Outcomes associated with timing of screening for gestational diabetes

Context: Screening for gestational diabetes (GDM) at recommended times, based on a pregnant woman’s risk for GDM, is important in order to initiate and optimize the management of GDM as early as possible, thus mitigating the risk of several adverse outcomes for both pregnant women and their offspring.

Objective: To explore the association between the timing of GDM screening and maternal and fetal outcomes.

Study Design and Analysis: This was a retrospective cohort study using deterministic linkage of two databases. The main independent variable was the “timing of screening for GDM” (appropriate or not appropriate). Significance was set as p < 0.05.Dataset: A combined dataset consisting of prenatal data from a primary care database and intrapartum data from a provincial hospital administrative database.

Population Studied: Women with singleton pregnancies who received prenatal care from a family physician MaRNet-FP sentinel between July 1, 2019 and December 31, 2022 and who also delivered within that timeframe were included. Exclusion criteria included a pre-pregnancy diagnosis of type 1 or type 2 diabetes.

Outcome Measures: Caesarean section, shoulder dystocia, LGA and macrosomia.

Results: This study had 198 participants. 69.4% of participants had initial screening for GDM undertaken at an appropriate time during pregnancy based on their risk for GDM. Appropriate timing of GDM screening was associated with lower rates of LGA (p = .016). When only participants who had elevated risk for GDM were examined as a subgroup, appropriate timing of GDM screening was still associated with lower rates of LGA (p = .047).

Conclusions: Linking longitudinal prenatal primary care data to hospital administrative data creates opportunities for future studies pertaining to prenatal care, potentially resulting in improvements in the care provided to all pregnant individuals and in particular individuals from vulnerable populations that experience disproportionate rates of GDM and type 2 diabetes.