First-Trimester Bleeding and the Vanishing Twin: A Report of Three Cases

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