Association Between a Flat Oral Glucose Tolerance Test Pattern and Small-for-Gestational-Age Infants: A Retrospective
Dinçer Sümer1, Gunel Aliyeva1, Ümran Özcan1
1Department of Perinatology, University of Health Sciences, Etlik City Hospital, Varlık Mahallesi Halil Sezai Erkut Cd. No:5, 06170 Ankara, Türkiye.
Journal of Clinical Medicine
|June 26, 2026
Summary
A flat oral glucose tolerance test (OGTT) pattern, indicating lower fasting and postprandial glucose, is linked to a higher risk of delivering small-for-gestational-age (SGA) infants. This specific glycemic pattern warrants further investigation in pregnancy care.
Area of Science:
- Obstetrics and Gynecology
- Endocrinology
- Perinatal Medicine
Background:
- The oral glucose tolerance test (OGTT) is crucial for diagnosing gestational diabetes mellitus (GDM).
- Distinct OGTT patterns, beyond GDM diagnosis, may have clinical significance for pregnancy outcomes.
- Fetal growth assessment is a key component of prenatal care.
Purpose of the Study:
- To investigate the clinical significance of a flat OGTT pattern.
- To assess the association between a flat OGTT pattern and obstetric and perinatal outcomes, particularly fetal growth.
- To determine if a flat OGTT pattern independently predicts adverse fetal growth.
Main Methods:
- Retrospective cohort study of 685 women undergoing a two-step OGTT between 24-32 weeks gestation.
- Defined flat OGTT as fasting glucose < 95 mg/dL and all postprandial values < 100 mg/dL.
- Used logistic regression to analyze associations with small-for-gestational-age (SGA) and fetal growth restriction (FGR).
Main Results:
- A flat OGTT pattern was observed in 5.7% of participants, characterized by attenuated postprandial glucose response.
- SGA was significantly more frequent in the flat OGTT group (20.5% vs. 6.7%, p=0.001).
- A flat OGTT pattern was independently associated with SGA (aOR 4.05, p=0.002) and showed a trend towards increased FGR.
Conclusions:
- A flat OGTT pattern represents a unique glycemic response with lower fasting and postprandial levels.
- This pattern is not generally linked to adverse obstetric outcomes but significantly increases the risk of SGA infants.
- The findings highlight the importance of considering specific OGTT patterns for fetal growth assessment.
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