Increased fetal heart rate variability in periventricular leukomalacia

Abstract

Objective: This study used quantitative analysis to determine whether increased variability in fetal heart rate (FHR) is related to the risk of developing periventricular leukomalacia (PVL).

Methods: We analyzed 124 FHR traces of neonates delivered preterm at 27-33 weeks' gestation to 105 mothers. FHR traces 1-3h before delivery were translated into power-spectrum curves using a fast Fourier transformation. The total power (the area under the curve of 1-10 cycles per minute), segmental power of every cycle per minute, peak power, and frequency edges were calculated, and their relationship with the subsequent development of PVL was examined.

Results: Total power was significantly higher in the PVL group (n=9, median 1813, range 1064-2426) compared to the non-PVL group (n=114, median 1383, range 381-3324, p=0.029). Infants in the PVL group had greater segmental power in segments with 1-2, 2-3, and 9-10 cycles per minute, than those in the non-PVL group. Total power of ⩾1550 was significantly correlated with the subsequent development of PVL and premature rupture of membranes. Furthermore, the frequency of pregnancy-induced hypertension was significantly reduced in the fetuses with a total power of ⩾1550.

Conclusion: Our study suggests that a fetus with increased FHR variability is at risk of developing PVL. This study provides additional evidence supporting the contribution of antenatal factors to the subsequent development of PVL.

Keywords: Fast Fourier transform; Fetal heart rate; Long-term variability; Periventricular leukomalacia.