At MySpermBank, our goal is the same as yours: for you to bring home a healthy baby. Genetic screening of sperm donors is one important way to help reduce the risk of inherited conditions in your future child.
It's important to remember that, no matter how conception occurs, there is at least a 3–5% background risk for any newborn to have a birth defect or genetic condition. Genetic screening helps lower that risk but cannot remove it completely.
Donor Genetic Screening at MSB has three parts: Genetic Risk Assessment, Chromosome (Karyotype) Testing, and Genetic Carrier Screening
Genetic Risk Assessment
A Genetic Risk Assessment (GRA) is performed by a certified genetic counselor trained in donor screening. The counselor reviews at least three generations of the donor's personal and family medical history. A GRA Report is created for your review based on the information provided by the donor which outlines medical conditions reported for the donor and each family member. Additionally, the GRA Report will state whether the risk to future children is expected to be the same or higher than the general population risk based on the donor's personal and family history. As with any family, the donor's family is expected to have common medical conditions, especially as family members age. However, the intention of the donor GRA is to identify patterns of significant medical conditions that may present an increased genetic risk to future children. Donor's with such a history would be excluded from donation based on ASRM and MySpermBank guidelines.
Chromosome (Karyotype) Testing
Chromosomes are packages of DNA that contain our genes. Humans typically have 46 chromosomes, arranged in 23 pairs—one of each pair from the egg and one from the sperm. Pairs 1–22 are the same for males and females; the 23rd pair determines sex (typically XX for females, XY for males).
MySpermBank performs a blood chromosome analysis (karyotype) on every prospective donor. Only donors with a normal male pattern (46,XY) are accepted. This significantly reduces the likelihood of a chromosome imbalance in an embryo, pregnancy or child that is inherited from the donor.
Sporadic (random) chromosome changes can still occur in any conception, often related to the age of the egg. These can be screened using preimplantation genetic testing for aneuploidy (PGT-A) before embryo transfer. You may discuss this option further with your fertility provider.
For more on chromosomes, visit MedlinePlus.
Genetic Carrier Screening
All humans carry several genetic changes, often without knowing it.
Carrier screening helps identify whether a person carries variants, or mutations, in certain genes associated with specific inherited conditions—especially those that begin in childhood.
Most of these conditions are autosomal recessive, meaning a child would only be affected if both the egg and sperm source carry a variant in the same gene. When that happens, there is a 1 in 4 (25%) chance of an affected child.
MySpermBank requires genetic carrier screening for all donors based on guidelines from the American College of Obstetricians and Gynecologists (ACOG), the American College of Medical Genetics (ACMG), and the American Society for Reproductive Medicine (ASRM).
Because testing technology and recommendations change over time, donors may have been screened using different panels. If your egg source is found to carry a variant in a gene the donor was not tested for, you or your provider may request additional testing on the donor.
Even with advanced technology, every test has limits. A negative genetic carrier screen result significantly lowers—but does not eliminate—the chance of carrying a condition. Each lab provides a "residual risk" estimate showing the remaining chance of being a carrier after having a negative result for a specific gene.
Additionally, no carrier screen tests for all genetic diseases, so a donor may still be a carrier for a condition not included in their screening panel. You can review the donor's genetic report for details about which genes were tested.
For more about genes and inheritance, visit MedlinePlus on genes and autosomal recessive inheritance.