New research from University Hospital Pitié-Salpêtrière at Sorbonne University, France indicates that couples at risk of transmitting Huntington’s disease to their children need more psychological support before pre-natal testing of the embryo’s genetic status, and additional counseling should they choose to reproduce again.
In practice, about 5-25% of men and women at risk for having Huntington’s opt for prenatal testing. Among those who know they carry the mutation, only 10-22 percent ask for the testing.
For the study, in addition to exploring how prenatal testing affects future choices and family structure, researchers explored how often children born after testing are informed of their genetic status.
The study “Prenatal testing in Huntington disease: after the test, choices recommence,“ included 54 women, of which 29 were female carriers of confirmed Huntington’s mutations, and 25 were spouses of male carriers. Among the women, 18% had one or more untested children before the first prenatal testing procedure.
The outcomes of the 101 prenatal tests in the group were evenly distributed — 50 favorable and 51 unfavorable results. The vast majority of couples who faced an unfavorable result chose to terminate the pregnancy. The report, published in the journal European Journal of Human Genetics, also showed that one woman miscarried, and only one of the 51 pregnancies led to a live birth.
Among the 29 women with a negative outcome in their first test round, 83% decided to get pregnant again and 87% of that group chose to go through the testing procedure a second time. However, only 37% opted for a third round of testing, while 30% chose to have an untested child.
Among the couples with a favorable result of their first testing, 62% decided not to have another child, and 10% decided to have an untested child.
Most women, as well as their spouses described the testing procedure as a painful experience. Couples facing an unfavorable outcome, understandably tended to describe the experience in more negative terms. Women who chose not to get pregnant again after terminating a pregnancy with an unfavorable outcome most often saw this as the only way not to transmit the disease.
Families informed children of their genetic status in 32% of cases. Among children older than 6.7 years, half the group was informed, while only 4% of younger children were informed. Most often, families waited to tell the child when they became older or when the disease symptoms began to show.