Intrauterine Systems

Question 1

How effective are IUDs?

Answer 1

Very effective - removing human error

Failure of 1.8 per 1000 women

Question 2

What is the dose of progesterone in the Mirena coil?

Answer 2

52mg of levonrogestrel, releases 20mcg per day

Question 3

Explain to a patient what the mirena coil is

Answer 3

Its a small, T-shaped plastic device that’s inserted through the vagina to sit in the uterus.
It lasts for 5yrs, it works by releasing a small amount of the hormone progesterone everyday. ( total levonestogel 52mg, daily dose of 20mcg).
Its a form of contraception but it also works well to manage heavy bleeding.
That’s one of the advantages, women with heavy periods notice a substantial decrease in bleeding, 90% of women will be ammenorrheic ( no periods) at 9 months.
It works as a contraceptive in 3 ways
- stops ovulation
- changes cervical mucous so more hostile to sperm
- acts as a physical barrier to implantation

Some side effects than can occur are - fluid retention, mood swings, reduced libido. These are due to the hormone but are less common than oral contraceptives because the device works locally, small amount of systemic absorption.

It’s inserted through the vagina, can be done in clinic, by GP or under GA as part of other procedure.
Risks associated with it include; risk of perforating uterus when inserting - less than 1%, its 0.2%, risk of infection 1%, risk of expulsion 5% esp with menorrhagia.
risk of failure - 1.8 per 1000 women, if it fails there’s a risk of having an ectopic pregnancy.

Question 4

Do I have to be under GA to get a mirena coil?

Answer 4

No, it can be done by your GP or in clinic.
The best time to insert it is at the time of you menstrual period.
It is physically easier to insert
If inserted within 7 days of start if a period it is effective immediately
If fitted after 7 days then additional contraceptive precautions needed for 7 days