Focal Nodular Hyperplasia in Pregnancy: Safety and Delivery Considerations
Focal nodular hyperplasia (FNH) is not dangerous during pregnancy, and women with FNH can safely deliver vaginally without increased risks. 1
Understanding FNH in Pregnancy
Focal nodular hyperplasia is the second most common benign liver lesion after hemangiomas, with a prevalence of 0.3% to 3%, and is commonly diagnosed in reproductive-aged women 1. Unlike hepatocellular adenomas, which require careful monitoring during pregnancy, FNH poses minimal risk to pregnant women.
Key Facts About FNH in Pregnancy:
- Behavior during pregnancy: FNH typically remains stable during pregnancy, with contemporary cohorts showing no significant changes in lesion size 1
- Complications: Only one case of hepatic rupture has been reported in the literature, making this an extremely rare complication 1
- Monitoring requirements: Unlike hepatocellular adenomas, FNH does not require monitoring during pregnancy regardless of size 1
- Delivery method: Vaginal delivery is not associated with increased risks for women with FNH 1
Management Recommendations
The 2023 European Association for the Study of Liver (EASL) clinical practice guidelines and the 2021 American Association for the Study of Liver Diseases (AASLD) practice guidance provide clear recommendations:
Pregnancy counseling: Women with FNH should be advised that pregnancy is not contraindicated 1
Monitoring during pregnancy: Imaging is not routinely recommended to monitor FNH during pregnancy 1
- This differs significantly from hepatocellular adenomas, which require ultrasound monitoring each trimester if present
Delivery planning: Vaginal delivery is not associated with increased risks and should not be contraindicated based on the presence of FNH 1
Differentiating FNH from Other Liver Lesions
It's important to ensure accurate diagnosis of FNH before pregnancy, as management differs significantly from other liver lesions:
- Hepatocellular adenomas: Require monitoring during pregnancy and may need intervention if ≥5 cm 1
- Hemangiomas: May require monitoring if large or exophytic 1
- FNH: No monitoring required regardless of size 1
Rare Exceptions
While most FNH remains stable during pregnancy, rare cases of growth have been reported 2. However, even in these uncommon situations, complications are extremely rare, and the lesions often decrease in size after delivery 2.
Conclusion
Based on the most recent guidelines from both European and American liver associations, FNH does not pose a danger during pregnancy, and women with this condition can safely undergo vaginal delivery without increased risks. No special monitoring is required during pregnancy for women with FNH.