Abstract
With increasing use of in vitro fertilization and intracytoplasmic sperm injection (IVF-ICSI) almost 2% of all babies born in the United States each year are now conceived with these technologies, making outcomes of IVF-ICSI extremely important not only to patients and families but to public health. Twin pregnancy rates after IVF-ICSI in the United States have declined since their peak in 2013 but remain at approximately 1 in 10 to 1 in 20 pregnancies. A review of the current international literature on twin versus singleton pregnancy outcomes after IVF-ICSI treatment confirms statistically significantly higher risks to maternal and perinatal health and statistically significantly higher health care costs. The field of infertility care should continue to work to develop practices that lower twin pregnancy rates to an absolute minimum to maximize the safety of these medical treatments.