After my third miscarriage—my first with IVF—my doctor said it was "likely" due to my age and therefore my egg quality. But testing was inconclusive. In other words, he did not know for sure. That's when my husband and I decided to do Pre-Implantation Genetic Testing (PGD), which assesses whether the embryos are healthy before transferring them to my womb.
In Vitro Fertilization is already so, so expensive, and doing PGD can add thousands of dollars extra; testing on a batch of 1-8 embryos is the same cost, so you also have to either get enough embryos to the 5-day mark, or do a few cycles to bank some.
But here's the thing: fertility clinics always grade your embryos based on their morphology – how they appear. But embryos that appear to be of poor quality can actually be healthy and vice versa. The only way to be certain is to test them.
If you are a carrier for a specific disease, you can do genetic screening to ensure that you only transfer embryos without those markers. Some diseases— like Tay Sachs—are a matter of life or death and parents who might not necessarily require IVF must do it so they can select the healthy embryos.
Other diseases and genetic markers might be a matter of choice, such as BRCA1, the marker which gives carriers 50% chance of developing breast cancer.
Testing to Prevent Miscarriage
For women like me who get pregnant easily but have experienced recurrent pregnancy loss (RPL), or older women, PGD can weed out the chromosomally abnormal embryos and ensure only healthy ones make it to the womb. That doesn't ensure a pregnancy —there are many reasons an embryo does not implant—but it can prevent further miscarriages.
For now, like all things fertility related, PGD is a personal decision, between you, your partner and your doctor.
Testing to Reduce Multiples
In the past, doctors would put in a number of embryos—sometimes up to four—to try to increase the chance that at least one would take. But that would often result in the birth of multiples —twins, triplets, quadruplets —which can often be hard to carry and have premature birth, causing future health problems. Many clinics now want to prevent multiples, and therefore only want to transfer one embryo at a time. The best way to do this? Find the healthiest embryo through testing.
Testing for "Family Balance"
Have three boys and want a girl? Have one girl and really just want one more kid—but only a boy? Embryo testing can also be used for gender selection—which, for some parents, is really important: One mother I know had a daughter who passed away, and really just wanted another girl.
Testing to Get Pregnant Faster
Sure, IVF is expensive, and PGD makes it even more so. But in addition to taking a toll on your bank account, fertility treatments take a toll on your emotions. Some feel that it's best to accelerate the entire process to reduce the emotional toll. So instead of putting in a few embryos every cycle (or every other cycle) and praying that one takes, you find only the healthy ones, and thereby cut your time in half—not to mention reducing those painful two-week waits.
Look, there are some downsides to doing PGD. If you have too few embryos, you might not want to risk waiting for them to make it to day 5 or other things that can go wrong in the lab (PGD does not harm otherwise healthy embryos.) You also may never have enough to test and that can prolong the process. Cost too, can be a prohibitive factor.