These seizures found in women only, are related to a type of epilepsy known as Catamenial Epilepsy. This refers to seizures which correlate with the menstrual cycle around ovulation and also approximately a week before the cycle begins.
Progesterone and estrogen are hormones which directly affect the nerve cells within the brain. Interestingly enough, research that was done demonstrated that an increased amount of estrogen can be detrimental for seizures as it created more, whereas increased progesterone levels in some cases, can be successful in alleviating them.
There are many different factors which can come into play with what affects each woman, for me there was never any particular trigger, when things were bad I could have up to about 80 plus absences a day which, quite frankly was exhausting!
Certain varieties of the pill have been known to have a positive impact on reducing seizures but always talk to your doctor before embarking on new contraception as there are certain medications which interfere making the pill ineffective and vice versa.