The sudden disappearance of chest distension in early pregnancy may be due to the cessation of embryonic development, or it may be a normal physiological reaction, as early pregnancy reactions change over time.1. Embryonic cessation: The estrogen and progesterone in the body will drop rapidly after the embryo stops developing, and the symptoms of chest distension will suddenly disappear as the breasts are locally affected by estrogen and progesterone. Through ultrasound examination, it may be found that the tension of the gestational sac becomes smaller, the primitive cardiac pulsation has disappeared, or the number of days of menopause does not match the size of the gestational sac, and the human chorionic gonadotropin as well as progesterone in the blood will drop, so the clearance surgery should be given as soon as possible; 2. Normal physiological reaction: In the early stage of pregnancy, which refers to the first trimester, the human chorionic gonadotropin in the body will double and rise every other day, so it makes the estrogen and Progesterone increase faster, may appear nausea, vomiting, anorexia, localized swelling and pain in the breast, breast enlargement and other symptoms of early pregnancy reaction. As the pregnancy continues, the hormone level in the body reaches its peak, the growth rate may gradually slow down and the localized breast swelling and pain will gradually disappear. This is a normal physiological phenomenon and no special clinical treatment is needed. It is recommended to do regular maternity checkups.