Topic Overview

There are pregnancy problems that can be more likely with a multiple pregnancy.

Risks of multiple pregnancy may include:

• Miscarriage of one or more babies (fetuses).
• Gestational diabetes.
• High blood pressure and preeclampsia.
• Anemia.
• Increased chance of cesarean delivery.
• Increased chance of giving birth before 37 weeks (preterm birth), which poses greater risks of illness, disability, and death. For more information, see the topics Preterm Labor and Premature Infant.
• Having a baby born with a birth defect that occurs when something is wrong with the genes or chromosomes. Certain genetic disorders may be more likely to occur in multiple pregnancies.

Multiple pregnancies conceived by the use of assisted reproductive technology (ART) may have a greater risk of certain pregnancy problems.¹ Talk to your doctor about the risks related to your treatment.

Your chances of having a multiple pregnancy

In the general population, less than 3 out of 100 births involve twins, triplets, or more.¹ Your chances of conceiving a multiple pregnancy increase when you use fertility drugs and assisted reproductive technology (ART).

Currently, about 20 out of 100 multiple pregnancies occur naturally, while the other 80 out of 100 are the result of using fertility drugs or assisted reproductive technology.² The majority of these pregnancies are twins, but there are also more triplets (or more) than in the general population.

When assisted reproductive technology (ART), such as IVF, is used, the risk of conceiving a multiple pregnancy is directly related to the number of embryos transferred to a woman's uterus. Because of the risks of multiple pregnancy to the babies, experts recommend limiting the number of embryos transferred.