Risk, autonomy, and responsibility: Informed consent for prenatal testing

Why is informed consent required for prenatal testing? Consent is routinely sought, but examination of the theory behind and the implementation of informed consent for prenatal testing suggests that we need to reconceptualize both the risks and the responsibilities involved in offering and accepting such prenatal tests. There are currently two distinct types of prenatal tests being offered to pregnant women that can give them information about the health of the fetus: prenatal diagnostic tests and prenatal screening tests. In general, it is the diagnostic procedures, such as amniocentesis and chorionic villus sampling, that people think of when they hear the term prenatal testing. These tests are invasive and carry some risk to the fetus and they require considerable procedural skill and are expensive to perform. Thus, they are only recommended for women considered to be at high risk of having a child with a birth anomaly. However, in the last decade, with the development of the maternal serum alpha-fetoprotein (MSAFP) test, prenatal testing has undergone a paradigm shift. MSAFP, a maternal blood draw that screens for neural tube defects (serious anomalies of the fetal brain and spine), represents the new prenatal screening: procedurally simple, inexpensive, and noninvasive procedures that can be offered to all pregnant women. From Diagnosis to Screening Alpha-fetoprotein is a substance normally produced by the fetus. In 1972, Brock and Sutcliffe of the United Kingdom reported finding elevated levels of this substance in the amniotic fluid of a woman carrying an anencephalic fetus.[1] During the course of one further study, Brock and Bolton identified a case of anencephaly through analysis of the concentration of alpha-fetoprotein in the pregnant woman's blood alone.[2] Replication of this finding with high risk women indicated that maternal serum levels were not reliably diagnostic, but might be an effective screen for a variety of neural tube defects. This led to a change away from the development of a diagnostic procedure to be used with women at risk, to a screening procedure to be used with all women. Interest in detecting neural tube defects was greater in the U.K., which has the highest worldwide incidence of these defects, than it was in the U.S. Widespread use of the test in the U.S. was resisted until strong impetus for its adoption was provided by the medical malpractice concerns of professional organizations such as the AMA,[3] at which point MSAFP quickly became a part of standard prenatal care. Alpha-fetoprotein soon turned out to be a marker of a broader range of health problems than was originally suspected. Serendipitous findings first linked out-of-normal-range amounts of AFP to Down syndrome and other fetal chromosomal abnormalities; later, some unexplained positive results were found to correlate with placental and other nonspecific problems with the pregnancy. MSAFP has very low positive predictive value for chromosomal defects and there are no specific recommendations for managing "at risk" pregnancies identified through MSAFP. Nevertheless, expanded uses for the test have aided its acceptance into routine prenatal care. The routine use of MSAFP screening during pregnancy has implications that extend beyond its current range of applications. Most profoundly, it has introduced the idea of a simple, unremarkable, and expandable modality of fetal testing that is appropriate for use in every pregnancy. Thus, for example, when it was found that additional analyses performed on the same maternal serum sample could improve the sensitivity of the test for Down syndrome, this multiple marker" screening was introduced with virtually no discussion of any new ethical, legal, or social issues it might involve. Only laboratory issues were considered relevant. As expanded genetic analyses or new maternal blood screening techniques, such as fetal cell sorting, become available, what safeguards exist to insure that the ethical and social entailments of these advances will receive appropriate consideration? …