Pregnancy can cause a number of changes in your skin, thanks to shifts in your hormones and blood flow. For example:

• Pigmentation changes. The area around your nipples and the skin on your inner thighs, genitals and neck might darken, possibly due to hormonal changes. You might notice a dark line from your navel to your pubic bone (linea nigra). Dark patches might develop on your face (chloasma). Avoid sun exposure, which can worsen chloasma. After childbirth, skin typically returns to its normal pigment over a period of several months. However, some dark patches due to chloasma might never go away.
• Acne. Some women have trouble with acne during pregnancy. To counter acne, wash with a gentle cleanser. Shampoo regularly, don't pick blemishes and be careful about what touches your skin.
• Varicose veins. You might develop enlarged veins in your legs (varicose veins) due to your uterus exerting greater pressure on these veins. Hormonal changes during pregnancy also might play a role. Varicose veins that develop during pregnancy generally improve without medical treatment three to 12 months after delivery.
• Stretch marks. Stretch marks (striae) are indented streaks that often appear on the abdomen, breasts, hips, buttocks and thighs. They're caused by the stretching of the skin and are common during the second and third trimesters. Many creams, ointments and other products claim to prevent or treat stretch marks. However, treatments are only partially effective and won't remove stretch marks completely.

If you're concerned about lingering skin changes, talk to your health care provider.