Bohut sey sperm raastey mein hi mar jatey hain. Jo aagey jatey hain unn mein sey aadhey ghalat tube mein chaley jatey hain kyun kay anda ek tube mein hota hai kis tube mein hai sperm ko iska ilm nahin hota iss tarah 30, 40 crore sperms mein sey sirf 2 hazar kay lug bhug sperm andey tak pohonchtey hain aur inn mein sey ek andey ko baar aawar karta hai.

    Aurat ki faraj kay khatmey per bacha daani (uterus) hoti hai jis mein bachey ki nashonuma hoti hai bachey daani ka munh faraj mein khulta hai bachey daani  kay donon taraf daaei'n baae'in 2 naaliyan hoti hain inko qazif naaliyan (fallopian tubes) kaha jata hai. Yeh naaliyan ek taraf bacha daani sey mili hoti hain aur doosrey sirey per do baeza daaniyon sey mili hoti hain baeza daaniyon mein laakhon ki ta'adaad mein baezey (andey) hotey hain har maah sirf ek hi andey ki nashonuma hoti hai, yeh baeza kisi ek baeza daani mein tayyar hota hai qudrati tor per har maah bari bari sey baeza daaniyon mein sey kisi ek mein sey baeza nikalta hai baeza rezi kay waqt anda kisi ek baeza daani sey nikal kar muta'alliqa qazif naali mein aa jata hai, doosri taraf sey mard ka nutfa aata hai donon kay milaap sey hamal theherta hai ju'nhi baeza aur sperm miltey hain to phir yeh bacha daani mein aa jatey hain jahan bachey ki parwarish hoti hai.

    Nutfa faraj mein 6 ghantey zinda reh sakta hai aur jab yeh bachey daani mein daakhil hota hai wahan 3 ta 5 din bul kay zyada bhi zinda reh sakta hai doosri taraf agar baeza raezi kay qareeb mubashrat hogi to hamal kay imkaanaat barh jatey hain. Waisey agar baqa'eda mubashrat ho to ek maah mein aurat kay hamla honey kay imkaanaat 60% hain (yani ek din chor ker ya rozana mubashrat ki jaey taa'hum ek din chor kar zyada mufeed hai)