Chromosomal Abnormalities and Infertility

A lot of individuals are unable to conceive, carry a pregnancy, and have children due to chromosomal abnormalities. In other words, their infertility is caused by these chromosomal abnormalities. Also, in some cases, it is due to an inherited chromosomal abnormality. In other instances, it could be due to a single-gene defect passed down from parent to offspring. These diseases and disorders happen when the normal DNA sequence is altered, because of one or multiple gene mutations. It is also possible that a woman will inherit issues, if other women in the family have problems like premature menopause, endometriosis, PCOS, etc.

How do chromosomal abnormalities cause infertility?

This causes a major issue in embryos, as they are the ones that are affected by these chromosomal abnormalities and have very poor implantation rates. In the chance that they eventually implant, they still have a very high chance of being miscarried. For others that escape miscarriage and are carried to term, they are born with several issues like impaired intellectual function, developmental delays, or physical impairment. Some of these chromosomal abnormalities include:

• Mutation – In this instance, there is a change in the gene’s DNA, a mutation, so to say.
• Translocation – Some chromosomal fragments may be translocated to the incorrect chromosome.
• Deletion – In this case, there is a missing piece of chromosome in the DNA.
• Inversion – This is a phenomenon where a chromosome is reversed or inverted.
• Aneuploidy – In this case, there are either too few or too many chromosomes in the DNA.

The most commonly occurring abnormality of the above listed is translocation. The parent that is a carrier is usually normal in this case, but they have their embryo receiving too much or too little genetic material. This usually results in a failure to implant or a miscarriage of the pregnancy. Most couples that are aware or have been made aware of the chromosomal abnormality will benefit massively from preimplantation genetic diagnosis, carried out as part of an IVF or surrogacy process. This is an example of how surrogacy or IVF treatment can help prevent the passing of chromosomal abnormalities to offspring. Down syndrome which is usually attributed to advanced maternal age, is also a good example of the aneuploidy phenomenon. It is caused by having an extra number of chromosomes, also referred to as trisomy.

Inherited genetic disorders causing infertility

Infertility could be due to the existence of an inherited genetic disorder due to abnormal genes or mutation but this is rare. Chromosomal analysis of parents’ blood highlights that it occurs in less than 5% of couples. Single-gene abnormalities are mutations that are caused by changes in the DNA sequence of the gene that produces the proteins that enable the normal functioning of cells. They cause an alteration of cell function due to the lack of a particular protein. These single-gene disorders are usually indicative of or highlight a family history of genetic diseases like cystic fibrosis, which is usually incurable and fatal, and affects the mucous membranes of vital organs. These diseases while rare, often prove very devastating to families.

However, due to technological advancements, progress has been made in detecting these issues before they can cause issues. This is usually by preimplantation genetic diagnosis done with IVF and surrogacy. They can be used to prevent disappointments in couples with previously known single-gene disorders in their families. This can even be done when there are no fertility issues in the couple, but a need to prevent the passing of this abnormality to their offspring.

Preimplantation Genetic Testing

Once embryos are produced through IVF, before the implantation, there is a genetic test that is carried out in order to examine them for genetic disorders. This test screens embryos for chromosomal and single-gene abnormalities before their transfer into the uterus. Even when surrogacy is applied for the pregnancy, it is beneficial to utilize preimplantation genetic testing. The benefits of this test include:

• Decreased risk of passing genetic diseases to the offspring.
• Elevated chances of a successful pregnancy and birth from IVF.

This test is usually done on the 3rd-5th day of growth of the embryo; they are usually at the eight-cell stage. A cell is removed from each of the viable embryos and then evaluated for genetic diseases and disorders. The loss of a cell has been proven not to be a problem and does not retard or affect embryonic development. After the testing, the embryos that are proven to be normal chromosomally and free from diseases are cleared for transfer into the uterus. Prenatal testing done during pregnancy is also recommended for women because there is a known error rate in preimplantation genetic diagnosis. Amniocentesis and chronic villus sampling can be performed in addition to PGD to eliminate the risk of misdiagnosis. The following diseases can be detected by this testing:

• Sickle cell anemia
• Fragile X syndrome
• Cystic fibrosis
• Huntington’s disease
• BRCA1 and BRCA2 mutations increase the risk of breast or ovarian cancer in female children.

Embryos that are found to have any of the above-listed conditions are not selected for embryo transfer.

Genetic counseling 

This is a consultation that helps a couple determine the genetic tests that will be beneficial to them, it is usually done by a counselor. This can be done during the screening, before conception, when the couple is still considering conducting genetic tests. These genetic counselors are healthcare providers that can give the couple some vital information about the genetic tests and help them make more informed decisions. They are available to help the couple examine their family’s medical history and assist in discovering the actual cause of experienced infertility. These counselors are good at helping to answer any questions that the couple may have and, in most cases, reveal the actual cause of infertility faced by the couple. This will help in establishing the most appropriate line of treatment that will help the couple achieve their goal of having a healthy baby.

Medical tourism can also play a part in helping couples achieve this goal; this is because some countries have more developed and economic healthcare than others. Overseas medical treatment is an option for couples who do not have adequate services in their home country. Medical travel agencies or meditour agencies can help in the arrangement of these services, which can be a form of health tourism.