Number of Eggs Retrieved Helps Predict IVF Success: Study
WEDNESDAY May 11, 2011 -- Retrieving about 15 eggs from a woman's ovaries in a single in vitro fertilization (IVF) cycle offers the best chance of achieving a live birth while avoiding complications from fertility medications, according to a new study.
Researchers analyzed more than 400,000 IVF cycles in the United Kingdom between 1991 and 2008 and found a strong association between live birth rates and the number of eggs retrieved in one cycle.
The live birth rate rose with an increasing number of eggs up to about 15, leveled off between 15 and 20 eggs, and declined steadily beyond 20 eggs.
The study appears online in the journal Human Reproduction.
"Our data show that around 15 eggs may be the best number to aim for in an IVF cycle in order to maximize the chances of a live birth while minimizing the risk of ovarian hyperstimulation syndrome (OHSS), which is associated with a high number of eggs, usually over 20," Dr. Arri Coomarasamy, a clinical reader and consultant in reproductive medicine and surgery at the University of Birmingham, said in a journal news release.
"Mild stimulation protocols aim to retrieve less than six to eight eggs; a standard stimulation should aim for 10-15 eggs, and we believe this is what is associated with the best IVF outcomes," said Coomarasamy. "When the egg number exceeds 20, the risk of OHSS becomes high."
Ovarian hyperstimulation syndrome can occur when women are given hormone drugs to stimulate the production of eggs for collection for IVF cycles. Abdominal pain, swelling, nausea and vomiting often appear in mild or moderate OHSS. In rare, severe cases, OHSS can be a life-threatening medical emergency.
The U.S. Centers for Disease Control and Prevention has more about assisted reproductive technology.
Posted: May 2011