Contraception for women: an evidence based overview
BMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b2895 (Published 07 August 2009) Cite this as: BMJ 2009;339:b2895All rapid responses
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Dear Sir,
I was pleased to see a review of Contraception in this recent BMJ,
especially as I try to stay up to date with this area as I see a lot of
women of child-bearing age.
I understand that in an article with the whole of Contraception to
cover there is limited space for detailed advice of each method. I was
however suprised to see that no mention was made of the complete
contraindication of the combined contraceptive pill in women with a BMI of
40 or more, as stated clearly at the website of the Faculty of Sexual and
Reproductive Healthcare (www.ffprhc.org.uk). So checking BMI at first
"pill" prescription does not seem something that can be omitted.
Also the patient should specifically be asked about migraine/aura;
the article does state that migraine with aura is a complete
contraindication to combined contraceptive pill use, but I feel that this
should be specifically asked about before first prescription.
Also no mention was made of St John's Wort in the list of liver
enzyme inducing drugs that reduce the efficacy of hormonal contraceptives
in box 1. This herbal treatment for depression is commonly taken, and
unless the clinician asks the patient about use of St John's Wort the
patient could be given an ineffective and therefore inappropriate method
of contraception.
Your BMJ article spefically advises asking "a personal and family
history of deep vein thrombosis and measuring blood pressure at baseline"
at first "pill" check, apparently in line with WHO advice, but limiting
history/examination to just these checks appears to be unsafe and poor
practice, indefensible if the patient was to suffer a serious side effect
as a consequence. With such clear guidance available at sites such as the
BNF and Faculty of Sexual and Reproductive Healthcare we ignore such
guidance at our peril. I recommend having their website as a "favourite"
so that their excellent advice can be readily referred to in the course of
our consultations.
Yours faithfully,
Dr Nicola D Jones
Competing interests:
None declared
Competing interests: No competing interests
Dear Editor,
In their evidence-based review on contraception in women the authors
state that combined oral contraceptives, progestogen-only pills,
mifepristone, and copper bearing intrauterine devices may be used for
emergency contraception (1). A recent cochrane review showed that
levonorgestrel-only emergency contraceptive was more effective and better
tolerated than the combined oral contraceptive (2). I would like to raise
the awareness of risk of ectopic pregnancy in those taking emergency
contraception (including progestogen-only pills).
Progesterone only emergency contraceptive pill (POEC) in the form of
levonorgesterol is one of the common modes of emergency contraception
which provides women with safe means of preventing pregnancy following
unprotected sexual intercourse or potential contraceptive failure.
Levonorgesterol inhibits or delays ovulation and alters tubal motility by
decreasing peristalsis and reducing fimbrial beating (3). POEC was first
licensed for use in the UK in 1999 and became available over the counter
from January 2001 allowing easier access (4).
Ectopic pregnancy can be an unwanted complication as a result of
emergency contraception. Ectopic pregnancies are reported in about 10% of
the pregnancies in emergency contraceptives with oestrogen (5). Ectopic
pregnancies are also reported with other forms of emergency contraception.
Five cases of ectopic pregnancy (three cases after mifepristone, two cases
after split-dose of levonorgestrel) were identified among 45,842 women
(2). Twelve cases of ectopic pregnancy (out of a total of 201 unintended
pregnancies) have been reported to the Committee on Safety of Medicines
following failure of POECs (6). In 2006, I saw a 21 year old woman with a
ruptured tubal ectopic pregnancy two weeks after use of emergency
contraception in the form of a single dose of levonorgestrel (1.5gm) which
was purchased over the counter.
The above reports and my anecdotal experience highlight the need to
maintain extra vigilance for ectopic pregnancy in women who have a
positive pregnancy test and have used emergency contraception recently.
References
(1)Amy JJ, Tripathi V. Contraception for women: an evidence based
overview. BMJ 2009 Aug 7;339:b2895. doi: 10.1136/bmj.b2895.
(2)Cheng L, Gülmezoglu AM, van Oel CJ, Piaggio G, Ezcurra E, van Look
PF. Interventions for emergency contraception. Cochrane Database Syst Rev
2007;(4):CD001324.
(3)Faculty of Family Planning and Reproductive Health Care Clinical
Effectiveness Unit. FFPRHC Guidance: emergency contraception (April 2003).
J Fam Plann Reprod Health Care 2003; 29: 9-16.
(4)Camp SL, Wilkerson DS, Raine TR. The benefits and risks of over-
the-counter availability of levonorgestrel emergency contraception.
Contraception 2003; 68: 309-17.
(5)Van Look PF, von Hertzen H. Emergency contraception. Br Med Bull
1993; 49: 158-70.
(6)Woolley J. Levonelle/Levonelle-2 emergency contraception: new
advice. CMO’s Update 35, January 2003: 9
Competing interests:
None declared
Competing interests: No competing interests
Dear editor,
I welcome Amy and Tripathi’s review of the evidence regarding female
contraceptive methods, in particular the article's emphasis on the
importance of patient choice and discussion of typical use failure
rates.(1) However, much of the article addresses the hormonal
contraceptive pill, with a relatively brief discussion of more effective
methods like intra uterine devices. As the article alludes to, perfect use
failure rates represent the theoretical minimum pregnancy risk associated
with each method, while typical use figures provide patients with a more
accurate picture of their pregnancy risk. Research shows that, for women,
the most important characteristic of a contraceptive method is its
effectiveness in preventing pregnancy.(2)(3)(4) The hormonal
contraceptive pill remains the most widely used method in the UK (5) but
is associated with significantly higher typical use failure rates than
more effective methods.(6) More effective methods also have equal or
better acceptability ratings and continuation rates (both of which are a
proxy measure of how tolerable any side-effects of a method are) compared
to the pill.(6) Therefore, clinicians providing evidence based
contraception counselling should ensure women understand the lower
pregnancy risk and high acceptability of the most effective methods; then
their choice of method will be fully informed.
Sincerely,
Dr Richard Lyus
bpas
20 Timothy's Bridge Road,
Stratford Upon Avon
CV37 9BF
(1) BMJ 2009;339:b2895
(2) Fam Plann Perspect 31 (1999), pp. 168–175.
(3) Obstet Gynecol 102 (2003), pp. 709–717
(4) Am J Obstet Gynecol. 2006 Jul;195(1):85-91
(5) Office of National Statistics, Contraception and Sexual
Health 2007/08
(6) Contraceptive Technology: Nineteenth Revised Edition. New
York NY: Ardent Media, 2007.
Competing interests:
None declared
Competing interests: No competing interests
I note from this article that the relationship between intrauterine
devices and ectopic pregnancy continues to cause confusion now just as it
did when my colleagues and I reported the relevant findings in our cohort
study in 1974 (Lancet 1974, 1, 495-98).
Amy et al state that " a meta-analysis of case-control studies showed
that ectopic pregnancy is not more common in women who conceive with an
intrauterine device in place." The meaning of this statement is not clear
to me but the clinically important fact is that if a woman with an
intrauterine device in situ presents with an accidental pregnancy she is
far more likely to have an ectopic pregnancy than a woman who has become
pregnant under other circumstances. Indeed, the review cited by Amy et al
gives the increase in risk as 10.6 fold under these circumstances. The
reason for this is that IUD's are far less effective at preventing ectopic
pregnancies than they are at preventing intrauterine pregnancies. Failure
to appreciate this fact could have disastrous consequences under some
circumstances.
Competing interests:
None declared
Competing interests: No competing interests
About 25 years ago a middle aged doctor wearing a tweed suit &
pearls
refuted the argument that the diaphragm is a messy method of contraception
by reminding her then young audience that "So is sex... if you're doing it
right!"
Now I am middle aged and the diaphragm's poor press based on
misleading
evidence persists (here its failure rate is lumped together with the
cervical cap
which is, indeed, fiddly).
It is illogical that the usual method of diaphragm use is as a sort
of female
condom that is inserted only when an erection is in sight, concentration
is
poor and the vagina has become both tender and slippery! Failure rates as
low as 2.8% (1) have been found, even without spermicide when women have
used the device continuously, taking it out only when they have a shower.
My own practice has been to suggest that it is inserted every night when
teeth are brushed and removed when the teeth are brushed again in the
morning: used thus it gains added advantage as the only contraceptive
method associated with a pearly white smile!
The arguments for the current fashion towards implanting, injecting
and
inserting hormones derive more from the pricing strategies of the
companies
that produce them than risk benefit analyses but patents ran out long ago
for
safer tried and tested methods, whatever their benefits to patients.
1. Effectiveness of the diaphragm, used continuously, without
spermicide.
Ferreira AE, Araújo MJ, Regina CH, Diniz SG, Faúndes A. Contraception.
1993
Jul;48(1):29-35.
Competing interests:
None declared
Competing interests: No competing interests
Dear Sir
In 2004 NICE stated in Clinical Guideline ‘11’ that "timing
intercourse to coincide with ovulation causes stress and is not
recommended. People who are concerned about their fertility should be
informed that sexual intercourse every 2 to 3 days optimises the chance of
pregnancy [para 1.1.2.1]".
To support this (surprising) statement they cite a single paper that
refers to postal questionnaires received from 20 women in North America*.
I contacted the authors who were astonished that some of their data had
been used by NICE and J. Wilson wrote that “as a general policy, one
simply cannot support the conclusion not to use timed intercourse, and it
is hard to understand how a research finding can get misapplied so badly
as policy”.
Compared with timed intercourse, surely NICE’s ‘every 2-3 days’
advice will also be stressful, particularly as many of these attempts to
get pregnant each month will be ineffective during the infertile days. Has
a clinical trial of this important advice been done since 2004?
I understand this Guideline was adopted by the RCOG and RCN, and it
is difficult to see why these august Colleges are also (officially)
against timed intercourse whilst many fertility experts are not.
NICE is due to review this Guideline next year but I was told that as
an individual I could not challenge their statement. Nevertheless I do
feel that better evidence is needed to support the advice NICE have given
so far, about whether intercourse should be timed or not.
Yours faithfully
C B Everett cbe@obdisk.co.uk
* Kopitzke EJ, Berg BJ, Wilson JF, Owens D. Physical and emotional
stress associated with components of the infertility investigation:
perspectives of professionals and patients. Fertil Steril 1991;55:1137–43.
Competing interests:
I have co-designed a simple plastic rotary calendar calculator that, based on a woman’s menstrual pattern, will readily indicate a woman’s most fertile days every month and should reduce the stress of timing considerably.
Competing interests: No competing interests
More factors important in contraception
It was nice to read an evidence-based update about
contraception. I regretted, however, the lack of reference
to two further indicators beside the perfect use and the
typical use failure rate, one is perhaps best termed the
failed intention rate (FIR)1. Women who have pledged to come
for an IUD after an induced abortion instead of having it
fitted directly, men who promise during their wives’ second
pregnancy to undergo a vasectomy soon after delivery, and
interval tubal occlusions (TO): perhaps 50%, 35 % and 40%
missed respectively, because courage, organisation, or money
is lacking. In my opinion, because the FIR was not
considered, the review understated the value of a TO
combined with a CS. Yes, there may indeed be more cases of
regret with a CS/TO, but there will also be far less chance
of an unintended pregnancy occurring within the following 20
years. Other methods have high FIRs. A study from the US
showed that 18% of women who missed their planned peripartum
sterilisation had an unintended pregnancy within a year2.
I understand that the third and fourth generation oral
contraceptives advocated so strongly by direct media
advertising in the US cost up to $50 a month. How many of
those women who desperately cannot afford to get pregnant
again can afford these pills? This represents a loss of
$12,000 if you missed your chance of a TO during a CS at age
30.
Another indicator not referred to in the review is the hype
resistance factor (HRF). In 1994, three thousand extra
abortions were performed and many delivered extra in the UK
because of a pill scare, and a somewhat similar situation
occurred later because of concerns about Norplant. A pill
scare appears to be developing currently in the US. No-one
makes any money from a TO performed with a spare length of
suture during a CS; perhaps I am being cynical, but could
this be a factor in the lack of advocacy for this method? In
view of the problems associated with climate change, it is
time we reassessed the relative importance of the rate of
regretted sterilisation versus the rate of unintended
pregnancy. If 100 TOs performed during CS despite proper
counselling, result in 2 cases of regret so serious that IVF
is indicated, let us (the NHS) provide it irrespective of
cost. If this approach has prevented 15 unintended
pregnancies plus any subsequent offspring, then we have done
our planet and most of our patients proud. An unintended
baby in a consumer nation produces over a lifetime up to a
1000 times4 more greenhouse gas emissions than one newborn
in a very poor country. There the misery associated with
many unintended pregnancies is experienced personally,
locally and regionally. Unless that is, the overpopulation
refugees move to high income countries and also learn to
become serious consumers. Besides, having not a TO with the
CS for your third baby increases the future chance of a
maternal mortality dramatically in very poor countries.
It is often claimed that LNG-IUS are at least as good as TO
in preventing pregnancy with the advantage of being easily
reversible. But in practice? A hundred women are discouraged
from having (or are not adequately informed about) a TO
during a CS and are advised to have an IUD fitted later
instead. 75 of them have the device indeed fitted within 6
months, and of these, up to 60% have it removed within 5
years because of side-effects3. Those who still use the
method after 5 years need to have it replaced, and then
again in another 5 years. It is likely that of the original
100 women, only 15-20 will, often indeed very contentedly,
stay the whole course. The large scale combining of
sterilisation with subsidised (less windmills needed)
storage of eggs or better semen would be much more climate
friendly than, in practice, the very fallible reversible
methods of contraception 5. But we are so afraid of
regretted
sterilisation.
Wouldn’t all the money invested in “we-need-a-new-patent
oral contraceptive” (medications that are largely only
somewhat superior in their capacity to cause thrombi) not be
better employed in developing a small device* to be fitted
around each fallopian tube during a CS? These devices could
then be activated at any later timepoint upon request with
the help of a strong magnet. This would more or less solve
the problem of (the fear of) unintended pregnancy for the
30% of women with a completed family in the US who have
undergone CS. The scientist who can develop such a device
should be awarded the Nobel Prize for Peace because
increased life expectancy, continued population growth with
or without an attempt at the more equitable distribution of
resources, will no doubt end in wars. This would be the
first step towards a completely different approach to
fertility. The default situation should be: unable to become
pregnant action is required (with an electronic key?) to
become/make pregnant. With the resources available in
industrialised countries it should be possible to prevent
unintended pregnancies, just as we prevent Cholera
epidemics.
*A relay, as seen in old fashioned burglar alarms,
incorporated in an inert sleeve to be a fitted around a tube
and activated with a magnet on the abdomen would probably be
sufficient.
1. Verkuyl DAA. Commentary. Intention to treat studies
crucial for contraception research. Contraception
2009;80:234-6.
2. Gilliam M, Shawna DD, Berlin A, Zite NB. A
qualitative study of barriers to postpartum sterilization
and women's attitudes toward unfulfilled sterilization
requests. Contraception 2008;77:44-9.
3. The National Institute for Health and Clinical
Excellence (NICE), United Kingdom (2005) Clinical Guideline
no 30. Long-acting reversible contraception.
http://www.nice.org.uk/nicemedia/pdf/cg030niceguideline.pdf
4. Satterthwaite D. The implications of population
growth and urbanization for climate change. Environment and
Urbanization 2009;21:545-67.
http://eau.sagepub.com/cgi/reprint/21/2/545
5. Hopkins Tanne J (2008) Problems with contraception play
big part in unplanned pregnancies, study says. BMJ 336:
1095. doi:10.1136/bmj.39576.554699
Competing interests:
None
Competing interests: No competing interests