biotechnology
Nice Genes

The Benefits, Costs, And Controversy Of Preimplantation Genetic Diagnosis

Couples who at one time would not have been able to have a baby are now living in a world where it seems anything is possible. Leaps in medical science have created solutions to issues that can affect both getting pregnant and carrying a baby to term. Of course, the main barrier — getting someone to have sex with you — was solved not by science, but by candles, some Kenny G, a glass of wine, and the fact that you’ve been working on your lats for, like, years.

away we go movie still

Still, if you’ve been doing it (thanks, lats!), but have faced issues that include advanced maternal age, chromosomal abnormalities, or the deeply awful experience of miscarriages, you’re definitely going to want to turn to science. In particular, preimplantation genetic diagnosis (PGD). Here’s what you need to know.

PGD Basics

Preimplantation genetic diagnosis can only be performed if you and your partner have already decided to go down the road of in vitro fertilization (IVF). In and of itself, IVF is a fairly common practice. That’s especially true for couples who have been diagnosed with infertility after a year of fruitless boot knockin’. But PGD is usually only added to IVF in specific circumstances. These include:

  • Women of advanced maternal age (over 35, ouch)
  • Individuals with chromosomal disorders
  • Individuals who carry sex-linked genetic disorders
  • Women who have lost multiple pregnancies
  • People who carry a single gene disorder
  • Women who have experienced more than one failed fertility treatment

PGD is used to detect a huge number of genetic disorders that can affect carrying a pregnancy to term. And PGD can chase down one of the over 100 genetic issues, which can increase the possibility of a healthy pregnancy from IVF by 20 percent.

But it’s important to note that this peace of mind comes at a price. It can increase the cost of normal IVF by a couple thousand dollars, depending on where the test is being done. And, obviously, you’re probably not going to choose Crazy Doc Larry’s IVF Barn for this.

How It Works

Couples who are electing to undergo PGD will start the IVF process as normal. Once the egg is fertilized in the lab it becomes a blastocyst after 5 days. At that point, specialists biopsy the outer layer of cells on the blastocyst. Doctors chose a couple cells from the layer to eventually become the placenta, thus ensuring the cells that will become the fetus aren’t harmed.

Clinicians send the biopsy to a laboratory that specializes in extracting and reading the genetic material. Doctors implant embryos that appear most viable during normal IVF rounds. They discard embryos that could contain chromosomal abnormalities.

While this is a huge leap in confidence about the future genetic health of your kid, it’s important to note that the process does not replace normal prenatal testing. Doctors still recommended procedures including nuchal translucency during pregnancy.

The PGD Controversy

There are some ethical questions and controversy surrounding PGD. Not the least of which comes from individuals who believe that life begins at conception. But beyond religious questions, there are also some bioethical considerations.

Inherited Disabilities

Some doctors and ethicists worry about parents who screen embryos for inherited disabilities and choose to do away with those carrying Down’s Syndrome or deafness. Experts suggest that future generations could erase a great many unique people who are crucial to the rich fabric of society.

On the flip side, others worry that deaf parents could choose only embryos that indicate deafness. Or that individuals affected by dwarfism might only choose embryos that indicate dwarfism.

Sex Selection

Currently, PGD does allow for additional testing (at even more cost) to determine the gender of the embryo. This is important especially for sex-linked chromosomal disorders. But even parents undergoing PGD who don’t have sex-linked issues can ask to select the gender of their child. Most often clinics allow this for what they call “family balancing.”

For ethical reasons, clinics do not generally offer sex selection to normal, healthy couples who would not otherwise undergo IVF. The fear being that people would choose one sex more heavily than the other, which would have serious cultural repercussions.

The Bespoke Child

Bioethicists have one ultimate issue with PGD. That is the fact doctors could eventually offer the proceedure to otherwise healthy adults who are seeking their perfect child. While the technology isn’t necessarily there yet, it’s possible that advances in PGD will allow a parent to chose from a list of traits, giving them the ability to chose an athletic, blond, blue-eyed boy.

But regardless of these issues, PGD remains an important tool for individuals who have been struggling with typical methods of conception, or those who fear passing on inheritable genetic and chromosomal defects. Which is great news, because your lats aren’t gonna do that for you, no matter how amazing they are.