Contraception: an update on implants and emergencies
In the second of his series, Professor John Guillebaud details the latest advice on implants, IUDs and emergencies
Impanon is a single 40mm x 2mm subdermal rod releasing etonogestrel – the biologically active metabolite of desogestrel – over three years. To date its effectiveness when actually inserted, assuming the insertion is not too late in a conception cycle, is unmatched by any other method.
In studies, mean insertion and removal times were well under five minutes. Special insertion training is vital. Frequent or prolonged bleeds affect around a fifth of users at one year. But there are no current worries over low estradiol levels (see below), so the high amenorrhoea rate is a bonus!
If put in too deep removal can be complex. Practitioners should contact Organon for advice about such cases and ultrasound guidance.
If irregular bleeding is unacceptable consider a trial of a suitable 20-30µg COC (if not contraindicated) for two-three cycles. Mercilon contains the same progestogen as Implanon and usually controls the bleeding while the tablets are being taken, with withdrawal bleeds.
Thereafter the woman may (or may not) achieve an acceptable bleeding pattern, though it always goes back to being less regular than on the COC. If the combined pill is contraindicated, in selected cases it is acceptably safe to use a similar cyclical course of a natural estrogen, preferably transdermally.
The blood levels of etonogestrel were lower in obese women and it has been suggested that in those over 100kg it may be appropriate to discuss replacing their Implanon early. But there were no failures at all in the pre-marketing trials, so if a 100kg woman is amenorrhoeic – which suggests continuing anovulation – she may continue with the implant to the end of the third year. Under 100kg I would not even discuss the point, unless raised by the patient.
Enzyme inducers lower the blood levels of etonogestrel, so the manufacturer recommends 'an additional contraceptive' but not two Implanons. The obvious progestogen-only pill as the chosen added method would be Cerazette, though on a named-patient basis (see p141 of ref1 or p535 of ref2) as this use is unlicensed. Condoms or Delfen foam are other options.
But if the woman is to be on an enzyme inducer long-term Mirena might be a better as well as a cheaper choice.
Depot medroxyprogesterone acetate (DMPA)
The injection frequency is 150mg every 12 weeks whether or not a woman is on an enzyme-inducer.
For late injections, I advise:
l Up to seven days late – give next dose, plus condoms for the next seven days
l Eight-14 days late, pregnancy test negative – give next dose with emergency contraception (if sexually exposed), plus condoms for next seven days
l More than 14 days late – usually no emergency contraception, and delay next dose until there have been 14 days of abstinence since last sex and pregnancy test is negative.
Much uncertainty persists about how long to use DPMA. My own protocol is cautious from the start if, and only if, there are strong risk factors for osteoporosis or arterial disease. Otherwise DMPA is a useful method for five years' use, after which switching to another long-term method is usual.
If the woman wishes to use it for longer, even much longer, it is as always her right to decide to do so, after counselling about the uncertainty – remembering it is clearly safer overall than the very acceptably safe COC – and discussion of all the new alternatives.
Intrauterine devices (IUDs)
The banded T-Safe Cu 380A is the first choice device unless an alternative is specifically indicated. The Multiloads are without any established advantages and Schering no longer markets the ineffective Nova-T 200.
Loading the T-Safe Cu 380A is a fiddle, using the little plastic loading capsule. Once the device is in the inserter tube, it is best to grasp the threads firmly at the other end: otherwise the capsule may take the device out again when removed. Alternatively, use sterile gloves.
Although the side arms of the device appear to present a rather large object to get through the cervix, the loaded assembly is actually quite nicely rounded and also narrow in one diameter. It usually passes through the cervical canal surprisingly easily in all parous women.
IUDs are broadly acceptable for nulliparous women in truly monogamous relationships and for them too the T-safe Cu 380A is the first-choice IUD, though it may be necessary to dilate to Hegar 5. It costs less than £10 and is on the drug tariff. Pre-medication with a NSAID should be routine for all insertions, and local anaesthesia, at least to 12 o'clock on the cervix, should always be offered.
It really is worth the effort to make this IUD one's first choice. It is licensed for eight years (10 years in other countries, so usable in practice until then) and 50 years of research shows most complications are insertion-related. Any copper IUD fitted after the age of 40 can be used for the rest of reproductive life.
The Nova T380 might be appropriate for a nulliparous woman using it for emergency contraception and definitely planning to have the device removed once established on a new method, such as DMPA, though the Flexi-T 300 is very easy to fit and at only £8.65 would be cheaper.
But when long-term use by a young fertile woman is expected, the Nova T380 should only be used if the T-Safe Cu 380A cannot be fitted for some reason3.
Mirena intrauterine system
Mirena5 is a major advance in contraceptive technology, with the added value in relief of pain4 as well as menorrhagia – facts that are still not widely enough appreciated.
But unlike copper IUDs Mirena is not suitable for postcoital contraception and it should normally be replaced after five years.
However, for contraception (not HRT) I am prepared to leave it in place for seven years on a named-patient basis after well-documented counselling.
If being used solely for menorrhagia and/or pain control, it may stay in place for as long as those benefits are maintained.
The new inserter is a real advance but attention to detail is important. The green slider must stay initially fully in the starting (forward) position, not only when loading the Mirena into the forward end and cleating the thread, but also when first passing the loaded inserter into the fundus.
If the green slider is even slightly back from its forward position, friction at the internal os can make the outer tube slide back, releasing the IUS in the cervix!
The use of Mirena by women on enzyme-inducers is a good choice and no added precautions need be taken, given that the levonorgestrel is released locally in high local concentration and should therefore still have its normal effects. But the woman should be advised there might be a minimal reduction in efficacy.
IUDs and IUSs do not, intrinsically, increase PID risk. The essential thing is to select monogamous couples and insert only through a cervix established by screening to be pathogen-free (at least for chlamydia).
Where there has been a past ectopic, both Mirena and banded IUDs are usuable with caution6, though anovulant methods would be even better.
Failure rates for female sterilisation (18/1000 in the USA at 10 years7) are very comparable to the T-Safe Cu 380A and the IUS (14/1000 and 11/1000 failures respectively by seven years)4. In the UK the RCOG estimates the lifetime failure rate of the Filshie clip as about 3:1000, whereas it is 5:10,000 for vasectomy8.
The levonorgestrel-only method has superseded other hormonal methods9,10 and since October 2003 giving the two 750µg tablets together has been the licensed norm11. WHO concluded this prevented 'a high proportion of pregnancies even up to five days after coitus'. So use of Levonelle up to five days is acceptable but only on a named-patient basis with appropriate consent1,2.
Aside from current pregnancy the only absolute contraindications to levonorgestrel-only emergency contraception would be known severe allergy to a constituent or known acute porphyria with previous attack(s). It can be used with caution in women on warfarin provided the INR is checked post-treatment.
Professor John Guillebaud is professor emeritus of family planning and reproductive health, University College London
01 Guillebaud J. Contraception Today. A Pocketbook for GPs (5th Ed) London: Martin Dunitz, 2004, pp26-37, 42-5,73-4,86,96,102-5,141
02 Guillebaud J. Contraception: Your Questions Answered (4th Ed) Oxford: OUP, 2004, pp199-212,213,218,535 and other pages expanding on those in reference 1
03 Skjeldestad F, Rauramo I. An open randomised trial of two copper IUDs, Nova T380 versus Gyne T 380 Slimline: three-year results. Abstract 38 presented at 29th British Congress of Obstetrics and Gynaecology, Birmingham, July 2001
04 Sivin I, Stern J. Health during prolonged use of levonorgestrel 20
(g/d and the TCu 380Ag intrauterine contraceptive devices:
a multicenter study. Fertil Steril 1994;61:70-7
05 Sturridge F, Guillebaud J. Gynaecological aspects of the LNG-releasing intrauterine contraceptive device (Review). Br J Obstet Gynaecol 1997; 104: 285-9
06 Dennis J, Hampton N. IUDs: which device? (Review).
J Fam Planning and Reprod Health Care 2002; 28: 61-68
07 Peterson H et al. The risk of pregnancy after tubal sterilisation:
findings from the U.S. Collaborative Review of Sterilisation.
Am J of Obstet Gynecol 1996; 174: 1161-70
08 Male and female sterilisation. Evidence-based Guidelines No 4.
Royal College of Obstetricians and Gynaecologists (RCOG): London, 2003. See < www.rcog.org.uk="">
09 WHO. Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Lancet 1998;352:428-33
10 Guillebaud J. Time for emergency contraception with levonorgestrel alone. Lancet 1998;352:416
11 Von Hertzen H et al. Low-dose mifepristone and two regimens of levonorgestrel for emergency contraception: a WHO multicentre randomised trial. Lancet 2002; 360: 1803-10
•Cooper A, Guillebaud J. Sexuality and Disability. London: Radcliffe Medical Press, 1999. [An often neglected subject]
•Kubba A et al (eds). Contraception and Office Gynaecology: choices in reproductive health care. London: Saunders, 1999
•McPherson A, Waller D (eds). Women's Health – Oxford General Practice Series. Oxford: Oxford University Press, 2003
This article represents the personal opinions of John Guillebaud, based wherever possible on published and sometimes unpublished evidence. Health care professionals must understand they take ultimate responsibility for their patient and ensure that any clinical advice they use from herein is applicable to the specific circumstances they encounter. The author has received payments for research projects, lectures, ad hoc consultancy work and related expenses from the manufacturers of contraceptive products.