Is HbA1c in the first trimester associated with adverse outcomes among pregnant Asian Indian women without gestational diabetes?

Aims: The aim of this study is to determine the association of elevated HbA1c in the first trimester (HbA1c-FT) with adverse events among pregnant Asian Indian women without gestational diabetes (GDM).Methods: This retrospective cohort study included 1618 pregnant women who delivered at a single urban tertiary care center and had HbA1c-FT estimation between January 2011 and December 2017. Those with GDM according to a 75-g OGTT after 24 gestational weeks were excluded. Multivariable logistic regression models assessed the association between elevated HbA1c-FT and adverse events.Results: At a cutoff of >37 mmol/mol, HbA1c-FT was associated with preterm birth at <37 gestational weeks (adjusted odds ratio (OR) 2.10, 95% CI 1.11-3.98). There was a continuum of risk for primary caesarean delivery with higher HbA1c-FT levels (adjusted OR per 5-mmol/mol increase in HbA1c-FT for primary caesarean delivery: 1.27, 95% CI 1.06-1.52). In the crude analysis, gestational hypertension was associated with HbA1c-FT, but not after adjustment for confounding factors. HbA1c-FT was not associated with other adverse events (macrosomia, large for gestational age babies, or other neonatal complications).Conclusions: Even without GDM, the results suggest an association of HbA1c-FT with preterm birth and primary caesarian delivery among Asian Indian womenStatistical analysisA data analysis was performed in the statistical software SPSS version 16.0 (Chicago, SPSS Inc.). The data were summarized with the mean and standard deviation for continuous variables and as numbers with percentages for qualitative variables. The clinical data and other variables in the HbA1c-FT groups were compared using an unpaired student’s t-test for continuous variables and a chi-squared test for categorical variables. The adverse pregnancy events were compared among women with HbA1c-FT below 37 mmol/mol and those with levels equal to or above 37 mmol/mol(5.5%). Cohen’s d and Cohen’s h effect size were determined. Furthermore, crude odds ratios (OR) for each adverse pregnancy events among women with HbA1c-FT > 37 mmol/mol (5.5%) were estimated. The continuous association of each adverse event with HbA1c-FT on a logit scale was analyzed, and the crude ORs were calculated per 5-mmol/mol (0.5%) rise in HbA1c-FT levels. The linearity condition of continuous variables was tested using squared terms and retained in cases of p value < 0.05. The study population was also stratified into four HbA1c categories: <30, 30-32, 33-36, 37-46 mmol/mol (<4.9, 4.9-5.1, 5.2-5.4, and 5.5-6.4%). Using HbA1c < 30 mmol/mol (4.9%) as a reference level, the crude OR for adverse pregnancy events was calculated for higher HbA1c categories. For adverse events with a crude OR p-value <0.05 in the HbA1c-FT based on the cutoff value (5.5%, 37 mmol/mol) (Table 1) in the continuous analysis (Table 2) and categorical analysis (Table 3), three multivariable logistic models were performed.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV