Fig. 2
Association and causal analyses for linoleic acid with GDM. A Association of linoleic acid levels with GDM risk across pregnancy. Adjusted for maternal age (years, continuous), education (primary or middle school, high school, and college or above), gestational age at baseline blood collection (weeks, continuous), parity (nulliparous and multiparous), cigarette smoking (ever and never), alcohol drinking (ever and never), physical activity (continuous, MET-hours/week), pre-pregnancy BMI (< 18.5, 18.5–24, 24–28, and ≥ 28 kg/m2), family history of diabetes (yes and no), and history of GDM (yes and no). B Correlations of linoleic acid levels with metabolic biomarkers in early pregnancy. Partial Spearman’s correlation coefficients were calculated, adjusting for the same covariates mentioned above. C Scatter plot of causal association between plasma linoleic acid and GDM. The slope of each line represents the MR effect estimate from different methods. D Forest plot for MR results. The “*” refers to random-effects multiplicative inverse-variance weighted method. BMI, body mass index; GDM, gestational diabetes mellitus; HbA1c, hemoglobin A1 C; HDL, high-density lipoprotein; HOMA-IR, homeostatic model assessment for insulin resistance; LDL, low-density lipoprotein; MET, metabolic equivalent task; MR, mendelian randomization; SNPs, single-nucleotide polymorphisms