Fetal circulation 60 to 80 minutes after vaginal prostaglandin E2 in pregnant women at term.

We combined real-time B-mode ultrasonography with a 2 MHz pulsed Doppler technique to record blood flow in the fetal descending aorta and in the intra-abdominal part of the umbilical vein in 14 pregnant women at term. The blood flow was studied before and after instillation into the vagina of either 4 mg prostaglandin E2 (PGE2) gel or placebo gel. The PGE2 gel was significantly more effective in cervical priming and labor induction than the placebo gel. After instillation of the gel neither group showed a change in the fetal volume blood flow or in the aortic blood velocity waveform. We conclude that the instillation of 4 mg of PGE2 gel does not affect fetal hemodynamics at term.