Recent advances in obstetrical ultrasound

Park, Yong Won; Hwang, Han Sung

Abstract

An obstetrical ultrasound examination provides invaluable information regarding the fetus. Many publications from the last years have advanced the use of ultrasound in obstetrics. With the advent of high-resolution ultrasound and transvaginal scanning, a significant amount of information about the fetus have been gained, and provided to the patient. It must be emphasized to evaluate the fetus for structural malformations, and searches for the sonographic markers of fetal aneuploidy in first trimester because it allows the early diagnosis of many conditions. The presence of sonographic markers including the nuchal fold, short femur and humerus, pyelectasis, hyperechoic bowel, echogenic intracardiac focus, and any major abnormality, either singly or in combination, will raise the baseline risk of aneuploidy using likelihood ratios calculated for each individual marker. Fetuses with abnormal Doppler velocimetry in the uteroplacental, umbilical, and fetal circulations but normal chromosomes are at higher risk for adverse pregnancy outcome, including preeclampsia and growth restriction. Improved technology has lowered the gestational age at which fetal cardiac anatomy scanning can be reliably performed by properly trained and experienced examiners. Early fetal echocardiography can be offered as a screening examination to at-risk and low-risk patients, with the condition that it be repeated following screen-negative scans at mid-gestation to exclude later developing lesions. This review describes the recent advances in the role of first trimester ultrasound in screening and diagnosis of fetal anomalies, a number of new ultrasound markers for fetal aneuploidy, Doppler ultrasonography, and fetal echocardiography.