Effect of chorionic villus sampling on serum alpha fetoprotein levels

Area of Science:

• Prenatal Diagnosis
• Maternal-Fetal Medicine
• Biochemistry

Background:

• Chorionic villus sampling (CVS) is an early first-trimester prenatal diagnostic technique.
• Maternal serum alpha-fetoprotein (AFP) screening is used for neural tube defect detection between 14-17 weeks gestation.
• Previous research indicated amniocentesis can elevate maternal serum AFP levels.

Purpose of the Study:

• To investigate the immediate impact of CVS on maternal serum AFP levels.
• To clarify potential alterations in AFP levels following CVS.
• To assess the implications for prenatal screening protocols.

Main Methods:

• CVS performed under sonographic guidance on 22 patients (6-12 weeks gestation) undergoing elective termination.
• Villi obtained using a Portex catheter.
• Maternal serum AFP levels measured by radioimmunoassay before and after CVS.

Main Results:

• No significant change in AFP levels observed in patients ≤ 8 weeks gestation.
• A significant rise in post-biopsy AFP levels noted in 7 of 14 patients > 8 weeks gestation.
• Suggests a gestational age-dependent effect of CVS on maternal serum AFP.

Conclusions:

• CVS may cause a transient increase in maternal serum AFP, particularly in later first-trimester gestations.
• Further research is needed to confirm these findings in ongoing pregnancies.
• Clarification is essential for integrating CVS into comprehensive prenatal screening strategies.