A total of 705 records were identified from MEDLINE, Embase, and Web of Science until the end of 16 January 2022, through a merged method of MeSH heading search strategy and the term: “diabetes, gestational” “randomized controlled trials” “hypoglycemic agents/insulin/insulin isophane/insulin aspart/insulin lispro/insulin determir/insulin glargine.” After removing duplicates and adding records through a published meta-analysis, we conducted a full-text search of 450 RCTs. The gene discussed is INS; the disease is diabetes mellitus.