A. Attacks, in a menstruating woman1, fulfilling criteria for 1.1 Migraine without aura and criterion B below
B. Documented and prospectively-recorded evidence over at least three consecutive cycles has confirmed that attacks occur exclusively on day 1 ± 2 (ie, days −2 to +3)2 of menstruation1 in at least two out of three menstrual cycles and at no other times of the cycle.
1. For the purposes of ICHD-3 (beta), menstruation is considered to be endometrial bleeding resulting from either the normal menstrual cycle or from the withdrawal of exogenous progestogens, as in the use of combined oral contraceptives or cyclical hormone replacement therapy.
2. The first day of menstruation is day 1 and the preceding day is day −1; there is no day 0.