Objective: To characterize current diabetes screening practices in the first trimester of pregnancy in the United States, evaluate patient characteristics and risk factors associated with early diabetes screening, and compare perinatal outcomes by early diabetes screening.

Methods: This was a retrospective cohort study of US medical claims data from patients diagnosed with a viable intrauterine pregnancy who presented for care before 14 weeks of gestation without pre-existing pre-gestational diabetes from the IBM MarketScan® database for the period of January 1, 2016, to December 31, 2018. Univariate and multivariate analyses were used to evaluate clinical factors and perinatal outcomes.

Results: There were 400,588 pregnancies identified as eligible for inclusion, with 18.0% of women receiving early screening for diabetes. Of those with laboratory order claims, 53.1% had hemoglobin A1c, 30.0% fasting glucose, and 16.9% oral glucose tolerance tests. Compared to women who did not have early diabetes screening, those that did were more likely to be older, obese, have a history of gestational diabetes, chronic hypertension, polycystic ovarian syndrome, hyperlipidemia, and a family history of diabetes. In adjusted logistic regression, history of gestational diabetes (aOR 3.99, 95% CI 3.73-4.26) had the strongest association with early diabetes screening. Early diabetes screening irrespective of the screening result was also associated with adverse perinatal outcomes including a higher rate of cesarean delivery, preterm delivery, gestational hypertension, pre-eclampsia, and gestational diabetes.

Conclusion: First trimester early diabetes screening was mostly commonly performed by hemoglobin A1c evaluation, and women that underwent early diabetes screening regardless of the result were more likely to experience adverse perinatal outcomes.