Multifetal pregnancy reduction may be performed between weeks 11 and 12 of gestation. It is an invasive procedure to reduce the number of fetuses if there are specific indications of serious complications both for the mother and the fetuses. A fine needle is inserted transabdominally under continuous ultrasound guidance and cardiac asystole of the selected fetus is induced via intracardiac potassium chloride infusion. The invasive reduction procedure carries a 4% risk of miscarriage when the initial number of fetuses is three, while it is 6-8% when the initial number is over four.