Primary prevention of Down's syndrome

Area of Science:

• Genetics
• Reproductive Medicine
• Public Health

Background:

• Antenatal screening detects over 90% of Down's syndrome pregnancies, facilitating therapeutic abortion.
• Primary prevention of Down's syndrome has seen limited progress despite extensive research.
• The fundamental cause of Down's syndrome remains unknown.

Purpose of the Study:

• To evaluate primary prevention strategies for Down's syndrome.
• To review etiological hypotheses for Down's syndrome.
• To inform future research directions for Down's syndrome prevention.

Main Methods:

• Consideration of three primary prevention strategies: maternal age, pre-implantation genetic diagnosis, and folic acid supplementation.
• Review of principal etiological hypotheses for Down's syndrome.
• Analysis of current evidence for each prevention strategy.

Main Results:

• Completing family building before maternal age 30 could reduce Down's syndrome birth prevalence by over 50%.
• Pre-implantation genetic diagnosis offers high pregnancy rates with very low Down's syndrome risk for eligible women.
• Insufficient evidence exists to support folic acid supplementation as a primary Down's syndrome prevention strategy without further clinical trials.

Conclusions:

• Delaying childbearing and utilizing pre-implantation genetic diagnosis are effective primary prevention strategies.
• Current folic acid supplementation guidelines for neural tube defects may offer incidental Down's syndrome prevention if high doses are used.
• Advancing primary prevention requires a renewed focus on understanding the etiological basis of Down's syndrome.