Insulin injections for pregnant women generally do not affect the fetus. Choosing oral medications for pregnant women suffering from diabetes is difficult because the oral medications commonly used in the market today for treating diabetes have more or less adverse effects on the fetus. The use of insulin to control the blood sugar of pregnant women belongs to a very safe treatment method. Insulin belongs to a kind of hormone drugs for diabetes, the molecular weight is relatively large, can not pass through the placenta, will not cause adverse effects on the fetus. During the use of insulin, pregnant women should choose the appropriate dose of insulin according to their own conditions and under the guidance of their doctors, and also pay attention to regular monitoring of blood glucose and timely adjustment of the dose of insulin. Pregnant women who need to take insulin during pregnancy must take obstetric checkups on time, follow the doctor’s instructions for treatment, and choose the right time to terminate the pregnancy under the doctor’s guidance.