A possible association between hydatidiform mole and the COVID-19 pandemic: A retrospective cohort study

Objective: To confirm an increase in the number of women with molar pregnancy during the COVID-19 pandemic. Methods: In this retrospective cohort study, all patients with complete or partial mole diagnosed at our institution between January 1, 2010 and October 31, 2020, were included. To verify whether there was an increase in the incidence of hydatidiform mole (HM) and deliveries in 2020, the incidences for each year from January 2010 to October 2020 were recorded. In addition, we identified all women who were diagnosed with HM from January to October 2020, and compared them with a control group who underwent uterine evacuation for missed abortion of a singleton pregnancy during the same period. We also documented the time taken to diagnose missed abortion or molar pregnancy to check if a delay in diagnosis can explain the increase in HM incidence. Results: Between 2016 and 2019, there was a statistically significant increase in the incidence of molar pregnancy. A further increase occurred in 2020 (odds ratio = 2.071). The mean gestational age of the embryo at the time of diagnosis was smaller in the HM group than in the missed abortion group (6.3 ± 1.67–7.4 ± 2.4, one-sided P = 0.034), meaning that it took more time (days) to diagnose molar pregnancy than missed abortion (22.38 ± 10.32 vs. 15.83 ± 7.83 days, P = 0.012). Conclusion: There was a significant increase in the incidence of molar pregnancy during the COVID-19 pandemic, possibly because of the delay in receiving medical care. We recommend providing gynecological primary care services during a crisis, such as a pandemic.