How to avoid multiple pregnancies in assistive reproductive technologies

Since 1980, there has been a worldwide dramatic increase in multiple births . This seems to be due to an increase in the age of reproduction, the use o f ovulation induction, and the use of in vitro fertilization. Scarce data s uggest that each of these causes is responsible for about one-third of the problem, although quintuplets and more are almost invariably due to ovulati on induction. There has been little or no effort to issue guidelines or reg ulations with respect to ovulation induction, but there has been much advic e as to how to control the problem in in vitro fertilization by limiting th e number of embryos to be transferred. In sum, a good selection of high-qua lity embryos on day 3 would allow a high rate of pregnancy with the transfe r of one or two blastocysts. Good results of cryopreservation must be part of an agreement in an in vitro fertilization program. If singleton live bir thrates were considered to be the principal outcome of assisted reproductiv e technologies reported by centers and registry, twin and triplet rates sho uld also be reported separately. And finally, if financial considerations w ould not limit the cost of reimbursement to in vitro fertilization procedur es, the number of procedures could be increased with fewer embryos transfer red.