Cutaneous Physiological Signs of Pregnancy
Thursday, October 13, 2011
As multiple signs occur in a large percentage of pregnant women,
physiological changes of the skin during gestation are important to
recognize and differentiate from diseases in order to reassure
women and avoid unnecessary investigations (Table 1).
The three major mechanistic factors that induce the development
of these changes are (i) an increase in circulating hormones
secreted by the ovaries and/or placenta, including estrogens,
progesterone, human placental lactogen and placental-like growth
factor (PlGF), (ii) intravascular volume expansion, and (iii)
compression from the enlarging uterus.
Estrogens display pleiotropic effects; they stimulate
melanogenesis and keratinocyte growth, cause cutaneous
vasodilatation, and may enhance angiogenesis. Progesterone acts
synergistically with estrogens on melanogenesis; however, it
intervenes solely to reduce collagenolytic activity. In addition,
an enlargement of the pituitary gland results in increased levels
of gonadotrophins, adrenocorticotrophic hormone (ACTH) and
melanocytic-stimulating hormone (MSH), which all have a direct
effect on the skin.
Therefore, the present article aims to give a view of how the
biology - and consequently the histology and physiology - of the
skin is influenced by pregnancy.
- Areolae, nipples, periumbilical skin, ano-genital region,
- Recent scars, naevi, freckles
- Linea nigra
- Pigmentary demarcation lines
Venous hypertension signs
- Varicose veins and venous telangiectasias of the legs
- Jacquemier sign
- Chadwick sign
- Non-pitting edema
- Episodic pallor, facial flushing, hot and cold sensations,
dermographism, cutis marmorata.
- Hemangiomas, glomus tumors, hemangioendotheliomas
- Hyperemia and hyperplasia of the gingival mucosa
- Oral pyogenic granulomas
Molluscum fibrosum gravidarum
- Reversible hirsutism, postpartum telogen effluvium, male-pattern
- Distal onycholysis, transverse grooves, longitudinal
melanonychia, subungueal hyperkeratosis
- Eccrine sweat glands: hyperhidrosis, miliara
- Apocrine sweat glands: decreased activity
- Sebaceous glands: increased activity, Montgomery's tubercles
Table 1. Physiologic changes of the skin and the mucosa
Hyperpigmentation is the most frequent skin modification found
in pregnancy,1 and it takes place, usually, during the
first trimester. Its pathogenesis is considered to rely on
increased serum levels of MSH, estrogens and, possibly,
progesterone that stimulate melanocytic activity.2,3
Changes are more pronounced in women with a dark complexion.
Hyperpigmentation is usually localized, targeting the areolae
and/or nipples, which are the most commonly affected sites (40%);
it also targets the face, the periumbilical skin, the axillae, and
the inner thighs. Recent scars, naevi, and freckles might also
darken during gestation. The linea alba becomes hyperpigmented in
approximately 75% of pregnant females.1
Melasma, chloasma, or mask of pregnancy usually begins after the
third month of gestation and can affect 5% of white females devoid
of sun exposure and up to 70% of those with a dark phototype. The
most common presentation is centrofacial melasma developing on the
forehead, the cheeks, the upper lip, and the chin. Maxillary and
mandibulary patterns are less frequent. Wood's light examination
helps to differentiate the epidermal (enhanced pigmentation) and
dermal (unchanged pigmentation) types.
Pigmentation usually regresses postpartum; however, it might
persist in some cases and/or worsen again after sun exposure.
Therefore, broad-spectrum sunscreen and sun avoidance are important
preventive measures during and after pregnancy.4
Additionally, its recurrence in future pregnancies or with oral
contraception is common.
Spider telangiectasias - also called spider angiomas or spider
nevi - develop in approximately 60% of white pregnant women;
however, they are far less common in dark-skinned
women.1 Typically, spider nevi appear at the end of the
first trimester in the area of skin drained by the superior vena
cava, namely the face, neck, arms and hands. Their number increases
throughout pregnancy,1 and they often disappear within
weeks after delivery; however, persistent lesions may be treated
with fine-needle electrocautery, pulsed dye laser, or intense pulse
Furthermore, palmar eythema appears within the first trimester
along with spider telangiectasias. Hyperthyroidism, cirrhosis,
lupus, and salbutamol intake are the main differential diagnoses.
Palmar erythema in pregnancy is attributed to venous capillary
engorgement, and fades within one week postpartum.
Secretion of pregnancy-related hormones induces and increases
the fragility of the elastic fibers in vessel walls.5,6
In addition, the enlarging uterus compresses the pelvic and
abdominal vessels, thus increasing venous pressure. These, as well
as prolonged standing, lead to saphenous, vulvar, and anal
(hemorrhoidal) varicosities that appear in 40% of women.
Varicosities usually regress postpartum. Use of elastic stockings
and elevation of the legs are, therefore, recommended to prevent
these phenomena. Prevention of constipation might also help to
prevent their exacerbation.
Likewise, the increased hydrostatic venous pressure detailed
above might also lead to fluid leakage in the extracellular milieu,
which results in non-pitting edema that mainly affects the legs,
but also possibly the face and the eyelids. It is more pronounced
in the morning and is observed in almost half of all pregnant women
during the last months of pregnancy.
However, one has to keep in mind that edema of the face and
hands might be indicative of pre-eclampsia. Purpura is caused by
the excessive fragility and permeability of capillaries, and is
common on the legs during the second half of pregnancy; although it
spontaneously regresses postpartum, it requires the elimination of
other causes of purpura.
Superficial or subcutaneous hemangiomas, beginning on the third
month of gestation, are reported in 5% of pregnant women and affect
the hands and neck particularly. More rarely, glomangiomas and/or
hemangioendotheliomas might develop around the eyes, the breasts,
and the umbilical skin.
Hyperemia and hyperplasia of the gingival mucosa is seen in
pregnant women, and develops in the third trimester of pregnancy
and progressively resolves postpartum. The interdental papillae are
the most affected site. Pre-existing periodontal disease, poor
dental hygiene, nutritional deficiencies, and local irritative
factors are co-stimulatory events.
Similarly, pyogenic granulomas seem relatively frequent during
pregnancy after the second trimester. The lesions correspond to
benign hyperplasia of mucosal capillaries and fibroblasts that
arises in reaction to triggers such as physical trauma or
irritations. Pyogenic granulomas are painless, but they might
bleed. Spontaneous regression is observed in the months after
postpartum; however, their recurrence is possible in later
pregnancies. Unless bleeding necessitates excision, surgery should
Striae distensae (striae gravidarum) occur in 60-90% of white
women; however, they are less common in black or Asian
women.1 The most significant risk factors for striae in
primiparous women include young maternal age, an elevated maternal
body mass index, as well as important maternal weight gain and baby
weight. Additionally, women with a history of breast or thigh
striae or a family history of striae gravidarum are at higher
The mechanisms of their appearance remain poorly known, but rely
on physical trauma such as stretching of the skin and hormonal
mediation through steroids, estrogens and relaxin, which leads to a
reduction in the elastic fiber network.8
Furthermore, preventive measures have no proven beneficial
effect. Treatment of recent purplish striae with a pulsed dye laser
or 0.1% tretinoin cream might partially improve their appearance;
however, it should, of course, be given only after
Molluscum fibrosum gravidarum corresponds to the skin tags, or
acrochordons, that grow during pregnancy, which appear as small
cutaneous pedonculated, lightly pigmented polyps located on the
The hair cycle changes during pregnancy, which results in less
anagen hair follicles entering the telogen phase and leads to the
thickening and brightening of hairs. In addition to the thickening
of scalp hair, body hair follicles increase in size and number,
especially on the face, but less often on the arms, legs, and back.
This kind of hirsutism is reversible within 6 months
Postpartum, scalp hair enters a prolonged telogen phase, causing
increased shedding (telogen effluvium), which might begin 4-12
weeks after delivery and last 3-4 months. After this period, hair
grows again within 6-15 months. An evaluation of the possibility of
an iron deficiency should be made.
Acne will not be discussed in detail here; however, it is a well
known phenomenon that acne can develop de novo or worsen during
pregnancy. The difficulty lies in choosing an allowed treatment
because most of them are forbidden during pregnancy.
In approximately half of pregnant women, the sebaceous glands on
the areolae enlarge and appear as multiple elevated brown papules
called Montgomery's glands or tubercles. They are visible from the
sixth week of gestation, representing an early sign of pregnancy.
Regression is classical after delivery.
In conclusion, this short review summarizes the diversity of the
interactions between pregnancy and a vast and complex organ such as
the skin - there is nearly a target receptor for any of the
pregnancy hormones on one or more cutaneous cell types. Therefore,
pregnancy can induce a wide range of changes, ranging from
pronounced physiological changes to more significant disorders.
Clinicians need to understand the molecular basis of these changes
and be able to interact with obstetricians in order to provide the
best treatment for pregnant women.
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pregnancy. Clin Dermatol
- Costin GE, Hearing VJ. Human skin pigmentation: melanocytes
modulate skin color in response to stress. FASEB J
- Grimes PE, Yamada N, Bhawan L. Light microscopic,
immunohistochemical, and ultrastructural alterations in patients
with melasma. Am J Dermatopathol
- Rendon M, Berneburg M, Arellano I, Picardo M. Treatment of
melasma. J Am Acad Dermatol
- Henry F, Quatresooz P, Valverde-Lopez JC, Piérard GE. Blood
vessel changes during pregnancy: a review. Am J Clin
- Torgerson RR, Marnach ML, Bruce AJ, Rogers RS 3rd. Oral and
vulvar changes in pregnancy. Clin Dermatol
- Chang AL, Agredano YZ, Kimball AB. Risk factors associated with
striae gravidarum. J Am Acad Dermatol
- Salter SA, Kimball AB. Striae gravidarum. Clin
- Rangel O, Arias I, García E, Lopez-Padilla S. Topical tretinoin
0.1% for pregnancy-related abdominal striae: an open-label,
multicenter, prospective study. Adv Ther