After pregnancy, if you have sex and reach orgasm, you will find that your belly bulges, mainly because orgasm causes uterine contractions and you will see a bulging uterus in your abdomen. Therefore, it is best to have a moderate sex life when you are pregnant. If frequent sex leads to frequent uterine contractions, it can cause intrauterine hypoxia in the fetus, which may even lead to fetal death in the womb. The first and second trimesters of pregnancy are not allowed to have sex, and in the middle of pregnancy, if you have sex, you should also give proper restraint to avoid frequent contractions caused by frequent sex, causing intrauterine hypoxia in the fetus, resulting in serious consequences. In the middle of pregnancy, even if you have sex, you should be gentle, to avoid strong contractions of the uterus due to rough stimulation.