Increased fetal nuchal translucency at 11-14 weeks

Area of Science:

• Maternal-fetal medicine
• Prenatal diagnostics
• Medical imaging

Background:

• Nuchal translucency (NT) is fluid behind the fetal neck, measurable via ultrasound.
• NT measurement at 11-14 weeks is a key component of first-trimester screening.
• Increased NT is linked to various fetal abnormalities beyond chromosomal defects.

Purpose of the Study:

• To evaluate the efficacy of nuchal translucency measurement in prenatal screening.
• To assess the combined use of NT, maternal age, and biochemical markers for chromosomal defect detection.
• To highlight the association of increased NT with other fetal anomalies.

Main Methods:

• Sonographic measurement of fetal nuchal translucency thickness between 11-14 weeks gestation.
• Integration of NT measurements with maternal age for trisomy 21 screening.
• Incorporation of maternal serum markers: free-beta human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A).

Main Results:

• Combined NT and maternal age screening identifies approximately 75% of trisomy 21 cases at a 5% invasive testing rate.
• Adding beta-hCG and PAPP-A to NT screening increases chromosomal defect detection to about 90%.
• Increased NT is also associated with other chromosomal abnormalities, congenital heart defects, skeletal dysplasias, and genetic syndromes.

Conclusions:

• First-trimester NT screening, especially when combined with maternal age and serum markers, is a highly effective method for detecting fetal chromosomal abnormalities.
• Increased NT serves as an early indicator for a spectrum of fetal anomalies, including structural defects and genetic syndromes.
• Adequate training and rigorous auditing are crucial for the accurate implementation of NT screening in clinical practice.