Gaps in Gestational Diabetes Diagnosis in Pregnant Women

According to research on gestational diabetes testing methods, more than half of pregnant women with the condition are not diagnosed using the existing NHS blood test methodology, resulting in avoidable difficulties for both mother and baby.

The study, conducted by Professor Claire Meek of the University of Leicester and colleagues at the University of Cambridge with funding from the National Institute of Health and Care Research (NIHR), discovered that processing blood sugar tests of mothers at risk of gestational diabetes more quickly could result in a more accurate diagnosis of this serious condition.

Gestational diabetes, which affects women in pregnancy, is very common in the UK and causes complications at the time of birth, affecting both mother and child.

Fortunately, most complications can be prevented by accurate diagnosis and access to treatment. However, if the diagnosis is not accurate, then affected mothers cannot access the treatment they need.”

Claire Meek, Professor of Chemical Pathology and Diabetes in Pregnancy, University of Leicester

Gestational diabetes is diagnosed using an oral glucose tolerance test (OGTT) between 24 and 28 weeks of pregnancy.

This test involves collecting the mother’s blood before she consumes a sugary beverage. Another sample is obtained and examined two hours later. However, red blood cells in the sample continue to consume glucose after the blood is drawn, therefore glucose concentrations in the sample tube fall over time, resulting in an incorrect result.

Processing the blood swiftly ensures that the glucose levels in the sample are most similar to those in the patient’s blood.

“We wanted to assess if processing the samples more quickly improved the accuracy of the OGTT test.” continued Professor Meek.

“We compared standard NHS sample processing procedures to an enhanced processing plan, where the blood was processed more quickly.”

According to routine NHS sample processing standards, 9% of the women in the research were diagnosed with the illness. The researchers discovered that when blood was processed faster, 22% of the women in the trial developed gestational diabetes.

This suggests that 13% of women were overlooked by the conventional test. More than half of the women discovered to have gestational diabetes in the study would have gone undiagnosed.

Scaling up, this might affect about 28,000-30,000 pregnant women in the UK each year.

Danielle Jones, the PhD student who coordinated the research project added: “Faster blood processing identified additional women with raised blood sugar levels that were missed by the standard test. Thirty seven percent of these women went on to have large babies – a complication which could have been prevented if undiagnosed women had access to treatment.”

The findings of this study imply that enhancing NHS sample processing is critical to improving gestational diabetes diagnosis. Access to treatment may also help keep newborns from being overly large. Most NHS settings can process blood more quickly (within 2 to 4 hours), which opens up new options to improve maternal and infant health.

For more information: Jones, D. L., et al. (2024) Enhanced glucose processing in gestational diabetes diagnosis: Effects on health equity and clinical outcomes. Diabetic Medicine. doi.org/10.1111/dme.15476.