Referential intervals of the pulsatility index of fetal umbilical artery in peruvian population

Objective: To describe the reference values of the umbilical artery Doppler pulsatility index in healthy fetuses of pregnant women aged 14-40 weeks attended at the National Maternal Perinatal Institute during the period 2011-2016. Material and methods: A Retrospective observational study. We evaluated all healthy fetuses of 2,633 pregnant women at low risk, in the fetal-obstetrics department of National Maternal Perinatal Institute, from 14 to 40 weeks, who were measured the pulsatility index between 2011 and 2016. Participants: Healthy fetuses in order to determine referential intervals of pulsatility index. Results: The percentile shows a progressive decrease from 14 to 40 weeks. The pulsatility index in percentile 50 started with 1.7 in week 14 and decreased to 0.81 in week 40. The pulsatility index percentile 95 started with 2.35 in week 14, decreased to 1.68 in week 20, 1.29 in week 30, to 1.18 in week 36 and to 1.13 in week 40. The pulsatility index 1.13 in percentile 95 is normal for everyone weeks. The pulsatility index 2.35 is abnormal for every one week. Conclusions: The pulsatility index curve of the uterine artery presents similar descriptions in previous studies of other populations; however, knowledge of the eigenvalues in the Peruvian population can be useful as an indicator to discriminate fetus in good conditions in our population.