In case of early pregnancy vomiting, because of the obvious vomiting and prolonged poor diet, metabolic acidosis may appear in the pregnant woman’s body, so the urine test results may show urinary ketone bodies (++), suggesting that the pregnant woman should be rehydrated and supplemented with various calories to correct acid-base balance disorders and electrolyte disorders, which is for early pregnancy vomiting. If a pregnant woman has gestational diabetes mellitus, her doctor will recommend a controlled diet, and some pregnant women will have a strictly controlled diet. Such pregnant women may suffer from a nutritional deficiency due to the controlled diet, which may lead to metabolic acidosis, and urinary ketone bodies (++) will also appear in their routine urine examination. If urinary ketone bodies (++) appear in gestational diabetes patients with diet control, it is clinically recommended that such pregnant women should slightly strengthen their diet, but at the same time, insulin should be used for treatment, so it is also a kind of follow-up of gestational diabetes diet control, which is helpful for clinical adjustment of treatment.