Is pigmentation of the skin during pregnancy common?

Q: I am 6 months pregnant. Since the third month of my pregnancy I am finding a straight line developing below and above the navel (stretching straight between breast right down to the vagina). Some people say it will disappear after giving birth but now at 6 months, it is somewhat thick and straight. Can you tell me what this actually is?

A:Hyperpigmentation can be found in about 90 percent of the pregnancies. Women of darker complexion are more likely to manifest hyperpigmentation. The area around nipples, umbilicus, and peri-anal skin may darken, and the linea alba (light white line between the mid stomach and pubic area) becomes linea nigra (turns dark). Some women develop dark patches on the face. Most of these changes disappear after childbirth. It helps to protect the face from sun or use sunscreen. Best of luck with your pregnancy.