Growth of hepatocellular adenoma during pregnancy: A prospective study.

BACKGROUND & AIMS: The presence of hepatocellular adenoma (HCA) in pregnant women requires special consideration, as it has been reported to carry the risk of growth and clinically significant haemorrhage. In this prospective study we assessed aspects of growth of HCA <5 cm during pregnancy.

METHODS: This was a multicentre prospective cohort study in pregnant women with suspected HCA <5 cm on imaging. Definitive HCA diagnosis was established by MRI with hepatobiliary contrast agents (LCE-MRI), preferably before pregnancy. If at study inclusion a definitive diagnosis was lacking, LCE-MRI was performed after giving birth. Growth of the adenoma (defined as an increase of >20%) was closely monitored with ultrasound examinations throughout pregnancy.

RESULTS: Of the 66 women included, 18 were excluded from analysis because postpartum LCE-MRI did not confirm the diagnosis of HCA and showed the lesion to be focal nodular hyperplasia. The remaining 48 women, with an HCA confirmed by LCE-MRI, were followed during 51 pregnancies. Median age was 30 years (IQR 27-33) and median body mass index 31.9 kg/m2 (IQR 26.3-36.6). Growth of HCA was seen in 13 of the pregnancies (25.5%); the median increase was 14 mm (IQR 8-19). One woman whose HCA grew to >70 mm successfully underwent transarterial embolization at week 26 of pregnancy to prevent further growth. The other 50 pregnancies proceeded without complications.

CONCLUSION: This study suggests that an HCA <5 cm confers minimal risk to a pregnant woman and none to her child. HCA increased in size during a quarter of pregnancies, so we recommend close monitoring with ultrasound examinations, enabling intervention if needed. In light of the large proportion of misdiagnosed HCA, LCE-MRI should be performed to prevent unnecessary anxiety in women with a benign liver lesion.

LAY SUMMARY: The presence of hepatocellular adenoma in pregnant women requires special consideration, as it carries the risk of growth and haemorrhage. In this study we followed 48 patients with hepatocellular adenoma <5 cm during 51 pregnancies and found that a hepatocellular adenoma during pregnancy confers minimal risk to the pregnant woman and none to her child.