When should women be counselled about the risks of vaginal delivery versus caesarean section when having a baby that is predicted to be larger than average?

Background

The above issue was explored in a case in which Clyde & Co LLP were instructed by NHS Resolution to represent the East and North Hertfordshire NHS Trust.

The claimant alleged that in 2015 she was not properly consented for a Vaginal Birth After Caesarean Section (VBAC). In summary it was said that:-

  1. There was a failure to provide information concerning the risks of requiring instrumental delivery; and
  2. There was a failure to provide information about the increased risks of failing to deliver vaginally with a baby weighing over 4kg.

The issues narrowed after exchange of expert evidence and it was apparent that the only real issue between the parties on breach of duty was whether there was any evidence of fetal macrosomia which in turn mandated discussions about the risks and benefits of different modes of delivery.

Fetal macrosomia

The claimant asserted that fetal macrosomia was defined as a predicted birth weight in excess of 4kg and relied upon the following factors to say that it was present in the index case:-

  • A private scan performed at 27 weeks when extrapolated to term showed an estimated fetal weight of over 4.2kg;
  • There were 3 plots on the NHS GROW chart which noted that fundal height was around the 90th centile; and
  • The 32 week NHS scan showed an estimated fetal weight on the 70th centile.

The positon of the Trust in response to the above was:-

  • There was no evidence that the Trust saw the results from the private scan performed at 27 weeks. They were however informed that there was some concern about fetal weight and thus organised the ultrasound scan at 32 weeks. This was reasonable practice;
  • Fundal height is not an indictor used to predict fetal macrosomia. It is a very imprecise assessment of growth and in any event, the measurements denoted normal growth; and
  •  A baby on the 70th centile has a normal birth weight. The evidence of the claimant would imply any measurement above the 50th centile is larger than normal and so presumably any measurement below the 50th centile is smaller than normal. This would confine "normal" to 1% of the population.

In short, the evidence from the Trust was that information concerning fetal macrosomia was only imparted to patients in 2015 when a growth scan predicted an estimated fetal weight over the 90th centile or when there were risk factors present for the condition. i.e. an abnormal BMI, gestational diabetes or a family history of fetal macrosomia.

When considering the breach of duty issues the claimant also faced the added difficulties of (a) various RCOG and NICE guidance referring to fetal macrosomia as being over 4.5kg and; (b) retrospectively it was calculated that the 32 week scan predicated a birth weight of 3.7kg.

In fact, the claimant's baby weighed 4.1kg at birth and she sustained a fourth degree vaginal tear. It was contended that in the absence of the negligence the claimant would have opted for caesarean section and thus avoided her injury. This aspect of the case was also in dispute as records from the claimant's first pregnancy and the index VBAC pregnancy indicated that she wanted a natural birth.

Outcome

The case was due to go to trial at the High Court in July 2020 but the claimant discontinued 1 week prior to the hearing. As a consequence of the successful defence the NHS Trust saved significant financial sums in respect of damages and costs.

Learning

As indicated above the case not only turned upon whether the Trust should have counselled the claimant about the risks of fetal macrosomia but also whether the claimant would have elected a caesarean section had different information been provided. Factual evidence from the Trust was key in responding to these points and the case again underlined the importance of the clinician's input in consent cases.

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