Postpartum uterine artery blood flow impedance following cesarean section or vaginal delivery

Purpose: To compare uterine arteries (UtA) blood flow after cesarean section (CS) or vaginal delivery (VD). Methods: We performed a prospective case-control study comparing UtA blood flow impedance in patients who delivered by CS or VD. The UtA pulsatility index (PI) was measured with Doppler ultrasound during post partum using a transabdominal convex probe. Maternal and gestational age, parity, gravidity, and delay between delivery and Doppler measurement were noted. Results: We examined 106 postnatal patients, of whom 35 had CS delivery and 71 had VD. The median delay from delivery to Doppler measurement was 35 hours for the CS group and 32 hours for the VD group. The mean PI following CS and VD was 1.62 ± 0.45 and 1.42 ± 0.47, respectively. Using a linear model, the regression coefficients for mean, right, and left PI were not significantly different depending on the mode of delivery. There was no difference between emergency and elective CS. Conclusions: Early postpartum UtA blood flow impedance is not significantly different after CS or VD.