Oral and Intravenous Maternal Hydration in third trimester Idiopathic Oligohydramnios:Effects and Duration

Objective:To study the effects of oral and intravenous maternal hydration in third trimester idiopathic or isolated oligohydramnios, and to determine the duration of actions. Design: Prospective clinical study. Setting:OB/GYN department, Benha Teaching Hospital, Benha, Egypt.; Patient(s):34 pregnant patients, about 35 weeks gestation, with idiopathic oligohydramnios. Intervention(s):acute oral and intravenous maternal hydration. Main Outcome Measure(s):The current study was conducted on 34 pregnant mothers with amniotic fluid index (AFI) of < 6 cm and gestational age of about 35 weeks. The pregnant women were equally divided into two groups, "A" and "B". Just before starting hydration and for all the participants, amniotic fluid index and urine specific gravity had been measured.Group "A", received two liters of water over 2 hours. Group "B", received intravenous 2 liters of isotonic saline over 2 hours. Reevaluations of AFI and urine specific gravity in both groups had been made 2 hours after finishing hydration. Then, AFIwas rechecked again every 2 days for a week. Independent t-test and paired t-test were used to compare the two groups and mean AFI before and after treatment, respectively. Result(s):Hydration of mothers, oral or parenteral, significantly increased the AFI. In group "A": (mean change: 1.5 cm; percentage 25%; paired t test: 11.77; P<0.001). In group "B": (mean change: 2.64±0.9cm; percentage 28%; paired t test: 9.27; P<0.001). There was a decrease in urine specific gravity in both groups. Two days post hydration, 11women (64.7%) from group "A" and 10 women (58.8%) from group "B"their AFI were <6cm. The maximum duration of actionof acute hydration was about one week. Conclusion(s): Oral hydration is effective as intravenous hydration in significantly increase the AFI in third trimester idiopathic oligohydramnios. Oral hydration is more convenient. It is cheaper, non-invasive and does not need special arrangement.The advantageous effect of maternal hydration is temporary; and oral hydration every two days may be recommended till delivery.