An estradiol of 12 pmol/L may indicate ovarian hypoplasia and low estrogen levels in the body. The normal estradiol level is 70~1835 pmol/L during ovulation, 48~521 pmol/L during pre-ovulation and 272~793 pmol/L during post-ovulation. Estradiol 12pmol/L indicates that the estrogen level in the body is significantly reduced, possibly due to endocrine instability or the body’s own ovarian function is diminished. Pregnant women are generally advised to go to the gynecology department for another ultrasound examination to see if the morphology of the uterus and ovaries is normal, and then according to the results of the examination, subsequent judgment and treatment will be carried out. If the estradiol level is found to be low at 12 pmol/L during the physical examination, further relevant examinations are needed to clarify the cause of the disease and then treat the symptoms.