A response to ovarian stimulation depends on a number of different factors, the most important include available eggs, appropriate hormone levels, proper administration of any medications and lifestyle/environmental factors.
In order to respond to ovarian stimulation, a woman must have eggs available to respond; this is sometimes referred to as ovarian reserve. If a woman has diminished ovarian reserve (identified by high blood levels of follicle stimulation hormone (FSH), low blood levels of Anti Müllerian Hormone (AMH) or a low antral follicle count on ultrasound), she may not have as robust (or any) response to stimulation. For these patients, an alternate stimulation protocol may be tried or donated eggs may be used (from a woman known or unknown to the patient).
It is possible that a woman does have the necessary eggs but lacks the appropriate pituitary hormones to respond. In this case, using a different medication- one which may contain both FSH and luteinizing hormone (LH) may allow for an optimal response.
Lifestyle factors can also affect a woman’s response to stimulation. Optimizing weight, diet and stress and cessation of use of tobacco, alcohol and recreational substances can also improve a response to ovarian stimulation.