Ovarian Stimulation Protocols for Low Responders prior to IVF
Low response to controlled ovarian stimulation represent a significant fraction of IVF population presenting for fertility treatment. Low responders may represent 30% or more of women seeking IVF. The proportion may be larger in some areas due to delay in childbearing as a lifestyle choice. Low response to ovarian stimulation is commonly defined as producing 5 eggs or less after stimulation. While may factors may contribute to low response e.g smoking, prior surgery of the ovary, exposure to chemotherapy, the vast majority of are age related. Sometimes low response happens in younger women e.g 30 year old. Young low responders has a better chance of conceiving because their eggs, though few, are healthier (chromosomally normal) than older e.g >38 low responders.
Few strategies can increase egg yield and possibly egg quality in low responders, usually employing one or a combination of
i. increasing the dose of gonadotropins,
ii. avoiding long lupron suppression before start of stimulation,
iii. adding an oral agent (clomid or letrozole),
iv. synchronizing follicles prior to start injections,
v. using androgen prior to cycle start and sometimes
vi. adding growth hormone.
There is no clear evidence to one protocol over the other. Increasing the dose above a total of 450 units per day does not seem to further increase egg yield in low responders. Some patients respond to one ovarian stimulation protocol over another. One example of low responder protocol is illustrated above. Estradiol and antagonist are used to synchronize the follicles before menses so that they are uniform in growth when stimulation starts. Short lupron is used (flare or microflare) to induce the release of internal gonadotropins. This is followed two days later by high dose of fertility medication (total 450 units per day).
There is some evidence that pre-treatment with androgens (testosterone) may improve egg yield. The evidence for the use of DHEA (dehydroepiandrosterone) is limited. There is also week evidence that the use of growth hormone may improve egg quality.
Embryological procedures are also sometimes suggested as ICSI of all available eggs to maximize fertilization and assisted hatching of the egg shell (zona pellucida). Pre-implantation genetic screening is unlikely to be helpful as few embryos are available for testing.Ovarian stimulation protocols for Low Responders prior to IVF by Dr. Amr Azim