"It should be obvious that from the moment a woman becomes pregnant her status in society changes as a result of both direct and indirect actions of the government and because of social mores. Except in very rare cases (primarily among the wealthy) she is certainly no longer “free in the enjoyment of all [her] faculties;...free to use them in all lawful ways; to live and work where [she] will; to earn [her] livelihood by any lawful calling; to pursue any livelihood or avocation....” Pregnancy, from the moment of conception, severely limits a woman’s liberty. In many cases of both public and private employment women are forced to temporarily or permanently leave their employment when they become pregnant. The employer has no duty to transfer a pregnant woman to a less arduous job during any stage of pregnancy (should the woman or her doctor consider this advisable); nor is there any statutory duty to rehire the woman after she gives birth.... [R]egardless of whether the woman wishes and/or needs to continue working, regardless of whether she is physically capable of working, she may nonetheless be required to stop working solely because of her pregnancy. In many if not most states women who are public employees are compelled to terminate their employment at some arbitrary date during pregnancy regardless of whether they are capable of continuing work."