Itching in Pregnancy

🔍 When to Suspect

Itching with or without a rash; be vigilant for obstetric cholestasis (OC), which typically presents after 28 weeks with severe itching on palms and soles without a rash

From the full topic in The Ocean Library: Itching in Pregnancy

🧭 When to suspect

Itching (pruritus) is reported in up to a quarter of pregnancies and is usually due to harmless skin changes. The diagnosis that matters is intrahepatic cholestasis of pregnancy (ICP) – previously called obstetric cholestasis (OC) – defined as otherwise-unexplained pruritus with a raised peak random (non-fasting) total bile acid concentration, with or without raised transaminases, and crucially no causative rash.

The classic picture is generalised itch, worse on the palms and soles and worse at night, arising in the third trimester (ICP rarely develops before 20 weeks). The intensity of the itch bears no relation to the bile acid level or to fetal risk. A primary rash points away from ICP and towards atopic eruption of pregnancy (eczematous) or polymorphic eruption of pregnancy (urticarial papules, often in abdominal striae).

Why it matters: the principal fetal risk is stillbirth, and that risk only rises materially once the peak bile acids reach 100 micromol/L or more. No drug reliably lowers bile acids or prevents stillbirth, so the entire clinical task is to stratify by peak bile acids and plan the timing of birth accordingly.

Peak total bile acids	Severity	Stillbirth risk and planned birth (singleton, no other risk factors)
19–39 micromol/L	Mild	Risk similar to background – planned birth around 40 weeks; may await spontaneous labour
40–99 micromol/L	Moderate	Risk similar to background until 38–39 weeks – consider planned birth at 38–39 weeks
≥ 100 micromol/L	Severe	Risk above background (around 3%) – consider planned birth at 35–36 weeks

Source: Royal College of Obstetricians and Gynaecologists (RCOG) Green-top Guideline No. 43

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