Perhaps psychologically, sympathy pains allow the man to go through the pain with the woman, so she doesn't have to do it alone. According to one article I unearthed on the subject, though, there is a biological foundation for these feelings. Men with pregnant partners were shown to have an increased level of estrogen and a decreased level of testosterone in one test.
William Blake (1757-1827) , English artist, mystic and poet wrote Songs of Innocence (1789): a poetry collection written from the child s point of view, of innocent wonderment and spontaneity in natural settings which includes Little Boy Lost, Little Boy Found and The Lamb;
The poet attempts to connect himself to nature and  relate with it. For example, in his poem I Wandered Lonely as a  Cloud, William Wordsworth compares himself to a drifting cloud,  and then rejoices in the beauty of a field of daffodils.    Victorian Poetry, however, is much harsher and realistic.