Early Gestational Hyperglycemia in Bangladesh: Discordance Between IADPSG and ADA Diagnostic Criteria

Pregnancy is a time of profound metabolic change, where the body's handling of sugar shifts to support a growing life. For some women, this shift goes too far, leading to high blood sugar levels that can threaten both mother and child. This condition, known as gestational diabetes, is a growing concern in countries like Bangladesh, where rates of the condition are rising. Doctors have long relied on a standard test to find it: a woman drinks a sweet liquid, and her blood is drawn at specific intervals to see how her body processes the sugar. However, a significant disagreement exists among medical experts about when to perform this test and what results count as dangerous. One major group of experts suggests that high sugar levels detected very early in pregnancy are a serious warning sign that needs immediate attention. Another group argues that the body naturally runs a bit hotter on sugar in the first half of pregnancy and that we should wait until the second half to make a diagnosis, using stricter rules to decide who is truly sick.

This uncertainty creates a confusing landscape for doctors and patients alike. If a woman is tested early and shows slightly elevated sugar, one set of guidelines might tell her she has a condition requiring treatment, while another set might tell her everything is fine. To untangle this, researchers at Bangladesh Medical University decided to look directly at the data. They gathered a large group of pregnant women and gave them the standard sugar test. Then, they took the exact same blood results and applied both sets of rules to see how many women would be diagnosed under each system. The goal was not to invent new rules, but to see how much the two existing systems actually agree with one another when looking at real people in a real hospital.

The study took place between May 2023 and January 2025, involving 753 pregnant women who came for their routine care. The average age of the participants was 27 years, and they had a median body mass index of 27.5, a measure of body size relative to height. The researchers did not just look at the final numbers; they carefully sorted the women based on how far along they were in their pregnancy. They focused on two specific time windows: the very early weeks, before 15 weeks, and the period between 15 and 23 weeks. This distinction is crucial because the two medical groups have different opinions on how to interpret sugar levels during these specific months.

When the researchers looked at the women who were tested before 15 weeks, the difference between the two systems was noticeable but not total chaos. Out of 66 women in this early group, the first set of rules identified 23 women as having gestational diabetes and 8 women as having a more severe form of diabetes that exists before pregnancy. The second set of rules, however, was much more conservative. It classified most of those same women as having normal sugar levels or only a mild, pre-diabetic state. While there was some overlap, the stricter system missed a large number of women that the first system caught.

The situation became even more dramatic when the researchers examined the women tested between 15 and 23 weeks. In this group of 220 women, the first set of rules identified 58 women with gestational diabetes. Under the second set of rules, every single one of those 58 women was classified as having perfectly normal sugar levels. The two systems were essentially talking past each other. The first system saw a clear medical problem in more than a quarter of this group, while the second system saw no problem at all. This created a massive gap in agreement, suggesting that for women in this specific window of pregnancy, the choice of which rulebook to use completely changes the diagnosis.

When the researchers looked at the entire group of 753 women together, the two systems appeared to agree more often, simply because the median gestational age at assessment was 27 weeks, meaning the majority of the cohort was tested after 24 weeks, yet both groups generally agree on what constitutes a problem in later pregnancy. However, when they zoomed in on the early weeks, the agreement nearly vanished. The data showed that the first set of rules consistently flagged a much larger number of women as having high sugar levels, while the second set of rules kept the number of diagnoses very low.

The study does not claim to know which system is the correct one to use. It simply shows that they produce very different lists of patients. The researchers noted that the first system might be catching women who are at risk but could also be labeling women who are simply experiencing normal pregnancy changes as sick. Conversely, the second system might be missing women who truly need help. Because this study only looked at the blood test results and not at the health of the babies or the mothers later on, it cannot say whether treating the extra women identified by the first system would actually improve outcomes. The researchers conclude that until more studies are done to see what happens to these women and their babies, the medical community faces a difficult choice: follow the stricter rules and treat more people, or follow the looser rules and risk missing those who need care. The current evidence suggests that for early pregnancy, the answer depends entirely on which set of guidelines a doctor chooses to follow.