Improved detection rate of structural abnormalities in the first trimester using an extended examination protocol

Area of Science:

• Prenatal diagnostics
• Fetal medicine
• Medical imaging

Background:

• First-trimester screening for fetal abnormalities is crucial for early intervention.
• Traditional screening methods may miss significant structural defects.
• An extended ultrasound protocol aims to enhance detection rates.

Purpose of the Study:

• To evaluate the efficacy of a detailed first-trimester sonography protocol in detecting fetal abnormalities.
• To assess the feasibility of this extended protocol using standard resources.
• To compare early detection rates with those in mid-pregnancy and postnatal evaluations.

Main Methods:

• Prospective, two-center study of 5472 unselected pregnant women at 12-13+6 weeks gestation.
• Utilized an extended morphogenetic ultrasound protocol including color Doppler cardiac sweep and early marker identification.
• In addition to basic evaluation, specific attention was given to contingent markers for major abnormalities.

Main Results:

• Prevalence of lethal and severe malformations was 1.39%.
• The first-trimester scan detected 40.6% of all identified cases and 76.3% of major structural defects.
• Detection rates for major congenital heart disease (90%) and central nervous system anomalies (69.5%) were high. Fetuses with increased nuchal translucency had a 96% detection rate for major anomalies.

Conclusions:

• A detailed first-trimester anomaly scan using an extended protocol is an efficient screening method for major fetal structural abnormalities in low-risk pregnancies.
• The protocol is feasible with existing ultrasound equipment and personnel during routine first-trimester screening.
• Early detection of severe malformations, particularly congenital heart disease, is improved with this extended protocol, including color Doppler.