Screening and the consequences of knowledge (part three)

This is the third and final part of an article in which I am raising questions about the consequences of knowledge. You can read from the beginning of this series here.


Screening for Group B Strep

I cannot help but wonder whether, if the same kind of rigorous analysis and thoughtful consideration of the implications of knowledge upon people’s feelings was applied to some of the screening tests that are available to pregnant women, fewer screening tests and more information might be offered? Group B strep (GBS) screening, for example, carries significant consequences for women who are found to carry this bacteria or be deemed as having an ‘at risk’ unborn baby. They have to decide whether to have intravenous antibiotics during labour with the additional interventions and risks that go along with this, and their decision is complicated by the fact that they have to consider the health and wellbeing not just of themselves but of their baby as well. As is the case with a number of the prophylactic interventions that are offered in maternity care, a treatment is offered in order to attempt to prevent a rare but potentially serious or fatal condition, yet the treatment itself may involve invasive procedures or drugs which carry risks of their own (Wickham 2019).

In this case, the intervention itself may not even be effective. The Cochrane Collaboration review of the evidence showed that, although antibiotic treatment reduces the rate of colonisation and infection in babies compared to no treatment, there is no evidence that it reduces mortality (Ohlsson & Shah 2014). When this detail is weighed up against the potential risks of antibiotics and the impact that being tethered by an intravenous drip has on a woman’s ability to move around in labour, it seems reasonable that some women would choose to decline such treatment. Their choices, however, are not always respected, and some of the responses that some units and professionals are choosing in relation to this highlight some rather worrying issues.

In some areas, if a woman who is found to be GBS positive declines intravenous antibiotics in labour, she is advised that her baby should be admitted to a special care unit and given antibiotics immediately after birth. I know of cases where health care professionals have told women that they are prepared to take legal action in order to force this intervention upon babies if necessary and it is perhaps inevitable that some midwives are now advising women who would not want themselves or their babies to have antibiotics to think carefully before consenting to GBS testing. The response to such measures, though, is that some hospitals now insist on treating a woman who has not consented to GBS screening as if she is carrying GBS; a rather inflexible and arguably unacceptable stance which further restricts women’s options and which, anecdotally, is leading some women to choose home birth even where this is not necessarily ideal for them in other respects.

Knowledge, Choice and Timing

The story with which I began this article further illustrates the relative inflexibility of some of the technologies and systems that are used in screening. When my scientist friends wanted to measure my haemoglobin level, it simply wasn’t possible for the machine to provide this outside of the context of a full blood count – which, as my friend realised, carried the risk of providing information above and beyond that which we wanted. In the same way, it is impossible to carry out certain genetic tests for pregnant women without gaining knowledge about the gender of the baby, which some parents do not wish to know ahead of time. In such cases, it may be possible to enlist the help of those who are carrying out the tests in removing such information, yet there are also situations where the people who work in these areas feel compelled to follow the rules and protocols that have been set up in their area of practice. A colleague of mine recently sent a woman’s blood sample to her local lab with a form requesting a specific test for rhesus antibodies. When the results came back, they were accompanied by the results of a full blood count. She queried this with the lab, as she had not requested this information and was told, “But we ALWAYS do a full blood count routinely, whatever the form says.”

With GBS, urine testing is a key problem. Some women have reported being given a pot by a GP’s receptionist and asked to provide a urine sample without being told that, if GBS bacteria is found in their urine, they will be offered intervention and may find that their decisions are restricted.

No matter whether it is the result of the limitations of technology, the attempt to create standardised systems within bureaucratic organisations or for some other reason, the grouping of tests into indivisible packages (such as the full blood count) has become increasingly common. In some countries, including New Zealand, it is virtually impossible for women to choose which of a plethora of tests will be carried out on blood taken via a neonatal heel prick for the purposes of newborn screening; you can choose all of them or none at all. In some areas it is also not possible to have such a test carried out without also accepting that the baby’s blood will be stored in a central repository and possibly used in the future to gain genetic or other knowledge about the baby. This is of particular concern to those people who have discovered that genetic or other testing has caused them to either be ineligible for certain types of insurance or to be asked to pay far more than they were expecting to for policies on the basis that they fall into an ‘at risk’ category.

In many of these examples, timing is a key factor.  One of the most profound aspects of Barbara Katz Rothman’s analysis was the way in which she unpacked the concept of screening in relation to time, noting that,

“Prenatal diagnosis never tells anything one wouldn’t have found out later on anyway. It simply changes the timing. In having prenatal testing the woman seeks immediately the information she would have had eventually.”[iii]

There are some situations where being forearmed with knowledge can prevent potentially serious problems. In others, there may be very little that we can do except to create anxiety and potentially ‘spoil the pregnancy’. As Katz Rothman discussed, the reason for early prenatal screening and diagnosis relates to the fact that abortion is possible at this stage in pregnancy. Yet, while some women welcome this option, others do not. Equally, some women would prefer to be forearmed with knowledge, even if nothing can be done to change the outcome, while others would rather wait and see. As is so often the case, it is no more useful to argue against any intervention than to argue for routine intervention. It seems so obvious that decisions can only be made by individual parents within the context of their family and situation, and yet the systems and guidelines that make recommendations about screening seem not to acknowledge the importance of taking into account people’s feelings around knowledge, choice and timing.

As midwives, we face a difficult task. In addition to the hundreds of things that we already do, the increased number of available tests and the attendant complexity of the issues mean that it is next to impossible to discuss every aspect of these in depth. Many midwives are rightly concerned about the potentially negative implications of piling mountains of information upon pregnant and labouring women when that information and the need to make decisions can itself create stress and anxiety. There are, unfortunately, no easy solutions. It is my hope, however, that by talking more about the specifics and complexities of such issues amongst ourselves we can deepen our own understanding of the threads that run through them. These threads include our society’s continued focus on risk, the problems that can arise from centralisation and bureaucratic organisation and the impact of our modern perception of time upon women’s birth experiences. Perhaps we can seek positive ways of opening such discussions with women and their families – both before and during pregnancy – and thus look together at the bigger picture in a way that will enable women to see the range of approaches that is on offer and choose the one that is most aligned with their hopes for their childbirth experience.



Katz Rothman B (2001) Spoiling the Pregnancy: Prenatal Diagnosis in the Netherlands. In: De Vries RG, Benoit C, Van Teijlingen E and Wrede S (2001) Birth by Design. New York: Routledge. Chapter 9: pp 180-198

Ohlsson A & Shah V (2014). Intrapartum antibiotics for known maternal Group B streptococcal colonization. Cochrane Database of Systematic Reviews 2014, Issue 6. Art. No.: CD007467.

Wickham S (2019) Group B Strep Explained. Avebury: Birthmoon Creations.


A version of this article was originally published as Wickham S (2009) Screening and the consequences of knowledge. Birthspirit Midwifery Journal 2: 9-12.