Decision making about preimplantation genetic diagnosis (PGD) is a complex, multiphase process for couples, a new study has found. Understanding it, the investigators say, may be helpful to prospective parents who know they're at risk for transmitting a genetic disorder, and to the professionals who advise them.
PGD is a procedure used by prospective parents who are trying to prevent a disease-causing genetic mutation from being passed on to their offspring. Couples first go through in vitro fertilization (IVF), in which their sperm and egg cells are brought together in a laboratory dish. PGD then requires removing a cell from an IVF-produced embryo and testing it for the specific genetic mutation. An embryo that doesn’t show the mutation can be implanted in a woman's uterus.
IVF-PGD procedures can be physically, psychologically and financially stressful.
Beginning in 2009, principal investigator Patricia Hershberger at the University of Illinois at Chicago and her colleagues conducted in-depth interviews of 22 couples (44 individuals) considering PGD, interviewing each person separately.
Participants knew they were at risk for transmitting a genetic disorder to their offspring, including: Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), facioscapulohumeral muscular dystrophy (FSHD), myotonic muscular dystrophy (MMD), unspecified muscular dystrophy, Charcot-Marie-Tooth disease (CMT), spinal muscular atrophy (SMA), and others.
Hershberger and colleagues, who published their findings in the May 2012 issue of Social Science & Medicine, found that couples go through four phases in their decision-making process. The investigators called these phases Identify, Contemplate, Resolve and Engage.
The Identify phase is characterized by learning more about the genetic disorder for which the couple is at risk and more details about their at-risk status.
During the Contemplate phase, people explore a range of reproductive options, including using a sperm or egg donor, adopting a baby and using PGD. Some stayed in this phase for as long as three years.
In the Resolve phase, people either accept PGD, decline it or "oscillate" (go back and forth) about the procedure. Nine of the 22 couples in this study ultimately accepted PGD, four declined it, and nine remained "oscillators" at the end of the study period.
The final phase — Engage — is a time when people carry out their PGD decisions, such as beginning the hormonal treatments required to start IVF, or moving down a different path, such as going ahead with natural conception or adoption.
"What is striking and universal about the couples in this study is the genuine care and concern they expressed for their future child(ren) and their understanding of the profound significance of their decision — regardless of their decision type," the investigators say in their May 2012 paper.
The authors conclude their published study by saying, "There is a burgeoning number of couples who will face decisions about whether to use PGD; research in this area is critical to aiding modern couples, clinicians and policymakers as we navigate the continuing technological advances of the 21st century."
Future studies are being planned. More information can be found at PGD: Couples' Decision Making at the Genetic and Reproductive Interface, a University of Illinois at Chicago College of Nursing website about Patricia Hershberger's PGD research, featuring a video by Hershberger.
For more information about preimplantation genetic diagnosis, here are some helpful resources: