A Single Centre Experience with Selective Termination of Anomalous Foetus in Multifoetal Pregnancies.

Dear Editor, The percentage of multiple births has increased over the past 3 decades, primarily as a result of advanced maternal age, the greater use and success of assisted reproductive technologies. The incidence of foetal malformations is higher in multifoetal pregnancies compared to singletons.1 In dizygotic (DZ) twins, there is essentially more than twice the risk per pregnancy (independent probabilities per foetus); while in monozygotic (MZ) twins, there is an increased risk of structural malformations and the rates of Mendelian and chromosomal abnormalities are comparable to those of singletons. In both MZ and DZ twins, nearly 85% of cases have malformation that is confined to one foetus and the co-twin is normal. After the diagnosis of foetal anomaly with an apparently normal co-twin, a couple would be faced with the dilemma of the following 3 options: expectant management, terminate the whole pregnancy or selective termination (ST) of the abnormal foetus. Aberg et al2 reported the first successful selective birth from a twin pregnancy discordant for Hurler syndrome in 1978 following which Kerenyi and Chitkara3 reported selective birth for twins discordant for Down syndrome in 1981. Throughout the 1980s, a number of small series of second trimester selective terminations appeared in the literature, showing high loss rates and morbidity.4-6 The main variable in selecting the technique of ST is chorionicity. In dichorionic (DC) twins, intracardiac injection of potassium chloride (KCl) in the affected foetus is safe for the normal co-twin as vascular communications do not exist; while in monochorionic (MC) pregnancies, the risk of passage of KCl into the circulation of the normal cotwin through placental anastomosis precludes this technique.