| Dr.
Hammitt has published numerous scientific articles over the
last twenty years on embryo cryopreservation, or the freezing
of embryos. The IVF laboratories she directed at the Mayo
Clinic from 1992 through 2005 were national and world leaders
in embryo cryopreservation. More than 60 percent of patients
entering the Mayo Clinic IVF program had extra embryos available
for freezing because of a unique method of grading and selecting
the best embryos for fresh embryo transfer and freezing the
remaining embryos for later use. The frozen-embryo transfer
(FET) pregnancy rate achieved over a 10-year period of using
this method was over twice the national average. A frozen embryo
transfer is much less costly and less invasive than an egg retrieval.
This high pregnancy rate with frozen embryos allows couples
to have a greater than 65 percent chance of pregnancy from one
egg retrieval or egg harvest procedure. High success rates with
frozen embryos lowers the overall cost of infertility treatment
and the time away from work for couples to achieve their goal
of conception and delivery of a healthy baby.
To
decrease the likelihood of multiple pregnancy, it is important
to limit the number of embryos transferred in each treatment
cycle. High success rates with frozen embryos permits transfer
of fewer embryos in the fresh retrieval cycle without wasting
the nontransferred embryos. In general women under 30 should
have only one or two embryos transferred per treatment cycle.
Women 30-35 should have no more than two to three embryos
transferred. Women over 35 should usually have no more than
three to four embryos transferred. Restricting the number
of embryos transferred in this manner decreases the incidence
of high-order multiple pregnancies, that is triplets or more.
Limiting the incidence of high-order multiple pregnancies
is important to protect the health of the mother and babies
born from Assisted Reproductive Technology (ART) procedures.
|
