A multi-specialty panel made up of representative from radiologists, obstetricians and gynecologists, and emergency providers is calling for stricter standards to determine the viability of a fetus in a first-trimester pregnancy.
The 15-member panel, led by Peter Doubilet, Ph.D., of Brigham and Women's Hospital and Harvard Medical School, was convened by the Society of Radiologists in Ultrasound; its conclusions were published in an article in the Oct. 10 issue of the New England Journal of Medicine.
"When a doctor tells a woman that her pregnancy has no chance of proceeding, he or she should be absolutely certain of being correct," Doubilet said in an announcement. "Our recommendations are based on the latest medical knowledge with input from a variety of medical specialties. We urge providers to familiarize themselves with these recommendations and factor them into their clinical decision-making."
Among the changes recommended by the panel: in order for a pregnancy to be diagnosed as nonviable in the first trimester, an ultrasound would have to show an embryo measuring at least seven millimeters without a heartbeat, up from the previously accepted measurement of five millimeters.
In addition, the panel recommended that the standard for nonviability based on the size of the gestational sac without an embryo should be increased from 16 millimeters to 25 millimeters, and suggested that the commonly used "discriminatory" level of the pregnancy blood test is not reliable for excluding a viable pregnancy.
The panel also warned physicians against taking any action that could damage a uterine pregnancy based on the results of one blood test if ultrasound findings are inconclusive and the woman is in stable condition.
"With improvement in ultrasound technology, we are able to detect and visualize pregnancies at a very early age," panelist Kurt T. Barnhart, M.D., an obstetrician-gynecologist at the Perelman School of Medicine at the University of Pennsylvania, said. "These guidelines represent a consensus that will balance the use of ultrasound and the time needed to ensure that an early pregnancy is not falsely diagnosed as nonviable. There should be no rush to diagnose a miscarriage; more time and more information will improve accuracy and hopefully eliminate misdiagnosis."