Should early non invasive prenatal testing be opposed?

It is now possible to detect fetal problems with just a sample of the pregnant woman’s blood. Women will probably be offered this test routinely in the first trimester. But the breakthroughs are said to raise serious ethical questions.

In 2008 Fan et al. (Proc. Natl Acad. Sci.USA 2008; 105:16266–16271) non-invasively diagnosed fetal chromosome abnormality from cell-free DNA in maternal blood. Recently, at least two companies have announced plans to introduce non-invasive prenatal diagnosis (NIPD) into health care.

The clinical role of NIPD is unclear. It could be used either as a screening test (with CVS or amniocentesis still required as a follow up diagnostic test) or it might replace invasive tests. Less likely, it might be interposed between current screening and invasive tests.

The most exciting, and potentially controversial, role of NIPD is if it can replace current invasive tests. Prenatal (cyto)genetic diagnosis could be achieved much earlier in pregnancy.

Should one step NIPD be available early?
There is debate whether this would be ethically desirable. Early NIPD could increase the proportion of pregnant women opting for termination, including for ‘unwanted’ fetal sex, minor abnormalities or other non-medical reasons. 

Uptake rates of NIPD might become as high as they are for current screening tests (up to 85% of women). Providing adequate pre-test counselling for such a large number of women would be challenging. Testing could become a one-step procedure with only one contact between the pregnant woman and the physician to discuss the pros and cons of NIPD. It has been questioned whether an autonomous decision-making process is still possible. But implementing new prenatal tests always demands changes – that is not a reason to reject the test.                                                                                                           
It is claimed that NIPD might reduce the reproductive autonomy of the woman. A fear is that women might not be able to make informed choices because they will feel under intense emotional pressure to choose an abortion. It may be difficult or impossible for a vulnerable woman to refuse the doctor’s "offer" of abortion for fetal abnormality. In one German survey, 25% of women stated that they opted for prenatal diagnosis because their physician wanted it; 36% thought that it was an almost mandatory part of routine maternal care; and 16% had either not given consent for the test or could not remember giving consent. It is true that many women have prenatal screening procedures about which they are ill-informed (Favre et al. Prenat. Diagn 2007; 27: 197–205). This is wrong and should be addressed. Informed consent is an important issue in all prenatal testing; it is not specific to NIPD so is not an argument to oppose its implementation.                                        
Prenatal testing ‘allows’ women to have (more) children. Many would decide to limit family size if testing and access to abortion was not available. For some women prenatal testing, especially early prenatal testing, provides the confidence that they need to have a much wanted healthy child.

Paradoxically, limiting prenatal testing and access to abortion may reduce family size. Some women who have a disabled child choose to stop having children or have fewer children than they would otherwise have had.

Is it wrong for more women to choose abortion?
It might be claimed that fewer women should be able to choose abortion because it is a relative wrong, or because women should accept life’s lottery. In addition, complications of abortion may result in adverse health outcomes. The option of abortion following the diagnosis of fetal abnormality is a major reason for offering testing. Lawful abortion is safer than full term pregnancy; there is no reason to restrict the number of women who might request abortion by arbitrarily limiting early testing.

There are many reasons that women might request abortion following prenatal diagnosis of an abnormality that some would consider to be minor. One is that it commonly raises concerns that it could be the only detectable marker of other syndromal abnormalities. And ultimately it is for the woman to decide if she will continue the pregnancy.

In western countries abortion for the ‘wrong’ sex is very uncommon. It may be that more women could request sex selection if NIPD is introduced. But there is no reason to suggest there would be a marked increase. In western societies prenatal sex preference tends to be related to couples balancing the family sex ratio, so there is no risk of a sex ratio imbalance.  In Asian countries sex selection is usually related to a cultural and economic preference for males; hence their sex imbalance. Their imbalance is a problem that needs addressing, but this is not a reason to deny women a major advance in prenatal testing.

Are ethical concerns worse for non-invasive than invasive prenatal tests?
Most people would consider that there are fewer ethical concerns when the test imposes no pregnancy risks. There are unlikely to be fetal risks in some current tests, such as ultrasound, and the tests are widely accepted. In addition, invasive tests not only have a risk of miscarriage, other non lethal complications can expose the future child to risk of resultant disabilities. These are more important than fetal mortality risk since the suffering may last decades e.g. amniocentesis can cause ruptured membranes and result in extreme prematurity.

The authors propose a two-step approach with counselling, followed by a second stage for decision-making and testing to ensure a ‘value-consistent shared decision-making process that also takes into account the welfare of the unborn child’. It is unclear what values they wish to promote, who they envisage should share decision-making and what fetal welfare issues they are considering. Women’s autonomy must be protected. But the obstetric world has long sought non-invasive prenatal diagnosis to replace invasive tests. If this is available early in pregnancy it could radically shorten the uncertain ‘tentative pregnancy’ phase that currently causes anxiety to women early in pregnancy. Women seek early prenatal testing – NIPD may be part of the answer for them.

  • Facebook
  • Twitter
  • Reddit

Comments are closed.


Subscribe Via Email