Amniocentesis and chorionic villus sampling for prenatal diagnosis

Area of Science:

• Prenatal Diagnostics
• Maternal-Fetal Medicine
• Genetic Screening

Background:

• Second trimester amniocentesis results are typically available after 18 weeks' gestation.
• Chorionic villus sampling (CVS) and early amniocentesis offer earlier diagnostic options between 9 and 14 weeks.

Purpose of the Study:

• To compare the safety and accuracy of second trimester amniocentesis, early amniocentesis, and transcervical and transabdominal CVS.
• Evaluate risks and outcomes associated with different prenatal diagnostic procedures.

Main Methods:

• Systematic review of randomized controlled trials (RCTs).
• Searched Cochrane Pregnancy and Childbirth Group trials register and Cochrane Central Register of Controlled Trials.
• Two reviewers assessed eligibility, quality, and extracted data.

Main Results:

• Second trimester amniocentesis showed a non-significant increase in pregnancy loss (1%) but a significant increase in spontaneous miscarriages compared to controls.
• Early amniocentesis demonstrated increased pregnancy loss and a higher incidence of talipes compared to CVS.
• Transcervical CVS had a significantly higher risk of pregnancy loss and spontaneous miscarriage compared to second trimester amniocentesis.
• Transabdominal CVS showed no significant difference in total pregnancy loss compared to second trimester amniocentesis.

Conclusions:

• Second trimester amniocentesis is safer than transcervical CVS and early amniocentesis.
• Transabdominal CVS is the preferred option for earlier diagnosis when compared to early amniocentesis or transcervical CVS.
• Transcervical CVS in the first trimester or second trimester amniocentesis are alternatives when transabdominal CVS is technically challenging.