Multifetal pregnancy reduction (MFPR) is a procedure used to reduce the number of fetuses in a multiple pregnancy, usually to two. When a pregnancy involves three or more fetuses (high-order pregnancy), the risks of miscarriage, stillbirth, and lifelong disability increase with each additional fetus.
The goal of MFPR is to increase the chance of a successful, healthy pregnancy. Multifetal pregnancy reduction:
- Is usually done early in a pregnancy, between the 9th and 12th weeks.
- Is most often done when there are four or more fetuses present.
- Can be used to reduce triplets to twins.
- Is known as "selective termination" when it involves a fetus with severe defects or one that is expected to die later in the pregnancy, which would threaten the life of the surviving fetus or fetuses.
The most common method of fetal reduction is transabdominal (through the belly) MFPR. For this procedure, the doctor uses ultrasound as a guide and inserts a needle through the woman's abdomen and into the uterus to the selected fetus. The doctor injects the fetus with a potassium chloride solution, which stops the fetal heart.
Because it is very small during the first trimester, the dead fetus is usually absorbed by the mother's body. This may include some vaginal bleeding. This absorption process is the same process that happens in the vanishing twin syndrome.
When there are three or more fetuses in the uterus, their risks of disability or death are higher with each additional fetus. A successful MFPR increases the chances of healthy survival for the remaining fetuses and reduces risks to you. But MFPR sometimes leads to miscarriage of the remaining fetuses, preterm labor, or infection.
What to think about
The decision to have a multifetal pregnancy reduction is difficult and traumatic. If you are faced with this decision, talk to your doctor about your personal risks from trying to carry multiple fetuses to term compared to the risks of choosing MFPR. Also consider discussing your decision with a counselor or spiritual adviser.
The American Society for Reproductive Medicine and the American Congress of Obstetricians and Gynecologists strongly recommend careful use of infertility treatment in the effort to avoid the risks of a triplet-or-more pregnancy and of MFPR. When embryos are transferred to the uterus, this means limiting the number of embryos that are transferred for each treatment cycle.