IVF treatment continues to be a popular choice for making babies.
The treatment, known formally as in vitro fertilisation, is successful in producing a live birth in 41.4 per cent of treatment cycles for women under age 35, according to information released Monday by the Society for Assisted Reproductive Technology.
Data for 2009, the most recent year analysed, showed the rate of live births per cycle with fresh embryos did not change much from 2008, when it was 41.3 per cent for women under 35. However, that's an improvement from 2003, when the rate was 37.5 per cent.
Success rates fall off quickly for older women, however. In 2009, the percentage of cycles with fresh embryos resulting in live births was 31.7 per cent for women aged 35 to 37, 22.3 per cent for women aged 38-40 and 12.6 per cent for those aged 41-42.
The more embryos transferred, the higher the risk of multiple births. Several years ago, the Society for Assisted Reproductive Technology called on doctors and patients to limit embryo transfers to one in healthy, younger women who have a good chance of pregnancy.
But it appears as if SART's goal of reducing the number of embryos transferred isn't enthusiastically embraced. Only 7.2 per cent of women under age 35 opted for a single-embryo transfer in 2009, up from 5.2 per cent in 2008. In 2003, the rate was 0.7 per cent.
Overall, the average number of fresh embryos transferred was 2.0 for all age groups in 2009 compared with 2.6 in 2003.
The rate of live births with twins for women under age 35 was 32.9 per cent, a trend that hasn't changed much since 2003. The rate of triplet births in that age group, however, was 1.6 per cent in 2009 compared with 6.4 per cent in 2003.
The leading, single cause of infertility continues to be the male factor, which accounts for 17 per cent of cases in which people seek IVF treatment. A diminished number of eggs, which occurs most often in women age 35 and older, accounted for 15 per cent of cases, and in 12 per cent of cases the cause of infertility cannot be explained.
The rate of patients who elect to have preimplantation genetic diagnosis, in which a cell from the embryo is screened for evidence of genetic disorders, was 4 per cent in 2009.
The reports on specific clinics' success rates can be found on the SART website at www.sart.org. The society announced plans to enhance its website for consumers later this year to make it easier to find data.
