Curvas normales de índices de pulsatilidad y tiempo medio de desaceleración de arteria umbilical fetal en población chilena

Abstract

Objective: To describe a normal curve of pulsatility index (PI) and half peak systolic velocity deceleration time (t/2) of fetal umbilical artery in chilean population. Method: Cross-sectional study including low-risk singleton pregnancy with childbirth at least 37 weeks. Doppler velocimetry was performed in umbilical artery between 11 and 41 weeks, IP and t/2 was measured. Results: 877 fetuses were studied; polynomial curves for IP were obtained (y = 0.0013 x2-0.105 x + 2.936, r2= 7425) are presented percentiles 5, 50, 90 and 95. For t/2, a linear curve was obtained (y = 6.4243 x + 14.448; r2= 0.7749), and are presented percentiles 5, 10, 50 and 95. On examinations less than 20 weeks is observed that 100[%] by 11 weeks fetuses had absent umbilical diastolic flow, this proportion decreases to 0[%] at 15 weeks. Conclusion: We present a cross-sectional study showing curves of pulsatility index and half peak systolic deceleration time for Chilean population, analyzing IP curves observed an important difference with Arduini curves with values between 18 and 22[%] lower, observation coincides with other recent tables and suggests that they should use these new values to avoid under diagnosis of placental insufficiency.