The amendment equates the life of the foetus to the life of the mother and criminalises abortion in Ireland.
Irish women soon joined Ms Maguire, with #repealthe8th trending in Ireland. Changes to the constitution can only be made through a referendum.
A coalition of pro-choice groups is calling for a referendum to repeal the amendment and more than 47,000 people have signed a petition by the UK-based human rights group Amnesty International urging Mr Kenny to change the law.
Ms Maguire argued it was only fair to share such details with Mr Kenny since "we know how much the Irish state cares about our reproductive parts".
Women from all over Ireland chimed in with contributions about their menstrual cycles. Mr Kenny is yet to respond.
In June, a report by Amnesty claimed pregnant women risk putting their health and lives in danger if they remain in Ireland.
"The human rights of women are violated on a daily basis because of a constitution that treats them like child-bearing vessels," said Amnesty`s Secretary General, Salil Shetty.
"Women who need abortions are treated like criminals, stigmatised and forced to travel abroad, taking a serious toll on their mental and physical health.
In February a proposed change to the abortion law to legalise terminations in fatal foetal abnormality cases was rejected by the Irish parliament.
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