Skin changes, especially colour changes, are often more noticeable in Caucasian women. Melanin is the brown colour in the skin that causes suntans. Melanin is made by cells in the skin called melanocytes. Melanocytes are controlled by a hormone or chemical messenger in the blood. This hormone is called melanocyte stimulating hormone (MSH) and is produced by the brain. During pregnancy, the levels of MSH increase and cause the characteristic skin colour changes.
On the face, some women develop “a mask of pregnancy” or chloasma. This is a patch of brown colouring of the skin on the nose extending across the upper cheeks or any area exposed to the sun. Although these changes tend to fade after delivery, some patches of brown may be left behind. Using sunscreens can help protect the skin from these changes. This is important because women are more likely to sunburn when pregnant.
The coloured skin surrounding the nipple is called the areola. During pregnancy the nipple, areola and breasts all grow larger. The nipple and areola may change colour, becoming browner. Early in pregnancy, within the areola a ring of little bumps becomes more prominent. These are called Montgomery’s glands and measure about two millimetres across. A secondary areola may develop outside the areola. It is fainter and has a vague border. After the baby is born, the secondary areola fades away. The nipple and areola become lighter but may still remain brown.
Other areas of the skin can experience pigment changes, too. A dark brown line can develop running vertically down the centre of the abdomen. This is called the linea nigra. The thighs may also darken in colour. During pregnancy the labia (lips of the vagina or birth canal) get larger and may also become browner. Moles may become a darker brown, but if you are concerned about changes to any moles, it is best to check them with your doctor. Many of these changes fade after pregnancy.
Pregnant women may get stretch marks on their abdomen and breasts. It is difficult to predict who will get stretch marks. The best hint is a look at your mother’s abdomen. If she has them, you will probably, too. When stretch marks first appear, they may be pink or purple. After the baby is born, they tend to get narrower and lighter. Eighteen months after the delivery they are pale or silvery-white. The medical name for stretch marks is striae gravidarum.
Blood vessels in the skin enlarge in response to the increase in the hormone estrogen. They may show up as small spider veins or nevi, which are clusters of narrow veins seen on the surface of the skin. The face, chest and legs are most commonly affected. After delivery most, but not all, will go away.
Hairs grow from hair bulbs in structures called hair follicles. These follicles go through different phases. A hair grows in the follicle in a phase lasting two to six years. When the hair bulb dies, the hair stops growing and rests. This phase is called telogen. After three months, a new bulb forms and a new hair shaft starts growing, shedding the old hair from the follicle. Each lost hair is replaced by another one a few weeks later.
Normally 15 to 20 per cent of scalp hair is in the telogen phase. In late pregnancy that figure falls to 10 per cent. Hair shedding is put on hold and pregnant women may notice that their hair gets thicker. The number of hair follicles in telogen rises to 30 per cent at nine weeks after delivery. This leads to accelerated hair loss when the baby is two to four months old. Since hair loss is spread out over the scalp, it does not result in bald spots. This usually ends about three months after delivery.
Nails grow in a similar manner to hair and may be noticeably different in pregnancy. They may be more likely to crack or split. Sweat glands may also be more active. All these changes are
Acne in pregnancy is caused by increased activity of the sebaceous glands in the skin. These are the glands that produce natural skin oils. Skin conditions such as eczema or atopic dermatitis usually worsen or may develop for the first time. Psoriasis, on the other hand, usually improves and in half of women ceases to be a problem during pregnancy. All of these conditions are treatable.
In pregnancy, the immune (defence) system is turned down to allow the baby to survive. Warts are caused by a virus and, if the immune system is turned down, they can grow more rapidly than normal. This can be a problem with warts in the genital area.
There are a few conditions of the skin specific to pregnancy. PUPP stands for pruritic urticaria and papules of pregnancy (meaning itchy hives and bumps). It usually begins with itchy bumps on the abdomen and then spreads to the upper arms and thighs. The condition can become quite miserable with severe itchiness disturbing sleep and enjoyment of life in general. If treatment with creams, antihistamines and sometimes steroids is not effective, the only cure becomes delivery of the baby. Noticeable itching of the skin, but no rash, may indicate a more serious condition of the liver and the woman needs to see her doctor.
Pemphigous gestationis or herpes gestationis (unrelated to the herpes virus) can show up as blisters on the abdomen about midway through the pregnancy. It usually settles late in pregnancy and may flare up again at delivery time. Steroid creams or pills are used to treat it.
Other conditions of the skin may be a sign of a medical problem such as liver disease. It is important that you ask your doctor’s opinion if you do not understand the skin changes you are experiencing.