Objective: To describe methods and results of in-vitro fertilisation (IVF) treatment during the first 12 years after the introduction of IVF treatment in the Netherlands. Design. Retrospective cohort study.
Method: A nationwide study was conducted among women who had had their first IVF cycle stimulated with gonadotrophins in 12 IVF centres in the Netherlands in the period 1 January 1983 to 31 December 1994 (n = 8, 184).
Results: The subfertility diagnosis related to tubal factors decreased from 70% in 1987 to 25% in 1994. The subfertility diagnosis related to a male factor increased from 8.7% in 1987 to 35.5% in 1994. The mean age at first IVF treatment remained roughly constant. During the introduction of GnRH agonists there was an increase in gonadotrophin dosages, the number of retrieved oocytes, the number of high responders and/or women who experienced an ovarian hyperstimulation syndrome (OHSS). The percentage of deliveries with at least one baby born alive after the first IVF cycle increased from 6% in 1984 to 18% in 1994. The number of live births per 100 transferred embryos increased from 2.5 in 1985 to 12 in 1994. Furthermore, the mean numbers of embryos transferred after the first IVF cycle decreased from 3.2 in 1987 to 2.2 in 1994. The overall success rate - defined as the proportion of women who had at least one child born alive after one or more IVF cycles - for women who had their first IVF treatment between 1983 and 1994 was 37.1%. The percentage of triplets or quadruplets decreased from 8.7 in 1989 to 1.2 in 1994. The percentage of twin deliveries remained about 25.
Conclusion: The introduction of GnRH agonists and the higher dosages of gonadotrophins led to a higher oocyte harvest. During the first years of IVF treatment there was an increase in the success rate after the first treatment cycle. The overall success rate remained constant after 1991. The risk of developing an OHSS increased whereas the rate of twin deliveries remained constant.