Oligohydramnios associated with prostaglandin synthetase inhibitors in preterm labour.

The use of prostaglandin synthetase inhibitors (indomethacin and ibuprofen) for greater than 72 h in women with preterm labour (n = 67) was significantly (P less than 0.001) associated with ultrasound-recorded oligohydramnios compared with the use of ritodrine or magnesium sulphate (control group, n = 67). Oligohydramnios developed in 26 of 37 women (70%) treated with indomethacin and 8 of 30 women treated with ibuprofen (27%) (P less than 0.01). Oligohydramnios developed in only two control subjects and one of these pregnancies was associated with intrauterine growth retardation. All 34 cases of oligohydramnios in the treatment group resolved after stopping medication, whereas the two in the control group did not resolve. No instances of renal failure, premature closure of the ductus arteriosus, pulmonary hypertension, or bleeding disorders were noted in any of the treated or control infants.