Mrs. XYZ Primigravida unregistered uninvestigated women came with complaints of 8 months pregnancy and preterm labour pains. On Examination, General condition was fair, per abdomen 34 wks cephalic presentation, FHS 160 beats/min regular, uterine activity 1-2/10/10. She was admitted and started on IV tocolytics and steroids. Her routine investigations were send which came in normal limits. Her USG obstetrics showed single live foetus average gestational age 35 wks 4 days. She complained of pain in abdomen after 2 days with leak per vaginum. On Examination : she was getting good uterine contraction of 2-3/10/20 and pervaginum examination : cervix was 2.5 cms dilated with membranes absent, vertex presentation, st at 0. Labour was allowed to progress she delivered 2.2 kgs Nearterm baby cried immediately afterbirth apgar 8,9,9. Placenta got expelled after 5 mins and methergin was administered to her.

On examination of the placenta there were two cords and the other cord was connected to paper like thin baby which was the foetus papyraceous or vanishing twin (Fig. 1).

Mother and baby otherwise didn’t had any other complication and she was discharged after 2 days.

Enbom1 has reported that the incidence of twin pregnancy with a single intrauterine death ranges from 0.5% to 6.8%. An incidence of 3.7% was reported in a prospective study of 188 monozygotic twins in the National Collaborative Perinatal Project figures. However, are overestimates owing to biases in case selection and reported gestation. “Vanishing twin syndrome” is described as a twin pregnancy that was diagnosed at one time, but with just one baby being eventually delivered. Even when there are two viable foetuses identified in the first trimester, the disappearance rate for one of them can reach 29%.2

The vanishing twin phenomenon is relatively common, and the prognosis for the surviving foetus is good.2 In contrast single foetal death in the second or third trimester is uncommon and has been shown to be associated with increased risk of mortality and morbidity for the surviving twin.3 In general, chorionicity rather than zygosity determines the risk of mortality and morbidity. Hence, it is important to determine the type of placentation by ultrasonography. The perinatal mortality of monochorionic twin pregnancies is double that of dichorionic twin pregnancies.4

Aetiology : Causes usually include twin-to-twin transfusion syndrome, velementous insertion of the cord.

Maternal Complications : The association between retention of dead foetus of twins in utero and maternal disseminated intravascular coagulation was first noted in 1950. The principal defect as a gradual reduction in fibrinogen level. This complication usually occurs 3 or more weeks after the foetal demise.

The traditional approach to the demise of a twin has been deliver the survivor to avoid embolization. Cattanach et al favour conservative management until 37 weeks gestation. If foetal movements, cardiotocography, and ultrasonography show no abnormalities.5 Santema et al have advocated treating impending preterm labour before 34 weeks with intravenous tocolytics.6 Carlson and Towers have recommended that delivery should be considered after 32 weeks if lung maturity is documented; if the lungs are immature, steroids could be given and maturity re-evaluated afterwards.7 It has been suggested that after 37 weeks pregnancy should be terminated.

The sequelae of a single foetal death in twin pregnancy depend on the gestation and in the second and in the late third trimester there is increase in mortality or morbidity in the surviving twin. Antenatal evaluation periodically by ultrasonography is important to reduce the potential risk. Conservative management remains the main stay but the risk of keeping the alive foetus in the hostile intrauterine environment has to be weighed against the risk of preterm delivery.