PURPOSE: to analyze the fetal heart rate (FHR) and umbilical artery Dopplervelocimetry between 18th and 20th weeks of gestation in pregnant women complicated by pregestational diabetes mellitus. METHODS: twenty-eight pregnancies with pregestational diabetes and 27 normal pregnant women were analyzed prospectively, in a cross-sectional and case-control study. The inclusion criteria were the following: singleton pregnancy between 18 and 29 weeks, no other associated maternal diseases and no fetal abnormality. Ultrasonography was performed and FHR was calculated by the interval between the beginnings of two consecutive cardiac cycles, in the three umbilical artery Doppler sonograms, obtained in the umbilical cord near to the placental insertion, using color Doppler. Five consecutive FHR cycles from each sonogram were measured, to analyze mean FHR and its variation. The following Doppler indices were studied: systolic/diastolic ratio, pulsatility index (PI) and resistance index (RI). Student's t test and Mann-Whitney Utest were applied to comparative study. p values were considered significant when p<0.05. Results: no significant difference was observed in mean FHR between the studied groups (diabetic group: 149.2 bpm, control group: 147.2 bpm; p = 0.12). FHR variation revealed similar results between the groups (diabetic group: 5.3 bpm; control group: 5.3 bpm; p=0.50). No significant difference was found in the Doppler indices S/D (p=0.79), PI (p=0.25) and RI (p=0.71) between the groups. CONCLUSIONS: the absence of differences in FHR characteristics between the 18th and 20th gestational weeks indicates similar neurological maturation of FHR regulatory systems in this period, between fetuses of diabetic mothers and controls. Abnormalities in the uteroplacental resistance were not identified in the studied period, in pregnancies complicated by pregestational diabetes.
Diabetes mellitus; Heart rate; fetal; Ultrasonography; doppler; Laser-doppler flowmetry; Ultrasonography; Umbilical arteries
