Medical Q&As

Mirena coil - contraceptive effect begins?

I had the Mirena coil fitted over 2 weeks ago, mainly to control heavy periods. The doctor answered a lot of questions for me but I forgot to ask if there was a certain amount of time that I have to wait until I have unprotected sex. I am in a long-term relationship. I had unprotected sex last night and I have nagging doubts as to whether I am protected against pregnancy yet.

You are protected so there is no need for you to worry. The Mirena coil is usually fitted within a week of the onset of a period and in that scenario the contraceptive effect begins from the day the coil was inserted. The coil can be fitted at other times in your cycle but it is usually recommended that additional contraceptive measures be taken for the first seven days after insertion. Therefore since it is two weeks between the insertion of your coil and last night’s act of intercourse you can take it that you were protected from an unwanted pregnancy. Assuming that your coil was inserted within the first seven days of your menstrual cycle that protection has existed for the past two weeks. The Mirena coil is licensed for five year’s use and after that time it needs to be removed and replaced with a new coil.