When it comes to procedures, experience counts.

In a recent op-ed in the WSJ, maternal-fetal medicine fellow Adam Wolfberg talks about the potential complications of chorionic villus sampling (CVS) (via Suture for a Living). Used to assess the risk of Down Syndrome in the fetus, it involves inserting a 3 1/2 inch needle into the mother’s uterus to obtain cells from the placenta. The rate of miscarriage is around 1 percent.

But studies have shown that doctors who perform more CVS procedures have a lower complication rate. Thus, a dilemma presents itself, where physician’s “present-day patients benefit at the expense of previous patients.”

Unlike surgeries, where doctors can learn within a team construct, CVS involves an individual doctor with a single needle. And despite the various ways institutions have tried to train doctors doing the procedure, such as using computer models, pigs, women undergoing elective abortions, none compare to doing it in a real-life situation.

Consequently, those that are qualified to perform CVS are swamped, and there’s a long wait for mothers who require the test.