Study claims 15 eggs ‘ideal’ for best IVF outcomes

FIFTEEN is the magic number for women undergoing fertility treatment, a study has found.

Doctors should aim to retrieve 15 eggs from a woman’s ovaries to give her the best chance of a live birth, say scientists. Live birth rates, which vary according to a woman’s age, decline when fewer numbers of eggs are used in a single cycle of IVF treatment.

Taking more than 15 eggs is not only less safe, but also no more effective, according to the research. The chances of giving birth level off between 15 and 20 eggs and then start to fall. As more eggs are taken, the risk of complications from over-stimulation of the ovaries increases.

Ovarian hyperstimulation syndrome (OHSS) can produce pain, weight gain, and in the most serious cases, dangerous blood clots and oxygen starvation.

The study, reported in the journal Human Reproduction, is the first major investigation of egg numbers in IVF treatment and live birth rates. Scientists analysed data from 400,000 IVF cycles in Britain between 1991 and 2008. A statistical technique was then used to produce a predictive model based on women’s age, numbers of eggs retrieved, and numbers of live births.

Dr Arri Coomarasamy, a consultant in reproductive medicine from the University of Birmingham, who co-led the research, said: “Our data show that around 15 eggs may be the best number to aim for in an IVF cycle in order to maximise the chances of a live birth while minimising the risk of (OHSS which is associated with a high number of eggs, usually over 20.”

Based on IVF outcomes between 2006 and 2007, the predicted live birth rate for women aged 18 to 34 with 15 eggs retrieved was 40%.