Pre-Implantation Genetic Diagnosis: An Overview

A few blogs ago, I had shared with you all a very unique Success Story about Mrs. B who had approached us for IVF after naturally trying for 7 to conceive with no success. To jog your memory, this case in consideration posed a unique challenge to our team at Indo Nippon. She initially underwent IVF but every time that she conceived it would result in preterm deliveries with the babies not surviving afterward. Using her cryopreserved Blastocysts we attempted a couple of fresh Embryo Transfers in a Surrogate, but in spite of a positive conception there were congenital defects detected in the anomaly scan and subsequent miscarriage.

At that point, although the couple had reached the end of their hope to have their own child, we at Indo Nippon decided to get to the root cause of the issue. We did a Karyotyping of the couple, and realised that there were some anomalies in the wife’s report. Given this new piece of information, we conducted a Pre-Implantation Genetic Diagnosis on the Day 5 cryopreserved embryos. The PGD allowed us to isolate 1 normal Blastocyst, which was then implanted in the Surrogate, eventually resulting into the delivery of healthy and beautiful Baby Girl for that couple! Given the major role played by Pre-Implantation Genetic Diagnosis (PGD) in the case of Mrs. B and the eventual successful birth of a healthy child, it became imperative that I share more information regarding this useful technology.

PGD refers specifically to when one or both genetic parents has a known genetic abnormality and testing is performed on an embryo to determine if it also carries a genetic abnormality.

The cures for many genetic conditions do not currently exist and are not likely to be found soon, and there are often some substantial risks or adverse effects related to the available treatments. The psychological impact of late onset conditions on those at risk and on their families is significant, even if effective, affordable treatment were available. Hence, it is a better option to prevent the condition versus waiting for a possible cure to eventually become available.

At this point I want to certainly highlight three very important advantages associated with PGD and that solidifies the benefit of conducting a PGD with IVF.

  • PGD provides an alternative to prenatal diagnostic testing: Couples can avoid the distress associated with diagnosis, particularly if late in an established pregnancy.
  • An alternative to termination of pregnancy: If prenatal testing (through amniocentesis or chorionic villus tests) reveals a genetic abnormality, the options available to parents are to have a child with a genetic condition or to undergo a pregnancy termination. This is a difficult and often traumatic decision. However, PGD is performed before pregnancy begins, thus eliminating this difficult decision.
  • The opportunity to conceive a pregnancy that is biologically the parents’ own and yet unaffected by a genetic condition in the family: Couples for whom the option of prenatal testing and termination is not an acceptable choice may not want to take the risk of a child having a genetic condition. In the past, potential parents with a genetic condition or those who know that they are carriers frequently chose adoption, embryo donation, or egg/sperm donation or chose not to have children in order to avoid the risk of passing on the condition. PGD now allows these couples the opportunity to have a child free of the condition.

But like all major scientific techniques, there are also few risks involved with PGD. Although most of the risks involved in PGD treatment are similar to those for conventional IVF such as:

  • Fertility drug reaction: mild reactions may involve hot flushes, feeling down or irritable, headaches and restlessness; symptoms usually disappear after a short time
  • Multiple pregnancy: risk of complications is higher in a pregnancy with twins or multiples (although we can reduce this risk to almost negligible by  transferring only one embryo)
  • Ovarian Hyperstimulation Syndrome (OHSS): Symptoms include abdominal pain and swelling, shortness of breath, nausea, vomiting, and a reduction in urine output; can result in mineral imbalances in the blood and clotting problems
  • Pelvic infection
  • Miscarriage: risk of a miscarriage after IVF is no higher or lower than after a natural conception
  • Ectopic pregnancy: pregnancy development in the fallopian tubes instead of the womb. This would not result in an ongoing pregnancy

Similar to the risks associated with PGD and pregnancy, there are conflicting concerns related to the health of the baby conceived after PGD. As a matter of fact, no strong evidence currently exists to suggest that babies conceived through this process are at any greater risk of complications than babies conceived through other forms of assisted reproduction. Furthermore several studies have concluded that are no major side-effects to the PGD treatment.

To know more about IVF and PGD, visit www.indonipponivf.com or write to me on goral@indonipponivf.com
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