Effect of maternal oral hydration on amniotic fluid index in women with pregnancy-induced hypertension

Objective: To evaluate the effect of maternal oral hydration on amniotic fluid index (AFT) in women with pregnancy-induced hypertension. Methods: Five women with pregnancy-induced hypertension and five normotensive gravidae at 32-37 weeks gestation with normal AFT (8-18cm) were hydrated by oral intake of 2 L of water over 1 h. Both groups were similar in age, parity and gestation. Repeat AFT was measured in all women after 3 h. The differences between pre- and post-hydration AFT in the two groups were analyzed with Student's t-test for statistical significance. Results: Maternal oral hydration resulted in a significant increase in AFT in both hypertensive and normotensive gravidae (1.7cm and 3.48cm, respectively). However, the extent of increase was significantly lower in the hypertensive group (P = 0.03). Conclusion: Pregnancy-induced hypertension adversely affects the increase in amniotic fluid volume with maternal hydration. This observation is of clinical relevance in the management of oligohydramnios associated with pregnancy-induced hypertension.