High estradiol in women after pregnancy usually indicates two possibilities: it may be due to multiple pregnancies, or it may be caused by a relatively good endocrine function of the ovaries. After pregnancy, the ovaries usually produce estradiol. Only after the third trimester, when the placenta grows, the placenta replaces the endocrine function of the ovaries and causes an increase in estradiol in the body. Therefore, an increase in estradiol in the first trimester of pregnancy is often the result of good endocrine function of the ovaries and indirectly reflects good growth and development of the embryo. However, if estradiol is particularly high, it should be considered in the early stages of pregnancy as a result of a twin or multiple pregnancy. This is because the ovaries need to secrete a large amount of estrogen to promote the growth and development of the embryo, so the amount of hormone secreted is significantly higher than in the case of a single pregnancy. However, the significant increase in estradiol has no effect on either single or twin pregnancies, as it only leads to better growth and development of the embryo and does not cause fetal malformations. Therefore, if a woman’s blood beta-hCG and estradiol are too high after pregnancy, there is no need to worry about it, but it is recommended to check the ultrasound after 45 days of menopause to confirm the growth and development of the embryo in the uterus.