Is menarche caused by ovulation or is it one of the first anovulatory cycles that a young gal will get?

Hormones come first: When a girl develops to the point where her body is making sufficient amounts of estrogen and progestin, the lining of the uterus prepares for possible implantation of a fertilized egg. If this doesn't happen, the lining of the uterus is shed, causing a menstrual period. The first time this happens, it is called menarche. Girls may not ovulate regularly for the first two years after menarche.

Maybe: Menses is triggered by the breakdown of the intrauterine buildup of tissue in response to hormones. Although the pacing of menses may match ovulation in the future, it is not necessary for the process to occur.A young woman may ovulate prior to her first menses (and become pregnant if exposed).She may also only ovulate occasionally, with some irregularity in pattern.