Pregnancy health

4 ways your skin changes during pregnancy—and when to see a doc

From stretch marks to acne, skin changes during pregnancy are very common. But when do they signal a bigger issue?

4 ways your skin changes during pregnancy—and when to see a doc

Photo: iStock/Eva-Katalin

Many people experience skin changes during pregnancy and these can happen as a result of physical, hormonal and immunological changes that naturally occur during pregnancy. While it is important to recognize what these changes are and why they occur, it is just as important to know when you should seek expert opinion.


Moles can change during pregnancy, but they are for the most part benign. In fact, up to 10 percent of pregnant women report a change in the size and colour of existing moles. These changes are primarily a physical phenomenon due to stretching of skin that naturally occurs as a part of pregnancy. Areas such as the abdomen or breasts tend to grow rapidly and moles on these areas will stretch along with them. Because of this, moles that originally looked small can become several times larger, making it seem like they are rapidly growing. A similar phenomenon can be seen with changing colours. As moles stretch, their pigment becomes distributed over a wider surface area and can thus appear lighter than they were before. As most people tend to become concerned by evolving moles, these physiologically normal developments can be falsely alarming.

So how do you know when you should be worried about a mole that is changing? Specifically, when is it a sign of a potential skin cancer, such as melanoma? While nothing should replace your physician’s assessment and input, a general set of rules to apply during regular self skin examinations is the ABCDEs:

A - Asymmetry: If the mole is cut in half, and one side does not look like the other, then it is considered asymmetric.

B - Border: The borders in a benign mole are usually smooth and sharp. Borders that are jagged or fade into the skin are considered more irregular.

C - Colour: Benign moles usually have less than 3 colors. Multiple colors or extremes of colors, especially black, should warrant more attention.

D - Diameter: Moles with diameters more than 6mm have a higher chance of being atypical.


E - Evolution: Moles that are rapidly changing are potentially more worrisome.

Ask your family doctor or your dermatologist for a skin examination if you notice changes to your existing moles, or development of new moles. Your physician can often employ clinical tools such as a dermatoscope to further delineate whether a mole is benign or requires additional investigations such as a biopsy.

Stretch marks

One of the most common skin changes seen in pregnancy is striae distensae, or stretch marks. Just like during puberty, these happen from rapid growth leading to stretching of the connective tissue fibres in the skin and are most frequently on the abdomen, breasts, buttocks, and hips. When these first occur, they are usually red and quite visible and are termed striae rubra. Over a period of months to years, the redness gradually fades and the stretch marks become closer to skin colour and are termed striae alba. While there is no perfect treatment to completely revert stretch marks back to normal skin, specific lasers can reduce the redness during the striae rubra phase and resurface the texture during the striae alba phase. Some topical medicines like retinoids have also shown some benefit in promoting healing of stretch marks.

Brown discoloration

Many pregnant women may notice a vertical brown line that develops on their abdomen. This condition is termed linea nigra and is a result of hormonal changes during pregnancy and is not a cause for medical concern. A similar physiological skin darkening can be seen in other areas including the areola, genitalia and inner thighs. These changes are benign and if they are not accompanied by symptoms such as itch or skin breakdown, then they are considered a natural part of pregnancy, which can gradually improve after pregnancy or be treated with cosmetic procedures. On the other hand, eczema is an inflammatory condition that can cause skin breakdown, itch and darkening of the skin, potentially affecting all the aforementioned areas. If you notice any symptoms associated with colour change, do not hesitate to seek your physician’s advice for treatment. Eczema can be safely and effectively managed with changes in bathing habits, use of moisturizers and application of prescribed treatments.


Acne can flare during pregnancy, can range from blackheads and whiteheads to inflamed papules and pustules, and is most commonly located on the face. While this is not too different in appearance to typical adolescent acne, it can be quite persistent throughout pregnancy and treatment can be quite tricky due to many acne medications being deemed unsafe during pregnancy and breastfeeding. Avoid attempting any acne treatment during these times until you have spoken to your physician and received clear information on which treatments can be safely employed.


Skin changes during pregnancy are very common and most are of no medical concern. Many of these changes gradually progress throughout pregnancy—but hang in there, as most will spontaneously improve after delivery. Of course, it's never a bad idea to involve your family doctor or your dermatologist in your skin care routines during this important period of your life so you'll know that what you are using is safe and effective for you and your future baby.

Dr. Danny Guo, MD/MSc, FRCPC, DABD, is medical director of Rejuvenation Dermatology in Calgary.

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