<prompt> Selective reduction of multi chorionic multifetal gestation is performed around4 to 6 weeks8 to 10 weeks10 to 13 weeks16 to 20 weeks  <response>: Selective Reduction Reduction of a selected fetus or fetuses in a multi chorionic multifetal gestation may be chosen as a therapeutic intervention to enhance survival of the remaining fetuses ACOG, 2013a.Transabdominal fetal reductions are typically performed between 10 and 13 weeks. This gestational age is chosen because most spontaneous aboions have already occurred, the remaining fetuses are large enough to be evaluated sonographically, the amount of devitalized fetal tissue remaining after the procedure is small, and the risk of aboing the entire pregnancy as a result of the procedure is low. The smallest fetuses and any anomalous fetuses are chosen for reduction. Potassium chloride is then injected under sonographic guidance into the hea or thorax of each selected fetusRef: Williams Obstetrics; 25th edition 