Advances in fertility technology can increase the chances of conception of a genetically healthy baby through Preimplantation Genetic Testing (PGT). While genetic abnormalities can and do happen at any age, the prevalence increases as a woman approaches age 38 and beyond. In addition to women with advanced maternal age, other candidates for PGT include those who have experienced two or more miscarriages with an unknown cause, chromosomal abnormalities in a previous pregnancy, two or more assisted reproductive cycles without a pregnancy, or a male infertility diagnosis indicating a low sperm concentration.
Each embryo contains 23 pairs of chromosomes, for a total of 46. Through three different testing options, we are able to screen for genetic and chromosomal abnormalities:
PGT-A: When there are more or less than 46 chromosomes present, aneuploidy occurs, or a chromosomal abnormality. PGT-A testing can identify numerical chromosomal abnormalities, which allows us to choose the healthiest embryo for transfer. This results in a significant increase in pregnancy rates and a decrease in miscarriage. All PGT-A testing also uses the most advanced technology available, known as Next-Generation Sequencing (NGS), which can detect chromosomal issues such as aneuploidies, mosaicism, and segmental alterations. NGS offers a high accuracy rate of 99%. Testing can be completed quickly, allowing for embryos to be transferred in fresh or frozen cycles. This option is best for couples when the women’s age is greater than 38.
- PGT-SR: Chromosomes can also be rearranged, known as translocation, which can lead to pregnancy loss.
This option is best for couples with balanced translocations and a history of pregnancy loss.
- PGT-M: For couples who have a family history of genetic disease or are known carriers of a genetic disease, PGT-M testing allows for embryos to be screened down to the level of genetic DNA. This level of testing can identify specific gene abnormalities such as Cystic Fibrosis, Down Syndrome, or Spinal Muscular Atrophy.
This option is best for couples with a known genetic disease they would like to screen.
All of the above testing methods allow us to improve the chances of success by selecting embryos that test the highest for genetic health for embryo transfer. The remaining screened embryos are then frozen for future use.
Research has shown that once an embryo undergoes genetic testing, there is no statistical difference in pregnancy rates when comparing those who transfer one embryo or multiple embryos. Couples can be confident in a single embryo transfer having the same rate of success, thus decreasing the chance of multiples and high-risk pregnancy.
Genetic Testing in 4 Steps:
- A cell biopsy from the tissue that will become the placenta is taken from an embryo for testing.
- The test sample is placed in a tube and shipped to a genetic testing lab for analysis. Embryos remain at the Fertility Centers of Illinois IVF center.
- Testing results are sent within 10-14 days to your physician in a genetic report. Your physician will call to discuss the results and next steps.
- The embryo(s) with the highest genetic quality are identified and one is transferred to the uterus. The transfer will occur in the following cycle. Patients receive medications to optimize the uterine lining and receptivity.
Employing PGT-A in IVF Can Double Ongoing Pregnancy Rates
Ongoing Pregnancy Rate Per Blastocyst Transfer