['To investigate the relationship between gestational diabetes mellitus (GDM) and the usual intake of fatty acids and indices of dietary fat quality [the atherogenicity (AI) and thrombogenicity indices (TI), and the ratios of hypo-and hypercholesterolemic (hH), ∑n-3/∑n-6, and polyunsaturated/saturated fatty acids (P:S)], during mid-pregnancy.', "799 adult pregnant women living in Ribeirão Preto, SP, Brazil were screened and accepted for this cross-sectional GDM study. The Multiple Source Method was used to estimate participants' usual diet, using two 24-hour dietary recalls during mid-pregnancy. Diagnosis of GDM was defined by the American Diabetes Association criteria of 2015. Logistic regression analysis were used to assess the association between GDM and dietary fat, adjusted for age, education, parity, gestational age at the time of the interview, pre-pregnancy and current BMI, prior GDM, family history of diabetes, smoking, physical activity, energy, fiber, and fatty acids.", 'The mean (standard deviation) age of the women was 28 (5) years, and 19% had GDM. After multiple adjustments, inverse associations between the highest tertile of ∑n-3 fatty acids intake [0.21 (0.08-0.56)], α-linolenic intake [0.15 (0.05-0.42)], and GDM were found. A positive association between GDM and the highest tertile of TI [2.66 (1.34-5.29)], and a negative association with the highest tertile of hH ratio [0.41 (0.22-0.77)], were observed. No association between GDM and other indices of dietary fat quality were found.'] Is indices of dietary fat quality during midpregnancy associated with gestational diabetes?