Exploring the relationship between fetal growth restriction and heart rate variability parameters

Abstract

Background: Fetal growth restriction (FGR) is a multifactorial disturbance of fetal nutrition with short- and long--term consequences (e.g. autonomic malfunction and delayed neurological maturation). Fetal heart rate variability (HRV) is critically dependent on autonomic regulation. This study focused on identifying a correlation between neonatal biometry and HRV variables. Material and methods: This was a descriptive cross-sectional study of 48 women at 22-36 weeks of pregnancy. The fetal cardiac signals were obtained from the maternal abdominal wall via non-invasive fetal electrocardiography (NI-FECG). The stress index (SI) was selected for evaluation among all linear HRV variables. Cardiotocographic parameters (short-term variation (STV) and long-term variation (LTV)) were determined, along with cardiographic: AC (acceleration capacity) and DC (deceleration capacity). Results: FGR was detected in 9 women. The fetal growth was appropriate in 31 patients. 8 patients were excluded from the study. The detected variables of HRV in FGR were different, however statistical significance was impossible to determine (small number of cases). A strong linear correlation was detected between all the HRV variables: AC, DC, SI, STV, and LTV. Whereas, AC and DC had significant correlation with the 1-minute Apgar score. Multivariate regression analysis showed a statistically significant correlation of SI with the gestational age at birth. Conclusions: SI could be of use in the advancement of conventional FGR management and has potential for further research.