Pemphigoid gestationis (PG) is a pregnancy-associated, autoimmune skin disorder. It usually begins abruptly during the 2nd or 3rd trimester of pregnancy, but it can begin at any time during pregnancy. Signs and symptoms often include the sudden formation of very itchy, red bumps and/or blisters on the abdomen and trunk, which may then spread to other parts of the body. Unrelenting itchiness (pruritus) often interferes with daily activities. Symptoms may improve at the end of pregnancy, but flares may occur during, or right after, delivery. While PG usually goes away on its own within weeks to months after delivery, it has been reported to persist for years in some cases.

PG is caused by a woman's immune system producing autoantibodies and mistakenly attacking her own skin, but the trigger for autoantibody production is poorly understood. Treatment aims to relieve itching and prevent blister formation, and may involve the use of topical corticosteroids, oral corticosteroids, and/or oral antihistamines. The lowest effective dose of medication should be used in order to minimize the risk to the mother and fetus.

The disorder may recur at a later time such as when menstruation resumes; with use of oral contraceptives; and/or during subsequent pregnancies.

Mothers with PG may be at an increased risk of having a baby that is small-for-gestational age or preterm. Some have suggested that mild placental insufficiency may be the cause of these risks. Sonograms of the baby during the third trimester might be appropriate and used to monitor fetal growth and development. Another risk associated with maternal PG is the placental trasnder of the PG antibody, resulting in neonatal PG; this occurs in about 5 to 10 percent of babies. The blisters resolve spontaneously without scarring over a period of weeks as the maternal PG antibodies are cleared by the baby. Babies with neonatal PG should be monitored for bacterial infections of the lesions. Early treatment can prevent progression to systemic infection.

In general, there are no long-term complications associated with PG. However, an association between PG and other autoimmune diseases like Graves' disease has been reported; therefore, it is performance of immediate and periodic screening tests of thyroid function is recommended. Some women will have persistent HG or recurrent flares lasting weeks or months following birth. Additionally, it is important to recognize that women who have had PG are at an increased risk of postpartum flare-ups, if they use oral contraceptives within 6 months of giving birth.