Earlier this year we began looking into the diagnoses behind fertility issues, starting with ovulatory dysfunction. In this post, we’ll be digging into the most common diagnosis, “diminished ovarian reserve”, affecting 31% of cases in the CDC’s report, which is based on ~260k IVF cycles performed in the US. Diminished ovarian reserve does not only affect IVF treatment but any kind of fertility (preservation) treatment, making it particularly relevant for the Ovally community.
What does “diminished ovarian reserve” mean? “Ovarian reserve” is a somewhat confusing term that refers not only to the number of eggs a woman has, but also to their quality. “Diminished ovarian reserve” is typically diagnosed by measuring hormone levels and/or counting “antral follicles” during an ovarian ultrasound, i.e., the number of follicles starting to mature during a given monthly cycle. Doctors and researchers still use slightly different definitions for “diminished ovarian reserve”; one recent review suggested converging on an antral follicle count of <5-7 follicles or an Anti-Muellerian Hormone (AMH) level of <0.5-1.1 ng/ml as definitional criteria.
A woman’s ovarian reserve diminishes naturally with age (e.g., women are born with millions of eggs that die off until menopause), and for some women the decline in number and quality of eggs happens faster than for others. A faster decline in ovarian reserve can be genetic (e.g., if early menopause runs in the family,) and is also associated with conditions like endometriosis, tubal disease, pelvic infection, as well as certain autoimmune disorders, ovarian surgery, chemotherapy and radiation, mumps, and smoking. However, there are also younger women with diminished ovarian reserve who have experienced none of these associated conditions and factors.
How does low ovarian reserve affect fertility treatment? Diminished ovarian reserve affects the outcomes of fertility treatment at many different stages: For instance, patients with low AMH typically respond less to the hormone stimulation aimed at getting a number of eggs to mature and later be retrieved for egg/embryo freezing or IVF. Sometimes women with low AMH respond so little to the follicle-stimulating hormones that very few or no eggs mature, and the treatment cycle has to be canceled. Low egg quality also has an effect at later stages of the IVF process: Low quality eggs (e.g., with genetic abnormalities) are much less likely to be able to be retrieved from their follicles, to fertilize, develop in the lab as embryos, implant in the uterus, and lead to a successful pregnancy. They’re also less likely to survive freezing or thawing.
What can be done about diminished ovarian reserve? So far, there does not appear to be a reliable way of improving diminished ovarian reserve, making it an incredibly frustrating diagnosis. Doctors often increase the levels of follicle-stimulating hormones for patients with low ovarian reserve in trying to get more eggs to mature while carefully monitoring the risk of ovarian hyperstimulation. Some research has shown a positive effect of taking dehydroepiandrosterone; however, other studies could not detect any effect of the supplement. With age playing such a big role in diminished ovarian reserve, egg or embryo freezing is a way of preserving younger and healthier eggs.
Since diminished ovarian reserve affects such a high percentage of fertility patients, we’ll keep you updated on this topic with the latest research.