Abnormal liver function tests in the symptomatic pregnant patient: the local experience in Singapore

The causes of abnormal liver function tests in pregnancy are varied and may or may not be pregnancy-related. Often, the diagnosis can be difficult. This study looked at the causes of deranged liver function tests in obstetric patients with significant symptoms and signs.

Data from 50 cases of abnormal liver function tests in pregnant patients, who presented from 1998 to 2001, were analysed. Their presenting symptoms included persistent vomiting (48%), pruritus (14%), jaundice (26%), upper abdominal discomfort (24%) and hypertension (46%).

Pregnancy-related causes accounted for 84% of the abnormal liver function tests. Abnormal liver function tests occurred more frequently in the first (34%) and third (58%) trimesters than in the second trimester (8%). Hyperemesis gravidarum (94%) and partial haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome (31%) were the commonest causes in the first and third trimesters respectively. Hepatitis B flare resulted in 2 maternal deaths. Seven patients with pre-eclampsia toxaemia, acute fatty liver of pregnancy or partial/complete HELLP syndrome had their liver function tests measured sequentially before and after delivery. All of them showed rapid improvement postpartum with their alanine aminotransferase (ALT) dropping 50% within 3 days.

The majority of patients with abnormal liver function tests had a cause related to pregnancy, and pregnancy-related causes in the third trimester improved rapidly postpartum. Hepatitis B flare was a significant non-obstetric cause leading to maternal mortality. This diagnosis must therefore be considered in ethnic groups where the incidence of chronic hepatitis B infection is high, especially in chronic hepatitis B carriers with suspected pregnancy-related disease who deteriorate postpartum.