The hormonal coil

The hormonal coil is the most reliable reversible contraception there is – and at the same time a treatment for women who bleed too heavily. The two together explain why it makes up the greater part of contraception consultations in this practice. What it does, what it costs, how insertion works and what really happens in the first months: it is all set out here.

What a hormonal coil is

A hormonal coil is a small, T-shaped plastic body which is inserted into the uterus. The vertical arm carries a cylinder containing the progestogen levonorgestrel, which is released evenly and in very small amounts over years. At the lower end sit two fine threads which reach through the cervix into the vagina. They are used to check its position, and through them the coil is later removed again.

Its technical name is intrauterine system, IUS for short – as distinct from the hormone-free copper coil, the IUD. The difference is not merely one of terminology: both sit in the same place but work in completely different ways and do exactly the opposite with the bleeding. Anyone considering a coil therefore decides first between these two families and only afterwards about the model.

Three hormonal coils are on the market in Austria: Jaydess, Kyleena and Mirena. They differ in size, amount of hormone and duration, but not in how they work. All three are fitted at this practice.

How it works – and why that barely affects the whole body

The hormonal coil releases levonorgestrel directly where it is meant to act. With Jaydess that is about 14 micrograms a day at first, with Kyleena 17.5 and with Mirena 20. For comparison: a progestogen-only pill delivers a multiple of that, and does so through the bloodstream to the whole body. With the coil the hormone level in the blood stays so low that the typical side effects of systemic hormone administration occur considerably less often.

Three effects work together:

1. The cervical mucus becomes thick. That is the most important mechanism. A thick, impenetrable plug of mucus in the cervix stops sperm before they even reach the uterus.
2. The motility of the sperm decreases. What does pass the mucus moves more slowly and with less direction.
3. The lining of the uterus barely builds up any more. It stays thin. That is why the bleeding becomes lighter – and why in some women it stops altogether.

Ovulation is as a rule preserved with the smaller models. For many women that is precisely an argument in their favour: their own cycle carries on, only the bleeding is lighter. With Mirena and its higher amount of hormone, ovulation is suppressed more often, though not in everyone there either.

How reliable it is

The Pearl index states how many out of a hundred women become pregnant within a year. It is given in two versions: with perfect use and with typical use. With the pill the two figures differ by more than twentyfold – 0.3 against 7. Not because the pill is bad, but because it gets forgotten.

This is exactly where the strength of the coil lies: once it has been inserted there is nothing left to do and therefore nothing left to get wrong. Perfect and typical use coincide.

The third row deserves a second look: on the figures the hormonal coil is more reliable than sterilisation – and, unlike sterilisation, reversible at any time. All the methods side by side are in the contraception comparison.

The three models compared

Jaydess is the smallest and has the least hormone. It stays in place for three years and is often chosen for young women and for women who have not given birth – not because the others would not work there, but because the thinner insertion tube makes insertion easier.

Kyleena has the same external dimensions and the same thin tube as Jaydess but contains more hormone and stays in place for five years. For many that is the sensible compromise: a small body, a long effect. It is the model most often chosen at this practice.

Mirena is the largest and has the most hormone. It is licensed for up to eight years for contraception and reduces bleeding most strongly. It is also the only coil that is additionally licensed as a treatment – more on that shortly.

All five coils offered at the practice, including the hormone-free ones, stand side by side with their price and cost per year in the coil comparison.

What happens to the bleeding

For most women this is the decisive question, and the answer has two parts which must not be separated.

In the long run the bleeding becomes lighter, shorter and less painful. After a year it stops altogether in about twelve out of a hundred women with Jaydess, in about 23 with Kyleena and in about 20 out of a hundred with Mirena. The absence of bleeding is not a sign that something is building up: the lining simply does not build up, so there is nothing there that would have to be shed. There is nothing medically worrying about it.

In the first three to six months it is the other way round. Irregular spotting is the rule during this time, not the exception – and it is the commonest reason why coils are removed early. Anyone who knows beforehand that this phase comes and goes again gets through it considerably more easily. Which is why this sentence stands here so expressly.

When the coil is a treatment as well

In Austria Mirena is licensed not only for contraception but also for the treatment of heavy menstrual bleeding. That is more than a formality: anyone coming because of bleeding that is too heavy who wants contraception anyway solves two questions with a single procedure.

What “too heavy” means is hard to describe in millilitres and easy in everyday life: when a pad or a tampon is soaked through in less than two hours, when bleeding lasts longer than seven days, when clots appear, when you plan your day around the bleeding or when your iron level is on the floor. The commonest causes are fibroids, polyps, a thyroid disorder or adenomyosis – all four belong investigated before a coil is inserted.

The hormonal coil is also used with endometriosis and adenomyosis, because the thin lining and the low local hormone level often relieve the pain markedly. And in the menopause Mirena serves as the progestogen component of hormone replacement therapy: anyone receiving oestrogen who has a uterus needs a progestogen with it in order to protect the lining. The coil takes that over without another tablet being needed.

Who it particularly comes into question for

• After a thrombosis or with migraine with aura. The hormonal coil contains no oestrogen and does not increase the risk of thrombosis – unlike the combined pill, the ring and the patch.
• For smokers over 35. The same consideration: without oestrogen the argument against the combined pill falls away.
• While breastfeeding. Levonorgestrel at this dose does not impair milk production. It is usually inserted twelve weeks after the birth.
• Where taking something daily does not reliably work. That is not a question of carefulness but of everyday life – shift work, travel, children, irregular days.
• With heavy or painful bleeding. See above: here it is contraception and treatment at the same time.

When it is out of the question

• in pregnancy
• with an acute infection in the genital area – treat first, then insert
• with unexplained bleeding – investigate first, then insert
• with malformations or large fibroids that distort the cavity of the uterus
• with a history of breast cancer – here the copper coil remains possible
• with certain liver diseases

The procedure at this practice: two appointments

A coil is not inserted here on the same day as the consultation. That is not a detour but the reason why the second appointment is short and bearable.

First appointment: consultation and preliminary examination

First the conversation: history, bleeding pattern, family planning, how you tolerate hormones, what you have used so far and why it did not suit. Then the examination: ultrasound to assess the size, shape and position of the uterus, a wet mount and swabs for organisms. At the end it is settled which model fits – and that there is no infection that could be carried upwards during insertion. That is precisely the most important gain in safety from this appointment.

Second appointment: the insertion

The procedure itself takes a few minutes. The cervix is prepared, the coil in its insertion tube is pushed through the cervical canal and released, the threads are trimmed to length. A final ultrasound check confirms that it is correctly in place. Afterwards you may stay lying down as long as you wish.

The point in the cycle is not arbitrary: at the end of or shortly after a period the cervix is somewhat softer and more open of its own accord, and pregnancy is reliably ruled out.

Does it hurt?

Yes, insertion is unpleasant. Claiming otherwise helps nobody. But the honest answer goes further: how unpleasant it is depends considerably on how it is done. Four things make the difference – the preparation of the cervix, the point in the cycle, the diameter of the insertion tube (3.8 against 4.4 mm sounds like little and is not) and the time taken.

What to expect: a short, strong cramping pain at the moment when the tube passes the cervix, then a dragging pain like strong period pain which eases over some hours. Some women take the rest of the day off; many go back to work. A painkiller an hour beforehand makes sense and is discussed with you. Bring someone with you if you would prefer that.

The first weeks and the checks afterwards

In the first days afterpains and spotting are normal. Baths, swimming and tampons are not recommended for the first week, because the cervix is still slightly open; showering is of course possible.

A check takes place four to six weeks after insertion, and yearly after that. Ultrasound shows whether the coil is still in the right place – it can move or be expelled, most likely in the first months and most likely during a period. This happens in two to five out of a hundred women. You can also feel for the threads yourself from time to time; if they can suddenly no longer be found, or are noticeably longer, an appointment is worthwhile.

Risks you should know about

• Perforation of the wall of the uterus during insertion: rare, of the order of one in a thousand, and if recognised in time mostly without consequences. Commoner shortly after a birth and while breastfeeding – which is why one usually waits twelve weeks there.
• Ascending infection: somewhat more likely in the first three weeks after insertion and not afterwards. The cause is not the coil but the possibility of carrying an existing infection upwards – against which the consultation appointment with its swabs protects. Fever, increasing lower abdominal pain or foul-smelling discharge in the weeks afterwards belong investigated the same day.
• Ectopic pregnancy: if pregnancy occurs despite the coil, it lies outside the uterus more often than usual – not because the coil causes that, but because it prevents implantation in the uterus particularly well. In absolute terms the risk with a coil is lower than with no contraception at all.
• Cysts on the ovary: somewhat commoner, mostly harmless and disappearing again without treatment.

What it costs

The practice is a private practice. The price for the insertion appointment covers the whole package: the examination, the ultrasound, a pregnancy test, the wet mount, the medical preparation, the insertion and the coil itself. Jaydess costs €500, Kyleena €600 and Mirena €750. The preceding contraception consultation with swabs is charged at €250.

Calculated over the time in place, the most expensive coil is the cheapest: Mirena costs around €94 a year over eight years, Kyleena €120 over five years, Jaydess €167 over three. Which one fits is nevertheless decided not by the price but by size, hormone dose and by what is meant to happen to the bleeding. All the amounts are on the page fees.

You submit the invoice to your health insurance fund, which reimburses 80 per cent of the corresponding public tariff – that is, 80 per cent of what the same service would have cost with a contracted doctor, not 80 per cent of the fee. The difference stays with you. Contraceptives themselves are not covered by public insurance in Austria. If you are insured outside Austria, the route is set out under health insurance and reimbursement.

Removal and afterwards

Removal takes seconds: a short pull on the thread, the coil folds its arms in and slides out. It hurts considerably less than insertion. Fertility returns immediately – unlike after the three-monthly injection there is no delay. Pregnancy is possible in the very first cycle afterwards.

Anyone who wants to continue with contraception can have the new coil inserted at the same appointment. Anyone who wants to conceive should think about folic acid beforehand: four weeks before conception, not afterwards.

Three ideas that persist stubbornly

“A coil is only possible if you have already given birth.” That was the teaching of the 1980s and is outdated. With the small models and thin insertion tubes it is well suited to young women and women who have not given birth; the professional bodies expressly recommend it there too.

“The hormonal coil makes you put on weight.” In the licensing studies the development of weight did not differ from that without hormones. What many experience is an effect of the passing years, not of the coil – which does not make the annoyance any smaller but locates the cause elsewhere.

“It causes an abortion.” The most important mechanism is the thick cervical mucus; as a rule fertilisation does not occur in the first place. Anyone asking this question for reasons of belief gets it answered here at length rather than brushed aside.

What happens next

If you are considering a hormonal coil, the next step is the contraception consultation – that is where it is decided which model comes into question and when the insertion appointment sensibly falls. Arranging an appointment, or get an overview beforehand: coils in overview, coil comparison and contraception comparison.

The manufacturers' patient information leaflets, translated into English in full, are on the pages for Jaydess, Kyleena and Mirena. The authoritative texts are the German originals reproduced on the German pages.