Ultrasounds that measure blood flow, known as Doppler ultrasounds, may highlight which smaller foetuses require extra medical attention, according to a study led by the University Medical Center Groningen (UMCG) and Amsterdam University Medical Center (UMC).
Around 10% of foetuses suffer from growth restrictions and are considered too small for their gestational age. In some cases, this requires medical intervention. The baby’s size is usually determined by routine ultrasounds. In this study, a Doppler ultrasound was also conducted which could shed light on the blood flow through the placenta. While such secondary ultrasounds aren’t routine, it was found that they could better detect and help monitor higher-risk cases. The study included 690 pregnant women.
A Doppler ultrasound is a noninvasive examination that uses sound waves to detect blood flow. It can measure the blood supply in a baby’s brain as well as the blood flow through the placenta. An increased blood flow to the brain indicates that a baby is overcompensating for issues with the placenta, which can increase the chances of stillbirths.
In their paper, the researchers said that the search for ways to differentiate between foetuses that suffer from growth restrictions and those that are small but otherwise healthy has been a long one.
The study also examined whether it would be better for babies whose Doppler measurements showed abnormalities if labour was induced before 37 weeks. This did not lead to better outcomes. Therefore, the advice is to wait until at least 37 weeks of pregnancy before inducing labour, unless there are other signs that the baby is having difficulty. Having the baby remain in the womb for as long as possible was found to be better, as long as there were no other health risks.
The paper was published in the British Journal of Obstetrics & Gynaecology.