Patent ID: 7374539

Claim:
A system for predicting maternal hypertension during pregnancy, comprising: a processor for calculating a coherence value using a magnitude-squared coherence function between a maternal blood velocity waveform and a fetal blood velocity waveform, the magnitude-squared coherence function defined by: |γ(ω)| 2 =(| S xy (ω)| 2 )/( S xx ((ω) S yy ((ω)), wherein |S xy (ω)| 2 is a cross spectrum of the maternal and fetal blood velocity waveforms and S xx (ω) and S yy (ω) represent a power spectra of the maternal and fetal blood velocity waveforms; a maternal sensor in communication with the processor for measuring the maternal blood velocity waveform; a fetal sensor in communication with the processor for measuring the fetal blood velocity waveform, wherein the maternal sensor and the fetal sensor are the same sensor; and a comparator configured to compare the coherence value to a predetermined threshold value to identify pregnancies at risk for subsequent hypertension.