Introduction

Polycystic ovary syndrome (PCOS) is associated with approximately 75% of the women who suffer from infertility due to anovulation (Adams et al. 1986, Hull 1987) and is frequently diagnosed for the first time in the infertility clinic. The majority of women with anovulation or oligo-ovulation due to PCOS often have clinical and/or biochemical evidence of hyperandrogenism. Almost all these women will have a typical ultrasonic appearance of the ovaries (Adams et al. 1985).

Making the diagnosis of PCOS is important as this will dictate the treatment plan and the prognosis, and will serve in the avoidance of possible complications of treatment. Before embarking on ovulation induction therapy, although not theoretically essential for initial therapeutic decisions, for screening I usually take a blood sample for luteinizing hormone (LH), follicle stimulating hormone (FSH), total testosterone, and fasting glucose and insulin concentrations. The ratio of fasting glucose to insulin levels gives a good indication of insulin sensitivity (Legro et al. 1998) and as hyperinsulinemia is present in about 80% of obese women and 30–40% of women of normal weight with PCOS (Dunaif et al. 1989) and is strongly associated with anovulation then it is certainly useful to know for possible therapeutic intervention. The LH value may be expected to be high in 40% of women with PCOS and is thought to be detrimental to successful ovulation induction and to the incidence of miscarriage (Balen et al. 1995).