In modern IVF practices, genetic procedures have become very popular recently and have contributed to pregnancy rates. As a result of the development of biotechnology, PGD applications have been used to increase the success of IVF. PGD procedure is performed in 3 ways:
- With egg biopsy (polar body biopsy)
- PGD from the embryo at cleavage stage
- From the embryo at blastocyst stage: Trophectoderm Biopsy
What is PGD? How is it performed?
The embryo obtained during the IVF process contains a total of 8 cells called blastomeres when it reaches the 3rd day. This embryo is called an embryo at the cleavage stage. The blastomere taken from the embryo at the cleavage stage is sent for genetic analysis and the transfer process is performed or canceled depending on the result. In the blastocyst stage embryo, there is the trophectoderm layer where the baby’s partner will develop in the future. A biopsy is taken from this layer with the help of a special needle and sent for genetic examination. These processes are performed separately for each embryo.
Compared Genomic Hybridisation (CGH Technique)
With this technique, 3rd or 5th-day embryos are examined by microarray-based comparative genomic hybridization technique, and genetic analysis of all chromosomes is performed. According to the results obtained after 24 hours, the healthy embryo is transferred to the mother’s uterus. With this method, while live birth rates increased, pregnancy losses are decreased.
What are the diseases that can be diagnosed with PGD?
• Single-gene diseases,
• Cystic fibrosis,
• Alpha 1 antitrypsin deficiency,
• Muscular dystrophy
• Chromosomal Irregularities
• Trisomies (embryos with a genetic structure consisting of 47 chromosomes), Triploidies (Normal human has 46, triploidy has 69 chromosomes)vb.
PGD is recommended to whom?
This procedure is a technique recommended for couples who have a high risk of genetic problems in their babies. With this technique, embryos are genetically screened before they are placed in the uterus. In this way, there is no need to wait for genetic analysis while pregnancy continues as in the past.
• Older women (as the age progresses, the probability of genetic problems in the embryo and the risk of miscarriage increases)
• Balanced chromosomal translocations that do not cause phenotypic problems in the parents (may occur as a disease in the embryo)
• Recurrent IVF failures.
• Recurrent pregnancy loss
• Unexplained Infertility
• Severe male infertility
• Defect in the Y chromosome (deletion)
• Couples with abnormal embryos