Analysis of the heart rate variability and ventricular repolarization during pregnancy and after labour

Investigates the time course of the ECG parameters that are affected during pregnancy and after labour through the analysis of heart rate variability and ventricular repolarization. In 29 pregnant women, three stages have been studied: at 6 months pregnant (6MP), at 9 months (9MP) and one month after labour (1ML). Time- and frequency-domain parameters were evaluated on 24-hour Holter ECG recordings, for diurnal and nocturnal periods. The obtained results showed: (1) 9MP vs. 1ML provides significant differences between the parameters in the time- and frequency-domains in diurnal and nocturnal periods; (2) only ventricular repolarization parameters can distinguish 9MP from 6MP during nocturnal periods; (3) 6MP vs. 1ML only shows significant differences between the time- and frequency-domain parameters during nocturnal periods. In conclusion, the parasympathetic influence on heart rate variability decreases with time during pregnancy, reaching its minimum in the last month and recovering after labour