The researchers found that women face a slightly increased risk of ectopic pregnancies after IVF. More surprisingly, they found that whereas in the normal population the risk of an ectopic pregnancy increases with women's age, after IVF the risk decreases with age in women who have had diseased Fallopian tubes.
Elizabeth Asung, an honorary research fellow at Leeds University and The Bridge Centre in London, UK, told the annual conference of the European Society of Human Reproduction and Embryology that she had analysed data from the UK's Human Fertilization and Embryology Authority (HFEA) on 97,240 women, aged between 18-50 who underwent either straightforward IVF embryo transfer (IVF-ET) or embryo transfer after ICSI (ICSI-ET) between 1991 and 1999.
She and her colleagues found that after ICSI-ET the incidence of ectopic pregnancies was 1.3% a figure that places it firmly in the range of incidence in the normal population. However, after IVF-ET the numbers increased by roughly a half from between 1-2% in the normal population to 2.8%.
Ms Asung said: "The difference in the numbers of ectopic pregnancies after IVF-ET and ICSI-ET may be because with ICSI the women tend to have no or fewer abnormalities associated with infertility because it's the man's fertility that is at issue. Whereas with IVF there's a higher proportion of women with compounding problems such as tubal disease, which may be contributing to their infertility and which are risk factors for ectopic pregnancies."
The study found that when women's Fallopian tubes had been damaged by tubal disease, the numbers of ectopic pregnancies increased to 6.1% in women under the age of 25, 4.1% between 25 and 29, 3.9% between 30 a
Contact: Emma Mason
European Society for Human Reproduction and Embryology