Association between insulin resistance trajectories and perinatal complications: a retrospective cohort study

During pregnancy, the maternal body undergoes adaptive regulation to support the normal growth and development of the fetus, such as the occurrence of insulin resistance (IR). When the degree of IR progresses continuously and is significantly higher than the normal range in the corresponding period, it will increase the risk of perinatal complications, including gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP). The study is to investigate the correlation and influenced factors between different levels of IR during pregnancy and adverse pregnancy outcomes, and to suggest the critical threshold for predicting pathological IR.

By applying the Group-based Trajectory Model (GBTM), the trajectories' classification based on IR index changes was constructed, including fasting serum insulin (FINS), insulin resistance homeostasis model assessment (HOMA-IR), and the quantitative insulin sensitivity check index (QUICKI), to analyze the differences in the differentiation of IR evaluation indicators. We used the Poisson Regression Model to analyze the correlation between various IR changing trajectories and adverse pregnancy outcomes.

Four gradient differences in IR change trajectories were fitted in the population using three IR evaluation indicators respectively, including low level, moderate level, high level and low-high level. For FINS trajectories, the GDM risk of the moderate level trajectory (aRR 1.73, 95% CI 1.21-2.47) and the high-level trajectory (aRR 2.40, 95% CI 1.58-3.65) showed a gradient increase. The low-high level trajectory, which only sharply increased in late pregnancy, exhibited a significantly higher difference in HDP risk (aRR 6.45, 95% CI 1.78-23.33) compared to the high level (aRR 5.86, 95% CI 2.41-14.25). In this study, the early pregnancy IR value of the population was used to predict GDM exhibited similar predictive ability (AUC 0.607, P<0.001). For predicting HDP, FINS showed the highest AUC value of 0.740 (P<0.001), comparing to HOMA-IR and QUICKI showed slightly lower AUC values of 0.73.

There are various subtypes of IR trajectories in pregnant women, which are significantly correlated with adverse pregnancy outcomes.