Two recent studies, published in the journal Human Reproduction last week, have revealed that implanting a single embryo during IVF procedures may result in improved pregnancy rates and could also be cheaper than when implanting two embryos.

Although implanting two or more embryos can improve chances of becoming pregnant during IVF, the practise has been linked to multiple births and associated medical problems such as premature birth, low birth weight and possible neurological problems, in addition a greater risk of other complications during pregnancy and birth. Further, multiple births are much more costly in terms of healthcare and other associated social costs than single births.

The first study utilised data from over 1,500 fertility patients under the age of 40, treated at Oulu University Hospital in Finland between 1995 and 2004. It found that when comparing the data from 1995 and 2000, when single embryo transfer (SET) was only used in 4.2 per cent of patients, with that from 2000-2004, when SET was used in 46.2 per cent of patients, the overall pregnancy rate and live birth rates were significantly higher and the multiple birth rate was lower.

Dr Hannu Martikainen, who led the first study, said 'This study shows that the implementation of an [elective] SET policy, together with an effective embryo freezing programme, results in a better outcome and lower treatment cost for women under the age of 40 having in vitro fertilisation, intra-cytoplasmic sperm injection (ICSI) or both. This refutes any concerns about the cost implications or efficacy of an eSET policy'. The study also found that a live birth from SET was on average nearly 20,000 euros less expensive than those born through double embryo transfer (DET).

In the second study, researchers used mathematical models to determine the cost-effectiveness of SET and double embryo transfer policies. 'A choice has to be made between three cycles of eSET, DET or standard treatment', said study leader Audrey Fiddelers, of the Academic Hospital Maastricht in the Netherlands. 'It is not cost effective to switch between these three treatment methods during the period of the three cycles of treatment', she said. The researchers said that the 'real-word' cost-effectiveness of each policy should be taken into account by policy makers in this area.

A single embryo transfer (SET) policy has been advocated by the Human Fertilisation and Embryology Authority in the UK, which regulates fertility clinics. Last year the British Fertility Society (BFS) and the Association of Clinical Embryologists (ACE) introduced new guidelines aimed at reducing the number of multiple births, recommending that a SET policy should be adopted for women under 37. SET remains elective, however, and it is up to patients and clinics to decide whether to transfer one or more embryos at a time.