How do Copper and hormone releasing IUDs act as contraceptive? Explain

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Please find below the solution to the asked query  
          
IUD's secreting hormone-like progestin (progestogens) are very successful in preventing emergency pregnancies. These devices inhibit ovulation, implantation and slow down the growth of sperms avoiding the chances of conception.

Copper ions suppress sperm motility and the fertilising capacity of sperms, thus preventing effective pregnancy. 

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