Noninvasive fetal electrocardiography showed cardiac time intervals increased with gestational age, with mean P-wave duration increasing from 43.9 ms at 18-22 weeks to 52.9 ms at ≥37 weeks (p<0.001).
Observational (n=100)
Noninvasive fetal ECG successfully detects cardiac time intervals, demonstrating that these intervals increase with advancing gestational age in normal fetuses.
OBJECTIVES: To evaluate the fetal cardiac time intervals from the longitudinal analysis of noninvasive fetal electrocardiography (fECG) in normal pregnancies. METHODS: One hundred singleton pregnancies were examined in this longitudinal study. Cardiac time intervals were derived from fetal electrocardiograms obtained noninvasively using three electrodes placed on the maternal abdomen. The variables measured included the durations of the P wave, PR interval, QRS complex, QT interval and T wave. RESULTS: Success rates for detecting the P, QRS and T waves were 74.6, 91.0 and 79.3%, respectively. Cardiac time intervals were significantly influenced by fetal age. The mean P-wave duration increased from 43.9 (18--22 weeks) to 52.9 ms (>/=37 weeks) (p /=37 weeks (p /=37 weeks respectively. From 18 to 22 weeks to >/=37 weeks, QT(c) values increased from 343.8 to 367.7 ms (p < 0.001), while T-wave durations increased from 123.8 to 152.4 ms (p < 0.001). CONCLUSIONS: Serial noninvasive fECG of normal fetuses from 18 to 41 weeks of gestation show good success rates of fECG detection. Cardiac time intervals generally increased with increasing gestational age.
Chia et al. (2005) conducted an observational in normal pregnancies (n=100). noninvasive fetal electrocardiography (fECG) was evaluated on fetal cardiac time intervals. Noninvasive fetal electrocardiography showed cardiac time intervals increased with gestational age, with mean P-wave duration increasing from 43.9 ms at 18-22 weeks to 52.9 ms at ≥37 weeks (p<0.001).