Keeping up to date on contraception
Dr Linden Ruckert interviews community gynaecologist Dr Jo Power of the Margaret
Pyke Centre about the latest developments
hat is your experience of Implanon?
Our experiences have been very positive. This is an extremely effective contraception with no failures in the trials to date. It provides progestogen at very low and steady doses so it has minimal metabolic effects. It is a useful choice, particularly for women with medical problems such as diabetes or hypertension. It is also an anovulant so it is suitable for women who have had past ectopics or dysmenorrhoea.
In terms of tolerability, the main side-effect, as you would imagine, is irregular bleeding. In the pre-marketing trial 18 per cent of women had frequent or prolonged bleeding which was problematic, 35 per cent had normal cycles and 21 per cent had amenorrhoea. The other 26 per cent had irregular but infrequent spotting.
Having had a bleeding problem with a previous progestogen method is not necessarily predictive of problems with Implanon.
The incidence of other side-effects is minimal as there is such a low systemic dose but might include acne, breast tenderness or weight gain.
Removal is simple; it is a single rod and mean removal time is 2.6 minutes. It lasts three years but early changing might be appropriate in the very obese our cut-off at this centre is 100kg.
In women who do have irregular bleeding, after excluding other causes such as chlamydia, you may get a more acceptable bleeding pattern following a short course of oestrogen, for example a couple of months of a COC such as Marvelon or a natural oestrogen.
Where does Gynefix fit in as an IUCD choice in practice? Are there any big disadvantages?
It is effective in the hands of experienced operators, but there is a learning curve to fitting this as the knot has to be effectively secured in the myometrium. With experienced fitters the risk of expulsion is less than for framed devices. Because it's a frameless device it is much more flexible and more suitable for women with distorted uterine cavities, such as women with fibroids or women with a small cavity where a conventional framed device may cause dysmenorrhoea.
Other groups it would be suitable for are those with increased risk of expulsion, such as those who have expelled a framed device, or women who have had pain or dysmenorrhoea with a framed device although Mirena IUS might also be suitable.
It has been suggested to be more suitable for nulliparous women who may have smaller uterine cavities but there is no definite data that the side-effects are fewer than conventional copper coils, so it wouldn't be my first choice, unless a women had the problems noted above.
There was a recent paper in The British Journal of Obstetrics and Gynaecology1 suggesting IUCDs per se affected fertility. Should a nullipara ever have one?
The article compared return to fertility among nulliparas after discontinuing contraception. In this study long-term IUCD use was associated with a delay in childbirth compared with those stopping COCs or barrier methods.
The results have not been reproduced by other studies and there are several possible confounding factors in this paper including age, smoking habits, previous attitudes towards fertility (on enrolment nearly twice as many women in the IUCD group reported not wanting children) and especially the number of reinsertions.
The study was done at a time when most IUCDs were licensed for two or three years, so these women had several reinsertions at a time when there was no pre-insertion screening or treatment with antibiotics. We know from the major 1992 WHO study2 that there is an increased risk of infection at the time of each reinsertion and this may be the cause of any infertility problem rather than the IUCD per se.
It does not represent current practice so may not be applicable. IUCDs are useable in nulliparas with the usual selection through careful counselling and provisos to prevent infection.
What are you using now the Cu T380S has been withdrawn?
We are using T-safe Cu 380A which is also licensed for eight years. There is a need to practise using the introducer which is different you need to feed in the arms of the coil. In women over 40 an IUCD can be left until the menopause but it is worth mentioning that this is not true of an IUS. It must be replaced at the usual five-year frequency for contraceptive efficacy as no one knows how effective is a frameless device depleted of progestogen.
Yasmin has just been launched with a new progestogen. What are the advantages and who should we be prescribing it for?
Yasmin has a new progestogen called drospirenone which has antimineralocorticoid and antiandrogenic actions. It has been shown to be beneficial for patients with acne and might also help hirsutism. As far as I know there is no data looking at effect on hirsutism, although one might expect it to be beneficial. Also it's been shown to have no unfavourable effect on weight.
Women followed up for two years initially had a small fall in weight. This may be due to diuretic effect (equivalent to taking 25mg spironolactone daily) but at the moment it is not possible to say why this happens,
There is not enough data available at the moment to comment on deep vein thrombosis (DVT) but as it is oestrogen-dominant one would expect it to have a similar risk to 'third-generation' progestogens. A recent BMJ report3 noted that Dutch GPs had been concerned about this risk but currently available data does not show the observed DVT risk to be different to other COCs.
It appears to date to have no adverse effect on blood pressure probably due to the antimineralocorticoid effect of drospirenone. It may be suitable as an alternative to or a follow-on from Dianette.
I understand there is a new anovulant POP on the way and it has already been used at the Margaret Pyke Centre. What is your experience of it?
Cerazette is a new POP which contains desogestrel. It is an anovulant POP so about 98 per cent of cycles compared with 40 per cent in other POPs are anovulant. This gives it the advantage that it can be used for women who have had a previous ectopic or pain with ovulation. Initially there is actually more irregular bleeding but in the longer-term a greater number of women are amenorrhoeic.
After nine months' use, about half of women in the trials were amenorrhoeic or had infrequent bleeding. Prolonged or frequent irregular bleeding is likely to remain a fairly frequent side-effect. It is much more efficacious than other POPs; it has an efficacy comparable with the COC. It is licensed with a three-hour rule for forgetting the pill but it is likely to be effective for longer than this.
Mirena has been a huge success. Are there other IUS devices on the way?
Fibroplant (the name of this product will probably be changed before marketing) is such a device but it is unlikely to be available for several years. It uses a frameless device similar to the Gynefix to deliver progestogen. It provides a slightly lower dose of levonorgestrel than Mirena so may cause fewer hormonal side-effects. It also may be suitable for some distorted uterine cavities, such as some cases of fibroids, or for women with previous expulsion of an IUCD or Mirena.
We have transdermal HRT. Are contraceptive hormones likely to be provided this way?
A new option is Evra, a transdermal contraceptive patch that is due to get a licence in the US this year and early in 2003 in the UK. It is a seven-day patch; patches are worn for three weeks then there is a patch-free week and a withdrawal bleed.
It gives similar systemic levels of hormone to Cilest and although it has no definite metabolic advantages in the studies it does appear to lead to better compliance than the oral COC and avoids the effects of gastrointestinal disturbance on drug absorption. It also avoids the peaks and troughs of oral doses and it would appear the serum concentration of hormone is maintained up to 10 days after a patch so there is a two-day leeway in being late to change the patch.
Are male contraceptives imminent?
No although there is a lot of research going on. The most promising area seems to be gonadotrophin suppression with progestogens and testosterone.
Several studies are looking at combinations of these, for example daily oral desogestrel with monthly intramuscular testosterone ester. Volunteers in the studies in Edinburgh are very positive; and in the surveys organised by the Edinburgh Research Network the overall anticipated acceptability of a male systemic contraceptive was 60 per cent.
IUCDs are useable in nulliparas with the usual selection through careful counselling and provisos to prevent infection~
There are no contraceptives for males imminent,
but there is a lot of research going on~