[Biochemical antenatal screening for fetal anomalies.]

Area of Science:

• Biochemistry
• Genetics
• Maternal-Fetal Medicine

Context:

• Antenatal screening for fetal chromosomal anomalies has historically relied on maternal age and invasive procedures.
• Biochemical markers in maternal serum have evolved from detecting neural tube defects to assessing chromosomal risk.
• Current strategies in Iceland, based on maternal age and fetal chromosome studies, require modernization.

Purpose:

• To review the evolution of biochemical antenatal screening for chromosomal anomalies.
• To highlight the development and potential of first-trimester screening protocols.
• To advocate for updating antenatal screening strategies in Iceland.

Summary:

• Biochemical screening began with maternal serum alpha-fetoprotein (MS-AFP) for neural tube defects.
• Low MS-AFP was associated with chromosomal anomalies, leading to multi-analyte screening tests.
• First-trimester screening using maternal serum pregnancy-associated plasma protein A (MS-PAPP-A) and free beta-human chorionic gonadotropin (MS-free β-hCG) combined with nuchal translucency ultrasound offers a more advanced approach.

Impact:

• Improved detection rates for fetal chromosomal anomalies.
• Potential for earlier and less invasive diagnostic interventions.
• Facilitates the adoption of evidence-based, advanced screening protocols in clinical practice.