What is a key advantage of transabdominal chorionic villus sampling (CVS) compared to transcervical CVS?

Transabdominal chorionic villus sampling (CVS) offers the key advantage of a decreased risk of maternal infection compared to transcervical CVS. The transabdominal approach involves inserting a needle through the abdominal wall under ultrasound guidance, which allows for a more direct sampling of the placental tissue. This method minimizes exposure to the cervix and the potential pathway for bacteria entering the uterus, thus reducing the risk of maternal infection.

In contrast, transcervical CVS involves passing a catheter through the cervix to the placenta, creating a higher risk for introducing pathogens from the vaginal flora into the uterine environment. This difference in the approach underlines the transabdominal method's safety profile regarding maternal infection risk.

While sample size is important, the amount obtained via transabdominal CVS is generally not significantly larger than that from transcervical CVS. Moreover, the training required for transabdominal CVS is often less complex than that for transcervical CVS, as it involves more familiar techniques related to ultrasound and needle guidance. Lastly, both methods can identify fetal abnormalities, but the prevalence of these abnormalities does not favor one approach over the other; rather, they are diagnostic interventions aimed at identifying potential issues.