The US Society for Assisted Reproductive Technology (SART) 2008 IVF Success Rate Report also showed the percentage of live triplets or more births of triplets remained below 2007 levels at less than 2 per cent. IVF multiple pregnancies are the single biggest health risk to both mother and child associated with fertility treatment, according to the British Fertility Society (BFS).
Multiple pregnancy increases the likelihood of miscarriage and death for the mother, and prematurity and low birth weight in the infant. It can also lead to long-term child health problems, and risks to mothers like pre-eclampsia, diabetes and heart disease. Single embryo transfer is the only effective method to reduce IVF multiple pregnancy rate.
The 2008 SART report includes figures from 361 fertility clinics, which reported on 140,795 IVF treatment cycles leading to the birth of 56,790 babies. SART has 392 member clinics, representing 85 per cent of fertility clinics in the US.
The report shows that the percentage of cycles using elective single embryo transfer (eSET) has increased from 2007, from 4.5 per cent to 5.2 per cent in under 35 year olds. In 2003, this figure was just 0.7 per cent. The percentage or live multiple births ranged from 25.2 per cent in 38-40 year olds to 35.2 per cent in under 35's.
In 2008, the Human Fertilization and Embryology Authority (HFEA) asked UK clinics to reduce multiple pregnancy rates from an average of 24 per cent to 10 per cent over three years. To help clinics meet these criteria and introduce an elective single embryo transfer policy for IVF treatment, guidelines were issued by the British Fertility Society (BFS) and the Association of Clinical Embryologists.
According to the BFS, one in four IVF births in the UK resulted in twins or triplets in 2008, compared to one in 80 births following natural conception. The UK's 2008 IVF success rates and figures will be available from the HFEA later this year.