Saidi, M.D., M. H.
Ultrasonic examination of early pregnancies can lead to the discovery of vanishing twins. The main reason for such an evaluation is bleeding in the first trimester. A vanishing twin need not adversely affect the development of a coexisting singleton pregnancy. Therapeutic dilation and curettage for threatened or inevitable abortion should be avoided until a sonogram rules out the presence of a potentially surviving twin.
The phenomenon of the vanishing twin is not widely recognized as a cause of first-trimester bleeding. Approximately 5% of patients who presented because of first-trimester bleeding carried this diagnosis. Significant numbers of patients with multiple pregnancy will experience first-trimester bleeding, but in those with a vanishing twin the incidence of early-pregnancy bleeding may be as high as 90%. Journal of Reproductive Medicine Volume 33, Number10/October 1988