First-Trimester Serum Screening Called Premature.

VAIL, COLO. -- Physicians now offering first-trimester screening for aneuploidies are jumping the gun, according to Dr. Richard L. Berkowitz, professor and chairman of ob.gyn. at Mt. Sinai School of Medicine in New York.

This screening approach has enormous potential, but "it's not ready for prime time," he declared at a conference on obstetrics and gynecology sponsored by the University of Colorado.

Key questions about first-trimester screening remain unanswered, but they are being addressed in the ongoing First And Second Trimester Evaluation of Risk for Aneuploidies Trial (FASTER). Every physician who cares for pregnant women should seriously consider sending patients for enrollment in this 35,000-patient trial, Dr. Berkowitz said.

"I strongly feel that this [first-trimester screening] is investigational despite the fact that there are places all over the country that are beginning to offer this commercially. I believe we will have the answer to our questions within a couple of years," he added.

FASTER is designed to definitively evaluate first-trimester screening for Down syndrome and other aneuploidies using serum biochemical markers and/or ultrasound to measure nuchal translucency--the space between the back of the fetal neck and the overlying skin.

The first-trimester serum biomarkers employed in the study are pregnancy-associated plasma protein-A (PAPP-A) and free [beta]-HCG.

One potential major advantage for first-trimester screening is that pregnancy termination is safer and technically much easier than with the current standard of care-the second-trimester maternal serum triple screen-which often doesn't lead to a definitive diagnosis until late in the second trimester. First-trimester screening is also often easier emotionally for the patient, since many people don't know she's pregnant.