[Doppler flowmetric fetal indices in low-risk pregnancies]

In order to measure the umbilical resistance and pulsatility Doppler indexes 60 pregnant women with low risk pregnancies were studied in a descriptive, observational and prospective study carried out at the Hospital de Gineco-Pediatria numero 48 del Instituto Mexicano del Seguro Social. Umbilical Doppler measurements were done of the fetal umbilical cord from the week 30 at the 40 of gestation. We carried out a total of 337 measurements and 178 (52.8%) corresponded to the resistance index and 159 (47.2%) to the pulsatility index. The average of the resistance index was 0.64 with a range average (average plus two standard deviations was 0.48-0.79) and the pulsatility index had an average value of 0.94 with an average range of 0.58-1.30. The percentil values of the resistance index were 0.52, 0.66 and 0.79 respectively in the percentil 5, 50 and 95 whereas the percentil values of the pulsatility index were 0.64, 0.94 and 1.28 respectively in the percentil 5, 50 and 95. The analysis of variance with the Bonferroni test for multiple comparisons showed that our found indexes can be applied from the week 31 to the 40 of gestation. Our findings are in according to reported by other authors and it should be kept in mind that the concept of normality of the Doppler velocimetry indexes is strictly statistical and that only its judicious use will offer the benefit to our pregnant patients to obtain products under good conditions of health.