However, there is a condition called 'cholestasis of pregnancy' which is serious enough to require additional treatment. 

Causes of Abdominal Itchiness
The most common cause of abdominal itchiness is stretching of the abdominal skin. As the baby grows during pregnancy, the skin must stretch to accommodate the size of the uterus. During the first trimester, the skin stretches slowly and mothers rarely feel the changes at all. As the pregnancy progresses, the baby grows more quickly and along with it the abdominal skin. Along with the belly, you may find that your bottom feels a bit itchy as it grows.

Important Facts About Abdominal Itchiness
If  you are feeling itchy over your entire body it is important to notify your obstetrician because itching can sometimes be cause by a more serious medical condition called 'cholestasis of pregnancy'. 

Treatments for Abdominal Itchiness
Before you start treating itchiness you must exclude a more serious condition such as cholestasis of pregnancy.  Scratching is the number one no-no in terms of relief. When the irritated skin is scratched, more irritation can occur and a cycle begins. Instead of scratching for relief, try applying a moisturizer to the area. Lotions made to curb itching, like calamine lotion, can also bring relief. Soaking in a warm bath with oatmeal and applying Vitamin E to the skin are natural home remedies known to curb irritation. Increasing water intake can also help to stave off dry skin which may be a secondary cause of the irritation. If dry skin is the culprit, try using a humidifier in the home to increase air moisture and decrease drying time of the skin.