Scientists have recently published the first successful differentiation of endometrial mesenchymal stem cells(EnSCs) into oocyte-like cells. Encouraged by their achievements, Smrekar and Šutić decided to induce EnSCs obtained from menstrual blood and differentiate them in-vitro into germ cells, using customized protocols of their own redesign. In ‘reProductive narratives’, the art project they are currently developing, they both view the process of in vitro transformation of one’s own menstrual blood stem cells into reproductive cells as a possibility that offers new potentials to women’s emancipation. Until now, reproductive cells have been available to women through the process of IVF (in-vitro fertilisation), which includes complex and potentially harmful interventions to the body, while this safer and more ethical form, opens the path to new ways of reproduction, independent of one’s biological characteristics or traditional family and societal structures. By loosening the seemingly essential social patterns we are also coming closer to empowering anyone who would like to adjust their reproduction to fit their personal stories.
Most female mammals have an estrous cycle, yet only ten primate species, four bat species, the elephant shrew and the spiny mouse have a menstrual cycle. The lack of immediate relationship between these groups suggests that four distinct evolutionary events have caused menstruation to arise.
Some anthropologists have questioned the energy cost of rebuilding the endometrium every fertility cycle. It has proposed that the energy savings of not having to continuously maintain the uterine lining more than offsets energy cost of having to rebuild the lining in the next fertility cycle, even in species such as humans where much of the lining is lost through bleeding (overt menstruation) rather than reabsorbed (covert menstruation).
Many have questioned the evolution of overt menstruation in humans and related species, speculating on what advantage there could be to losing blood associated with dismantling the endometrium, rather than absorbing it, as most mammals do. Humans do, in fact, reabsorb about two-thirds of the endometrium each cycle. Some work asserts that overt menstruation does not occur because partial endometrial loss is beneficial in itself. Rather, the fetal development of these species requires a more developed endometrium, one which is too thick to reabsorb completely. There is a correlation between species that have overt menstruation to those that have a large uterus relative to the adult female body size.
Recent reviews suggest that menstruation itself is not an evolved, adaptive trait. Rather, it is an inherent consequence of spontaneous decidualization evolving as a derived trait from non- spontaneous decidualization.
Beginning in 1971, some research suggested that menstrual cycles of cohabiting human females became synchronized (menstrual synchrony). However, there is currently significant dispute as to whether menstrual synchrony exists. A 2013 review concluded that menstrual synchrony likely does not exist.