Alterations in hormonal balance and mechanical stretching are responsible for several changes in the integumentary system.

The following changes occur during pregnancy:

a. Linea Nigra. This is a dark line that runs from the umbilicus to the symphysis pubis and may extend as high as the sternum. It is a hormone- induced pigmentation. After delivery, the line begins to fade, though it may not ever completely disappear.

b. Mask of Pregnancy (Chloasma). This is the brownish hyper pigmentation of the skin over the face and forehead. It gives a bronze look, especially in dark-complexioned women. It begins about the 16th week of pregnancy and gradually increases, then it usually fades after delivery.

c. Striae Gravidarum (Stretch Marks). This may be due to the action of the adrenocorticosteroids. It reflects a separation within underlying connective tissue of the skin. This occurs over areas of maximal stretch–the abdomen, thighs, and breasts. It will usually fade after delivery although they never completely disappear.

d. Sweat Glands. Activity of the sweat glands throughout the body usually increases which causes the woman to perspire more profusely during pregnancy.