Members Evidence Request - Supporting Clinical Practice

The Clinical Effectiveness Unit (CEU) provides an evidence-based enquiry service for FSRH members. The CEU will conduct a literature review and summarise the available evidence in relation to a particular medical condition and/or contraceptive method.

Recent Questions and Answers that have been submitted to the CEU can be seen below. Please note, the full answer includes references to more information and guidance.


To gain access to the enquiries service, please log in to ‘My FSRH’ and click on ‘My Clinical Enquiries’ to search for questions or submit your own question. This service is available to current FSRH members. If you are an FSRH member and have not yet created your ‘My FSRH’ account, please click the ‘Register’ button on the top right of this website and follow the steps to gain access to your account.

Example Question One

Can a woman in her mid 30s with Von Willebrand's disease (mild), have a Mirena inserted? Would it be recommended to be fitted at a hospital rather than GP setting? 


Von Willebrand’s disease (VWD) is a common inherited bleeding disorder in which certain proteins—von Willebrand factor (vWF) and factor VIII—are deficient or defective and thus interfere with haemostasis. Individuals with this condition may experience excessive bleeding following injury or medical procedures, long-lasting nose bleeds, and anaemia. Women with VWD can suffer from very heavy menstrual bleeding.[1,2] Those with the mildest form of VWD, Type 1, are not prone to spontaneous bleeding but are likely to experience excessive bleeding with any trauma.[3]

The CEU conducted a review of the available literature and found limited evidence relating to levonorgestrel intrauterine system (LNG-IUS) insertion for women with VWD. A number of studies discuss the benefits of LNG-IUS for women with VWD, but only a handful provide any detail of the insertion procedure.

In a 2004 study[4] of 16 women with inherited bleeding disorders, the 13 women with VWD received desmopressin (DDAVP) for haemosatic cover prior to insertion. LNG-IUS were inserted using local anaesthetic and the authors did not report any complications. In a 2013 study[5] of 20 women, 12 of which had Type 1 VWD, haemostatic cover was provided for only 2/23 insertions: 1 woman with VWD received tranexamic acid and 1 haemophilia A carrier received recombinant factor VII. The authors stated that there were no immediate complications and no bleeding associated with insertion. In a 2017[6] study of 13 women with bleeding disorders, 12 of which had VWD, anaesthesia with “periprocedure hemostatic therapy” was used prior to LNG-IUS insertion and the authors stated there were no complications.

A 2007 review[7] of LNG-IUS use for women with bleedings disorders mentioned a 2006 study[8] which the CEU was unable to access. According to the review, insertion was performed without hemostatic cover in 13 women and there were no complications related to bleeding. The authors further comment that tranexamic acid administered one hour before insertion and routinely over the course of the following day would be sufficient.

They importantly state that liaison with a woman’s haematologist is essential.

Based on the dearth of guidance or evidence regarding LNG-IUS insertion in women with VWD, the CEU recommends discussing with the woman’s haematologist and/or local haematology prior to attempting LNG-IUS insertion.

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Example Question Two

For which contraceptives is there evidence that their use reduces the incidence of Bacterial Vaginosis? 


The CEU conducted a review of the literature to determine the risk of bacterial vaginosis (BV) with various types of contraception.

Combined hormonal contraception (CHC):
Seven studies were identified that considered CHC and BV risk. A 2013 systematic review found that CHC reduced BV risk by 10-20%.(1) The odds ratio (OR) for women using CHC developing BV compared with women using non-estrogen containing contraception or no contraception ranged from 0.4-0.66 in four observational studies.(2-5) A meta-analysis of 55 studies found an OR of 0.73 (95% CI 0.68-0.78) for women using CHC.(6) One robust randomised controlled trial (RCT) of 404 women treated for BV found those using CHC were half as likely to experience recurrence than women not using CHC.(7) This study adjusted for frequency and type of sexual activity, condom use, and history of BV.

Oral Contraception (OC):
Five observational studies evaluated “OC” of unknown formulation and found ORs for women using OC developing BV compared with women using other or no contraception developing BV ranging from 0.43-0.86.(8-12) When omitting the finding with no statistical significance, the range narrows to 0.43-0.76.

Progestogen-only contraception (POC):
The aforementioned meta-analysis of 55 studies included 13 that examined POC use and determined that women who used POC had an OR of 0.69 (95% CI 0.59-0.80) for developing BV.(6) The 2013 systematic review found that progestogen-only injectable contraception (DMPA) reduced risk of BV by 18-30%.(1) One observational study(2) found that the OR for the progestogen-only pill was 0.42 (95% CI 0.20-0.88) and another(10) found an OR of 0.64 (95% CI 0.53-0.76) for DMPA/progestogen-only implant. Both study groups were compared with women using non-hormonal or no contraception.

Barrier contraception:
A 2007 systematic review and meta-analysis found that women using condoms reduced their BV risk by 20% (risk ratio [RR] 0.8, 95% CI 0.8-0.9) compared with those not using condoms.(13) Seven observational studies estimated the reduced risk as 20-70% (OR/RR/hazard ratios 0.3-0.8).(4,9,12,14-17)

Intrauterine contraception (IUC):
Four observational studies(9,12, 18,19) found a significantly increased risk of BV for women using IUC compared with women not using IUC (ORs from 1.46-2.98) while one study found no association between BV and IUC use.(4) One study examining cervical smear samples received at a pathology department found that BV was 12% more common in women who used IUC.(20)

While the CEU does not consider spermicide to be reliable contraception, it is important to note that two studies considered its use in relation to BV risk. One observational study(5) found that spermicide (type unspecified) halved the risk of BV, but the results were not statistically significant (OR 0.5, 95% CI 0.2-1.5). Another observational study(21) found that nonoxynol-9 had a dose-dependent effect on BV prevalence, with more episodes of usage per week leading to a higher risk of BV (OR 2.3, 95% CI 1.1-4.7). The authors did not adjust for potential confounding factors such as number of partners or condom use, which may have influenced the results.

The CEU recommends that there is evidence to suggest that non-intrauterine hormonal contraception as well as condoms can reduce the incidence of BV. This includes long-acting reversible contraceptive (LARC) methods such as the progestogen-only implant and DMPA, which are more effective than CHC/OC with typical and perfect use.(22)

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Example Question Three

Is the contraceptive implant a suitable method for a 20 year old patient on peritoneal dialysis (due to IGA nephropathy) - will its efficacy be affected?


The CEU sought expert advice from renal physicians, who confirmed that there is very little evidence on the topic of contraception for women on peritoneal dialysis. Numbers of women of reproductive age who are on peritoneal dialysis are small.

Regarding effectiveness:

One small case control study(1) considered ten women (five on peritoneal dialysis and five controls) given a 35 mcg ethinyl estradiol/1 mg norethindrone combined oral contraceptive (COC). The study found that progestogen clearance was unchanged between cases and controls but that with multiple doses of COC dialysis patients appeared to have decreased clearance of EE compared with the controls (p = .02). The authors suggest that their findings indicate that women may be given low-dose COC. It is of interest that progestogen clearance was not seen to be affected by dialysis. However, this is a very small study and ovulation and/or pregnancy outcomes have not been studied.

There is no evidence that progestogen-only contraception should be contraindicated in renal disease.

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Please note: The advice given by the CEU should be considered as guidance only and is meant to be used alongside clinical judgement to guide clinical practice or policy. Questions that are a matter of clinical judgment and not evidence should be directed to local sexual and reproductive health leads.