The Mayo Clinic in Rochester, Minnesota, reports that a 30-year-old procedure for in vitro fertilization (IVF) is surging after fertility specialists addressed significant complications it can cause. It’s called the minimal stimulation method, or MiST IVF.
Doctors say women of advanced reproductive age or those who produce fewer eggs may benefit from the procedure, which is less expensive than other forms of IVF. MiST IVF is more tolerable than conventional IVF because it primarily uses oral medications instead of injectables.
MiST IVF has remained popular outside the U.S. due to its lower cost. However, fertility doctors here stopped recommending it in the 1990s when it was discovered that oral medications often destroyed the lining of the uterus, leading to low success rates.
Cryopreservation is the key
The procedure is becoming popular again after doctors found an answer to the uterine lining issue, namely, waiting to transfer the resulting embryos. Under the procedure, women take medications to produce eggs, which are harvested and fertilized, but, rather than transferring the resulting embryos shortly after the eggs are retrieved while the woman’s lining may be impaired, any embryos that result are frozen.
A waiting period then ensues during which the affected uterine lining is allowed to shed during menstruation. Then, once a new lining develops during the woman’s next cycle, the cryopreserved embryos are transferred. Once they reach this stage, fertility experts say chances for pregnancy are about the same as for those undergoing conventional IVF.
Considerations for MiST IVF
The procedure is far from mainstream. As the Mayo Clinic points out, the patients it sees most often have had unsuccessful IVF procedures elsewhere. While each patient is different, doctors say several factors affect IVF success, especially age, body mass index and tobacco use.
MiST IVF can benefit some due to it being less invasive. It also reduces the amount of medication used, thereby lowering the risk for ovarian hyperstimulation syndrome (which can result in mild to severe complications). It is also less expensive than conventional IVF. Mayo fertility specialists say the method’s main benefit is giving some aspiring parents a second chance for a successful pregnancy after previous failures.