Treatment of oligohydramnios with maternal 1-deamino-[8-D-arginine] vasopressin–induced plasma hypoosmolality

Abstract

OBJECTIVE: Maternal 1-deamino-[8-D-arginine] vasopressin (a selective antidiuretic agonist) and oral water loading decrease maternal and fetal plasma osmolality and markedly increase fetal urine flow in sheep. We hypothesized that a titrated reduction in maternal plasma osmolality would increase human amniotic fluid volume. STUDY DESIGN: Pregnant women ( n = 5) with oligohydramnios at term were administered oral water loading (20 ml/kg) and intravenous 1-deamino-[8-D-arginine] vasopressin (2 μg) to induce antidiuresis. Maternal plasma and urine osmolality and urine production were measured hourly, and water replacement was titrated for 8 hours to reduce plasma osmolality by 15 to 20 mOsm/kg. The amniotic fluid index determined by ultrasonography was measured at baseline, 8 hours, and 24 hours. A control group of pregnant women ( n = 5) with oligohydramnios at term was observed for 8 hours with maintenance intravenous hydration. RESULTS: In 1-deamino-[8-D-arginine] vasopressin - treated women, maternal urine flow increased with oral water loading, decreased with 1-deamino-[8-D-arginine] vasopressin administration, and remained reduced for 8 hours. Maternal plasma osmolality significantly decreased (285 ± 4 to 265 ± 4 mOsm/kg) and the amniotic fluid index significantly increased (4.1 ± 0.6 to 8.2 ± 1.5 cm) at 8 hours. Although maternal urine osmolality returned to basal values at 24 hours, plasma osmolality was reduced and the amniotic fluid index remained significantly increased (8.2 ± 1.3 cm). There was no change in the amniotic fluid index (4.3 ± 0.4 to 4.7 ± 0.7 cm) in control patients observed with maintenance intravenous hydration. CONCLUSIONS: Maternal 1-deamino-[8-D-arginine] vasopressin and oral water administration can reduce and stabilize plasma osmolality and increase amniotic fluid volume. 1-Deamino-[8-D-arginine] vasopressin therapy has potential for the prevention and treatment of oligohydramnios. (AM J OBSTET GYNECOL 1996;174:1608-13.)