Gestational diabetes mellitus patients with small fetus, commonly associated with gestational diabetes mellitus blood glucose control does not meet the standard, dietary control is too strict, combined with other metabolic diseases. According to different etiological factors, corresponding clinical management is needed: 1, for gestational diabetes mellitus patients with overly strict dietary control, it is necessary to actively adjust the diet, pay attention to dietary diversification, in order to meet the demand for nutrients during pregnancy, and at the same time eat appropriate carbohydrates, avoiding overly strict control of carbohydrates. 2, gestational diabetes mellitus glycemic control does not meet the standard, it is necessary to actively adjust the insulin dosage If the blood sugar control of gestational diabetes is not up to standard, the insulin dosage should be adjusted positively and the insulin application program should be adjusted to make the blood sugar control up to standard, with the fasting blood sugar control below 5.3mmol/L and the two-hour postprandial blood sugar control below 6.7mmol/L. 3. For patients with other metabolic diseases, the examination of relevant indexes such as nail function should be improved positively.