Screening before pregnancy is optimal. If both partners find that they are carriers of the same disease, they will have time to research the disease they carry, discuss their reproductive options with a genetic counselor and other advisors, and make an informed decision on their own schedule.
Screening can also be done for a pregnant couple. It is important to note that if the couple discovers their carrier status once they are already pregnant, their only options, if the fetus is affected, are to continue or terminate the pregnancy.
When the woman is already pregnant, both partners should be screened at the same time. If they are both found to be carriers, this allows for earlier fetal testing and decision-making.
Note: fetal testing for Jewish genetic diseases is not possible unless the parents have already been screened and their particular genetic mutations are identified.
For more information on the screening process, watch the video A Genetic Counselor on Screening.