What you need to know about intrauterine contraception

The COVID-19 pandemic has affected almost every aspect of healthcare – but one of the deepest impacts has been on the availability of LARCs. Refreshing your knowledge on this topic might help more women to access these most effective methods of contraception

The number of prescriptions in general practice for long-acting reversible contraceptives (LARCs) fell by 17% in the first year of the COVID-19 pandemic, 2019-2020, compared to the previous year, a trend described by the Faculty of Sexual and Reproductive Healthcare (FSRH) as ‘deeply worrying’.

Another worrying trend is that the number of general practice nurses trained to fit LARCs is declining, partly because of the ageing workforce, and partly because nurses who would be interested in training are put off by the process and costs, according to a report by the Primary Care Women’s Health Forum.

If women are to avoid unintended pregnancy, it is important that they are able to access the full range of contraceptive methods, and that ‘normal service’ is resumed as soon as possible.

But what are LARCs, and why are they more effective than other methods of contraception? This article, which focuses on intrauterine contraceptive (IUC) methods, aims to answer these questions.

DEFINITION

A long-acting reversible contraceptives (LARC) is a contraceptive method that requires administration less than once per cycle or month.¹

LARCs have licensed durations of use ranging between 3–10 years, depending on the device used.² There are two types of intrauterine contraception (IUC) are available in the UK: the levonorgestrel intrauterine system (LNG-IUS) and the copper intrauterine device (Cu-IUD).

The LNG-IUS is a polyethylene T-shaped intrauterine device with a levonorgestrel reservoir around the vertical stem. The Cu-IUD is a non-hormonal intrauterine device that comes in various shapes and sizes. Most are composed of plastic with copper wire or fitted with copper bands, while some also have a central core of silver to prevent copper fragmentation.²

HOW LARCS WORK

The levonorgestrel intrauterine system (LNG-IUS) acts mainly by its progestogenic effect on the endometrium, which prevents implantation of the fertilized ovum. In addition, changes in cervical mucus inhibit the penetration of sperm into the uterus.

The LNG-IUS releases levonorgestrel (a progestogen) into the uterus after insertion into the uterine cavity, and the rate of release of levonorgestrel depends on the device prescribed and how long it has been in situ. More than 75% of women will continue to ovulate while using the LNG-IUS. The incidence of anovulation is lower with the 13.5 mg LNG-IUS than with the 52 mg LNG-IUS.

LNG-IUS only need to be replaced every 3–5 years.²

The copper intrauterine device (Cu-IUD) inhibits fertilisation by its toxic effect on sperm and ova; copper has been shown to adversely affect the motility and viability of sperm as well as the viability and transport of ova. If fertilisation does occur, the local endometrial inflammatory reaction resulting from the presence of the Cu-IUD prevents implantation. A Cu-IUD is effective immediately following insertion.

Cu-IUD only need to be replaced every 5–10 years.²

CONTRACEPTIVE EFFECTIVENESS

The most effective methods of intrauterine contraception are the levonorgestrel intrauterine system (LNG-IUS) and the T-shaped copper intrauterine devices (Cu-IUDs) with at least 380 mm2 copper and copper bands on the transverse arms.²

For the LNG-IUS when used perfectly 0.2% of women will conceive within the first year of use due to method failure.³

For the Cu-IUD when used perfectly 0.6% of women will conceive within the first year of use due to method failure.³

ADVANTAGES AND DISADVANTAGES OF LARCS

The advantages of LARCs are centred on the fact that they provide safe and effective long-term contraception (only need to be replaced every 3–10 years, depending on the device used). Normal fertility returns as soon as the device is removed. Sex need not be interrupted to use these methods as would be the case with barrier methods.⁴

Periods usually become lighter and shorter, and sometimes less painful. They may stop completely after the first year of use. They can be used:

• From 4 weeks postpartum (off-label use)
• Immediately after surgical or medical termination of pregnancy (although there is a small increased risk of expulsion).
• Whilst breastfeeding (although there is an increased risk of uterine perforation if it is inserted during lactation).
• By women of any age, and can be continued through to menopause.
• When combined oral contraceptives (COCs) are contraindicated (such as in women with migraine or venous thromboembolism).

The 52 mg LNG-IUS is effective in reducing menstrual blood loss and can be used in the management of heavy menstrual bleeding and may reduce pain associated with primary dysmenorrhoea, endometriosis, or adenomyosis. The Mirena® LNG-IUS can be used to provide endometrial protection in conjunction with oestrogen therapy for up to 5 years (off-label use).

For copper intrauterine devices there are no drug interactions, no hormonal adverse effects and they may be associated with a reduced risk of endometrial and cervical cancer.

The disadvantages of the LARCs include the fact that an internal pelvic examination is needed prior to insertion, to check that the device is suitable. A trained healthcare provider must insert and remove the device; the woman cannot do these on her own. They do not protect against sexually transmitted infections (STIs) and adverse effects may occur, such as pain on insertion, acne, headaches, unscheduled bleeding, perforation of the wall of the uterus, and expulsion of the device.²

ASSESSMENT

General practice nurses offering intrauterine contraception should hold the appropriate letter of competence in intrauterine techniques from the FSRH, or an equivalent.

If a LARC is being considered you should carry out a full medical and sexual history to assess the woman's suitability for use of the method and the woman's risk of STIs. Check the UK Medical Eligibility Criteria for Contraceptive Use to assess the woman’s eligibility.⁵

In women with heavy menstrual bleeding, consider the need for additional investigations, such as full blood count, pelvic ultrasound scan, and endometrial biopsy, prior to or at the same time as LARC insertion, particularly if other treatments for heavy menstrual bleeding have not been effective or if a woman has risk factors for gynaecological disease.⁶

If a woman attends to discuss IUC in advance of the procedure, pelvic examination is not required unless indicated by the clinical history.²

At the time of insertion, the GPN should perform a bimanual pelvic examination before inserting the IUC after first obtaining valid consent from the woman.²

In all circumstances insert the LARC at any time in the menstrual cycle if it is reasonably certain that the woman is not pregnant or at risk of pregnancy (off-label use if inserted after day 7 of the menstrual cycle). There are however differences between the use of LNG-IUS and Cu-IUD which are outlined below.

In the specific case of using an LNG-IUS and when it is inserted on days 1–7 of the menstrual cycle, no additional precaution is required.²

If however the LNG-IUS is inserted at any other time in the menstrual cycle (off-label use), advise the woman to avoid sexual intercourse or use a barrier method of contraception (such as condoms) for 7 days after insertion of the LNG-IUS.²

If starting the LARC in the postpartum period (including post caesarean section and breastfeeding) insert the device within 48 hours of delivery, or from 4 weeks after delivery if it is reasonably certain that the woman is not pregnant or at risk of pregnancy.

If starting the LARC following an abortion (all induced terminations of pregnancy [ToP] or spontaneous abortions less than 24 weeks gestation): post-surgical ToP, insert the LARC at the end of the procedure: post medical ToP, insert the device any time after completion of the second part of the termination (that is, passage of products of conception confirmed by clinical assessment and/or local protocols).

SWITCHING FROM OTHER CONTRACEPTIVE METHODS TO LARCS

Once more there are differences between the two different types of LARCs, which are outlined in detail as follows.

If switching from combined hormonal contraception (CHC) to the LNG-IUS in week 2 or 3 of the CHC cycle or day 1 of the hormone-free interval (HFI) insert the LNG-IUS immediately. No additional precaution is required provided the CHC has been used correctly for 7 days prior to insertion.

In week 1 of the CHC cycle or after day 1 of the HFI insert the LNG-IUS immediately. Advise the woman to avoid sexual intercourse or use a barrier method of contraception (such as condoms) for 7 days, or continue the CHC for 7 days. Advice for switching during the HFI may be overcautious, but there is a theoretical risk that ovulation may occur as early as day 10 after stopping CHC, before the LNG-IUS is fully effective.

If switching from a traditional progestogen-only pill (POP) to the LNG-IUS insert the LNG-IUS at any time. Advise the woman to continue the POP for 7 days, or avoid sexual intercourse or use a barrier method of contraception for 7 days.

If switching from a desogestrel POP to a LARC you can insert the LARC at any time. No additional precaution is required.

If switching from all other methods of contraception to the Cu-IUD you should insert the Cu-IUD at any time in the menstrual cycle provided that the other method of contraception has been used consistently and correctly and it is reasonably certain that the woman is not pregnant or at risk of pregnancy (except in those circumstances that would qualify for use as EC). No additional precaution is required.

If switching from a progestogen-only implant to an LNG-IUS and if the implant has been in situ for up to 3 years you should remove the implant, and insert the LNG-IUS immediately. No additional precaution is required.

If the implant has been in situ for more than 3 years but no longer than 4 years you should perform a pregnancy test. If the pregnancy test is negative and all episodes of unprotected sexual intercourse (UPSI) occurred 21 days ago or longer, insert the LNG-IUS immediately. Advise the woman to avoid sexual intercourse or use a barrier method of contraception for 7 days. If the pregnancy test is negative but UPSI occurred within the last 21 days, insert the LNG-IUS immediately. Advise the woman to avoid sexual intercourse or use a barrier method of contraception for 7 days and to take a pregnancy test no sooner than 3 weeks after the last episode of UPSI.

If the implant has been in situ for over 4 years you should perform a pregnancy test. If the pregnancy test is negative and all UPSI occurred 21 days ago or longer, insert the LNG-IUS immediately. Advise the woman to avoid sexual intercourse or use a barrier method of contraception for 7 days. If the pregnancy test is negative but UPSI occurred within the last 21 days, consider the need for emergency contraception.

Delay insertion of the LNG-IUS until pregnancy is excluded by negative pregnancy test no sooner than 3 weeks after the last episode of UPSI. Consider bridging with CHC, POP, the progestogen-only implant, or depot medroxyprogesterone acetate (if other methods are unacceptable or unsuitable).⁷

If switching from a progestogen-only injectable to an LNG-IUS: if it is 14 weeks or less since the last progestogen-only injection you should insert the LNG-IUS immediately. No additional precaution is required.²

If it is more than 14 weeks since the last progestogen-only injection you should perform a pregnancy test. If the pregnancy test is negative, insert the LNG-IUS. Advise the woman to avoid sexual intercourse or use a barrier method of contraception (such as condoms) for 7 days.²

If switching from a barrier method of contraception to an LNG-IUS on days 1–7 of the menstrual cycle you should insert the LNG-IUS immediately. No additional precaution is required.

After day 7 of the menstrual cycle you should insert the LNG-IUS immediately if it is reasonably certain that the woman is not pregnant. Advise the woman to avoid sexual intercourse or use a barrier method of contraception for 7 days.²

If switching from the copper intrauterine device (Cu-IUD) to the LNG-IUS you should remove the Cu-IUD, and insert the LNG-IUS immediately. Advise the woman to avoid sexual intercourse or use a barrier method of contraception for 7 days after insertion of the LNG-IUS. If sexual intercourse has occurred in the previous 7 days, advise the woman that the Cu-IUD should be left in place for a further 7 days from that episode and that she should use extra precautions in that time, before changing to the LNG-IUS.⁸

If switching from the levonorgestrel intrauterine system (LNG-IUS) to the Cu-IUD advise the woman to abstain from sexual intercourse or use a barrier method of contraception for 7 days before replacement in case the Cu-IUD cannot be inserted.⁸

If an existing LARC is being replaced with a new LARC you should replace the existing device with the new device at any time in the menstrual cycle. If the new device is inserted immediately after removing the existing device, no additional contraception is required after insertion. However, advise the woman to avoid sexual intercourse or use a barrier method of contraception for the 7 days before the replacement, in case the device cannot be inserted.

POSSIBLE RISKS AND ADVERSE EFFECTS OF LARCS

Possible risks and adverse effects of LARCs include: pain on insertion; pelvic pain; perforation of the wall of the uterus — this is rare (occurs in less than 2 in 1000 women); expulsion (the risk of expulsion is around 1 in 20 and is more common in the first year of use); pelvic inflammatory disease (1.6 per 1000 women-years); ectopic pregnancy (very low risk at about 1 in 1000 at 5 years); ovarian cysts (1–10% of women); and unscheduled bleeding (irregular, prolonged, or frequent bleeding may occur in the 3–6 months following insertion, but menstrual bleeding patterns tend to improve with time); weight gain; and decreased libido.

The LNG-IUS can also cause hormonal adverse effects, but these usually settle with time. Depression can also be an adverse effect of the LNG-IUS.²

INFORMATION AND ADVICE FOR PATIENTS

GPNs should discuss the mode of action, contraceptive efficacy, advantages and disadvantages, and possible risks and adverse effects LARCs.²

Advise the woman how to check for the threads and the importance of doing this regularly (for example, after every menstrual period), and that the LARC can be removed at any time if she wishes to become pregnant and there is no delay in return to fertility.

It is important that the woman is aware that the LARC does not provide protection against STIs. Only a barrier method of contraception (such as a condom) can reduce the risk of STIs.⁹

Advise the woman to seek medical advice if:

• Menstrual abnormalities (such as unscheduled bleeding) persist beyond the initial 6 months of use
• She experiences possible features of pelvic inflammatory disease (pain or tenderness in the lower abdomen, fever, or abnormal or odorous vaginal discharge), especially within the first 3–4 weeks after insertion of the LARC.²
• She has mild lower abdominal pain and ‘lost threads’, especially with a history of pain at the time of insertion. These may indicate uterine perforation.
• The device causes discomfort to her or her partner during sexual intercourse.² (The threads can be cut shorter or flush within the cervical os if they cause irritation to a partner’s penis.)

Provide information on the specific LARC which has been inserted and when it needs to be removed and/or replaced. Offer other sources of useful information and advice regarding the LARC. For example, the Family Planning Association (FPA) has a useful leaflet.

MANAGING UNSCHEDULED BLEEDING

Irregular, light, or heavy bleeding is common in the first 6 months of using a LARC. Some women will have infrequent bleeding or be amenorrhoeic after 1 year of use.¹⁰

Exclude and/or manage situations that could result in unscheduled bleeding, such as STIs, pregnancy (perform a pregnancy test), a misplaced device (if this is suspected, arrange for ultrasonography to locate the device), gynaecological conditions, such as cervical and endometrial cancer (if suspected, refer the woman using a suspected cancer pathway referral).²

Consider performing a speculum and pelvic examination for persistent bleeding beyond the first 3–6 months of use, for new symptoms or a change in bleeding after at least 3 months of use, if the woman has not participated in the NHS Cervical Screening Programme regularly, and if there are other symptoms, such as pelvic pain, dyspareunia, or postcoital bleeding.²

Consider referring the woman for a transvaginal ultrasound scan and/or hysteroscopy if structural abnormalities (such as endometrial polyps) are suspected. If no other underlying cause of irregular bleeding is suspected, and speculum and pelvic examinations are normal, the bleeding can be assumed to be caused by the LARC.²

Providing the woman has no other symptoms, reassure her that irregular bleeding is normal and is not due to the hormone 'running out'. Consider managing heavy unscheduled bleeding by treating with a combined oral contraceptive (30–35 micrograms of ethinylestradiol with levonorgestrel or norethisterone) either cyclically or continuously for up to 3 months (off-label use). If heavy bleeding remains unacceptable or if there is evidence of anaemia, consider changing to another method of contraception.¹⁰

Refer the woman to gynaecology if the cause of the bleeding cannot be determined or treated in primary care.¹⁰

MISSING THREADS

Intrauterine contraception (IUC) threads may not be visible in the vagina as a consequence of IUC expulsion, perforation of the wall of the uterus, or pregnancy, but often the cause is retraction of the threads into the cervical canal or uterus.²

If the woman cannot feel the threads of her LARC you should exclude pregnancy and perform a vaginal examination.²

If threads are not visible on speculum examination and uterine placement of the LARC cannot be confirmed clinically, refer the woman for an ultrasound scan to locate it.

Advise the woman to use a barrier method of contraception (such as condoms) or avoid unprotected sexual intercourse until it is confirmed whether or not the device is correctly in place. Consider the need for emergency contraception if sexual intercourse occurred in the preceding 7 days.⁹

If it is confirmed on ultrasound that the LARC is correctly located, it can be left in situ.

If removal is required, a thread retriever or Spencer Wells forceps can be used if you have had appropriate training and experience.²

If ultrasonography cannot locate the device, and pregnancy has been excluded, arrange for an abdominal and pelvic X-ray. If the device is extrauterine or if partial perforation or embedment into the uterine wall is suspected, refer for surgical retrieval. If the device is not located, this confirms expulsion. Offer reinsertion of a new LARC or an alternative method of contraception.²

ADVERSE EFFECTS

Pregnancy

If a woman is found to be pregnant while using a LARC seek immediate advice from a gynaecologist.¹¹

Actinomyces

Actinomyces israelii is a commensal of the female genital tract. Actinomyces-like organisms (ALOs) have been identified in women with and without intrauterine contraception (IUC), but the role of ALOs in infection in women using IUC is unclear.²

If the woman has ALOs and is asymptomatic, there is no need to remove a LARC. For women who require a replacement device, there is some evidence to suggest that immediate reinsertion or a short delay of 3–5 days is safe. If the woman has ALOs and pelvic pain you should consider removing the LARC. GPNs should also assess the woman for signs and symptoms of pelvic inflammatory disease and assess for other more common causes of pain, including STIs.²

Pelvic inflammatory disease

There is a low risk of pelvic inflammatory disease (PID), which is strongly related to the insertion procedure and background risk of STIs. The risk of pelvic infection is greatest in the first few weeks following insertion of intrauterine contraception.

If PID is diagnosed in a woman using a LARC, there is no need for routine removal of the device. Instead test for the causative organism, and start the appropriate antibiotic treatment. Consider removing the LARC if the woman wishes or if symptoms have not resolved within 72 hours. If the device is removed and the woman has had unprotected sexual intercourse within the last 7 days, consider offering emergency hormonal contraception.²

GPNs should follow up the woman 72 hours after treatment and 2–4 weeks after treatment to check for clinical improvement.

Uterine perforation

Perforation of the wall of the uterus is rare and is dependent on the skills of the clinician. There is an increased relative risk of perforation at the time of insertion of IUC in the postpartum period (within 36 weeks after giving birth) and during breastfeeding; however, the absolute risk of perforation remains low.²

If perforation is identified at the time of insertion stop the procedure, remove the device, monitor vital signs (blood pressure and pulse rate) and level of discomfort until the woman is stable.

If there is any possibility of perforation at the time of insertion or later you should arrange an ultrasound scan and, if indicated, a plain abdominal and pelvic X-ray as soon as possible in order to locate the device.²

Advise the woman to avoid sexual intercourse or use a barrier method of contraception in the interim.²

Note that mild lower abdominal pain, ‘lost threads’, and a history of pain at the time of insertion may indicate uterine perforation. The threads may remain in the vagina and may break off at attempted removal if an IUC has become embedded in the uterine wall or has perforated the cervix.²

FOLLOW UP

Consider arranging follow up after the first menses following insertion of the LARC or 3–6 weeks later, to exclude infection, perforation, or expulsion. However, it is not essential.

Advise the woman to return at any time if she has symptoms of pelvic pain, abnormal bleeding, infection, perforation, or expulsion or is unable to feel the threads of her LARC, or if she thinks that she might be pregnant or wants to change her method of contraception or her LARC is due to be changed.²

CONCLUSION

Long-acting reversible contraception has proven to be a positive therapeutic advance for many women as it is safe and effective. It is however, not without potential adverse effects and risk. However, in the hands of an experienced practice nurse it can be a highly effective method of managing long-term contraception for many women. Knowledge of the different types of IUD and IUS and how to assess each woman, provide the widest range of contraception options and advice is key to the best provision of care for women who need contraceptive services.

REFERENCES

1. NICE CG30. Long-acting reversible contraception; 2005 (updated 2019). https://www.nice.org.uk/guidance/cg30

2. Faculty of Sexual and Reproductive Healthcare (FSRH). FSRH Clinical Guideline: Intrauterine contraception; 2015 (amended 2019). https://www.fsrh.org/standards-and-guidance/documents/ceuguidanceintrauterinecontraception/

3. Trussell J. Contraceptive failure in the United States. Contraception 2011;83(5):397-404

4. NICE Clinical Knowledge Summaries. Contraception – IUS/IUD; 2021. https://cks.nice.org.uk/topics/contraception-ius-iud/

5. FSRH. UKMEC UK Medical Eligibility Criteria for Contraceptive Use; 2019. https://www.fsrh.org/ukmec/

6. FSRH. Contraception for women aged over 40 years; 2019. https://www.fsrh.org/documents/fsrh-guidance-contraception-for-women-aged-over-40-years-2017/

7. FSRH. Progestogen-only implant; 2021 https://www.fsrh.org/standards-and-guidance/documents/cec-ceu-guidance-implants-feb-2014/

8. FSRH. FSRH Guideline: Emergency contraception; 2020. https://www.fsrh.org/documents/ceu-clinical-guidance-emergency-contraception-march-2017/

9. NICE QS129. Contraception. https://www.nice.org.uk/guidance/qs129

10. FSRH. Problematic bleeding with hormonal contraception; 2015. https://www.fsrh.org/standards-and-guidance/fsrh-guidelines-and-statements/management-of-srh-issues/problematic-bleeding/

11. FSRH. Contraception after pregnancy; 2017 (amended 2020) https://www.fsrh.org/documents/contraception-after-pregnancy-guideline-january-2017/