Abstract: A computer-implemented method for detecting fetal peaks in a maternal ECG signal includes steps of receiving the maternal ECG signal and preprocessing the maternal ECG signal wherein preprocessing includes removal of mECG R-peaks to form a process ECG signal that includes both fetal and noise peaks. Both fetal and noise peaks are detected using a peak detection algorithm which yields an array of peaks Xk×1. Permutations of all peak differences are calculated by subtracting elements of Xk×1 from its transpose Xk×1T to form a matrix Mk×k. Characteristically, elements in the matrix Mk×k corresponds to different sample periods that are used to determine peak positions. An array of periods denoted an array LP×1 is calculated. A 3-dimensional matrix GP×k×k is constructed by dividing Mk×k by each element of LP×1. An optimal Mk×k is determined by finding the Mk×k in the 3-dimensional matrix GP×k×k that has it's first row with the most elements near a whole number.