Preimplantation genetic diagnosis can detect genetic abnormalities before a new live birth. This chromosome test is done in conjunction with in vitro fertilization, which is the mixing and fertilizing of egg cells and sperm outside of the uterus, to be later implanted into the woman’s womb.
This is not a new testing procedure, as it began in the early 1990s. Now, over 400 different hereditary conditions can be screened for couples that have a history of family genetic abnormalities, or for couples who want to conceive later in life. This could be after the age of 38, but who do not want the associated higher risks.
The type of preparation for preimplantation genetic diagnosis will depend on the quality and quantity of the sperm and fertility of the eggs.
The Tests
Initially, blood tests must be done in a laboratory to determine the woman’s cycle along with its waves of fluctuations. Cycle evaluations are done by way of mucus testing from a sample of the cervix, which is done similarly to a pap test. Ultrasounds are done frequently to evaluate the follicles (group of egg cells). The post-coital test is to know the success of the survival of the sperm, and is done during an office visit. Intercourse must be done either the evening before or the morning of the appointment.
A sonohysterosalpingogram can be done, usually in the physician’s office, to check the tissue of the uterus and fallopian tubes. This is done via the cervix with saline solution and guided by a transvaginal ultrasound. At times, a laparoscopy is necessary to see for possible fertilization problems. This type of surgical testing is done under a general anesthetic (put to sleep), and is done on an out-patient basis (go home the same day). A scope is placed via the belly button to view the fallopian tubes, the uterus, the ovaries and the pelvis area. By doing a laparoscopy, the doctor can see if there are any cysts or scar tissue that could interrupt a possible pregnancy or fertility treatment.
A thin instrument may also be used to look inside the uterus. This procedure is called a hysteroscopy and is occasionally done at the same time as a laparoscopy. This procedure is best to be performed after a menstrual cycle when the endometrium (tissue or lining of the uterus) is thin. An endometrial biopsy may be performed to discover the amount of progesterone that is produced after ovulation.
Stimulation of the Ovaries
Fertility medications normally by injections are given to the woman to stimulate the ovaries. The goal of ovarian stimulation is to encourage the ovaries to create multiple eggs and embryos.
Sperm Washing
Sperm washing increases male fertility by separating and removing semen and inactive sperm from the healthy sperm. The good sperm only is used for the fertility process and preimplantation genetic diagnosis.
Cryopreservation
With this process, the sperm is collected and frozen to be used at a later date.
Swim-up Technique
The swim-up technique is a good way of retrieving active healthy sperm. The sperm is placed into a glass test tube. A culture medium is placed on top of the semen, and the sperm try to swim up to it. The test tube sits for about an hour, and only the healthy sperm is selected. This sperm may be used for preimplantation genetic diagnosis.
