Family Balancing FAQs
What is Family Balancing?
Even though each pregnancy has a 50% chance to be male and a 50% chance to be female, some families have more children of one gender. Gender selection for Family balancing can help these couples have a child of the underrepresented gender in their family.
Gender selection for Family Balancing can be accomplished using Preimplantation Genetic Diagnosis (PGD), a form of prenatal diagnosis performed on early embryos prior to implantation in the uterus and initiation of pregnancy. Only embryos of the desired gender are returned to the uterus, which provides a nearly 100% accuracy rate if pregnancy is achieved.
Why should I use IVF if I have not been diagnosed with infertility?
In order to have more than one embryo to test, an IVF cycle and follicle-stimulating medications are needed to coax the ovaries to mature more than one egg at a time. We also need to have access to the embryos before implantation so that one or more cells may be removed and used for genetic testing.
What should I know about infertility drugs?
The medications necessary to mature multiple egg follicles must be monitored by measuring levels in the blood, as well as looking at the ovaries with ultrasound. Your reproductive endocrinologist will work with you to maximize the number of follicles that form while using the lowest levels of medications necessary. IVF medications have been used for over 30 years. Studies investigating long-term effects of exposure to these medications have not identified risks for ovarian or other cancers at levels above background risk. Short-term side effects usually involve symptoms similar to those of pre-menstrual syndrome, although some women may also have ovarian swelling and discomfort.
If I am having my PGD cycle at GIVF, then how long would I need to be at your office in Fairfax, VA?
We work with many patients from all areas of the United States and abroad. If IVF monitoring is available near a patient's home, then the patient needs to arrive in Fairfax, VA, a couple of days prior to the egg retrieval. On average, most women need to be at our facility for just over a week.
How likely am I to get pregnant if I use PGD?
Human reproduction is very inefficient, and the likelihood of getting pregnant naturally in any given month is only around 10%. With the transfer of three embryos on average, the pregnancy rate in our PGD program is approximately 30-35%. Many other factors may make the likelihood of getting pregnant lower or higher. The decision regarding how many embryos to transfer is made together with the couple to maximize the likelihood of achieving pregnancy, but also to minimize pregnancies with multiple fetuses.
When does PGD happen in the IVF cycle?
After embryos are created in the laboratory, they are grown for three days. On day three, the PGD biopsy is done and one or two cells are removed from the embryo. The genetic material inside these cells is tested for gender. On day five, the woman returns to the Genetics & IVF Institute to discuss her PGD test results. Decisions regarding selection of embryos to transfer into the uterus are made with the advice of the medical team.
Is PGD Safe?
Yes. Data from many years of PGD in animals and humans indicate that PGD does not lead to an increase in birth defects or chromosomal disorders. PGD is done before the embryo’s genetic material becomes "active." Since it is done so early, the cells inside the embryo are still all identical and each cell is capable of becoming any part of a baby. Removal of a few of the cells of the early embryo does not alter the ability of that embryo to develop into a complete, normal pregnancy.
How do they get the cells out of the embryo?
Embryos created in an IVF cycle are cultured in the laboratory for three days. By this time they contain approximately eight cells. Each embryo at this point is called a blastomere. Embryos with normal development on day three will have one or two cells removed for testing in a procedure called a biopsy. The embryos are placed under a powerful microscope and very tiny glass instruments are guided to make a small cut in the zona pellucida (a tough outer membrane holding the embryo together). Depending on the health and size of the embryo, one or two cells are taken out. The cut then snaps shut and no cells can "fall out" accidentally.
In order to obtain results of the biopsy, the one or two cells removed must contain a nucleus, as the nucleus contains the genetic information necessary for testing. If the cell removed has no nucleus or if the nucleus breaks open as it is being prepared, testing is unable to be performed on that cell. Additionally, since embryos are actively growing and dividing, sometimes the cell taken out contains two nuclei. This could mean the cell is abnormal or is caught in the process of division. Testing of these cells may be difficult to interpret.
How exactly is the PGD test performed?
Gender is determined by our sex chromosomes. PGD testing is different than most genetic testing, since it is done on only one or two embryonic cells and must be completed within 48 hours to allow embryo transfer by day five. Since standard chromosome analysis takes several days, a different method called fluorescence in-situ hybridization (FISH) is performed.
Each chromosome has unique areas of DNA present only on that chromosome. A small DNA probe is used to recognize these unique patterns and fluoresce, or light up, when it attaches to the chromosome. Each probe shines light in a different color, allowing several chromosomes to be tested at the same time. This technique is called FISH.
FISH probes for X and Y are used to determine the gender of each embryo. The presence of these chromosomes are viewed simultaneously. A normal cell should show two FISH signals (or lights) for the numbered chromosome, and either two X signals for a female or one X and one Y signal for a male.
| An example of a FISH test showing one X chromosome (green) and one Y chromosome (aqua) for a male. There are two signals for the control FISH probe for a numerical chromosome (yellow).
An example of a FISH test showing two X chromosomes (green) and no Y chromosomes (aqua) for a female. There are two signals for the control FISH probe for a numerical chromosome (yellow).
Can you test for other chromosomes at the same time as the gender?
Yes, GIVF offers another “panel” of chromosome testing.
How are embryos chosen for transfer?
Embryos that have both a normal PGD test result and appearance should be considered for transfer. Sometimes embryos that have normal PGD results will not progress well, while other embryos that have abnormal PGD results will progress well. The combination of normal PGD results with normal embryo development gives each embryo the highest chance of becoming a healthy pregnancy.
What physical characteristics are used to determine normal appearance?
Embryologists give a “score” to the embryo based on the uniform size of the different cells, the number of cell fragments present, as well as other criteria reflecting the physical appearance of the embryo. Embryos that do not have at least give cells on day three or embryos that are given a poor score rarely go on to successfully implant.