Purpose: to evaluate the effectiveness of diagnostic amnioinfusion in severe oligohydramnios. Methods: twelve patients with severe oligohydramnios in the second and third trimester of pregnancy were submitted to amnioinfusion. The procedure was done using a warm physiological saline at a rate of 20 mL/min followed by the instillation of 5 mL of dye. The amniotic fluid index (AFI) was measured before the procedure and 30 min afterwards and in case of fetal anomalies, it was documented. The gestational age ranged from 18 to 34 weeks (average 25 ± 4 weeks). The average of the initial ILA was 10.3cm and after the procedure was 16.4 cm. The volume of saline solution infused ranged from 300 to 1000 mL (605.4 ± 224.1 mL). Results: in nine patients (75%) the procedure led to an etiologic diagnosis: four cases of premature rupture of membranes and major malformations in five fetuses. In two patients the oligohydramnios was considered idiopathic and in one patient the pathological examination revealed a placental infarct. Nine pregnancies (75%) were interrupted after the diagnosis and in three cases it was maintained for 8.8 weeks after the amnioinfusion. All fetuses died, seven of them had neonatal death and the remaining had intrauterine death. Conclusion: amnioinfusion is an effective method with high precision, enabling the etiologic diagnosis of severe oligohydramnios in 75% of the cases.
Amnioinfusion; Oligohydramnios; Fetal malformations; Premature rupture of membranes
