Fetal hepatic artery flow assessment in prenatal diagnostics – a review of the literature

Abstract

Standards of screening tests for the most frequent fetal chromosomal defects in modern non-invasive prenatal diagnostics provide sensitivity of about 93-96%, with the false positive rate of 2.5%. During the first trimester scan, routinely performed between 11 and 13+6 week of pregnancy, the calculation of the risk for chromosomal aberrations is based on maternal age (MA), nuchal translucency (NT), levels of free β human chorionic gonadotropin (free β-hCG), pregnancy associated plasma protein A (PAPP-A) in maternal blood, as well as the parameters from extended ultrasound examination like evaluation of the nasal bone (NB), blood flow in ductus venosus (DV), visualization of the tricuspid valve with potential regurgitation (TR) or measurement of the frontomaxillary facial angle (FMFA). The 100% detection rate remains unachievable at present, despite constantly improving guidelines for specialists, quality of imaging, and advancement in ultrasound technology. Therefore, several studies have been undertaken to establish the group of ‘additional markers’ of chromosomal defects which, when combined with basic markers of routine screening tests, might increase the detection rate and approach it to 100%. Results of recent studies imply that evaluation of blood flow in fetal hepatic artery performed during the first trimester scan may become a new additional marker for chromosomal defects.