Biphasic hypertriglyceridemia in pregnancy with apolipoprotein C-II deficiency

Apolipoprotein C-II (ApoC-II) deficiency is a rare genetic cause of familial chylomicronemia syndrome (FCS) that predisposes affected individuals to severe hypertriglyceridemia and acute pancreatitis. Evidence guiding management during pregnancy is limited. We report a woman with ApoC-II deficiency (ApoC-II Wakayama mutation) who showed a biphasic triglyceride (TG) elevation. TG increased markedly in the second trimester, improved with intensified dietary restriction, and rose again to 1400 mg/dL (15.8 mmol/L) in the third trimester. Because she remained asymptomatic and TG had responded to dietary therapy, medical therapy and plasma exchange were not initiated. Labour was induced at 36 weeks, resulting in uncomplicated vaginal delivery and rapid postpartum TG reduction. This case highlights trimester-specific monitoring and individualized reassessment of dietary, medical, plasma exchange, and delivery strategies in FCS.