Clinical factors that influence chorionic villus sampling sample size.

Area of Science:

• Prenatal Diagnostics
• Medical Genetics

Background:

• Chorionic villus sampling (CVS) is a crucial early-gestation prenatal diagnostic procedure.
• Understanding factors influencing sample size is vital for diagnostic accuracy and procedural success.

Purpose of the Study:

• To identify clinical and procedural factors affecting sample size in chorionic villus sampling (CVS).
• To investigate the impact of maternal Body Mass Index (BMI) on CVS sample yield.

Main Methods:

• Retrospective cohort study of singleton pregnancies undergoing transabdominal (TA) and transcervical (TC) CVS (2020-2023).
• Analysis of prenatal and maternal data from electronic medical records.
• Linear regression used to determine factors associated with sample yield.

Main Results:

• A total of 240 CVS procedures were analyzed (91 TC, 149 TA).
• Transcervical CVS yielded larger sample sizes compared to transabdominal (37.1 mg vs 32.4 mg).
• Higher BMI was significantly associated with smaller sample yield, even after adjusting for approach and placental location.

Conclusions:

• Chorionic villus sampling remains a key tool for early prenatal diagnosis.
• Higher maternal BMI is a significant factor associated with reduced sample yield in CVS.
• Procedural approach and placental location did not fully mitigate the effect of BMI on sample size.