The Compendium of Caraka 4.3.11_3

4.3.11_3

sātmyasevināṃ punaḥ strīpuruṣāṇāmanupahataśukraśoṇitagarbhāśayānāmṛtukāle sannipatitānāṃ jīvasyānavakramaṇādgarbhā na prādurbhavanti/

On the other hand, in women and men who consume wholesome things, whose semen, menstrual blood, and uterus are undamaged, who have united at the proper season, embryos do not manifest because the living entity does not descend.