4, 231.7 ± 43.5, and 206.2 ± 38.3 minutes for groups 1–4, respectively; P < 0.001). The differences in the duration of the second stage of labor were also significant between groups: 64.3 ± 13.9, 54.8 ± 16.2, 51.3 ± 11.9, and 49.8 ± 11.4 minutes, respectively (P = 0.01). Differences in duration were not significant (P = 0.58) for the third stage of labor. In group 1, 53.3% of patients needed oxytocin augmentation compared with 20.0% in group 4. The percentages of patients who underwent each mode of delivery did not differ significantly. Eight women in group 1 and 2 women in group 4 had a cesarean delivery because of failure to progress or other complications; differences among the 4 groups were not significant. Three newborns in group 1 and 1 neonate in group 3 had an Apgar score less than 7 at 1 minute, but no infants in groups 2 and 4 had scores less than 7. The 4 groups did not differ in volume of oral fluid intake. The incidence of vomiting was 10%, 13.3%, 3.3%, and 6.6% in groups 1 to 4, respectively. Providing adequate hydration during labor is a major concern for obstetric professionals. Infusing Ringer’s lactate solution significantly reduced the mean duration of active labor. A patient’s self-regulated intake of drink and food during labor can help reduce stress and create a feeling of control. Intravenous hydration administered to nulliparous women in active labor significantly reduced labor duration and the frequency of both prolonged labor and oxytocin administration without increasing the occurrence of adverse effects.