According to the medical calculation of the gestational months, 120 days of pregnancy is usually defined as 4 months plus 1 week of gestation. The gestational month is calculated based on 28 days as 1 month, i.e. 4 gestational weeks, and 10 months as 280 days for the entire pregnancy. Therefore, 120 days of pregnancy is 4 months plus 1 week of gestation. At this time, the fetus has already entered the middle of pregnancy, and it starts to develop rapidly, with a length of about 18cm, a top-rump length of about 13cm, and a weight of about 160g, and the pregnant woman will show her pregnancy. It is recommended that pregnant women change their maternity pants at this time to prevent the usual bottoms and jeans from being too tight and increasing the pressure on the abdomen, which is not conducive to the normal growth and development of the fetus. Most pregnant women can feel the fetal movement at this time, and they should pay attention to regular maternity checkups. In addition, 120 days of pregnancy, the fetus is relatively stable, pregnant women can have a proper sex life, but not too often, and the action should not be too rough.