FLOW VELOCITY WAVE-FORMS OF THE UTERINE ARTERY IN PREGNANCY - TRANSVAGINAL VERSUS TRANSABDOMINAL APPROACH

Our objective was to compare recordings of flow velocity waveforms fro m the uterine artery via the transvaginal and transabdominal approach in normal human pregnancies. In a cross-sectional study from 16 to 40 weeks' gestation, 88 healthy pregnant women underwent a continuous-wav e Doppler examination of their uterine arteries by both the transvagin al and the transabdominal approach. Measurements were recorded for bot h uterine arteries and averaged. Values recorded transabdominally were significantly lower than those obtained transvaginally in all patient s less than or equal to 27 weeks' gestation. From 28 weeks to term, tr ansabdominal values remained lower, but the difference was smaller and insignificant, and noted only as a trend. Transvaginal velocimetry of the uterine artery produces significantly higher systolic:diastolic r atios than that of transabdominal recordings until 27 weeks' gestation . Thereafter, trophoblastic invasion of the uteroplacental circulation is maximal, and the difference between the values are minimal and ins ignificant. However, a pattern of lower resistance in the transabdomin al approach remains consistent until term.