Giving women a third scan at the end of their pregnancy could dramatically reduce the number of unexpected breech births and the risk of babies being born with severe health problems, research suggests.
Pregnant women in the UK have routine scans at 12 and 20 weeks only, with no further scan offered in the third trimester unless they are considered at risk of a complicated pregnancy. The researchers hope their findings could lead to a change in guidance for clinicians that will improve maternity care.
Prof Asma Khalil, who led the study at St George’s, University of London, said: “For the first time we’ve shown that just one extra scan could save mothers-to-be from trauma, an emergency C-section, and their babies from having severe health complications which could otherwise have been prevented.”
She said the two routine scans were “far too early” to establish how the baby would be positioned during labour. “That’s why a third scan at 36-37 weeks could be a gamechanger to pregnancy and birth care.”
The researchers estimated that the additional scan could result in a cut of 70% to unexpected breech births, which happens to about 4% of babies at the moment. This is where the baby is positioned feet or bottom first, putting them at risk of being admitted to the neonatal unit, receiving a brain injury due to a lack of oxygen, or death.
The research, published in the PLOS Medicine journal, was based on a comparison between the rate of unexpected breech births and the health of the newborn after different third trimester scan policies were introduced at St George’s university hospital NHS foundation trust (SGUH) and Norfolk and Norwich university hospital NHS foundation trust (NNUH).
At SGUH, 16,777 received only the usual antenatal ultrasound scans and 7,351 had an extra ultrasound scan by a sonographer at 36 weeks. At NNUH, 5,119 women received standard ultrasound scans and 4,575 were given a scan with a portable device.
Both types of third trimester ultrasound scan dramatically reduced the rate of unexpected breech births – 71% lower with the standard type of ultrasound and 69% lower with the handheld device.
The babies of women who had the third ultrasound were 16% less likely to be admitted to the neonatal unit for closer monitoring, and were between 40% and 77% less likely to have a low Apgar score – which assesses wellbeing including heart rate, ability to breathe and skin colour – at five minutes after being born. The mothers were also less likely to need an emergency caesarean.
This happened to Kate Bayliss, who only found out her baby was breech as she went into labour, at 41.5 weeks. She was told “under pressure” to choose between a difficult natural birth or an emergency caesarean. If she had a scan at 36-37 weeks, there would have been time to turn the baby around or to schedule a planned C-section.
“It would be really reassuring, and for someone like me it would have given me more of a chance to make a decision. I’d be an advocate for everyone having a late scan. You’ve got to see a midwife and a doctor all the time anyway; if they could just have a quick look, that would be amazing,” she said.
The research follows the emergence of widespread concerns about the safety of NHS maternity services, after a series of scandals at several NHS trusts, rising maternal mortality rates, and the ombudsman warning that mothers and babies are being put at risk.
Khalil suggested more midwives could be trained to use the handheld ultrasound device to improve access to the third trimester scan.
Fran Harlow, a consultant obstetrician for NNUH, said her trust had provided training to use the devices to all midwives. “We are delighted that this study has shown that the benefits to the mother and baby [of using a handheld ultrasound device] are equivalent to a formal scan performed by an ultra-sonographer. This keeps care in the community and woman-centred.”
A spokesperson for the National Institute for Health and Care Excellence said guidelines recommend midwives examine women’s abdomens by touch at all appointments after 36 weeks to identify possible breech presentation, which is followed up by a scan if this is suspected.
He said: “The safety of mothers and their babies is at the forefront of our committee’s mind when they produce evidence-based recommendations. We welcome technological development and the generation of new evidence in this important area, and we will review this study to see if our recommendations need to be updated.”
