Prenatal screening for neural tube defects.

Area of Science:

• Obstetrics
• Medical Genetics
• Developmental Biology

Background:

• Neural tube defects (NTDs) are prevalent birth defects, occurring in 4-15 per 10,000 live births.
• NTDs result from the failure of the neural tube to close during embryonic development.
• Periconceptional antiepileptic drug use (e.g., valproate, carbamazepine) and folate deficiency are linked to increased NTD incidence.

Purpose of the Study:

• To review current prenatal diagnostic methods for neural tube defects.
• To highlight the implications of prenatal diagnosis for obstetric management and public health programs.
• To discuss the effectiveness and limitations of various diagnostic procedures.

Main Methods:

• Review of established prenatal diagnostic procedures for NTDs.
• Assessment of serum markers: maternal serum alpha-fetoprotein (MSAFP) and acetylcholinesterase (AChE).
• Evaluation of prenatal ultrasonography and amniocentesis for NTD detection.

Main Results:

• Elevated MSAFP and AChE levels ( >2 multiples of the median) indicate NTDs, with optimal screening at 10-18 weeks gestation.
• Antenatal ultrasonography offers comparable sensitivity to serum markers with lower false positivity rates.
• Amniocentesis shows elevated amniotic fluid AFP and AChE but carries a risk of iatrogenic fetal loss.

Conclusions:

• Prenatal diagnosis of NTDs is crucial for obstetric management and preventive strategies.
• Ultrasonography is a valuable, non-invasive tool, though expertise is required for early detection.
• Comprehensive couple counseling is an essential component of NTD screening programs.