Maternal Right Hypogastric Artery Blood Flow during Normal Pregnancy and 6 Weeks Postpartum

Abstract

To document and quantify the temporal hemodynamic changes occurring in the pelvic circulation in normal human pregnancy, and to compare these changes with those found 6 weeks postpartum. Thirty-three patients had color pulsed Doppler evaluation of the right hypogastric artery six times during pregnancy and once 6 weeks postpartum. Pulsed Doppler waveforms were digitized to assess the time velocity integral (area under the Doppler curve = TVI) and the peak flow velocity (maximum velocity = PFV). The diameter of the vessel was determined during systole using high-resolution two-dimensional ultrasound from a longitudinal plane. A quantitative estimate of the blood flow through this vessel was calculated by multiplying the TVI by the calculated cross-sectional area of the vessel. The cross-sectional area and the indexed volume of blood flow per minute of the hypogastric artery were significantly greater during pregnancy compared with the postpartum value. The estimated vascular resistance index was significantly decreased during pregnancy. Time velocity integral was significantly lower at the initial study compared with the postpartum value. The hypogastric artery undergoes significant hemodynamic changes during pregnancy when compared to the postpartum period. Furthermore, the pelvic circulation displays these changes early in gestation.