Estradiol 400 pmol/L is normal in early pregnancy. Anywhere between 300-1000 pmol/L of estradiol in early pregnancy is normal, and estradiol levels continue to rise as the pregnancy increases. In the early stages of pregnancy estradiol 400 pmol/L is normal and estradiol can help maintain a normal pregnancy during pregnancy. It is important to take regular pregnancy tests, especially in early pregnancy to monitor progesterone, chorionic gonadotropin and estradiol and ultrasound. If they are low or high, prompt medical attention should be sought and medication given if necessary to avoid adverse consequences.