Introduction: Despite the established role of HbA1c in assessing chronic glycaemia, its role the management of gestational diabetes mellitus (GDM) is still unclear. We aimed to determine the association between HbA1c and obstetric outcomes among our patients with GDM.
Methods: We reviewed the antenatal records of 512 singleton pregnant women followed up in our center. Among the 180 patients that did a 75 g Oral Glucose Tolerance Test OGTT, 64 met the IADPSG criteria for GDM. Sociodemographic, clinical and laboratory parameters were extracted for the patients with GDM. The associations between HbA1c and variables including insulin treatment, birth weight, maternal and neonatal complications were analysed.
Results: The mean age of the subjects with GDM was 33.2 ± 4.7 years and 12% had a previous history of GDM. In the OGTT profile the 0 min was the most commonly abnormal OGTT parameter using the IADPSG which was abnormal in 72% of the patients, compared to the 60 and 120 min which was abnormal in 44% and 42% respectively. Among the subjects, 20% required insulin therapy, 72% required a Caesarean section (CS) while 17% had birth weight > 4.0 kg. Maternal and neonatal complications occurred in 42% and 34% of the patients respectively. HbA1c correlated with the OGTT parameters, (r = 0.76, 0.54 and 0.55 for 0, 60- and 120-min glucose respectively; P< 0.05). The mean HBA1c among the patients that required insulin was higher than those who did not (8.7 ± 1.6% vs. 6.3 ± 1.3%; P < 0.05). There was no association between HbA1c values and birth weight, need for CS, maternal or neonatal complications.
Conclusion: Although Hba1c is useful in predicting the need for insulin therapy, it is not significantly associated with birth weight, maternal or neonatal outcomes among patients treated for GDM.