KNOWLEDGE YOU CAN USE

KNOWLEDGE YOU CAN USE
Business and science in conflict: Why is the number of multiple births – twins, triplets, and more – on the rise?

Question 25.12

Q: Multiple births are in the news a lot. Are they on the rise? Yes! between 1980 and 2008, the incidence of twins in the United States increased by 70%. The rate of triplets and higher multiples increased even more.

Question 25.13

Q: Why are there so many more multiple births? Consider this: if you are running a fertility clinic, one of the most important pieces of information that will lead to the success or failure of your clinic is the percentage of treated couples who become pregnant. Unfortunately, in most ART procedures, this number is influenced by the number of embryos transferred into the woman: 5 –10 transferred embryos are more likely to result in pregnancy than 1– 4 transferred embryos. The problem is, though, that with 5 –10 embryos transferred, the risk of “multiples”—twins, triplets, or more—also increases, as does the health risk to the mother and the babies. And so the decision regarding the number of embryos to transfer involves a trade-off between the perceived effectiveness of the clinic and the risk to the mother. This point was vividly illustrated in 2009 by the case of Nadya Suleman (called “Octomom” by the media), a California woman who gave birth to octuplets after eight embryos were implanted.

Question 25.14

Q: Are fertility clinics bringing the rate back down to safer levels? In the past 10 years, the proportion of in vitro fertilization cycles in which four or more embryos were transferred dropped from 62% to 21%. This has significantly reduced the incidence of triplets, but the rate of twins has remained high. And although, for women under 35, the American Society of Reproductive Medicine now recommends the transfer of just a single embryo during ART procedures, for women above 35, it still recommends 3–5 embryos be transferred.

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