April 16, 2019

expert reaction to study on additional routine ultrasounds

Research published in PLOS Medicine suggests that late pregnancy ultrasounds could eliminate undiagnosed breech presentation of babies and improve the health of mothers and babies.

Professor Basky Thilaganathan, Consultant Obstetrician, Royal College of Obstetricians and Gynaecologists, said:

“This is a very interesting study which shows that a routine ultrasound scan at 36 weeks could identify almost all pregnancies with a breech baby. This is significant because the current standard method of assessment to detect a breech baby is through a manual examination of a woman’s abdomen by a midwife, obstetrician or GP – but around half of cases of breech presentation are missed this way.

“Identification of a breech baby before labour provides an opportunity to turn the baby into the head first position to enable a vaginal delivery, or to have a planned caesarean birth. These are much safer options than discovering a breech baby during labour which may lead to an unplanned vaginal breech birth or emergency caesarean which both carry increased risks of complications for both mother and baby – especially in a first pregnancy.

“The use of an ultrasound is quick and safe way to identify the baby’s position and this study demonstrates the health benefits of scanning at 36 weeks. This scan could also screen for signs of slow growth of the baby which can suggest other complications that may need careful management to improve health outcomes for both mother and baby.

“As this paper suggests, the current financial costs of routine scanning at 36 weeks are not insignificant. More research is needed to determine the benefits of all health outcomes for mother and baby from a policy of routine use of ultrasound scanning at 36 weeks, before it can be recommended for use in all maternity units across the country. But so far the evidence for its use looks very promising.” 

Prof Jean Golding, Emeritus Professor of Paediatric and Perinatal Epidemiology, University of Bristol, said:

“This interesting paper calculates the economics of recommending routine ultrasound examinations at 36 weeks to identify breech presentations, and concludes that this would be cost effective, and would be beneficial to mother and child. However, the basis for these assumptions is a relatively small study which did not use appropriate controls (i.e. it was not a randomised trial).

A major advantage of identification of breech at this stage of pregnancy would be the possibility of changing the presentation of the baby using a procedure known as ECV, (which is a non-invasive procedure that turns the baby) and thus avoiding the risk of a caesarean section. However, this Cambridge study appeared to have a low rate of success at ECV, which raises the question as to whether the current obstetricians are sufficiently trained in the procedure.

Although the current opinion is that a breech baby at term should be delivered by caesarean section, this is not a benign procedure, and there are long-term consequences for the mother (e.g. increased risk of endometriosis) and the child (increased risk of obesity even into adulthood). These consequences were not taken into account in the economic calculations, and should have made the benefits of identifying breech using ultrasound at 36 weeks more striking especially if ECV was able to be used more successfully than in the present study.

This study is interesting but highlights the need for a randomised controlled trial to compare results of routine ultrasound at 36 weeks with a population without such a routine.”

Prof Andrew Shennan, Professor of Obstetrics, King’s College London (KCL), said:

“This study modelled the likely impact of offering routine scans in late pregnancy to determine breech presentations. An economic analysis suggested this would be less than£20 per scan but would avoid undiagnosed breech. Breech can be difficult to manage in labour if previously unsuspected as labour can be quick. This can also be a stressful situation for clinicians and mother as breech deliveries have some risk, and counselling and decision making in labour can be challenging. Scans are routinely available now, and minimal skills are required to determine breech presentation. This should be implemented.”

‘Screening for breech presentation using universal late-pregnancy ultrasonography: A prospective cohort study and cost effectiveness analysis’ by ‘Wastlund et al. was published in PLOS Medicine at 19:00 UK time on Tuesday 16 April. 

Declared interests

Prof Jean Golding: “I have no conflicts of interest.”

Prof Andrew Shennan: “None at all”