May women use the coil as a contraceptive method?

Fatwa, posted 4.22.2010, from South Africa, in:
Religious Authority: 
Ebrahim Desai
Fatwa Question or Essay Title: 
May women use the coil as a contraceptive method?

In the event of a female using the coil or loop as a contraceptive, two possibilities exist:

1. It may prevent fertilization by destroying the sperm and the ovum prior to their interaction.

2. If fertilisation takes place, the fertilised ovum is expelled from the uterus by the coil. This expulsion takes place within one or two weeks after fertilisation.

In the first case where the coil acts as a preventative measure against fertilisation, it is similar to any other contraceptive thus rendering it permissible in the Shari