Genetic screening of embryos, also known as preimplantation genetic screening (PGS) or preimplantation genetic testing for aneuploidy (PGT-A), is a reproductive technology used during in vitro fertilization (IVF) to examine the genetic makeup of embryos before they are transferred to the uterus. The primary goal of genetic screening is to identify embryos that have the correct number of chromosomes (euploid) and are less likely to result in chromosomal abnormalities or genetic disorders.

1. In vitro fertilization (IVF): Eggs are retrieved from the female partner’s ovaries, and sperm is collected from the male partner or a donor. The eggs are fertilized with the sperm in a laboratory setting to create embryos.

2. Embryo culture: The resulting embryos are allowed to grow and develop in a controlled environment for a few days, usually up to the blastocyst stage (around 5-7 days).

3. Biopsy: A few cells are carefully removed from each viable embryo. This process is typically performed using a laser to make a small hole in the embryo’s outer layer, and a few cells are extracted for analysis.

4. Genetic analysis: The extracted cells are then subjected to genetic testing to determine the number of chromosomes in each embryo. The most common method used for this analysis is next-generation sequencing (NGS) or polymerase chain reaction (PCR).

5. Selection: After the genetic analysis is complete, the embryos that are determined to be euploid (with the correct number of chromosomes) are identified. These embryos are considered more likely to develop into healthy pregnancies.

6. Embryo transfer: The selected euploid embryos are then transferred into the uterus of the female partner in the hope that one or more will successfully implant and lead to a successful pregnancy.

1. Increased chances of successful pregnancy: Selecting euploid embryos can enhance the chances of implantation and reduce the risk of miscarriage.

2. Reduced risk of chromosomal disorders: Genetic screening can help avoid transferring embryos with chromosomal abnormalities such as Down syndrome (trisomy 21) and other aneuploidies.

3. Fewer multiple pregnancies: By selecting healthier embryos, the likelihood of multiple pregnancies (e.g., twins, triplets) is reduced, which can carry higher risks for both the mother and babies.

It’s important to note that genetic screening of embryos is an optional procedure and may not be recommended or necessary for all couples undergoing IVF. The decision to undergo genetic screening should be made based on individual circumstances, including medical history and risk factors. Additionally, genetic screening does not guarantee a successful pregnancy, as other factors can also influence the outcome.