Ovarian Reserve Tests

The rising trend towards delayed parenthood is resulting in a greater number of women seeking conception at an older age. It has become very important to assess accurately the ovarian performance, as determined by the number of primordial follicles left in the ovary. Social habits, non-clinical and clinical factors have been shown to contribute to the decline of the follicle pool either directly or indirectly.

Chronological age is considered as a simple way of obtaining information on the extent of ovarian function, in terms of both quantity and quality. However chronological age cannot always be used as a surrogate of ovarian age. Various blood tests and ultrasound markers of ovarian performance have been employed in routine clinical practice to assess how the ovary works, but their accuracy is not optimal. Recently, measurement of anti-Müllerian hormone (AMH) levels has been proposed by Mr Luciano Nardo and other researchers as marker of ovarian follicular reserve. Several studies have suggested that AMH concentrations are highly correlated with the number of antral follicles and reflect the ovarian reserve better than other known clinical markers such as day 2-3 follicle stimulating hormone (FSH), inhibin B and oestradiol (E2). Unlike AMH, these hormones are subject to cycle-to-cycle fluctuations.

Anti-Müllerian hormone is expressed in both sexes at different stages of development and it is best understood for its role in fetal sex differentiation. In females, AMH is not detected before 36 weeks of gestation and is produced throughout reproductive life. Anti-Müllerian hormone is secreted by the granulosa cells of small antral follicles in the ovary. It is known that AMH levels reflect the number of selectable follicles during the early follicular phase. Low levels suggest a reduced ovarian follicle pool and poor ovarian prognosis.

A quantitative measurement of ovarian ageing may also be obtained by ultrasound assessment of the number of small antral follicles measuring between 2-6mm. Like AMH, antral follicle count (AFC) correlates significantly with ovarian performance and is highly predictive of clinical pregnancy in women undergoing in-vitro fertilisation.

While baseline FSH remains a screening ovarian reserve test, AMH and AFC are diagnostic markers with greater precision than anything else available, and they may be requested as diagnostic tests in many areas of women's health, including puberty, polycystic ovary syndrome (PCOS), subfertility and premature menopause. The appropriate use of these markers, which lead to accurate information, is of paramount importance when counselling, referring for and planning treatments.

Adequate ovarian response to gonadotrophin stimulation is a prerequisite for successful in vitro fertilization (IVF) treatment. While exaggerated ovarian response can be complicated by ovarian hyperstimulation syndrome (OHSS), poor response may result in cycle cancellation or decreased pregnancy rate. Identification of patients at risk of extremes of ovarian response prior to controlled ovarian hyperstimulation (COH) is of paramount importance in selecting the best treatment protocol and the starting dose of gonadotrophins.

A search for a marker that better reflect the quantity and quality of growing follicles has led to more recent emphasis on anti-Müllerian hormone (AMH) and antral follicle count (AFC) because of their advantages as compared with other predictors such as follicle stimulating hormone (FSH), oestradiol (E2), inhibin B and ovarian volume.

AMH can be measured at any time throughout the menstrual cycle, making it a versatile and friendly test. AFC can be performed by ultrasound scan only during the first few days of the menstrual cycle (day 2-4). The inter-cycles variability of AFC is a limitation of its overall predictive capacity. Although the evidence suggests that AMH is superior to AFC in predicting excessive ovarian response to stimulation, both markers were found to be equally effective in prediction of poor response.

Various blood tests and ultrasound scan markers can be used to assess how the ovaries work, but their accuracy is not perfect. A newer diagnostic approach involves measuring the anti-Müllerian hormone (AMH) in the blood stream and counting the number of small follicles present in the ovaries within the first few days of the menstrual cycle (day 2-4) by ultrasound scan.

Several studies have demonstrated that AMH concentrations and AFC are closely linked with the number of eggs in the ovaries and reflect the ovarian reserve better than any other markers, which tend to fluctuate from cycle to cycle.

When attending the Ovarian Reserve Clinic, Mr Nardo will perform a transvaginal ultrasound scan of the pelvis to calculate the AFC. He will then couple this with the results of the previously arranged AMH test to obtain a prompt and accurate assessment of the ovary. Other additional hormone tests might be arranged if necessary.