Serological prenatal screening and diagnosis for Down syndrome

Area of Science:

• Medical Genetics
• Prenatal Diagnostics
• Public Health

Background:

• Birth defects pose a significant public health challenge.
• Prenatal screening plays a crucial role in the secondary prevention of congenital anomalies.
• Existing screening protocols require continuous evaluation for efficacy.

Purpose of the Study:

• To review and summarize first-trimester, second-trimester, and sequential prenatal screening methods.
• To analyze the effectiveness of the current prenatal screening system in preventing birth defects.
• To assess the detection rates of chromosomal abnormalities and neural tube defects.

Main Methods:

• Inclusion of 3,665 pregnant women undergoing 14-20 week screening (AFP, beta-hCG, ultrasound).
• Inclusion of 512 pregnant women undergoing 9-12 week early screening (beta-hCG, PAPP-A, NT).
• Karyotype analysis for high-risk cases.

Main Results:

• Overall high-risk rate of 8.52% identified.
• Detection of five trisomy 21, one trisomy 18, and one "47, XXY" case among 308 karyotyped fetuses.
• Diagnosis of one anencephalus and one open spina bifida case among 37 NTD-affected high-risk pregnancies.

Conclusions:

• The prenatal screening system achieved a 3.25% detection rate for chromosomal abnormalities.
• The system effectively identifies and allows for intervention in cases of serious teratogenic fetuses.
• Prenatal screening is vital for secondary prevention of birth defects.