Immunologic, metabolic, vascular, and endocrine changes in pregnancy cause cutaneous changes in almost all pregnancies. Hyperpigmentation is related to increased levels of melanocyte-stimulating hormone, estrogen, and progesterone. Vascular changes are related to the effect of estrogen causing congestion, distention, and proliferation of blood vessels.
Few interventions have been successful at preventing these changes, which occur as the result of physiologic processes. Judicious use of sunscreen may reduce the appearance of hyperpigmentation and melasma. Varicosities in the legs may be prevented by leg elevation, support hose, and avoiding prolonged sitting or standing.
Hyperpigmentation occurs in up to 90% of women, and it is more pronounced in women with darker skin tones. It is most frequently localized in the nipples, areolae, and axillae. The linea alba darkens to become the linea nigra, a dark linear streak on the midline of the abdomen.
Melasma, also known as chloasma or “the mask of pregnancy,” is a symmetric brown hyperpigmentation in malar, mandibular, or central facial areas. It is exacerbated by exposure to the sun and certain cosmetics.
Erythema begins in early gestation and appears either diffuse and mottled or focused in the palmar and thenar areas.
Venous congestion and vascular permeability during pregnancy can lead to varicosities in up to 40% of women. They result from increased venous pressures by the gravid uterus on femoral and pelvic vessels.
Dilation of arterioles leads to central erythematous spots with fine vessels radiating outward, called capillary hemangiomas (spider angiomas). They are most commonly seen around the gums, tongue, upper lip, and eyelids.
Striae, pinkish or purplish lines, may form on the abdomen, buttocks, and breasts. Striae form as a result of structural changes in the skin caused by weight gain and hormonal influence. Increased activity of the adrenal gland during pregnancy may increase their occurrence.
Nonpitting edema of the face, eyelids, and extremities is observed in many pregnant women, with changes most pronounced in the morning and improving throughout the day.
Changes in the distribution and amount of hair are common during pregnancy. Increased hair growth in facial areas and around the breasts occurs, particularly during the second and third trimesters. Importantly, there are no signs of virilization, and hirsutism regresses slightly or remains unchanged postpartum. Increased recruitment of hair follicles into the growing phase (anagen) may result in thickening of scalp hair in late gestation. Postpartum loss of hair is fairly common. During pregnancy, the number of hair follicles in the resting phase (telogen) is decreased by about half and then nearly doubles in the first few weeks postpartum.
Nails may become brittle with transverse grooving, distal onycholysis, and subungual hyperkeratosis. These changes are benign and do not require treatment.
It is important to distinguish physiologic changes in pregnancy from more worrisome conditions. Erythema, for instance, might be diagnostic of hyperthyroidism, cirrhosis, or systemic lupus erythematosus. Striae are normal findings in pregnancy but may be observed with adrenocortical hyperactivity. Edema, while common, is also an important symptom of preeclampsia, and this condition should be considered in affected women. When pronounced nail onychodystrophy is seen, psoriasis, lichen planus, and onychomycosis should be excluded.
In general, cutaneous changes of pregnancy are of cosmetic concern only. Some vascular changes result in discomfort that may respond to supportive therapy.
Because most changes occurring in pregnancy improve postpartum, no therapy other than reassurance is required. Many remedies have been proposed for striae in pregnancy (vitamin E oil, lubricants, lotions), but none are effective. Laser technology is under investigation as a potential treatment and has shown some promise. If hyperpigmentation does not resolve postpartum, some patients respond to retinoic acid and corticosteroid preparations. Vascular changes are not likely to completely regress postpartum and may be treated with laser, electrodessication, or sclerotherapy.
Hyperpigmentation decreases or, in most cases, disappears postpartum. Vascular changes may become less pronounced but may not resolve completely. Striae usually become silvery-white and sunken, but they rarely disappear. Hair loss usually stops 2–6 months postpartum as the hair follicles enter the growing phase (anagen).
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Kumari R, Jaisankar TJ, Thappa DM. A clinical study of skin changes in pregnancy. Indian J Dermatol Venereol Leprol