FSH stands for follicle stimulating hormone. It is produced by the pitutary gland in the brain. As the name suggests, it stimulates the growth of the follicle inside the ovary. Its level in the blood are in turn regulated by the estradiol and inhibin produced by the growing follicle inside the ovary.
FSH levels are measured along with antimullerian levels( AMH) and antral follicle count( AFC) to assess the ovarian reserve of the patient. As the FSH levels vary throughout the menstrual cycle, it should be done on day2/3 of the cycle and preferably along with estradiol levels for correct interpretation.
As the age advances, the number of follicles decline in the ovary resulting in low AMH and High FSH levels. However in around 10% of the patients accelerated ovarian ageing occur and they present with low AMH and high FSH levels at a younger age. Certain autoimmune disorders , prior radiation , chemotherapy , as well as certain viral infections may cause ovaries to fail prematurely which is defined by FSH levels > 40 mIU/ml .
High FSH and low AMH entails need for aggressive fertility treatment. IVF remains cornerstone therapy in these patients.
The success rate of IVF using self eggs varies from 6% to 30% depending upon the age of the patient and cause of the decreased ovarian reserve. A young patient with decreased ovarian reserve or high FSH has a better prognosis than a old patient with high FSH. The challenge for fertility specialist in such patients is at many levels. Poor response to stimulation requiring high dose of gonadotropins, obtaining less number of poor quality oocytes which in turn form poor quality of embryos with chromosomal abnormalities. This result in poor implantation rate and high miscarriage rates . Prestimulation with DHEA , and aggressive individualised stimulation protocols may help in some patients
The success rate of IVF using donor eggs is upto the tune of 60% to 70%. Since donors are typically of a young age, the chances of miscarriage are of a young woman with normal ovarian reserve. Donor egg is also treatment of choice for patients with premature ovarian failure.
Every couple should be thoroughly counselled so that they are able to take an informed, individualised decision.
It is in research that patients at risk of developing decreased ovarian reserve may be identified through screening of FMR1 gene premutations. These patients may be offered fertility preservation through ovum or embryo preservation. Patients undergoing chemotherapy or radiation therapy may be offered ovarian cortex cryopreservation.
Therefore treatment options for patients with high FSH are highly individualised and need thorough discussions and counselling with the fertility specialist.