Aim: To compare neonatal outcomes between women with early GDM (eGDM: diagnosed<20 weeks’ gestation), incident GDM (iGDM: diagnosed ≥ 24 weeks’ gestation) and normoglycemia Methods: Pregnant women with GDM risk factors were enrolled <20 weeks’ gestation into an eGDM treatment trial across 17 sites in Australia, India, Europe. Women undertook a 2-h 75g oral glucose tolerance test on entry & at 24-28 weeks’ gestation. GDM was defined by WHO 2013 criteria. Logistic regression compared outcomes between women with eGDM, iGDM and normoglycemia adjusted for age, body mass index (BMI), site, smoking status, parity and tertiary qualifications. Women randomized to receive eGDM treatment were excluded from this analysis. Results: Baseline characteristics differed by age, BMI, parity and glycemia across the 3211 women (Table 1). Similar proportions of eGDM and iGDM women received pharmacotherapy. eGDM group gestational weight gain was lower; eGDM and iGDM neonatal outcomes were similar; neonatal intensive care unit admission and respiratory distress were higher in offspring of eGDM than normoglycemic women. Conclusions: Adverse neonatal outcomes are increased in pregnancies complicated by eGDM with delayed treatment. Disclosure D.Simmons: Consultant; Sanofi, Speaker's Bureau; Abbott Diabetes. M.Mclean: None. A.Sweeting: None. V.Mohan: None. J.Harreiter: None. Tobogm core investigator group: n/a. J.Immanuel: None. N.Cheung: None. W.Hague: None. H.Teede: None. C.J.Nolan: None. H.E.Backman: None. E.Hibbert: None. M.J.Peek: None. Funding National Health and Medical Research Council (1104231, 2009326); Region Örebro Research Committee (OLL-970566, OLL-942177); Medical Scientific Fund of the Mayor of Vienna (15205); South Western Sydney Local Health District Academic Unit (2016); Western Sydney University Ainsworth Trust (2019)

Aim: Umbilical cord leptin is higher than expected in some babies (relative cord hyperleptinaemia) . We test the hypothesis that a higher cord leptin:fat mass ratio, putatively reflecting “leptin resistance” might be associated with adverse pregnancy outcomes. Methods: Secondary analyses from Vitamin D And Lifestyle Intervention for gestational diabetes prevention (DALI) trial a pan European study among women with a BMI ≥29 kg/m2 between 2012-14. Cord sampling and skin caliper measurements followed standardized methods. Serum cord leptin (µg/l) to fat mass ratio (kg) was classified into low, middle, and high tertiles across (where stated) and within sexes. Large/small for gestational age (SGA) used GROW. Pregnancy outcomes were compared between low and high tertiles adjusted for potential confounders using binomial logistic regression. Results: Among the 349 eligible babies (mean gestational age 39.7 ± 1.4 weeks, female 49%) the median (interquartile range) leptin-fat mass ratio (both sexes combined) was 20.2 (11.4-30.8) , top tertile (TT) was >25.3 and low tertile (LT) was <14.9 . Compared with babies in the LT group, those in the TT group had higher cord erythropoietin (30.2 (16.7-59.2) vs. 20.3 (12.4-35.6) µg/l p = 0.002, respectively, both sexes) with higher cord serum C peptide (0.7 (0.5­-1.0) vs. 0.5 (0.3-0.8) µg/l p = 0.005) , lower birthweight (3435 ± 5vs. 37± 412 gm, p = 0.002) in boys but not in girls. Cord glucose was similar. Among males, those in the TT had higher risk of SGA (25.0% vs. 8.5%; OR 3.61 (95%CI 1.21-10.76)) but lower risk of cesarean section (0.39 (0.17-0.88)) . Among females, mothers in the TT had higher rate of pregnancy induced hypertension (3.93 (1.21-12.71)) . Conclusions: Relative cord hyperleptinaemia is associated with reduced fetal growth (boys only) , and possible relative fetal hypoxia (both sexes) . Further studies are required to evaluate the implications of these findings on future metabolism. Disclosure J.Immanuel: None. D.M.Jensen: None. E.R.Mathiesen: Consultant; Novo Nordisk A/S, Speaker's Bureau; Novo Nordisk A/S. D.J.Hill: None. P.Damm: Advisory Panel; Novo Nordisk A/S. F.J.Snoek: Advisory Panel; Abbott Diabetes, Lilly Diabetes, Roche Diabetes Care, Research Support; Novo Nordisk A/S, Sanofi, Speaker's Bureau; Insulet Corporation. J.Adelantado: None. E.Wender-ozegowska: None. D.Simmons: Other Relationship; Elsevier, Research Support; Abbott, Hitachi, Ltd., Novo Nordisk, Speaker's Bureau; Sanofi. G.Desoye: None. M.Vanpoppel: None. A.Kautzky-willer: None. R.Corcoy: None. A.Bertolotto: Research Support; AstraZeneca, Novo Nordisk, Speaker's Bureau; Abbott Diagnostics, Lilly Diabetes. F.P.Dunne: None. J.Harreiter: None. L.Andersen: None. Funding EU FP7 (242187)