83 The variability of the maternal heart rate during labor of pregnant women with pre-eclânpsia and normotensive pregnant women and their correlation with maternal and perinatal outcomes.

Abstract

Objectives The association of autonomic modulation with maternal and perinatal outcomes was evaluated in preeclamptic women and in normotensive pregnancy women. Studied groups were matched for important determinants of HRV. Methods This is a prospective cross-sectional study evaluated the HRV in 36 pregnant women with gestational age over 28th weeks. All women had single fetus gestation and did not present any systemic disease prior pregnancy or were not using any type of medication during pregnancy. Seventeen women had preeclampsia (PE) and 19 normotensive pregnant (NP) women. Pregnant women with PE were kept in absolute rest in the left lateral decubitus and submitted to eclampsia prophylaxis with 6 g of magnesium sulfate at 50%, followed by 2 g/h continuous infusion. NP women did not receive any medication. During rest in the left lateral position, in the absence of uterine contractions or pain, patients were monitored Holter ECG recordings used for HRV analysis for 20 min. Natural logarithm (Ln) of mean NN (LnMean NN ), the the standard deviation of NN intervals (LnSDNN), the square root of the mean squared differences of successive NN intervals (LnRMSSD), low frequency (LnLF) and high frequency (LnHF) and LH/HF ration were used to evaluate HRV. Neonatal outcomes were evaluated immediately after birth being registered weight, Apgar index at 1 ° and 5 ° min and gestational age calculated by Capurro method. To compare the variables between groups we used ANOVA (ANOVA One Way) and for comparison post hoc Tukey test. Multivariable regression was performed using SPSS (Statistical Package for Social Sciences, Inc., Chicago, IL) version 16.0 for Windows. Descriptive data were presented as mean, SD and median. Student t test , Mann–Whitney and Chi-square test were using where apropriated. P 0.05 was considered significant. Results The comparative analysis of HRV demonstrated that PE women had significantly lower LnSDNN (25,93 ms vs. 41,72 ms, P .05) and LnRMSSD (13,25 ms vs. 24,76 ms, P 0.05). The LnSDNN was inversely correlated with the systolic blood pressure (SPB) (r-0.36, P .05) and diastolic blood pressure (DPB) (r-0,36, P .05) and directly correlated with gestational age (r 0.38, P .05). The LnRMSSD presented a positive correlation with gestational age (r 0.39, P .05). LF/HF was elevated in two groups (PE 7,5; NP 2,97). LnHF was directly correlated with gestational age (r 0.34, P .05). PE women had increased SBP (164,71 mmHg vs. 104,74 mmHg, P .001) and DBP(109,41 mmHg vs. 67,89 mmHg,P .001); newborns had lower weight (2694,67 g vs. 2937,89 g, P .05), lower Apgar Score in the 1 ° min (7,0 vs. 8,0, P .05) and in the 5 ° min (9,0 vs. 10, P .05). Three neonates from PE women were admitted to the neonatal ICU and one of them dies. Conclusion The study demonstrated that PE women have lower autonomic modulation by HRFcompared to NP women. This reduction is association to higher maternal blood pressure and lower gestacional age.