What actually happens at a coil fitting

Written by Dr Shivani Malhotra, MBChB, MRCGP, GP, Aarva.

A coil fitting is a short procedure in which a doctor places a small T-shaped device inside the womb through the vagina and cervix. The fitting itself usually takes around five minutes, within an appointment of about 30 minutes that includes a conversation, a check that it is safe to go ahead, and time to rest afterwards. Most women feel cramping during the fitting, which settles over the following hours or days.

If you are considering a coil fitting in Sutton Coldfield, this guide explains each step so there are no surprises. It sits within our wider women’s health service.

Which types of coil are there?

There are two main types, and the choice between them shapes much of the conversation beforehand.

• The copper coil (IUD) contains no hormones. It works from the moment it is fitted and, depending on the type, can last between 5 and 10 years. Some women find their periods become heavier or more painful with it, particularly in the first few months.
• The hormonal coil (IUS) releases a small amount of hormone into the womb. Depending on the type, it lasts between 3 and 8 years. Periods often become lighter, and some women stop having them. It is also a recognised treatment for heavy periods, which we cover in heavy periods: when to investigate, not just manage.

Both are more than 99% effective at preventing pregnancy. Neither protects against sexually transmitted infections.

What happens before the fitting?

Before anything is fitted, a doctor will talk with you about your health, your periods, your contraception history and what you want from a coil.

We will check that you are not pregnant. A coil can be fitted at any point in your cycle as long as pregnancy can be reasonably ruled out, which usually means you have used reliable contraception or not had unprotected sex since your last period. If there is any doubt, a pregnancy test is done and the fitting may be rescheduled.

Depending on your circumstances, we may suggest testing for sexually transmitted infections first, because an untreated infection can increase the risk of pelvic infection after a fitting.

Eat normally on the day. If over-the-counter painkillers are suitable for you, taking your usual dose about an hour before can help with cramping afterwards.

Related readingHeavy periods: when to investigate, not just manageRead the article →

What happens during a coil fitting, step by step?

1. You undress from the waist down, with a sheet to cover you, and lie on the couch. A chaperone is offered.
2. The doctor gently examines you with two fingers to feel the size and position of your womb.
3. A speculum is inserted, as in a smear test, so the cervix can be seen and cleaned.
4. Local anaesthetic may be offered to numb the cervix. Ask about this if you are anxious.
5. The cervix is held steady and a thin instrument measures the length of the womb. This is often the most uncomfortable moment.
6. The coil is passed through the cervix in a narrow tube, and its arms open inside the womb.
7. The threads are trimmed so they sit just inside the vagina, and the speculum is removed.

You can ask the doctor to pause or stop at any point, and you will be told what is about to happen before it happens.

Does a coil fitting hurt?

Experiences vary. Some women describe a strong period-type cramp for a minute or two; others find it more painful. Women who have not given birth vaginally, or who have painful periods, may feel more discomfort.

Some people feel faint or light-headed as the cervix is handled. This is a common reflex and passes with rest.

What should I expect afterwards?

• Cramping for a few hours to a few days, usually helped by painkillers and a hot water bottle.
• Spotting or irregular bleeding, which can continue for several weeks, and sometimes for three to six months with a hormonal coil.
• A follow-up check is usually advised after your next period or around six weeks, to make sure the coil is settled.

A hormonal coil works straight away if fitted in the first seven days of your cycle. Otherwise, use condoms or avoid sex for seven days. A copper coil works immediately.

We will show you how to feel for the threads so you can check they are in place, ideally after each period.

What are the risks?

• Infection: a small increased risk in the first three weeks after fitting.
• Expulsion: around 1 in 20 coils are pushed out by the womb, most often in the first few months.
• Perforation: around 1 in 1,000 fittings, the coil passes through the wall of the womb. This is rare but may need surgery to remove it.
• Pregnancy: very unlikely, but if it happens with a coil in place there is a higher chance it is ectopic, meaning outside the womb.

When to see a doctor sooner

Contact a doctor promptly, or call NHS 111, if after a coil fitting you have:

• pain in your lower tummy that is getting worse rather than better, or pain during sex
• a high temperature, or unusual or smelly discharge
• very heavy bleeding, or bleeding that is not settling
• threads you cannot feel, threads that feel longer, or you can feel the hard part of the coil
• a positive pregnancy test or a missed period

Call 999 or go to A&E if you have sudden, severe pain in your tummy, pain in the tip of your shoulder, or you feel faint, particularly if you could be pregnant. These can be signs of an ectopic pregnancy, which is an emergency. If you cannot feel your threads, use condoms until the coil has been checked.

This list is not exhaustive. If you are not sure about something, see a doctor.

If you are thinking about a coil, or you are unsure which option suits you, the first step is a conversation with a doctor. Book a consultation, or if you are not sure where to begin, find your starting point.

This article is general information and does not replace a consultation with a doctor.