Early human embryos develop within an outer coverin called a zona pellucida. Before the embryo can implant in the uterus, the embryo must break through this covering. In some cases, it appears that human embryos sometimes lack the ability to do this.
The technique of assisted hatching involves measuring the thickness of the zona pellucida in embryos that are candidates for the procedures. If an embryo has not initiated the thinning process naturally, a small "window" is created chemically in the wall of the protein coat, using a dilute acidic solution pulsed onto the embryo surface, through an extremely fine glass micromanipulation needle. The embryos are then implanted normally into the uterine cavity.
The most extensive experience with assisted hatching has been reported from Cornell University, where implantation rates of 25% per embryo are reported, as compared to 18% per embryo, with regular IVF in non-assisted cycles.
You may be a candidate for assisted hatching if you are 38 years of age or older, or if you have previously had one or more IVF cycles, with failure of your embryos to implant, despite otherwise good results.
This procedure allows couples the opportunity to limit the number of embryos transferred to the uterus and to freeze remaining embryos for later use. Cryopreservation may reduce the number of stimulations and retrievals necessary to achieve a pregnancy. It is important to note that not all embryos will be selected for freezing. Only those embryos that are viable and reach the blastocyst cell stage will be chosen for this procedure.
Similar to IVF, but used when the woman has at least one normal fallopian tube. Three to five eggs are placed in the fallopian tube, along with the man's sperm, for fertilization inside the woman's body.
Preimplantation Genetic Diagnosis is a technique combining the recent significant advances in molecular genetics and assisted reproductive technology. PGD allows physicians to identify various genetic diseases in the embryo prior to implantation, that is, before the pregnancy is established. It is of special value for those who are at risk of having children with serious genetic problems. A couple known to be at risk for having a child with a severe genetic disease undergoes IVF where several pre-embryos are produced. These embryos have 1-2 cells removed when they reach the 8-cell stage. These cells are then tested to determine which pre-embryos are affected with the disease and which are not affected. Unaffected embryos are subsequently placed in the uterus to establish a pregnancy. PGD is a procedure technically demanding and very complex, which requires special skills. Because of the difficulty of the procedure, PGD is available in very few infertility centers.
A hybrid of IVF and GIFT. The eggs retrieved from the woman's ovaries are fertilized in the lab and replaced in the fallopian tubes rather than the uterus.
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