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

Hydatidiform mole (HM) incidence has shown contrasting temporal trends across different regions. We analyzed HM incidence in Lombardy, Italy, from 2009 to 2022. HM cases were identified through regional registry data. 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). The study suggests that diagnostic practices and demographic shifts may have influenced HM trends, while also confirming persistent ethnic and age-related risk patterns.