Normal fetal cardiac flow velocity waveforms between 11 and 16 weeks of gestation

Abstract

Objectives: The purpose of our study was to determine the nature of fetal cardiac flow velocity waveforms in late-first- and early-second-trimester pregnancies.

Study design: Eighty-eight normal pregnancies were studied according to a cross-sectional study design between 11 and 16 weeks of gestation.

Results: Fetal waveforms at the semilunar level showed a gestational age-related rise in peak systolic flow velocities, with significantly higher velocities in the ascending aorta. Similarly, a gestational age-related rise in peak-E wave (early diastolic filling) and peak-A wave (atrial contraction) velocity was observed at the atrioventricular level, with significantly higher velocities at the tricuspid valve level.

Conclusions: Compared with late gestation, these data suggest a reduced ventricular compliance or ventricular relaxation rate and a raised cardiac afterload in the normally developing late-first- and early-second-trimester fetus.