A Typical PGD Case
A typical PGD/IVF cycle consists of an in vitro fertilization
(IVF) cycle and genetic testing on cells from the resultant embryos. The
following vital phases include:
Ovarian Stimulation and Monitoring (Approximate
cycle days 1-14)
A combination of medications are used
to stimulate the ovaries and results in the maturation of several eggs.
After the follicles containing the eggs have reached a certain size
and number, a last injection is given to ensure their final development.
The mature eggs are retrieved thirty-five to thirty-six hours after
the last injection.
Egg Retrieval (Approximate cycle day 15)
Under the guidance of vaginal ultrasound,
a physician extracts the mature eggs. During this short procedure, intravenous
sedation is given to minimize discomfort.
Semen Collection, Processing and Insemination (Approximate
cycle day 15)
Shortly before or after egg retrieval,
a semen sample is collected. This sample is processed to identify the
strongest, most active sperm. The sperm and eggs are placed together
in a dish in the laboratory where fertilization takes place. Sometimes
an alternate technique called intracytoplasmic sperm injection (ICSI)
is used to fertilize the eggs. ICSI involves the injection of a single
sperm into each egg.
Fertilization and Embryo Development (Approximate cycle
days 15-18)
After initial incubation, the eggs will
be examined to verify fertilization. Following fertilization, the embryos
are allowed to grow in the laboratory for approximately three days.
At this time, the embryo should contain about 8 blastomeres (embryonic
cells).
Embryo Biopsy (Approximate cycle day 19)
On the morning of biopsy, the embryos
are evaluated for appearance and morphology. One or two blastomeres
are removed from each embryo that has a normal appearance and is at
the optimal stage for embryo biopsy (usually 6-10 cells). Following
biopsy, the embryos are returned to the incubator and allowed to continue
development.
Genetic Testing (Approximate cycle days 19-21)
The blastomeres that are removed from
the embryos are tested separately using highly sophisticated laboratory
techniques. The genetic testing results are discussed with the couple,
and together the couple and their medical team determine which embryos
should be transferred into the uterus.
Embryo Transfer (Approximate cycle day 21)
Approximately two days after the biopsy,
the selected embryos are placed in a small tube that is passed through
the cervix and into the uterus. In this brief procedure, the embryos
are transferred to the uterus and the tube is removed, after which implantation
is allowed to take place. Medication is given to promote successful
implantation and pregnancy.
Pregnancy Test (Approximate cycle day 35)
A blood test for hormones present
during pregnancy is performed approximately 14 days after embryo transfer.
