From the Guidelines
The workup for itching in pregnancy should begin with a thorough history and physical examination, followed by liver function tests and bile acid levels to rule out intrahepatic cholestasis of pregnancy (ICP), as recommended by the most recent guidelines 1. The initial evaluation should include liver function tests (ALT, AST, bilirubin, alkaline phosphatase, and GGT) to rule out ICP, which typically presents with pruritus without rash, particularly on palms and soles.
- Complete blood count and renal function tests should also be ordered to rule out other potential causes of pruritus.
- Bile acid levels should be measured, as elevated bile acids (>10 μmol/L) are diagnostic for ICP, according to the American Gastroenterological Association (AGA) clinical practice update 1.
- Skin examination is essential to identify conditions like pruritic urticarial papules and plaques of pregnancy (PUPPP), which presents with erythematous papules starting in striae, or pemphigoid gestationis, characterized by vesiculobullous eruptions.
- For persistent unexplained pruritus, consider testing for underlying conditions like thyroid dysfunction, iron deficiency, or diabetes.
- Ultrasound imaging may be warranted to assess liver and biliary tract if hepatic causes are suspected. The diagnosis of intrahepatic cholestasis of pregnancy is based on a serum bile acid level >10 mmol/L in the setting of pruritus, typically during the second or third trimester, and treatment should be offered with oral ursodeoxycholic acid in a total daily dose of 10–15 mg/kg 1. This systematic approach helps differentiate between benign conditions requiring symptomatic management and serious disorders like ICP that may require medication and closer fetal monitoring due to increased risks of adverse outcomes including preterm birth and stillbirth, as highlighted by the Society for Maternal-Fetal Medicine consult series 1 and the European Association for the Study of the Liver (EASL) clinical practice guidelines 1.
From the Research
Workup for Itching in Pregnancy
The workup for itching in pregnancy involves several steps to determine the underlying cause of the symptom.
- The diagnosis of intrahepatic cholestasis of pregnancy (ICP) is based on symptoms of pruritus, typically including the palms and soles, as well as elevated bile acid levels 2.
- Other liver function tests, such as alanine aminotransferase and aspartate aminotransferase, are also frequently elevated, and other causes of liver dysfunction should be ruled out 2.
- Serum levels of total bile acids (TBA) should be monitored in ICP patients throughout the pregnancy, as concentrations above 40 μmol/L define severe ICP, which is associated with an increased risk of fetal complications 3.
Differential Diagnoses
Itching in pregnancy can have various causes, including:
- Intrahepatic cholestasis of pregnancy (ICP) 4, 2, 3, 5
- Polymorphic eruption of pregnancy (PEP) 6
- Pemphigoid (Herpes) gestationis 6
- Pruritus gravidarum 6
- Atopic dermatitis (AD) 6
- Systemic diseases, such as renal or liver failure 6
Diagnostic Tests
Diagnostic tests for itching in pregnancy may include: