What are normal skin changes in pregnancy?
During pregnancy there are marked changes in sex hormones, the immune system, and the cardiovascular system, and this can lead to changes in the skin. Many changes in the skin, hair, and nails of pregnant women are common and considered normal (physiological).
Pigmentation in pregnancy
- Linea nigra, darkening of pigmented areas (ie, nipples, areolae, genitals), and generalised increase in pigmentation appears in the first trimester of pregnancy. It affects 90% of pregnant women, particularly those with skin of colour (Fitzpatrick skin types IV-VI). This pigmentation fades after delivery, but usually not completely.
- Melasma develops in the second half of pregnancy in 70% of women, especially those with dark complexions. This usually presents as irregular, sharply marginated areas of pigmentation in a symmetrical pattern, either on the forehead and temples, or on the central face. Melasma usually fades completely after pregnancy. Prevention includes strict sun protection.
- Melanocytic naevi may show transient changes in clinical and dermoscopic appearance, but any signs suggestive of melanoma should be investigated.
Changes in pigmentation in pregnancy
Striae gravidarum
Stretch marks (striae) are extremely common in pregnancy, affecting up to 90% of women in the second and third trimesters. They are linear, pink or purple, atrophic bands that develop at right angles to the skin tension lines on the abdomen, breasts, thighs, and buttocks.
Common skin and hair changes in pregnancy
Hair changes with pregnancy
- Many women notice their hair becomes thicker during pregnancy. In the third trimester, the proportion of hair follicles retained in the anagen (growing) phase increases.
- Telogen effluvium post-delivery is a compensatory decease in hair growth and shedding of hair. Spontaneous recovery back to pre-pregnancy levels usually occurs within 6–12 months. Mild frontoparietal recession (female pattern hair loss) may occur.
- Hypertrichosis (increased hair growth in a non-hormonal pattern) is minor and not uncommon, particularly along the midline suprapubic area. New, soft, fine hairs may disappear around six months post-delivery, but coarse hair typically persists.
- Hirsutism (hair growth in a male pattern) can develop in the second half of pregnancy particularly in women with dark hair. When accompanied by acne and other signs of virilisation, it may rarely result from an androgen-secreting tumour, luteoma, lutein cysts, or polycystic ovary syndrome. These conditions should be thoroughly investigated to avoid masculinisation of a female fetus. In the absence of a tumour that can be removed, the problem tends to recur in subsequent pregnancies. Hirsutism may regress between pregnancies, but this is not always complete.
Nail changes in pregnancy
Nail changes commonly occur during pregnancy. Increased brittleness, leukonychia, onychoschizia, and ingrown toenails are most common. Increased nail growth, onycholysis, melanonychia, grooving of nails, and subungual hyperkeratosis are also described. [see Nail terminology]. Benign, uniform, symmetrical hyperpigmentation of multiple nails is reported during pregnancy with fading postpartum; however, irregular pigmentation with cuticle involvement should prompt investigation of possible melanoma.
Glandular function changes in pregnancy
- Eccrine sweat gland activity increases across the body, except on the palms, during pregnancy and may present clinically as hyperhidrosis and miliaria.
- Sebaceous gland excretion of sebum tends to increase during pregnancy due to increasing levels of maternal progesterone and androgen in the third trimester.
- Montgomery glands provide lubrication to the nipples and areolae for breastfeeding. They enlarge during pregnancy and appear as papules on the areolae (Montgomery tubercles). [see Lactation and the skin].
Vascular changes of pregnancy
The vascular changes of pregnancy are probably brought about by the general increase in vascularity associated with high oestrogen levels and increased blood volume.
- Non-pitting oedema of the legs due to increased hydrostatic pressure can occur in up to 50% of normal pregnancies. Involvement of the face and hands has also been described.
- Varicose veins of the legs, haemorrhoids, and vulvar varicosities are frequent complications of pregnancy.
- Spider telangiectases are very common in pregnancy and disappear post-partum. They appear in areas drained by the superior vena cava which include the face, neck, upper chest, and arms.
- Palmar erythema is common, affecting at least 70% of women with Fitzpatrick skin types I and II, and 30% of women with darker skin types.
- Pyogenic granuloma can present on the fingers, face, gums, or vulvovaginal mucosa in 5% of pregnancies.
- Superficial thrombophlebitis and deep vein thrombosis in pregnancy is usually associated with factor V Leiden or prothrombin G20210A gene mutation.
Common vascular changes in pregnancy
Immune changes in pregnancy
A switch from cell-mediated to humoral immunity (TH1 to TH2 shift) during pregnancy is important to make sure the mother’s body does not reject the developing fetus. This influences a woman’s susceptibility to skin disease, increasing the tendency towards autoimmune disease and reducing her cell-mediated immunity.
Diseases that are TH1-driven, such as psoriasis, tend to improve while TH2-driven diseases, such as atopic dermatitis and systemic lupus erythematosus, are exacerbated. Reduced cell-mediated immunity during normal pregnancy probably accounts for the increased frequency of and severity of certain infections such as candida, herpes simplex, and varicella/zoster.
What skin conditions occur specifically during pregnancy?
There are four main conditions that occur specifically during pregnancy. These are called pregnancy-specific dermatoses.
- Intrahepatic cholestasis of pregnancy
- Pemphigoid gestationis
- Polymorphic eruption of pregnancy
- Prurigo of pregnancy (atopic eruption of pregnancy)
Pregnancy-specific dermatoses
Other conditions have a variant specific to pregnancy:
- Erythema nodosum
- Pustular psoriasis of pregnancy
- Pyoderma faciale (rosacea fulminans)
What skin conditions worsen during pregnancy?
- Acne (in early pregnancy)
- Atopic dermatitis
- Generalised pustular psoriasis
- Melasma
- Periorificial dermatitis
- Psoriasis (may worsen, improve, or stay the same)
- Rosacea
- Skin tags
- Systemic lupus erythematosus
- Vesicular hand dermatitis
What skin conditions improve during pregnancy?
- Acne (in late pregnancy)
- Atopic dermatitis
- Fox-Fordyce disease
- Hidradenitis suppurativa
- Psoriasis (may worsen, improve, or stay the same)
Skin conditions associated with pregnancy
What skin conditions are associated with complications of pregnancy?
- Ehlers-Danlos syndrome, types I and IV
- Hand foot and mouth disease
- Intrahepatic cholestasis of pregnancy
- Leprosy
- Pemphigoid gestationis
- Pemphigus
- Pityriasis rosea
- Sexually-acquired human papillomavirus (HPV) infection
- Syphilis
- Systemic lupus erythematosus
- TORCH infections
What is the outcome for changes in the skin after pregnancy?
Most pregnancy-associated physiological changes in the skin improve after delivery but may not completely clear. Hair, nail, vascular, immune, and glandular changes usually resolve in the months following delivery.
Pre-existing skin conditions that worsen or improve during pregnancy usually return to the pre-pregnancy state post-partum.
Skin conditions that are associated with complications during pregnancy can cause temporary or permanent complications for the mother, fetus, or neonate. These conditions need to be diagnosed early and managed to minimise the risk or treat the complications as they arise. When possible, mothers with pre-existing conditions should plan their pregnancy in consultation with their doctor to ensure the best outcome for mother and baby.