Does the number of embryos transferred differ for day 3 and day 5 embryo transfers?
Multiple-infant births are associated with greater problems for both mothers and infants, including higher rates of caesarean section, prematurity, low birth weight, and infant disability or death. Part A of Figure 38 shows that among the 16,813 live births that occurred following day 3 embryo transfer, 69% were singletons, 28% were twins, and about 3% were triplets or more. Thus, approximately 31% of these live births produced more than one infant. In 2005, 7,947 live births occurred following day 5 embryo transfer. Part B of Figure 38 shows that 36% of these live births produced more than one infant (approximately 34% twins and 2% triplets or more). As shown in Figure 37, fewer embryos were transferred on day 5 than on day 3. While the reduction in the number of embryos transferred on day 5 was associated with a decrease in triplet‑or‑more births, it also was associated with an increase in twin births. Thus, the risk of having a multiple‑infant birth was higher for day 5 embryo trans
