SQUID biomagnetometry of the uterine arteries in normal and pre-eclamptic pregnancies

Abstract

Aim: This study was designed to investigate the hemodynamics of the uteroplacental circulation in normal and pre-eclamptic pregnancies using the biomagnetometer SQUID.

Method: Twenty-two pregnancies complicated by preeclampsia and 49 normal pregnancies were included in this study. All were near term. Biomagnetic signals were recorded from the uterine arteries. After statistical Fourier analysis, the findings were designated in terms of spectral amplitudes as high (140–300 fT/√Hz), low (50–110 fT/√Hz) and borderline (111–139 fT/√Hz).

Results: The uterine artery waveforms and the corresponding spectral densities were of high amplitudes in most (89.7 %) normal pregnancies and of low amplitudes in most (81.8 %) pregnancies complicated by preeclampsia (p < 0.005). These findings were of statistical significance and were correlated with fetal heart rate (FHR) monitoring, pH, Apgar score at 1 and 5 minutes and birth weight percentiles: high amplitude cases were related with normal FHR patterns, pH > 7.25, Apgar score >7 and birth weight > 75^th percentile, while low amplitude recordings were connected with abnormal FHR patterns, pH < 7.25, Apgar score < 7, and birth weight < 10^th percentile (8 cases) and < 50^th percentile (10 cases).

Conclusion: Biomagnetic measurement of the uterine artery flow, is a promising procedure in assessing fetal health, especially in high-risk pregnancies.