A team of researchers found that women’s success rates using in vitro fertilization (IVF) did not improve much after the first three cycles. About one in three women had a baby after their first attempt with IVF, and nearly half carried a child to term the second time. But by the third attempt, the success rate did not rise much further, the AP reports.
The study, which was presented Wednesday at the American Society for Reproductive Medicine conference in Denver, was based on data on more than a half-million IVF procedures performed in the U.S. between 2004 and 2008. Among about 300,000 women who underwent IVF, there were 171,327 first-time deliveries.
The live birth rate was 36% with the first IVF cycle, 48% after the second try and 53% on the third. From that point, the success rate did not increase much: among women who tried IVF for seven cycles or more, the chance of a live birth was 56%. (More on Time.com: Building a Brighter Kid: Consider IVF)
“Don’t quit if the first cycle isn’t successful. Your chances go up with the second cycle,” lead researcher Barbara Luke of Michigan State University told the AP. “[But] if you haven’t gotten pregnant by the third, the chances are slim to continue.”
While this type of data could potentially be of great help to doctors and hopeful women deciding how long to continue trying IVF — an expensive procedure at $12,400 per cycle on average — the results of the current study are too preliminary to guide treatment.
Also, the researchers did not control for factors that affect fertility, such as age, weight and other factors. Because it is so difficult to predict the individual response of each woman attempting IVF, it is equally difficult to say when or whether a woman should quit trying or switch to other options, such as using donor eggs. Further study will attempt to clarify the odds. (More on Time.com: 5 Pregnancy Taboos Explained (or Debunked))
Other findings presented at the Denver conference:
A new contraceptive gel effectively prevented pregnancy in 18 women, without causing side effects common to the birth-control pill, such as weight gain, sickness and dampened libido. [Via New Scientist]
In a study of women, average age 35, who were seeking fertility treatment, those who had Type O blood showed signs of having fewer eggs and lower fertility. [Via BBC]
Men who ate more saturated fats (burgers and fries, e.g.) had fewer and less active sperm than men who ate less; men who ate more polyunsaturated fats (fish, whole grains) had more active and healthier looking sperm than men who ate less. [Via HealthDay]
More on Time.com:
Video: Filming Embryos Improves Chances of Pregnancy