There are a number of normal pregnancy-induced skin changes that may be alarming to some women. There are also several pregnancy-specific dermatoses, and some are associated with adverse perinatal outcomes. And of course, any skin disease that affects women of childbearing age may be encountered in pregnancy.
A number of factors are responsible for normal skin changes during pregnancy. These include that fetoplacental hormone production or alteration of clearance may increase plasma availability of estrogens, progesterone, and a variety of androgens. There is accumulating evidence that sex steroids have modulating influences on some skin diseases (Kanda and Watanabe, 2005). There are also profound changes in the availability or concentrations of some adrenal steroids, including cortisol, aldosterone, and deoxycorticosterone. Moreover, presumably as a result of enlargement of the intermediate lobe of the pituitary gland, plasma levels of melanocyte-stimulating hormone (MSH) become remarkably elevated by 8 weeks’ gestation. Production of pro-opiomelanocortin has been demonstrated in placental extracts, and this ultimately is a source of α- and β-MSH. Neurotropins and neuropeptides, some produced by trophoblastic cells, may also play a role in skin and hair changes (Botchkarev and associates, 2006; Imperatore and colleagues, 2006).
A synopsis of these changes is shown in Table 56-1. They are also discussed in more detail in Chapter 5, Skin. Nguyen Huu and associates (2009) found that fetal microchimerism may also involve the skin. Thus, endothelial-type fetal cells become grafted in maternal skin cells discussed with nevi. This phenomenon has been associated with maternal autoimmune diseases such as lupus, sclerosis, Hashimoto thyroiditis, and other conditions. Its mechanisms are considered further in Chapters 3, Immunological Considerations of the Fetal–Maternal Interface, 53, Autoimmunity and Thyroid Disease, and 54, Immune-Mediated Disease and Pregnancy.
Table 56-1. Some Pregnancy-Induced Skin Changes |Favorite Table|Download (.pdf)
Table 56-1. Some Pregnancy-Induced Skin Changes
Hyperpigmentation pronounced in normally hyperpigmented areas
Chloasma (melasma) common
Skin tags—common in neck area
Only 3 percent enlarge
Scalp hair thickens
Hirsutism—some degree in most women
Telogen effluvium-postpartum hair loss
Nails become soft and brittle
Spider and capillary hemangiomas
Some degree of skin darkening from melanin deposition into epidermal and dermal macrophages develops in 90 percent of pregnant women. Pigmentation is more pronounced in brunettes and in women with dark complexions, especially those of Hispanic descent (Aronson and Bass, 2000). Its exact cause is not known, but it is doubtful that elevated serum levels of MSH are responsible. Estrogens play a role in melanogenesis and may be the inciting ...