Fertility Chronicles is proud to present a special blog series, “From the Fertility Experts,” where leading fertility experts answer commonly asked questions for patients about their fertility health and treatment options. We hope this series can help patients navigate their personal fertility journeys.—Catherine T. Yang, Editor, Fertility Chronicles
Univfy’s “Fertility Chronicles” guest blogger Dr. Ernesto Bosch shares his insights advice on personalizing infertility treatment:
Pregnancies and live birth rates using in vitro fertilization (IVF) have increased dramatically over the last three decades. One big reason: The evolution of controlled ovarian stimulation (COS) protocols, which lead to greater production of follicles and eggs than the natural cycle.
COS protocols work by shutting down the hormones which regulate your menstrual cycle. This is performed in order to have a better control of the stimulation and to avoid a spontaneous ovulation before egg retrieval. Specifically, synthetic hormones, called gonadotropin-releasing hormone (GnRH) analogs, are prescribed to shut down secretion by your pituitary gland of your own follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This can be done either with a GnRH agonist used to shut down both FSH and LH production in the “down regulation” phase of treatment, or with a GnRH antagonist, which is started on the second half of the stimulation.
The base of COS is to replace your own FSH with increasing doses of synthetic FSH to grow multiple follicles. When enough large follicles are present, egg retrieval takes place. Then, a LH-like hormone, usually human chorionic gonadotropin (hCG), is given as a “trigger shot” to spur final egg maturation and then ovulation.
Although overall pregnancy and live birth rates have risen using these protocols, not all patients have benefited from this “one size fits all” approach. The FSH dose for your stimulation protocol may be slightly modified, for example, based on your physician’s clinical experience and evaluation of any medical conditions you may have [e.g. endometriosis, polycystic ovarian syndrome (PCOS), uterine fibroids], response to FSH in a prior treatment, or other characteristics, such as your age and body mass index (BMI).
Your standard FSH ovarian stimulation protocol may be modified by the addition of LH activity with FSH during the stimulation cycle. Clinical studies demonstrate that the addition of LH may improve follicle growth in “low responding” patients in general and is especially helpful for older women. Adding LH with the FSH dose in the older patient may result in a better embryo implantation rate and ongoing pregnancy rate. LH may exert these positive effects by supporting better egg quality and endometrial receptivity. Younger patients do not necessarily receive the same benefit from added LH, showing that your age can affect whether some protocol modifications will work for you. The factors that can predict how well your follicles will respond to FSH include your baseline serum FSH level, body mass index (BMI), and the number of antral follicles at your baseline ultrasound.
Despite taking these factors into consideration, many patients experience suboptimal results from their first IVF cycle. Clearly, there is work to be done to identify the best ovarian stimulation protocols for each patient. New prediction models can now weigh the relative influence of various factors on an individual patient’s chances of IVF success.
In Part II of this series, we will look at specific biomarkers, such as anti-mullerian hormone (AMH) and basal androgen levels, now used to personalize COS. In Part III, we will look at emerging technologies, such as genetic markers, which may someday be used to identify the best stimulation protocol for a particular patient.