No, ovarian response to stimulation varies among women. Doctors can estimate how well the ovaries might respond by measuring antral follicle count (AFC) and anti-Müllerian hormone (AMH) levels. The FSH dosage is then adjusted based on these markers, as well as age and BMI.  

However, each woman’s follicular sensitivity to FSH is unique, meaning some may over-respond or under-respond, even with a carefully calculated dose.  

Women undergoing ovarian stimulation are generally classified into three groups based on their ovarian reserve:  

• Normal responders (expected response to stimulation)  

• Hyper-responders (excessive response, often seen in PCOS)  

• Hypo-responders (poor response, often linked to low ovarian reserve)  

This classification helps personalize treatment protocols.  

How Are Hyper-Responders Treated?  

Women classified as hyper-responders often have PCOS or an excess of antral follicles. To reduce the risk of overstimulation, they typically receive lower doses of FSH and are ideally treated with the GnRH antagonist protocol.  

If the ovarian response is excessive, raising concerns about ovarian hyperstimulation syndrome (OHSS), doctors may:  

• Trigger ovulation with a GnRH agonist instead of hCG, as hCG can worsen OHSS.  

• Freeze all embryos and delay the embryo transfer to a later cycle, avoiding the risks associated with OHSS.  

Before the introduction of the antagonist protocol, the agonist protocol was commonly used. In hyper-responders, doctors sometimes had to apply coasting—a brief pause in hormone administration—to reduce the risk of OHSS. Today, this approach is rarely needed since hyper-responders are no longer treated with the agonist protocol.  

How Are Hypo-Responders Treated?  

Hypo-responders usually require higher doses of FSH to stimulate follicle growth. The antagonist protocol is commonly used, though some doctors may opt for a short protocol.  

Unfortunately, despite these adjustments, the ovarian response remains weak, often resulting in fewer mature eggs available for fertilization. Some pre-treatment strategies, such as DHEA supplementation for several months or the use of growth hormone, have been explored to increase the number of recruitable follicles, but their effectiveness remains unproven.