The reliability of various tests will also affect a patient’s decision about genetic
testing and abortion. The physician should try to give the patient a realistic
understanding of what test results mean. No test is without false positives and
false negatives. It is never wise to tell a patient that the amniocentesis was
normal and therefore the fetus is normal. If the baby is born with a defect that
was not detected on the amniocentesis, the family may have more trouble
dealing with the problem and may be very angry with the physician who
indicated the baby was healthy. On the other hand, a woman who appears to
be carrying a defective fetus must understand that many tests are uncertain
and there is some possibility that there is no defect. It is difficult to tell a
patient this without raising unreasonable hopes. If the decision to abort is
made, patients should not be encouraged to ask for testing on the abortus
unless this will provide useful medical information for future pregnancies.
There is little to be gained from second- guessing an irrevocable decision.