More Assisted Reproduction, But Fewer Multiple Births
THURSDAY May 28, 2009 -- Each year, 219,000 to 246,000 babies conceived through assisted reproductive technology (ART) are born worldwide, says an international study that also found that the number of ART procedures increased by more than 25 percent between 2000 and 2002.
Researchers analyzed 2002 data from 1,563 clinics in 53 countries but noted data were missing from a number of countries, mostly in Asia, Africa, Oceania and the West Indies.
"There are several important points to highlight," said Professor Jacques de Mouzon, a public health specialist at INSERM in Paris who led the International Committee for Monitoring Assisted Reproductive Technology that wrote the study.
"There has been a constant increase in ART activity: it increased by more than 25 percent in the two years since the previous report for the year 2000. This is due not only to an increase in the number of countries participating in this report but also to an increase in ART activity in most individual countries," de Mouzon said in a news release.
"However, there are wide variations between countries in the availability and quality of ART. There are several reasons for this, such as fertility rates, women's age, insurance cover, the national economy, but the most important is certainly inequality in access to health care and ART. In Western Europe it is easier for people to access good health care, and funding for ART tends to be more generous than in developing countries," de Mouzon said.
Among the other findings:
- Between 2000 and 2002, the use of intracytoplasmic sperm injection (ICSI) -- as opposed to conventional in vitro fertilization (IVF) -- increased up to 61 percent in North America, 54 percent in Europe, 76 percent in Latin America and over 92 percent in the Middle East.
- Even with a decrease in the number of embryos transferred, pregnancy and delivery rates have increased for both frozen and fresh embryo cycles. In 2002, more than 601,250 ART cycles resulted in delivery rates per aspiration (attempt at egg retrieval) of 22 percent for IVF, 21 percent for ICSI and 15 percent for frozen embryo transfer. In 2000, those rates were 19 percent, 20 percent and 12 percent, respectively.
- When fresh embryo and frozen embryo cycles were combined, the global cumulative delivery rate per aspiration was 26 percent.
- There was a decrease in transfers of multiple embryos, which resulted in a small decline in multiple births. The percentage of transfers of four or more embryos decreased from 15.4 percent in 2000 to 13.7 percent in 2002. The percentage of twin pregnancies decreased from 26.5 percent to 25.7 percent, and the rate of triplet pregnancies decreased from 2.9 percent to 2.5 percent.
A 47 percent increase in the proportion of frozen embryo transfer cycles was notable because it led to improved cumulative pregnancy and delivery rates and decreased the number of multiple embryo transfers and multiple births, de Mouzon said.
"Our report shows that delivery rates per aspiration increased in 2002 even though the average number of embryos transferred was reduced. For example, in Australia, where a mean average of 1.8 embryos were transferred, the delivery rate per aspiration was 19.5 percent for fresh cycles and 29.4 percent for fresh and frozen cycles together. This should encourage countries to implement embryo transfer policies that reduce the risk of multiple births," he said.
The study was published online May 28 in the journal Human Reproduction.
The U.S. Centers for Disease Control and Prevention has more about ART.
Posted: May 2009