15 weeks of pregnancy is more than 3 months and less than 4 months, which is a mid-term pregnancy. The duration of pregnancy is counted from the first day of the last menstrual period, 7 days is 1 week, 4 weeks is 1 month, 1 month of pregnancy is 28 days of pregnancy, therefore 15 weeks of pregnancy is more than 3 months of pregnancy, at this stage the fetus is already formed, you can go to the hospital for mid-term Down’s syndrome screening to exclude trisomy 21. Before 12 weeks of pregnancy is early pregnancy, 12-28 weeks is mid pregnancy, 28-37 weeks of pregnancy is late pregnancy, 37-42 weeks of pregnancy is the time of normal delivery, therefore, 15 weeks of pregnancy is mid pregnancy. During this period, pregnant women should pay attention to rest, maintain a happy mood, avoid overworking and forbid taking a tub bath. At the same time, you can take folic acid and calcium tablets as needed, and have regular prenatal checkups.