International Journal of Epidemiology International Journal of Epidemiology, Oxford University Press (OUP), In press, ⟨10.31219/osf.io/fxygt⟩ International Journal of Epidemiology, In press, ⟨10.31219/osf.io/fxygt⟩ Sharp, G C, Fraser, A, Sawyer, G, Kontourides, G, Easey, K, Ford, G, Olszewska, Z, Howe, L, Lawlor, D, Alvergne, A & Maybin, J A 2021, ' The COVID-19 pandemic and the menstrual cycle: research gaps and opportunities ', International Journal of Epidemiology . https://doi.org/10.1093/ije/dyab239 Sharp, G C, Fraser, A, Sawyer, G R, Kountourides, G, Easey, K E, Ford, G K, Olszewska, Z, Howe, L D, Lawlor, D A, Alvergne, A & Maybin, J 2021, ' The COVID-19 pandemic and the menstrual cycle : research gaps and opportunities ', International Journal of Epidemiology . https://doi.org/10.1093/ije/dyab239