So-called "prenatal portraits" and ultrasound parties, in which parents-to-be visit commercial outfits for the chance to see and coo at their growing babies, may be trendy, but the Food and Drug Administration is speaking out against both practices. This week, the group issued a revised consumer update discouraging the use of fetal ultrasounds and heartbeat monitors to create "keepsake images" and videos, emphasizing that ultrasounds should be performed only when there is a medical need -- and under the supervision of appropriately trained medical professionals. "Although there is a lack of evidence of any harm due to ultrasound imaging and heartbeat monitors, prudent use of these devices by trained health care providers is important," Shahram Vaezy, an FDA biomedical engineer, said in the update.