Doctors determine IVF success rate

[Posted: Thu 15/01/2009 by Deborah Condon - www.irishhealth.com]

Scientists have determined the chances of having a successful live birth following IVF (in vitro fertilisation) treatment.

During IVF, a woman’s egg and a man’s sperm are fertilised in a laboratory and then implanted in the woman’s womb. The first IVF baby was born just over 30 years ago and since then, more than one million infants have been conceived using this treatment.

According to US researchers, when deciding whether or not to pursue IVF treatment, the obvious question most patients ask is, ‘what is the chance that this therapy will result in a baby?’ They now have an answer.

In the largest study of IVF patients to date, US researchers followed the progress of more than 6,000 women through six IVF cycles.

They found that the chances of a successful live birth following IVF therapy ranged between 65 and 86% in women under the age of 35 and between 23 and 42% in women aged 40 or older.

"This shows that, overall, IVF is extraordinarily effective and largely overcomes infertility, especially in younger women," said lead author, Dr Beth Malizia of IVF centre, Boston IVF.

Dr Malizia explained that traditionally, IVF has been reported as pregnancies per IVF cycle. However these calculations cab be difficult to comprehend. They can also be misleading because they do not take into account the difference in success between first time patients and patients who did not become pregnant in previous IVF attempts.

“Our goal in conducting this study was to provide information that would answer the patient's primary question – What is the chance that I will walk away with a baby?" she explained.

Each IVF cycle consists of four steps:
-The patient takes a course of fertility medication to encourage egg development.
-Eggs are then retrieved through a minor surgical procedure.
-The retrieved eggs are then fertilised in the laboratory.
-Approximately three to six days following egg retrieval, fertilised embryos are implanted in the woman's uterus.

The researchers used an analysis method which involved repeated observations of the study group over time and provided a more accurate estimate of a woman's history over multiple IVF cycles. From this, they calculated the cumulative live birth rate of the population.

"Our results showed that among 6,164 patients who underwent 14,248 cycles of IVF, the overall cumulative live birth rate after six cycles was 72% with the optimistic analysis and 51% with the conservative analysis," Dr Malizia said.

She pointed out that the chance of a live birth for women under the age of 35 was between 65 and 86%, while the figures were between 23 and 42% for those over the age of 40.

She also noted that of the 3,126 live births, the majority were ‘singletons’, while 27% were twin births and 2% were triplet births. There were no multiple births beyond triplets.

"IVF treatment has come of age. Although we continue to address the challenge of age-dependent decline in fertility, with these successful results, we have shown that fertility can be restored to the majority of young women who want to have a baby,” said the study’s lead author, Dr Alan Penzias of Boston IVF.

Details of these findings are published in the New England Journal of Medicine.