The vanishing twin

Women with twin pregnancies have some unique problems and some that occur more frequently than those seen in singleton pregnancies. Examples of the former are the 'vanishing' twin and death of one fetus. With the advent of sonography, a twin pregnancy may be diagnosed in early gestation. Serial sonographic examinations can show the disappearance of one of two twins. A 30-year-old multipara, who had 7 weeks 2 days gestation according to last menses period, was admitted to our department for routine sonographic examination. She had previous 3 healthy term pregnancies but there were no history of curettage and abortion before. We observed twin pregnancies in woman, who had their ultrasound examination at the 8th week of pregnancy. Positive heartbeat and yolk sac were registered in both embryos. When a further sonographic examination took place at the 11 th week for nuchal translucency, intrauterine death of one of the embryos was observed. Pregnancy continued as singleton pregnancy to uneventful term deliveries. After singleton term delivery a thickening of the membranes opposite to the main placenta showed degenerated chorionic villi embedded between one layer of amnion and chorion; no fetal parts were observed.