Are ovarian reserve tests reliable in predicting ovarian response? Results from a prospective, cross-sectional, single-center analysis

While live birth is the principal clinical outcome following in vitro fertilization (IVF) treatment, the number of eggs retrieved following ovarian stimulation is often used as a surrogate outcome in clinical practice and research. The aim of this study was to explore the association between egg number and live birth following IVF treatment and identify the number of eggs that would optimize the IVF outcome. Anonymized data on all IVF cycles performed in the UK from April 1991 to June 2008 were obtained from the Human Fertilization and Embryology Authority (HFEA). We analysed data from 400 135 IVF cycles. A logistic model was fitted to predict live birth using fractional polynomials to handle the number of eggs as a continuous independent variable. The prediction model, which was validated on a separate HFEA data set, allowed the estimation of the probability of live birth for a given number of eggs, stratified by age group. We produced a nomogram to predict the live birth rate (LBR) following IVF based on the number of eggs and the age of the female. The median number of eggs retrieved per cycle was 9 [inter-quartile range (IQR) 6-13]. The overall LBR was 21.3% per fresh IVF cycle. There was a strong association between the number of eggs and LBR; LBR rose with an increasing number of eggs up to ∼15, plateaued between 15 and 20 eggs and steadily declined beyond 20 eggs. During 2006-2007, the predicted LBR for women with 15 eggs retrieved in age groups 18-34, 35-37, 38-39 and 40 years and over was 40, 36, 27 and 16%, respectively. There was a steady increase in the LBR per egg retrieved over time since 1991. The relationship between the number of eggs and live birth, across all female age groups, suggests that the number of eggs in IVF is a robust surrogate outcome for clinical success. The results showed a non-linear relationship between the number of eggs and LBR following IVF treatment. The number of eggs to maximize the LBR is ∼15.

Ovarian reserve is a complex clinical phenomenon influenced by age, genetics, and environmental variables. Although it is challenging to predict the rate of an individual's ovarian reserve decline, clinicians are often asked for advice about fertility potential and/or recommendations regarding the pursuit of fertility treatment options. The purpose of this review is to summarize the state-of-the-art of ovarian reserve testing, providing a guide for the obstetrician/gynecologist generalist and reproductive endocrinologist. The ideal ovarian reserve test should be convenient, be reproducible, display little if any intracycle and intercycle variability, and demonstrate high specificity to minimize the risk of wrongly diagnosing women as having diminished ovarian reserve and accurately identify those at greatest risk of developing ovarian hyperstimulation prior to fertility treatment. Evaluation of ovarian reserve can help to identify patients who will have poor response or hyperresponse to ovarian stimulation for assisted reproductive technology. Ovarian reserve testing should allow individualization of treatment protocols to achieve optimal response while minimizing safety risks. Ovarian reserve testing may inform patients regarding their reproductive lifespan and menopausal timing as well as aid in the counselling and selection of treatment for female cancer patients of reproductive age who receive gonadotoxic therapy. In addition, it may aid in establishing the diagnosis of polycystic ovary syndrome and provide insight into its severity. While there is currently no perfect ovarian reserve test, both antral follicular count and antimüllerian hormone have good predictive value and are superior to day-3 follicle-stimulating hormone. The convenience of untimed sampling, age-specific values, availability of an automated platform, and potential standardization of antimüllerian hormone assay make this test the preferred biomarker for the evaluation of ovarian reserve in women.

In women, anti-Müllerian hormone (AMH) is exclusively produced by granulosa cells of ovarian follicles during the early stages of follicle development. After an initial increase until early adulthood, AMH concentrations slowly decrease with increasing age until becoming undetectable ∼5 years before menopause when the stock of primordial follicles is exhausted. However, major individual variability exists in the pace of follicle pool depletion and the initial size of the follicle pool, reflected by a wide range of age at menopause. Individual AMH serum concentration does accurately reflect the size of the pool of antral follicles, representing the quantity of the remaining primordial follicles. Accordingly, AMH levels may vary significantly in women of the same chronological age, allowing AMH to predict the remaining length of a woman's reproductive lifespan.