There will however be some women who will have hormonal acne throughout the entire pregnancy. Or the acne might disappear in the second trimester and reappear after the woman has given birth due to the decreased estrogen levels after giving birth. So once again there is no absolute rule of thumb as each woman is different and each pregnancy is different. Hormonal acne is such that it cannot be predicted. It cannot be prevented. It cannot really be treated. It is just endured by most women. Medications used to treat acne cannot be used during this time due to the risk they pose for birth defects.