Abnormal liver function tests in pregnancyBMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f6055 (Published 25 October 2013) Cite this as: BMJ 2013;347:f6055
- Ian Walker, consultant medical biochemist1,
- Lucy C Chappell, clinical senior lecturer in maternal and fetal medicine2,
- Catherine Williamson, professor of women’s health2
- 1Department of Biochemistry, Wexham Park Hospital, Slough, UK
- 2Women’s Health Academic Centre, King’s College London and King’s Health Partners, London SE1 1UL, UK
- Correspondence to: C Williamson
- Accepted 4 September 2013
Symptoms and signs associated with the commonest pregnancy-specific liver diseases are pruritus, upper abdominal pain, and jaundice
Reference ranges for liver function tests for alanine and aspartate transaminases, bilirubin, and alkaline phosphatase are different in pregnancy
Abnormal liver function tests in conjunction with relevant symptoms or signs should result in referral to secondary care, as should raised serum bile acids or coexistent hypertension or proteinuria
Palmar erythema, spider naevae, and isolated raised alkaline phosphatase in the third trimester can occur in uncomplicated pregnancy and do not usually require further investigation
A 34 year old South Asian nursery worker presented to her general practitioner at 32 weeks’ gestation in her first pregnancy complaining of increasingly severe itching. There was no relevant medical or family history, and she was not taking regular medication. Physical examination was normal with no evident rash. Her blood pressure was 115/65 mm Hg, and there was no proteinuria. The liver function tests were: total bilirubin 6 μmol/L, alkaline phosphatase 178 IU/L, alanine transaminase 42 IU/L, and albumin 34 g/L.
What is the next investigation?
Alkaline phosphatase normally increases during pregnancy because of production of the placental isoenzyme and, by term, may reach three times the normal adult upper reference value. The value of 178 IU/L is therefore likely to be normal (table 1⇓). Pregnant women with isolated raised alkaline phosphatase in this range do not need any further investigation. Likewise, albumin is often decreased in normal pregnancy (table 1⇓) as a consequence of haemodilution. In contrast, the concentrations of the transaminases (alanine and aspartate) and γ-glutamyltransferase normally decrease during pregnancy, and it is important to compare values to an appropriate reference range (table 1). The alanine transaminase result of 42 IU/L is therefore not normal and, because liver disease in pregnancy can have serious consequences, should be followed up within a week.