Therefore , immunity against hCG during this time frame would function as an abortifacient , as confirmed by experiments in baboons .
For the first 7 -- 9 weeks in humans , the corpus luteum secretes the progesterone necessary to maintain the viability of the endometrium for pregnancy .
Immunity against hCG during this time frame would function as an abortifacient , as confirmed by experiments in baboons .
For the first 7 -- 9 weeks in humans , the corpus luteum secretes the progesterone necessary to maintain the viability of the endometrium for pregnancy .