Fertility treatment in women with WHO type II ovulation disorder

Infertility affects about 10 to 15 percent of all couples that are trying to conceive. One of the main diagnoses of infertility is ovulation disorders. The World Health Organization (WHO) categorizes ovulation disorders in type I, II and III. WHO type I ovulation disorders are caused by hypothalamic pituitary failure. Type II ovulation disorders are defined as dysfunctions of the hypothalamic-pituitary-ovarian axis and includes polycystic ovary syndrome (PCOS). Type III ovulation disorders are caused by ovarian failure.
This thesis describes studies based on cohort and cross-sectional studies that have included women with WHO type II ovulation disorder, the largest group of women. At this time clomiphene citrate (CC) was the preferred first-line treatment for ovulation induction in women with WHO II ovulation disorder. Most guidelines nowadays advise to use letrozole as it is more effective and seems to result in less multiple pregnancies, but as letrozole is off-label for this indication, CC is still commonly used as first-line treatment. Women that do not ovulate on CC can undergo ovulation induction with letrozole, gonadotropins or laparoscopic ovarian drilling before moving on to IVF. Ovarian hyperstimulation syndrome (OHSS) is a complication of IVF. Women with high antral follicle counts (AFC), such as in women with PCOS, are at increased risk of developing OHSS. In vitro maturation (IVM) is an alternative treatment for IVF that is offered to prevent OHSS.
In this thesis we evaluated the effectiveness, safety and associated costs of the different treatment options, with special focus on the prevention of OHSS.