title: The vanishing sac syndrome. Ultrasound evidence of pregnancy failure in multiple gestations, induced and spontaneous.
abstract: During a five-year period an ultrasound diagnosis of multiple gestations was made in 162 women. Four cases evidenced an empty gestational sac or sacs associated with viable, normal-appearing gestations. Three of the four patients had ovulation-induced pregnancies. Resorption of these empty sacs was documented. First- and early-second-trimester vaginal bleeding occurred frequently in these pregnancies and was a warning of the possible loss of one or more of the sacs.
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D010062:Ovulation Induction; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011272:Pregnancy, Multiple; D014463:Ultrasonography; D015017:Yolk Sac / Q000473:pathology