Hydatidiform mole incidence in Lombardy, northern Italy, 2009–2022: continued decline or plateau

Introduction: Hydatidiform mole (HM) incidence has shown contrasting temporal trends across different regions. Methods: We analyzed HM incidence in Lombardy, Italy, from 2009 to 2022. HM cases were identified through regional registry data. Results: A total of 1,131 HM cases occurred among 1,471,567 pregnancies, averaging 77 cases per 100,000 pregnancies. A significant decline was observed between 2009 and 2015 (p=0.01), but no consistent trend emerged over the full period (p=0.76). HM incidence was highest in women aged ≥46 (699.1/100,000) and <20 (107.6/100,000), and among women of Asian origin (110.4/100,000). Discussion: The study suggests that diagnostic practices and demographic shifts may have influenced HM trends, while also confirming persistent ethnic and age-related risk patterns.