medwireNews: Dysglycemia in the last trimester of pregnancy despite prior negative testing for gestational diabetes may predispose the offspring of obese mothers to increased weight gain during early childhood, German research shows.
Therefore “a negative [gestational diabetes] test at the end of the second trimester should not be understood as an ‘all-clear signal’ and should not result in reduced attention of caregivers and a false sense of security in the mothers, say Regina Ensenauer (Heinrich Heine University Düsseldorf) and co-investigators.
Overall, more than a third of 749 obese pregnant women in the Programming of Enhanced Adiposity Risk in Childhood–Early Screening (PEACHES) study had a high glycated hemoglobin (HbA1c) value (≥5.7% [39 mmol/mol]) at delivery, including 30.1% of 448 without gestational diabetes and 45.2% of 301 with gestational diabetes.
Among those without gestational diabetes, the researchers found that 75 g oral glucose tolerance test values were higher, but below diagnostic cutoffs, at the time of gestational diabetes testing (second trimester) in the women with high HbA1c values at delivery compared with those with normal HbA1c at delivery.
Furthermore, gestational diabetes-negative women with late-pregnancy dysglycemia had the highest rates of excessive total and third trimester gestational weight gain, at 85.5% compared with rates of 47.3–74.4% among the other women in the study.
They also had the second highest rate of babies that were large for gestational age and the second highest cord blood C-peptide level, both of which were similar to those seen in women with gestational diabetes and high HbA1c at delivery.
At age 4 years, the children of the gestational diabetes-negative women with high HbA1c at delivery had a significantly higher mean BMI z-score than the children of gestational diabetes-negative women with normal HbA1c at delivery (1.01 versus 0.46), and each 0.1% increase in maternal HbA1c at delivery was associated with a 0.07-point increase in BMI z-score.
By contrast, 4-year BMI z-scores did not differ between the children of mothers with gestational diabetes with high versus normal maternal HbA1c levels at delivery (0.58 versus 0.62), and were in fact below those of the children of the gestational diabetes-negative women with high HbA1c at delivery.
Among the gestational diabetes-negative mothers, the investigators found that excessive third-trimester weight gain was associated with a 1.72-fold increased risk for late-pregnancy dysglycemia, and that high versus normal HbA1c at delivery was associated with a fourfold increased risk for future prediabetes.
Writing in PLOS Medicine, Ensenauer and co-authors say their analysis points “to the necessity of guidelines for identifying and managing late-pregnancy complications in obese pregnancies with negative [gestational diabetes] testing.”
By Laura Cowen
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