Assisted reproductive technology practice patterns and the impact of embryo transfer guidelines in the United States  Judy E. Stern, Ph.D., Marcelle I. Cedars, M.D., Tarun Jain, M.D., Nancy A. Klein, M.D., C. Martin Beaird, David A. Grainger, M.D., M.P.H., William E. Gibbons, M.D.  Fertility and Sterility  Volume 88, Issue 2, Pages 275-282 (August 2007) DOI: 10.1016/j.fertnstert.2006.09.016 Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Percentage of cycles for each year in which a given number of embryos were transferred (ET): red squares, 1 or 2 embryos; yellow diamonds, 3 embryos; and green triangles, ≥4 embryos. (A) Women <35 years of age; (B) women 35 to 37 years of age; (C) women 38 to 40 years of age; and (D) women >40 years of age. The percentage of women with ≥4 embryos transferred declined for each of the first 3 age groups. Fertility and Sterility 2007 88, 275-282DOI: (10.1016/j.fertnstert.2006.09.016) Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

Figure 2 Percentage of HOM births (triplets or greater) for each year in age groups of women <35 years, 35 to 37 years, 38 to 40 years, and >40 years. Percentage of HOM births declined in the <35 and 35- to 37-year-old groups. Fertility and Sterility 2007 88, 275-282DOI: (10.1016/j.fertnstert.2006.09.016) Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

Figure 3 Effect of the 1998 guidelines on embryos transferred. (A) Percentage of transfers meeting the following criteria: for age <35 years, the percentage of cycles in each year with ≥4 embryos transferred is shown; for age groups 35–37 years, 38–40 years, and 41–42 years, the percentage of cycles in each year with ≥5 embryos transferred is shown. The vertical dotted line represents the year that the guidelines were first published (1998, in January). (B) Data are rates of change for each of those 4 age groups, calculated as the percentage difference between 2 consecutive years. Fertility and Sterility 2007 88, 275-282DOI: (10.1016/j.fertnstert.2006.09.016) Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

Figure 4 Modal numbers transferred: percentage of clinics. The y axis is the percentage of clinics in each category, where categories are the modal number of embryos transferred. A mode of 2 means that in each clinic for that age category, the most frequently transferred number was 2 embryos. Shown are the percentage of clinics with a mode of 2 (red diamonds), a mode of 3 (blue squares), a mode of 4 (green triangles), and a mode of ≥5 (yellow circles). (A) Women <35 years of age, (B) women 35 to 37 years of age, and (C) women 38 to 40 years of age. Fertility and Sterility 2007 88, 275-282DOI: (10.1016/j.fertnstert.2006.09.016) Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions