Multifetal pregnancy reduction and selective termination

Key content Multifetal pregnancy reduction (MFPR) and selective termination (ST) are conceptually different procedures. Essential prerequisites for delivering these interventions are detailed counselling, multidisciplinary input within a tertiary fetal medicine service, careful choice of operative technique and appropriate gestational age, depending on the type of pregnancy and indication. Operative techniques that may be used are chemical, thermal, radiofrequency and laser, depending on chorionicity as well as other factors. Intracardiac potassium chloride is appropriate to employ when there is independent chorionicity and carries a lower risk of pregnancy loss; vascular occlusion using radiofrequency ablation, bipolar coagulation or intrafetal laser can be employed in monochorionic fetuses and twin reversed arterial perfusion pregnancies, but carry a higher risk of pregnancy loss. Women struggle with decision-making, particularly with fetal reduction, and should be supported with frank discussion of the risks, but also emotionally: the need for emotional and psychological support may long outlast the pregnancy. Learning objectives To know the differences between first trimester MFPR, second trimester cord occlusion and third trimester ST. To understand that MFPR is an intervention to reduce preterm birth-related disability in high-order multifetal pregnancies. To understand procedural outcomes and complications of MFPR and ST to enable adequate planning for subsequent obstetric care. Ethical issues The decision to undergo ST to improve the chances of survival of one fetus over another may have consequences on the parental project and the grieving process. Ethical questions are raised when MFPR occurs following in vitro fertilisation in which more than two embryos were intentionally transferred. In uncomplicated twin pregnancies, MFPR to singleton may reduce the risk of late preterm birth, but the benefit in long-term outcomes is less clear.