Or is it more in line with your first answer, that the whole female body is influenced by estrogen. And there is no need to focus on the hymen ?
One thing that always stuck with me about hymen was this piece of information, that's why I was really expecting something on estrogen.
I only threw in the vaginal atrophy shit, because the hymen and the vaginal walls have estrogen receptors, so maybe when estrogen or lack thereof is causing changes in vaginal walls that result pain, it could also be happening to the hymen or hymen remnants (carunculae )
But as the midwife in her blog below notes, we should do more research on this topic.
Despite cellular definitions of hymenal tissue and remaining tag structures, little is known about the continue physiologic role of the hymenal ring or carunculae myrtiformes in vaginal anatomy, sensation, interrelationship with neighboring tissues and organs, and support for women who experience pain in the area of the fibrous hymenal ring. Clearly, however, its recognition is not missed as an anatomical reference point, its palpable difference to surrounding tissue, and pain- and pleasure-sensing points.
Lessons learned?
The hymenal ring is different for everyone, vascular, sensitive, and an area of vaginal anatomy that likely could use additional research as to its vaginal elasticity related to estrogen supply, elasticity during childbirth, involvement with dyspareunia or vestibulodynia, and varied positioning in regards to a landmark structure for pelvic organ prolapse and suturing.
Read more:
http://www.feministmidwife.com/2013/01/07/14-things-you-never-knew-about-the-hymenal-ring/