Indomethacin and corticosteroids: An additive constrictive effect on the fetal ductus arteriosus

The objective of this paper is to study the possible additive effect of cor ticosteroids to the known effect of indomethacin on potency of the human du ctus arteriosus. Systolic and diastolic blood flow of the fetal ductus arte riosus was measured by echo Doppler at 26-32 weeks of gestation. Four group s of patients were studied according to the treatment they have received: g roup A (exposure to indomethacin and betamethasone); group B (indomethacin alone); group C (betamethasone); and group D (controls). Children in whom d uctal constriction was noted in utero were followed by repeat cardiac echo Doppler examinations at the age of 1 to 2 years. In group A (indomethacin a nd betamethasone) fetal ductal constriction was significantly higher (p = 0 .02) and occurred in 1 1 out of 15 fetuses (73.3%), compared with 5 out of 14 (37.2%) of the fetuses in group B (indomethacin alone). In group C (beta methasone) and D fetuses (no treatment), no significant ductal constriction was observed. Pathological tricuspid regurgitation and right ventricular d ilation were found more frequently in fetuses from group A. No long-term se quella was noted in the infants in whom ductal constriction had been noted in utero. Corticosteroids and indomethacin have a synergistic effect on the frequency and severity of fetal ductus arteriosus constriction. In short-t erm treatment this effect is transient, and has no deleterious effects bn f etal and neonatal cardiac function.