Human fetal cardiac function during the first trimester of pregnancy

Abstract

Objective: To investigate first trimester human fetal cardiac function in relation to cardiac volume blood flow, and peripheral arterial and venous blood flow patterns. Methods: Transvaginal Doppler ultrasonography was performed in 16 uncomplicated pregnancies at 6+, 7+, 8+, 9+, and 10+ gestational weeks. The shape of the inflow waveform and the presence of atrioventricular valve regurgitation (AVVR) were noted. The outflow mean velocity (Vmean) was calculated. The proportions of the isovolumetric relaxation (IRT%) and contraction times (ICT%) of the cardiac cycle were defined. Ductus venosus and umbilical artery pulsatility indices (PI) were obtained. Results: Every inflow waveform was monophasic before 9+ weeks. At 9+ weeks 11 of 16 and at 10+ weeks all waveforms were biphasic. At 7+ and 8+ weeks AVVR was documented in one case. At 9+ and 10+ weeks AVVR was present in four and seven fetuses, respectively. Mean (SD) outflow Vmean increased between 6+ and 8+ weeks from 3.6 (1.5) to 8.4 (3.0) cm/s (p , 0.05). IRT% decreased significantly from 6+ to 7+ weeks (39.8 (2.6) to 19.2 (6.2), p , 0.001). ICT% decreased between 8+ and 9+ weeks from 13.2 (4.0) to 8.5 (2.5) (p , 0.05). Ductus venosus PIs were unchanged. Umbilical artery Vmean increased between 7+ and 10+ weeks from 1.59 (0.51) to 5.06 (1.06) cm/s (p , 0.001) and PIs remained unchanged. Conclusions: The first trimester of pregnancy is characterised by significant improvements in cardiac diastolic and systolic function with a concomitant increase in cardiac volume blood flow. At 10+ weeks AVVR is a common finding. Placental volume blood flow increases significantly with no change in the placental vascular impedance.

Imaging Tools for the Developmental Biologist: Ultrasound Biomicroscopy of Mouse Embryonic Development

“…Diastolic cardiac function has been studied at mid-to late gestation, extending into the early postnatal and young adult stages. As characterized by the E/A waves across the atrioventricular valves, diastolic function matures through gestation and through the third week of postnatal life, with progressive improvements in active ventricular filling (57), similar to data found in other studies of mice and human (56,58). Thus, UBM-Doppler appears well-suited as a tool to study embryonic, fetal, and postnatal developmental cardiovascular physiology.…”

Evaluation of Conventional Doppler Fetal Cardiac Function Parameters: E/A Ratios, Outflow Tracts, and Myocardial Performance Index

“…1, 2). The biphasic shape of the E/A waveform can be seen from as early as 9 weeks of gestation as documented by Mäkikallio et al [1]. …”

A Reference for Ductus Venosus Blood Flow at 11-13⁺⁶ Weeks of Gestation

“…These results confirmed that cardiac compliance still increased during this gestational age range. A previous report showed that the DV blood flow showed antegrade flow during atrial contractions at a gestational age of less than 10+ weeks [12], and the fetal heart still had decreasing isovolumetric relaxation time during 11-14 weeks of gestation, indicating improving diastolic function [13]. As recommended by Bahlmann et al [14], the DV Doppler indices have greater reproducibility than only flow velocities.…”