Discrimination between chronological and ovarian age in infertile women aged 35 years and older: predicting pregnancy using basal follicle stimulating hormone, age and number of ovulation induction/intra-uterine insemination cycles

A marked decline in fertility rates has been demonstrated inwomen >35 years of age. We have previously demonstrated theimportance of basal follicle stimulating hormone (FSH) concentrationsplus chronological age to predict pregnancies in women aged40 years undergoing ovula-tion induction therapy. The purposeof the current study was to extend our previous study and determinethe impact of age, basal FSH concentrations and ovulation induction/intra-uterine insemination (IUI) treatment cycles on pregnancyrates in infertile women aged 35 years. This prospective observationalstudy was performed at a tertiary university fertility centre.Assessments of basal hormonal status and ovulation inductionprotocols were performed. The main outcome measured was clinicalpregnancies. A total of 770 treatment cycles in 179 women aged35 years were analysed. The impact of basal FSH concentrationson treatment outcomes could be bifurcated into a favourablegroup (FSH 23 mlU/ml) and a poor prognosis group (FSH 24 mlU/ml).A multivariate logistic regression model was generated whichaccurately predicted pregnancies. There was a high degree ofcorrelation between predicted pregnancies and observed pregnancies(r = 0.86). We conclude that age, number of treatment cyclesand the interaction term basal FSH x age are useful and significantpredictors of pregnancies in patients aged 35 years undergoingovulation induction/IUl therapy.