Striae (or “stretch marks”) and skin tags are conditions that may be exacerbated by, although are not unique to, pregnancy.

• Striae are linear tears in dermal connective tissue that are often initially red or purple in color and occur in approximately 50% to 80% of women. These marks may be pruritic and can appear in multiple locations including the abdomen (most commonly), breasts, thighs and buttocks, and axilla and groin. Risk factors for development of striae include having a maternal history, young age, race (increased in nonwhite), higher initial body mass index, higher weight gain, increased circumference of abdomen and hips, and fetal macrosomia. Patients with striae have an increased future incidence of pelvic organ prolapse. There is no known effective topical treatment for striae. Many dermatologists recommend frequent use of moisturizer because dry skin is generally more susceptible to wear and tear. Pulsed dye laser is helpful to decrease redness of early striae, but there is currently no evidence whether this treatment has better outcomes than long-term observation.

• Skin tags are soft, pedunculated or papular growths consisting of fibrous connective tissue and epithelial tissue that are either similar in color to a person's skin tone or dark brown. They are not unique to pregnancy, but patients may notice an increase in number during the gestational period. Common locations for these to appear are the neck, axilla, or groin, and they tend to persist after delivery. Treatment is relatively simple with electrocautery or sharp removal in the outpatient setting.

Vascular changes affecting the skin in pregnancy are primarily due to increases in vascular proliferation due to changes in hormone levels. Telangiectasias are persistently dilated blood vessels that can be seen through the skin. A spider angioma is a central arteriole with radiating vascular “legs” that is most predominant in sun-exposed areas. Most of these regress spontaneously, but persistent lesions can be treated with laser ablation or low-energy electrocoagulation. Many pregnant women also experience palmar erythema, which requires no treatment and resolves spontaneously after delivery.

Pyogenic granuloma is a vascular lesion that can present in pregnancy and can cause particular concern because of the symptoms/presentation. These lesions are red, nodular, and often pedunculated. They are often ulcerated and can have a purulent-appearing discharge. They most often appear on the gums, scalp, fingers, toes, and upper trunk but can appear anywhere. The name is a misnomer because a true granuloma is macrophage dominant, and these lesions are composed mostly of proliferating blood vessels and some other inflammatory cells. Treatment is surgical excision or electrocautery but is commonly delayed until after delivery because some lesions will spontaneously regress.

Pigmentation changes are very common in pregnancy with up to 91% of women experiencing hyperpigmentation. The areola and genitals are the most common areas of the skin to be affected. Additionally, many women develop a linea nigra, which is hyperpigmentation of the linea alba (the longitudinal line that runs along the midline of the abdomen).

Melasma is a hyperpigmentation of the face that occurs in up to 70% of pregnant women and commonly appears on the forehead, cheeks, and bridge of the nose. Women are advised to use sunscreen (sun protection factor 15 or greater) and avoid sun exposure to prevent melasma and minimize the hyperpigmentation. Discoloration improves for a majority of women shortly after giving birth. In persistent cases, treatment is available with a variety of topical options but can require a prolonged treatment course.

Pregnant women can experience changes or enlargement of existing nevi or appearance of new nevi during pregnancy. The incidence of changes in or development of new melanoma during pregnancy is no greater in pregnant women than in nonpregnant women. Women should still be encouraged to have any changing or new nevi examined during pregnancy.