Scottish Unexplained Infertility Trial (SUIT) – A pragmatic randomised controlled trial of clomiphene citrate versus intra-uterine insemination for the management of unexplained infertility
Jill Mollison with Siladitya Bhattacharya, Allan Templeton (Aberdeen), Helen Lyall (Glasgow), Tony Harrold (Dundee), Clement Tay (Edinburgh), David McQueen (Falkirk) and Sarah Wordsworth (Oxford)
Infertility affects one in seven couples. In a quarter of these cases, the cause remains unexplained and treatment involves a variety of empirical interventions that can be stressful, expensive and potentially morbid. The literature remains divided over the choice of effective treatments. Although the absolute treatment effect is small, oral clomiphene citrate (CC) remains a popular and non-invasive option, whilst intrauterine insemination (IUI) without gonadotrophin stimulation potentially offers the best chance of success whilst avoiding the risks of multiple pregnancy. Some couples will become pregnant without treatment, thus an expectant management control group is required to assess the background live birth rate in the Scottish population of couples with unexplained infertility.
SUIT is a three arm parallel group randomised controlled trial conducted in 5 infertility centres in Scotland. Couples are randomly allocated to receive CC or IUI (six consecutive treatment cycles over 8 months) or delayed treatment (six months of expectant management). The primary outcome is live birth rate per couple with secondary outcomes including pregnancy rates, acceptability and satisfaction, service and patient costs, multiple pregnancy rates and ovarian hyperstimulation. Target sample size was 582 couples. Recruitment commenced in September 2001.
