It is possible that a little drop in estradiol in early pregnancy may affect the development of the fetus, depending on the value of the drop. If estradiol drops more in early pregnancy, then it may affect the normal development of the fetus and may also lead to fetal arrest. If the drop is not much, then it can be observed to see how it develops afterwards. Estradiol generally promotes the repair and thickening of the uterine lining to provide a good environment for the embryo to conceive, and low estrogen can lead to abnormal development of the fetus. Therefore, the amount of estradiol, HCG and other hormones must be rechecked regularly during pregnancy. However, it is important to note that the value of estradiol should not be used solely to determine whether or not fetal arrest has occurred, but also needs to be combined with the results of ultrasound, blood HCG and progesterone to make a comprehensive judgment.