Technique modifications for reducing the risks from amniocentesis or chorionic villus sampling.

Area of Science:

• Perinatal medicine
• Obstetrics
• Fetal medicine

Background:

• Current guidelines for amniocentesis and chorionic villus sampling (CVS) lack specificity on instrument choice, leading to varied operator practices.
• A survey in UK specialist centers revealed significant practice variations, highlighting the potential impact of standardized techniques on procedural safety.

Purpose of the Study:

• To systematically review and compare the safety and effectiveness of all amniocentesis and CVS techniques used for prenatal diagnosis.

Main Methods:

• Searched the Cochrane Pregnancy and Childbirth Group's Trials Register for randomized controlled trials comparing different amniocentesis or CVS methods.
• Included studies involved amniocentesis after 15 weeks' gestation or transabdominal/transvaginal CVS. Excluded quasi-randomized studies.
• Two authors independently assessed study eligibility, quality, and extracted data, with accuracy checks performed.

Main Results:

• Five randomized studies (1049 women) evaluated technique modifications in amniocentesis (3 studies) and CVS (2 studies).
• For amniocentesis, interventions like intramuscular progesterone, hexoprenaline, and puncture site selection showed no conclusive benefits.
• Similarly, terbutaline tocolysis and continuous vacuum aspiration during CVS lacked conclusive evidence of benefit.

Conclusions:

• The overall quality of evidence is insufficient to alter current clinical practice for amniocentesis and CVS.
• In the absence of strong evidence, practitioners should continue using familiar techniques and instrumentations.
• High-quality randomized trials with adequate power and safety outcome measures are needed to guide practice modifications.