Next generation sequencing (NGS) helps individuals and couples dealing with infertility. It minimizes the risks of implanting an embryo fertilized by in vitro fertilization (IVF) into a woman’s uterus. By analyzing the embryo’s genome, doctors can determine its chances of developing into a healthy fetus.
What Is In Vitro Fertilization?
IVF is a form of assisted reproduction where sperm and eggs are combined in vitro, or “within the glass”. After a woman begins ovulation, a doctor extracts one or more eggs from her body and places them together with sperm in a culture. Upon successful fertilization, the resulting embryo(s) can then be placed into the woman’s uterus and develop into a fetus.
What Is Next Generation Sequencing?
NGS is a type of preimplantation genetic screening (PGS) that tests embryos for genetic defects. This non-invasive liquid biopsy allows doctors to detect chromosomal anomalies more accurately than other tests, making NGS the premier option for gene sequencing. It also stands out in terms of speed, scalability, throughput, and cost-effectiveness. NGS is also called second generation sequencing or massive parallel sequencing.
How Does Next Generation Sequencing Work?
NGS can greatly increase the success of pregnancy from IVF. Chromosomal defects may result in a miscarriage or birth defects if the fetus is carried to term. NGS uses noninvasive liquid biopsy technology to quickly and accurately identifies the genetically fittest embryos for transfer, creating the best scenario for the mother and fetus.
A healthy embryo has 46 chromosomes: 23 from the sperm and 23 from the egg. However, that is not always the case. Errors can cause the embryo to have missing or extra chromosomes. If such a fetus makes it to term, it will likely face developmental challenges such as physical abnormalities, stunted growth, and cognitive issues. Examples of chromosomal disorders include Down syndrome, Klinefelter syndrome, and Turner syndrome.
In most cases, NGS can identify an issue with an embryo by the five or six-day mark. If the test shows a healthy genetic makeup, the doctor can safely transfer the embryo into the woman’s uterus.
Who Should Consider NGS?
Any couple can benefit from next generation sequencing. The test is quick, noninvasive, and carries virtually no risk. While NGS is not required for a successful pregnancy, doctors may recommend the test for couples with certain risk factors:
- Women over the age of 35 have a higher chance of producing less viable eggs, which can lead to genetic defects.
- Women with a history of failed IVF procedures or recurrent miscarriages
- Obese men who may be more prone to infertility and sperm defects
- Aspiring parents with a chromosomal mutation may be more likely to produce an abnormal embryo.
In vitro fertilization allows couples to conceive despite infertility. However, genetic abnormalities may threaten the success of the pregnancy. Next generation sequencing is a highly accurate, non-invasive test that can dramatically improve the odds of the mother carrying the fetus to term, and giving birth to a child free of genetic defects.