Is the waiting period (iddah) of a woman who has an IUD valid, or must she remove it before beginning the waiting period until it is over?

The IUD does not affect a woman's waiting period (iddah), nor is it necessary to remove it. The waiting period for a divorced woman is three menstrual cycles for one who menstruates, by giving birth for a pregnant woman, and three months for one who has not menstruated or has despaired of menstruation. If menstruation ceases for a known reason, she waits until menstruation returns to observe her iddah with it, unless she becomes one of those who have despaired, in which case her iddah is three months. If the cessation is for an unknown reason, then her iddah is a full year (nine months for pregnancy and the iddah of one who has despaired). The waiting period for a woman whose husband has died is four months and ten days, except for a pregnant woman, whose iddah is by giving birth.