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