Our objective was to investigate whether maternal administration of prostaglandins PGE2 and PGF2(alpha) is associated with changes in fetal ductus venosus flow velocity waveforms. Second-trimester termination of pregnancy was induced in 11 women (group A) by intra-amniotic instillation of 40 mg PGF2(alpha). In group B, 19 patients received 0.5 mg PGE2 intracervically for preinduction cervical ripening. Doppler flow velocity waveforms were recorded from the fetal ductus venosus immediately before and 40-60 min after prostaglandin administration. The paired t-test was used for statistical analysis of the ductus venosus index (DVI). The mean DVI decreased after PGF2(alpha) administration from 0.62 +/- 0.12 to 0.52 +/- 0.13 (p < 0.01); and from 0.62 +/- 0.10 to 0.58 +/- 0.12 (p < 0.05) after PGE2 administration. Atrial peak velocities were significantly increased after the procedures. No significant changes were found for systolic peak velocity values. The data indicate that major changes in ductus venosus hemodynamics are induced by PGF2(alpha) and PGE2.