Predicting Long Term Outcomes: MRI at term for very preterm babies

The most recent Acta Paediatrica includes 2 articles. One from parents of a very preterm infant that we looked after at Sainte Justine. They recount their experiences of having a baby at 25 weeks, and what happened to them when they had a brain MRI when their daughter reached term.

This story is accompanied by an article by Annie and me, discussing how that situation affected us, and what the evidence is regarding whether or not the information that we gain from a term MRI actually helps parents or not. If you read the article you will see photos of neonatology’s very attractive power couple (Annie and me), and also our skepticism about routine MRI just before discharge of very preterm babies. An investigation that is now being used as a screening test in many centers, but which does not fit any criteria for a screening test, as there are many false positives and many false negatives (if long term impairment is the problem that we are screening for) and nothing treatable (or very rarely anything treatable) to be discovered.

I have been reviewing the articles regarding this issue for a while, and the best large cohort studies have very low positive predictive value for developmental delay (almost always less than 50%) and very low positive predictive value for movement disorders. In contrast the negative predictive value for cerebral palsy is high, but as most cerebral palsy among preterm infants is relatively mild, and does not lead to serious disability, I am not sure how useful it is to do a test which reduces the probability of having that diagnosis. Especially when the PPV for other abnormalities is so low. There is also no standardized way of doing the test (with many sequences available) and no standardized way of interpreting them.

One thing that many want to screen for is cerebellar injury as it is said to have a much higher PPV for long term problems, indeed that is what Maren Baardsnes had. But as you can see from the article, and appreciate from the great photo of Maren, that hasn’t actually happened. She is great. (In fact another article from earlier this year Hou D, Shetty U, Phillips M, Gray PH: Cerebellar haemorrhage in the extremely preterm infant. J Paediatr Child Health 2012, 48(4):350-355. showed that infants with cerebellar hemorrhage may actually do quite well, even though it was very rare in their cohort, and therefore few affected babies to evaluate).

We would be much better off using the resources currently used for doing the MRI to provide services to the families, including early intervention programs for families who have limited means.

About Keith Barrington

I am a neonatologist and clinical researcher at Sainte Justine University Health Center in Montréal
This entry was posted in Neonatal Research and tagged , . Bookmark the permalink.

1 Response to Predicting Long Term Outcomes: MRI at term for very preterm babies

  1. HK says:

    Stumbled upoon this post while Googling use of MRI scans on neonates. I am a parent, not a doctor. Thank you for your views – I thoroughly enjoyed reading them. We as a family went through sheer hell following my son’s MRI (not only coming to terms with the results, but also coping with the crazy amount of intervention which was put in place – it felt like such an invasion of our privacy). 16 months later and, although my son has some mild difficulties, he is doing much much better than predicted and I am left wondering why we had to go through all of that. I am not at all comfortable with labelling children as brain damaged. It is very clear to me that certain assumptions about a child’s potential are made, which are not helpful. We have also experienced a disregard for our son and our family’s privacy, with the results of the MRI being shared widely (all in the name of “helping” – though none of this “help” is clinically proven). I think there is a very serious ethic issue here which is currently being overlooked.

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