| luteoplacental shift | The change in site of production of the oestrogen and progesterone essential for human pregnancy from the corpus luteum to the placenta; ovariectomy always terminates pregnancy in most mammals because their placentas never produce enough oestrogen and progesterone, but, after the sixth week of pregnancy, a human placenta can produce enough of these hormones to prevent abortion despite ovariectomy. (05 Mar 2000) |
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