Effect of maternal hydration on oligohydramnios: a comparison of three volume expansion methods. Maternal hydration increases amniotic fluid index. Maternal hydration increases amniotic fluid index in women with normal amniotic fluid. A randomized clinical trial comparing the effect of maternal intravenous hydration and placebo on the amniotic fluid index in oligohydramnios. A randomized trial of increased intravenous hydration in labor when oral fluid is unrestricted. A prospective randomized study of saline solution amnioinfusion. [Intrapartum amnio-infusion in patients with oligohydramnios]. Prophylactic amnioinfusion as a treatment for oligohydramnios in laboring patients: a prospective, randomized trial. A prospective, randomized evaluation of intrapartum amnioinfusion. Fetal acid-base status and cesarean delivery.
To determine the effect of maternal hydration with intravenous (i.v.) isotonic fluid, i.v. hypotonic fluid, and oral water on amniotic fluid index (AFI) in women with oligohydramnios.
                Patients with low AFI and gestational age over 35 weeks without maternal complications were randomized into four groups (2 L/2 h i.v. isotonic fluid, 2 L/2 h i.v. hypotonic fluid, 2 L/2 h oral water, control). Maternal plasma osmolality, AFI, hematocrit, and hemoglobin concentration were measured before and after hydration.
                Eighty-four patients (n=21/group) completed the study without any maternal adverse effects. The mean increase in AFI after hydration was significantly greater in the i.v. hypotonic and oral water groups (2.8+/-1.9, P < .001; 3.8 +/-1.9, P < .001, respectively), but not in the i.v. isotonic group (0.5+/-1.1), compared with the control group (0.5+/-1.1). Significant decreases in maternal hematocrit and hemoglobin concentration were found only after i.v. isotonic hydration (32.0+/-2.9 to 29.5+/-2.3, P < .001; 11.0+/-1.6 to 10.1+/-1.4, P < .001, respectively). Changes in maternal osmolality correlated with the changes in AFI in both the i.v. hypotonic group (r=.58, P < .001) and oral water group (r =.63, P < .001).
                Maternal hydration with either i.v. hypotonic fluid or oral water increases AFI in oligohydramnios. Maternal osmotic change rather than maternal volume expansion had a more direct impact on increasing amniotic fluid volume with short-term acute hydration. Although adequate amniotic fluid (AF) volume is considered an important aspect of fetal well-being, the etiology of decreased AF volume is not well understood. A randomized blinded trial was designed to examine our hypothesis that maternal hydration would increase the AF index in women with low AF indexes. Women seen in our testing centers were randomized into control or hydration groups. The control group was instructed to drink their normal amount of fluid; the hydration group was instructed to drink 2 L of water, in addition to their usual amount of fluid, 2-4 hours before the post-treatment AF index. The women returned for the post-treatment AF index the same or following day. The mean post-treatment AF index was significantly greater in the hydration group (6.3 versus 5.1; P less than .01), as was the mean change in AF index (post-treatment AF index--pre-treatment AF index: 1.5 versus 0.31; P less than .01). These findings suggest that maternal oral hydration increases AF volume in women with decreased fluid levels. To test the hypothesis that maternal oral hydration would increase the amniotic fluid (AF) index in pregnancies with normal AF.
                Forty women with a normal AF index (7.0-24.0 cm) were randomized to either the control or hydration group. Women in the hydration group drank 2 L of water and returned for the post-treatment AF index in 4-6 hours, whereas women in the control group drank only 100 mL of water during the same time period. The investigator performing the AF index was blinded to the subject's group. The pre- and post-treatment AF indexes and maternal urine specific gravities were compared between the groups.
                The mean AF index in the hydration group increased significantly by 3.0 +/- 2.4 cm (P < or = .0001) whereas it declined significantly by 1.5 +/- 2.7 cm in the control group (P < or = .02). The maternal urine specific gravities also changed significantly in the expected direction, with those in the hydration group decreasing and those in the control group increasing (P < or = .0001). There was a regression coefficient of -0.6 (P < or = .0001) between the change in urine specific gravity and the change in AF index. The mean time between the pre- and post-treatment AF indexes was not different between the groups.
                Maternal oral hydration increased the AF index by approximately 16%, whereas fluid restriction decreased the AF index by 8% in women with normal AF. These findings support previous data that maternal hydration increased the AF index by 31% in women with decreased AF and suggest that maternal fluid volume or osmolality may have a role in maintaining the AF volume. To compare the treatment of acute intravenous hydration with placebo in term pregnant women manifesting oligohydramnios.
                All patients with oligohydramnios who met the inclusion criteria were offered participation in this randomized, double-blind, placebo-controlled study. After ruling out rupture of membranes and maternal and fetal complications, we recruited 44 women with third trimester singleton pregnancies having an amniotic fluid index (AFI) of less than 6. Patients were randomized into treatment or control groups. Patients in the treatment group received a continuous intravenous infusion of (1/2) normal saline (NS) at a rate of 1000 mL/h for two hours. Patients in the placebo group received an intravenous infusion of (1/2) NS at 10 mL/h for two hours. The AFI was re-assessed by the same sonographer one hour after the hydration was completed. Both the patient and the examiner were blinded to the study groups.
                Maternal age, parity, gestational age, and birth weight were not significantly different between the two groups. The AFI increased significantly in both treatment (3.8 +/- 1.2 vs. 5.3 +/- 2.5, p < 0.05) and placebo (4 +/- 1.3 vs. 5.5 +/- 2.4, p < 0.05) groups. Moreover, the changes in AFI did not significantly differ between the treatment and the placebo groups (1.2 +/- 2.1 vs. 1.5 +/- 2.1, respectively; p > 0.05).
                There are statistically significant short-term increases in the AFI in patients with oligohydramnios whether the patients are treated with intravenous fluids or not. The short-term increase in AFI may reflect physiologic diurnal variations in the amniotic fluid. Increased intravenous (IV) hydration is associated with decreased labor duration and oxytocin augmentation in nulliparous women when oral fluid is restricted. The objective of this study was to determine the effect of increased IV hydration on the duration of labor when access to oral fluid was unrestricted.
                Term, nulliparous women with uncomplicated singleton pregnancies were randomly assigned to receive lactated ringers at 250 ml per hour (IV fluid group) throughout active labor or usual care. All women were allowed unrestricted access to oral fluids.
                Eighty women completed the study, 37 in the IV fluid group and 43 in the usual care group. There was no difference in the primary outcome of total duration of labor (9.5 versus 9.4 hours) or in the secondary outcomes of duration of the first stage (7.9 versus 8.0 hours), duration of second stage (1.6 versus 1.4 hours), or rate of oxytocin augmentation (51% versus 44%).
                Increased IV hydration does not decrease labor duration in nulliparous women when access to oral fluid is unrestricted. We performed a prospective randomized study of saline solution amnioinfusion in four types of pregnancy complications: postterm pregnancy, variable decelerations in labor, preterm labor, and oligohydramnios-suspected growth retardation. A total of 100 patients were randomized, 43 to undergo amnioinfusion and 57 to be in a control group. Patients undergoing amnioinfusion had a significantly decreased incidence of postpartum endometritis (2.4% vs 19%, p = 0.01) and a lower incidence of cesarean delivery that was due to fetal distress in labor (4.7% vs 16%, p = 0.07). The use of amnioinfusion also made a significant contribution to the four-quadrant ultrasonographic estimate of amniotic fluid volume (14.7 vs 9.8 cm, p less than 0.001). All other maternal and neonatal outcome parameters were similar between the two groups. We conclude that saline solution amnioinfusion in labor may be a beneficial procedure but that further studies are needed. Patients with oligohydramnios are at increased risk of developing fetal distress during labor, presumably as the result of umbilical cord compression. Intrapartum saline amnio-infusion for short-term amnionic fluid replacement was performed in a prospective randomized manner in 60 cases of oligohydramnios during period of 1-year. Patients receiving amnio-infusion had significantly lower incidence of neonatal asphyxia and less cesarean sections as compared with the controls. No neonatal nor maternal complication occurred. The effect of amnio-infusion was also confirmed by B type ultrasonic examination. These results suggested that intrapartum saline amnio-infusion might be a hopeful therapy for patients with oligohydramnios. Prophylactic amnioinfusion was studied in a randomized sample of 305 patients with oligohydramnios in labor. One hundred seventy-five patients underwent amnioinfusion with the remainder serving as controls. Amniotic fluid was titrated to an amniotic fluid index greater than 10.0 cm in the treatment group. Patients receiving amnioinfusion had significantly less operative intervention for fetal distress (p = 0.0001) and fewer cesarean sections (p = 0.0001). Umbilical artery pH at the time of delivery also was increased (p = 0.0001). Rates of amnionitis and endometritis were not significantly different between infused patients and controls, although the length of hospital stay was significantly decreased (p = 0.002) in the treatment group. Our data support earlier reports in the literature that amnioinfusion is a useful technique for decreasing intrapartum morbidity for both mother and fetus. Pregnancies with decreased amniotic fluid volume are prediposed to umbilical cord compression and variable fetal heart rate declerations. Intrapartum amnioinfusion has been utilized in an effort to reduce cord compression. Previous studies suggested that amnioinfusion may improve the fetal metabolic state and reduce the incidence of cesarean delivery in selected patients. In this study the hypothesis was tested that intrapartum amnioinfusion will relieve cord compression in pregnancies complicated by oligohydramnios and will result in a reduced incidence of fetal intolerance to labor as well as improved fetal acid-base status at delivery. Thirty-five patients fulfilling the inclusion criteria were randomized to either the control (n = 16) or amnioinfusion treatment group (n = 19). Analysis of the data suggested that the two groups were similar for the perinatal parameters evaluated. No differences were observed in the umbilical artery blood gas analysis or incidence of cesarean section between the two groups. Intrapartum amnioinfusion does not appear to improve the perinatal outcome in pregnancies with oligohydramnios.
Simple maternal hydration appears to increase amniotic fluid volume and may be beneficial in the management of oligohydramnios and prevention of oligohydramnios during labour or prior to external cephalic version. Controlled trials are needed to assess the clinical benefits and possible risks of maternal hydration for specific clinical purposes.