Background Gangliosides are a class of sphingolipids that are present in the cell membranes of vertebrates. Gangliosides influence a broad range of cellular processes through effects on signal transduction, being found abundantly in the brain, and having a role in neurodevelopment. Objective We aimed to assess the effects of maternal daily consumption of ganglioside-enriched milk vs non-enriched milk and a non-supplemented group of pregnant women on maternal ganglioside levels and pregnancy outcomes. Design Double-blind parallel randomized controlled trial. Methods 1,500 women aged 20-40 years were recruited in Chongqing (China) between 11 and 14 weeks of a singleton pregnancy, and randomized into three groups: Control-received standard powdered milk formulation ([greater than or equal to]4 mg gangliosides/day); Complex milk lipid-enhanced (CML-E) group-same formulation enriched with complex milk lipids ([greater than or equal to]8 mg gangliosides/day) from milk fat globule membrane; Reference-received no milk. Serum ganglioside levels were measured in a randomly selected subsample of 250 women per group. Results CML-E milk was associated with marginally greater total gangliosides levels in maternal serum compared to Control (13.02 vs 12.69 [mu]g/ml; p = 0.034) but not to Reference group. CML-E milk did not affect cord blood ganglioside levels. Among the 1500 women, CML-E milk consumption was associated with a lower rate of gestational diabetes mellitus than control milk [relative risk 0.80 (95% CI 0.64, 0.99)], but which was not different to the Reference group. CML-E milk supplementation had no other effects on maternal or newborn health. Conclusions Maternal supplementation with milk fat globule membrane, as a source of gangliosides, was not associated with any adverse health outcomes, and did not increase serum gangliosides compared with the non-supplemented reference group. Trial registration Chinese Clinical Trial Register (ChiCTR-IOR-16007700). Clinical trial registration ChiCTR-IOR-16007700; www.chictr.org.cn/showprojen.aspx?proj=12972.