Birth Small Talk

Talking about birth

CoVid19 and the CTG

Given that you are reading this on the inter-webs, I am going to assume that you have heard concerns about the novel coronavirus or CoVid19 infection. Professional organisations have been quick to act in putting out guidance for their members. This is quite challenging as everything is very new and knowledge about the disease is in a state of constant flux. Advice about what those of us in maternity care should be doing is particularly tricky, as the number of pregnant women with confirmed disease is (by quantitative research standards) quite small.

I was heartened to see that the Royal College of Obstetrics and Gynaecology (that’s the UK professional body for obstetricians) put out a guidance statement on Monday. (Note that some of the recommendations are only relevant to the UK setting.) I’m not a virologist, respiratory physician, or epidemiologist so I can’t critique most of the document, which seems pretty sound. 

What I do know a lot about is CTG monitoring. So the following advice caught my eye:

If birth at home or in a midwifery-led unit is planned, a discussion should be initiated with the woman regarding the potentially increased risk of fetal compromise in women infected with COVID-19 (as was noted in the Chinese case series of nine women). The woman should be advised to attend an obstetric unit for birth, where the baby can be monitored using continuous electronic fetal monitoring. This guidance may change as more evidence becomes available. 

RCOG Coronavirus CoVid-19 virus infection in pregnancy. Information for healthcare professionals. p 14.

This and a later recommendation that women who have tested positive for the virus, and who have no, or only mild symptoms should have intrapartum CTG monitoring raised the following questions for me:

  • What is the quality of the evidence on which this recommendation is made?
  • What prior evidence do we have that might be relevant?
  • What might be the consequences if this recommendation is enacted in the event that significant numbers of pregnant women become infected with CoVid19?

What does the new evidence say?

First, let’s review the evidence described in the guidance paper that was used to form the basis of this recommendation. It comes from two papers (freely accessible and linked at the bottom of this post) reporting on outcomes from women hospitalised in Wuhan province in China, early in the evolution of the epidemic. 

The first paper (Chen, et al., 2020) included 9 women, 8 of whom had viral pneumonia, and the remaining woman had fever and a cough, having experienced prelabour membrane rupture at 36 weeks of gestation. The abstract stated that “fetal distress was monitored in two cases” but provided no further information about how this was determined. All infants had normal Apgar scores (one was not recorded) and none had evidence of neonatal asphyxia. 

It is difficult to ascertain whether the 10 women whose outcomes were reported in the second paper (Zhu, et al., 2020) include some of the women reported in the previous paper. Let’s assume that these are all unique individuals. All ten women were symptomatic with signs of viral pneumonia. The findings stated that six fetuses exhibited “intra-uterine distress” without expanding on how this was determined. Two women out of the ten had vaginal births, with both these fetuses being classified as having “distress”. All infants had normal Apgar scores. While some of the infants went on to develop symptoms from CoVid19 (with one death), there was no suggestion in the paper that any infant experienced symptoms suggestive of prior intrauterine hypoxia.  

The small number of women (19) used to generate a recommendation which might be carried out on thousands of women worldwide is concerning. The Cochrane review on CTG monitoring included over 37,000 women and it is often argued that the research still has not included enough women to generate reliable answers. These papers do not offer any useful information about the risk of intrapartum fetal hypoxia in women who have tested positive, but who have no, or mild symptoms secondary to CoVid19, as all the women in the papers were hospitalised with significant symptoms. Therefore using these findings as the basis of a recommendation for CTG monitoring is not consistent with how evidence-based care is conducted.

The diagnosis of “fetal distress” is highly subjective. It is possible that fetal tachycardia was considered to be a sign of “fetal distress”, yet this is an appropriate compensatory fetal response to maternal fever, a common symptom of more viral pneumonia with CoVid19. Given the absence of any postnatal signs that any baby had experienced fetal hypoxia (normal Apgar scores and no symptoms of hypoxic injury), it is difficult to have confidence in the diagnosis as it has been provided in these reports. It therefore is also not appropriate to summarise that the incidence of “fetal distress” among women who test positive for CoVid19 is high.

What do we already know?

Second, let’s look at what we already know about intrapartum CTG monitoring. Research shows no improvements in perinatal mortality with the use of CTG monitoring during labour (Alfirevic, et al., 2017). That’s true whether the women are considered to be at low-risk, or high-risk, for having a baby who experiences intrauterine hypoxia. There is no reason to presume that viral infection will change this. We also know that more women will give birth by caesarean section or instrumental birth when they have intrapartum CTG monitoring (Alfirevic, et al., 2017). This prolongs their time in hospital and places a greater demand on hospital resources, in addition to making women more vulnerable to secondary complications.

We know that for most well young adults, CoVid19 causes mild respiratory symptoms and there is therefore no pathophysiological mechanism which would suggest that fetal hypoxia is more likely to occur. This is of course not the case in women who themselves are hypoxic as a consequence of severe infection. CoVid19 infection reminds us yet again that the best approach to maintaining the health of the fetus is to maintain the health of the pregnant woman.

We have seen this “risk averse” decision making plenty of times before in obstetric practice – where ineffective (or harmful) interventions are introduced to deal with a new risk, on the dangerous assumption that doing something is always better than doing nothing. This seems to be the driver for this particular decision.

What might happen?

Finally, let’s imagine some of the potential consequences of this recommendation. Bringing pregnant women into hospital settings, when they had already planned to give birth at home or in another community setting, increases the exposure of hospital staff to CoVid19. This isn’t just about midwives, doctors, and nurses. It includes such people as the cleaning, kitchen, administration, and laboratory staff without whom clinicians can’t function. Each hospital employee who needs to be quarantined when they too become infected has a significant impact on the capacity of the health service to provide care to the anticipated large numbers of individuals with severe illness. By focussing efforts on the prevention of the relatively rare outcome of fetal hypoxic injury through CTG monitoring (which doesn’t work anyway), we risk other people dying from conditions which would benefit from hospital care because no such care is available. 

Even a small increase in the caesarean section rate has significant consequences. Caesarean section often requires the woman to be moved some distance through the hospital to an operating theatre and increases the number of clinicians and other people in close contact with the woman. After use, the operating theatre needs to be closed while being thoroughly cleaned, a time-consuming process which prevents other surgery from occurring. If the experiences we are beginning to see in Italy are suggestive of what lies ahead, then it is likely that most operating theatres and birth suite rooms will be transformed into high dependency settings for the care of non-pregnant people with CoVid19. Suggesting an ineffective intervention that is known to increase the use of precious hospital resources is not good practice at the best of times, but when you are potentially facing severe resource restrictions it is downright dangerous and simply pointless.

If the governments and health departments of high-income countries are to get serious about preventing perinatal death (not to mention maternal death) in relation to CoVid19, then the best way to do so is to prevent pregnant women from being infected with CoVid19 in the first place. My suggestions are:

  • Health departments need to rapidly introduce or expand out of hospital options for maternity care provision, particularly in the home. Doing so avoids bringing pregnant women into environments where it is more likely they will encounter the virus.
  • Pregnant women should make an informed decision, based on their personal risk of exposure to CoVid19, about self-isolation until after the birth of their baby, or the peak of the epidemic. 
  • Self-isolation should include limiting contact with family members (particularly children who appear to act as asymptomatic carriers of the virus) of pregnant women, given that this will reduce the risk of transmission to the pregnant woman via her family contacts. 
  • Governments should provide adequate financial support for all pregnant women and their families to ensure that self-isolation is a financially viable option.

And don’t make a blanket recommendation that all women who test positive for CoVid19, regardless of other circumstances, or the woman’s own intentions, should have CTG monitoring during labour. It’s not good science. I hope that the Royal College does indeed update this decision as new information comes to light.

Alfirevic, Z., Devane, D., Gyte, G. M. L., & Cuthbert, A. (2017). Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database Syst Rev, 2(CD006066), 1-137.

Chen, H., Guo, J., Wang, C., Luo, F., Yu, X., Zhang, W., . . . Zhang, Y. (2020). Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records. The Lancet, 395(10226), 809-815. doi:10.1016/s0140-6736(20)30360-3

Zhu, H., Wang, L., Fang, C., Peng, S., Zhang, L., Chang, G., . . . Zhou, W. (2020). Clinical analysis of 10 neonates born to mothers with 2019-nCoV pneumonia. Transl Pediatr, 9(1), 51-60. doi:10.21037/tp.2020.02.06

Please note that these are my personal opinions and do not constitute guidance for pregnant women or their practitioners. 

Categories: CTG, EFM, New research

6 replies

  1. A well-considered and important post, Kirsten. Thank you for sharing your perspective. It’s very welcome. We need educated and reasoned thinking in this situation as we do in every situation where women and birth are concerned.

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  2. Sanity at last. Thank you.

    Like

  3. Thank you for your well considered post Kirsten. Lots of discussion about Covid-19 but evidence is very thin on the ground – and we react with risk and safety bias already in place. Wisdom is always welcome

    Like

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