Informative value of maternal heart rate variability detrended fluctuation analysis for gestational complications prognosis

Abstract

Aim: to assess the prognostic value of maternal heart rate variability (HRV) detrended fluctuation analysis (DFA) for the early prediction of gestational pathology taking into account special characteristics of neuroautonomic regulation in pregnant women. We have examined 102 somatically healthy women with uncomplicated pregnancy (control, Con) and 469 women at low and moderate pregnancy risk with different types of gestational pathology (GP group) diagnosed retrospectively (after delivery). The categories of obstetric complications considered were preeclampsia, intrauterine growth restriction, labor abnormalities and miscarriage. Mean age and gestational time at the moment of exam were 24.9±4.7 yrs. and 21.2+3.1 wks. (M+SD) respectively. I70.1% of them were primiparas. DFA decrease in dynamics of maternal moderate voluntary hyperventilation (not more than 1.5 of respiratory minute volume determined at rest), was found in 61.4 and 6.2% of GP and Con groups respectively (p<0.001) in women with autonomic misbalance of sympathetic predominance (overactivity). So, positive likelihood ratio (LR+) of DFA test was 0.614/0.062=9.9. As a comparison, women at unload condition and with one of the biased autonomic profile (sympathicotonic, vagotonic or baroactive) show LR+ value as low as 1.4. The positive DFA test result in the form of this index decrease under maternal voluntary hyperventilation upon initial condition of increased sympathetic activity in pregnant women enhances pretest odds for gestational pathology approximately tenfold. It makes this test informatively valuable as much as “gold standard” for the early prediction of pregnancy complications.