Ultrasound Method Could Improve Diagnoses of Perinatal Deaths in Low-Resource Settings

Perinatal mortality—deaths occurring some weeks before or after birth—remains unacceptably high in low- and middle-income countries (LMICs). Understanding the causes of these deaths is critical to designing effective prevention and care strategies. A new study led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by “la Caixa” Foundation, shows that a simple ultrasound method could improve the accuracy of gestational age estimates in foetal and perinatal deaths, paving the way for better diagnoses.

The challenge: missing gestational age data

Determining gestational age is vital to distinguish between two leading causes of perinatal death: prematurity and intrauterine growth restriction. While both conditions are common, they require very different approaches to prevention and management. However, in many low-resource settings, data on gestational age is often incomplete.

“This is because recall of the last menstrual period is frequently imprecise, and first-trimester ultrasounds are rarely performed,” explains Natalia Rakislova, co-senior author of the study together with Jaume Ordi, both researchers at ISGlobal. To address this challenge, they explored whether post-mortem ultrasound measurements of the cerebellum—a part of the brain—could provide an accurate estimate of gestational age in foetal and perinatal deaths.

The test: validating the ultrasound method

Between August 2020 and November 2022, Rakislova and colleagues conducted a study at Barcelona’s Hospital Clinic, performing post-mortem ultrasound assessments on the cerebellums of 137 foetal and perinatal deaths. These assessments included measurements taken both within the uterus and after the foetus had been removed.

The results were promising. Among the various types of cerebellum measurements tested, the extrauterine transcerebellar diameter emerged as the most reliable predictor of gestational age. Importantly, its accuracy was not affected by factors like the trimester of gestation, restriction growth, or central nervous system abnormalities.

“Our results demonstrate that this method is valid for estimating gestational age,” says Núria Peñuelas, first author of the study.

What This Means for LMICs

This relatively simple and non-invasive method holds particular promise for low- and middle-income countries (LMICs) where MITS – a technique pioneered by ISGlobal – is being used to determine causes of death with almost the same precision than complete autopsies. By integrating ultrasound-based gestational age estimates into MITS, researchers and healthcare providers could significantly improve diagnostic accuracy.

Certainly, access to ultrasound equipment may pose challenges in LMICs. But low-cost, portable ultrasound devices have been successfully used in these settings, even when operated by personnel without highly specialised training.

“Future studies should validate our findings in larger and more diverse populations, especially in low-resource settings,” emphasises Rakislova. “Importantly, the technique can be done by trained laboratory technicians, without the need of a doctor,” she adds. Ultimately, this ultrasound method could improve the understanding of the causes of perinatal deaths, and help to design targeted interventions to prevent them.

Reference

Peñuelas N, Saco A, Marimón L et al. Gestational age assessment by ultrasound cerebellar measurements in fetal and perinatal deaths. AJOG. 2024. https://doi.org/10.1016/j.ajog.2024.11.016