Objective To excavate the information needs of women with gestational diabetes based on latent Dirichlet allocation (LDA) theme model, and to provide reference for medical workers to carry out effective information services. Methods The users′ question and answer (Q&A) data of gestational diabetes in online Q&A communities were obtained by using the web crawler program.The LDA theme model was used to identify the theme of the data and analyze the information needs. Results Through LDA thematic analysis of 126,616 pieces of data, the information needs regarding gestational diabetes were factored into eight categories: maternal and infant harm and inspection, maternal and infant self-monitoring, nutritional weight control and fetal growth and development, screening and prenatal examination, experience sharing and emotional support of patients, the selection of food categories and sugar raising effect, maternal and infant health management during and after childbirth, blood glucose control and diet, and insulin medication. Conclusion The information needs of women with gestational diabetes are diversified, professional and meticulous, with the needs falling into multiple dimensions of cognition, physiology and emotion.Medical workers should play their role as the mainstay in information service, and provide professional, sophisticated and comprehensive information services for gestational diabetes.