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 Lamb  is a poem by William Blake, published in Songs of Innocence in 1789.he lamb is a common metaphor for Jesus Christ, who is also called The Lamb of God in John 1:29. This poem has a simple rhyme scheme: AA BB CC DD AA AA EF GG FE AA. The layout is set up by two stanzas with the refrain: Little Lamb who made thee/Dost thou know who made thee.