Methods of contraception work in a variety of ways by affecting the processes of ovulation, fertilisation or implantation. Interestingly about half of all UK pregnancies are unplanned despite around 75% of women between the ages 16-50 using some form of contraception. About 20% of the unplanned pregnancies are aborted. Effective use of contraception therefore is vital in helping to protect the health and future fertility of women who would otherwise contemplate abortion.
Many factors need to be considered when providing contraceptive advice:
- Age of the woman
- Obstetric history of the woman
- Personal opinions and beliefs of the woman
- Side effects of contraceptive methods
- The woman’s family plans
Sterilisation of either partner is used by about half of couples in the 40s or older. Women in the 30s or younger tend to favour the contraceptive pill.
The ‘Pearl’ index is used to measure the effectiveness of each method of contraception. It is calculated by taking the number of unplanned pregnancies that would arise from 100 women using that form of contraception for a year. Two figures are sometimes quoted, one is for ‘perfect’ use (so if 100 women used the method perfectly as prescribed for a year) or ‘typical’ use.
Many couples calculate fertility and when this is done properly (taking into account cycles, body temperature and vaginal secretion data) it can be as effective as barrier methods. The benefit to this method is that it uses no hormones and is particularly appealing to Christian women as it does not work by preventing implantation.
When used correctly, condoms are over 98% effective, but this is still less than hormonal methods. Latex free condoms are as effective as those that are latex. STDs can be transmitted if the condom is used improperly. Condom use can reduce the risk of transmission of HIV, syphilis, Hep B, HPV, herpes simplex virus, Chlamydia, gonorrhoea, and trichonionas vaginalis.
If a condom fails, emergency contraception may be considered; however, it is equally important to consider the risk of STDs being transmitted. In this case, information must be offered and guidance on testing. Spermicide is not normally recommended with condoms.
Fraser competence criteria indicates that children under the age of 16 can be given contraception advice without their parents’ knowledge if they are deemed to be mentally competent to make an informed choice. The criteria requires that a child must be able to understand the advice, if the patient cannot be persuaded to involve their parent/guardian, if the child is likely to continue having sexual intercourse regardless of contraceptive status, if the child’s health may be adversely affected by withholding advice or treatment, or it is in the best interests of the child to have access to have advice or treatment without the knowledge or consent of their parent/guardian. The child in this situation must be made aware that confidentiality is not complete, as if there is reason to suspect the child has been coerced into sex or is being exploited or maltreated other agencies may need to be informed.
Advice and guidance of sexual health and contraception is available form practice staff, GUM clinics, sex education in school or youth groups or sexual health/family planning clinics.
The first-line contraceptive for pre-menarche children is the condom, however the contraceptive pill may in some cases be used, if there are no medical contraindications other than age.
Hormone Treatment Interactions
Some combined oral contraceptives (COC) have been proven to be effective at treating acne vulgaris; Cilest, Yasmin, and Marvelon may also be effective, although results vary. Dianette is often used to treat acne but is not currently licensed as a contraceptive.
The contraceptive pill may be used with anti-fungals such as fluconazole, itraconazole and ketoconazole. Griseofulvin however, is not compatible with the contraceptive pill or patch.
The contraceptive pill does not reduce the efficacy of antibiotics, however, in some cases, an antibiotic can decrease the efficacy of the contraceptive. Therefore women are advised to use condoms while they are undertaking a short course of antibiotics, as well as for 7 days after the course has ended.
COCs, contraceptive patches and rings and progestogen only pills (POPs) should not be used if the patient is taking drugs to induce liver enzymes such as rifampcin, many retro-virals or some anti-convulsants. COCs and contraceptive patches can generally be used if the patient is on long term antibiotics which do not induce liver enzymes.
Condom use is advised to prevent transmission of HIV.
St John’s Wort may decreases the efficacy of COCs and the combined contraceptive patch. If a patient has a personal history of DVT, they would be at high risk if they were to have the pill, patch or ring. Likewise, hormonal contraceptives are contraindicated in those who:
- Have a BMI greater than 40kg/m2
- Are breastfeeding at less than 6 weeks post partum.
- Have multiple risk factors for CV disease (smoking, obesity, diabetes, hypertension).
- Uncontrolled hypertension greater than 160/95 (either systolic or diastolic).
- Have vascular disease including IHD, intermittent claudication, hypertensive retinopathy, TIA, or cerebrovascular disease, VTE, high risk of VTE (including prolonged stasis – surgery, thrombogenic mutation, Raynaud’s disease with lupus anticoagulant)
- Valvular or congenital heart disease if complicated by pulmonary hypertension, AF, or subacute bacterial endocarditis, migraine with aura, or migraine without aura (if 35 or over), gestational trophoblastic neoplasia, breast cancer in the last 5 years, diabetes with neuropathy, retinopathy or vascular disease or greater than 20 years’ duration, cirrhosis of the liver or liver tumours.
Pain control is advised before fitting an IUCD, which is effective for at least 5 years.
The risk of ectopic pregnancy is reduced with an IUCD. This form of contraceptive may increase the risk of pelvic infection for 3 weeks following fitting, but antibiotic prophylaxis is not generally recommended.
Fertility generally returns after an IUCD has been removed. IUCDs have a less than 1% failure rate, and most failures are caused by expulsion of the device, this is most common in the first year of use and has a 1:20 risk of occurring.
Bleeding to some degree is likely within the first 6 months of fitting. If bleeding occurs after 6 months, medical guidance ought to be sought.
Uterine perforation occurs in less than 0.1% of insertions.
Fitting must be instructed by a professional according to manufacturer’s guidance. They should be used with spermicide, and due to their latex material ought not to be used with oil-based preparations as this can damage the latex. The cap can be inserted any time prior to intercourse. More spermicide may need to be applied if sex occurs more than 3 hours post application. The cap must be left in situ for 6 hours post intercourse, and must be removed within 30hours of the insertion. The silicone cap ‘FemCap’ can be inserted for 48 hours. After use the cap must be washed and dried carefully.
Contraceptives and Migraine
Women with migraines with aura may use IUCDs, barrier methods and natural methods, they may with caution use POP, progestogen only patches and injections and Mirena, however these may need to be discontinued if a patient develops migraine with aura while using them. COCs, the vaginal ring and combined contraceptive patch should not be used for patients with migraine with aura.
For women with non-migraine headaches, COC, combined contraceptive patch, POP progestogen only injections, copper IUCDs and Mirena IUCD, barrier methods and natural methods are all recommended although if patients develop non-migraine headaches while on combined oral contraceptives; may need to employ caution if wanting to continue with COC or combined contraceptive patch.
For patients with a past history of migraine with aura can use copper IUCD, barrier methods and natural methods. POPs, progestogen only implants and injections, and Mirena coils can generally be initiated but COC, combined contraceptive patch and ring, however, are not normally recommended.
This works during the first six months post partum as long as the woman is fully or almost fully breastfeeding and if there is complete amenorrhoea. This method has a higher failure rate than other methods.
Other Post-Partum Contraception Methods
Breastfeeding mothers who are less than 6 week post partum can also use POP, PO implants, copper IUCDs and Mirena as well as barrier methods (IUCDs ought to be fitted from 4 weeks post-partum).
Progestogen only injections can also usually be used. IUCDs are not generally recommended from 48 hours post partum to 4 weeks post partum. COC and CC patches are not suitable post partum. Natural methods can be used if used previously, a new user would need to wait until her periods had restarted.
Male and female sterilisations are as effective as each other; men ought to be advised that another form of contraceptive needs to be employed until azoospermia is confirmed. (This involves two semen samples 12-16 weeks apart being sperm-free).
Sterilised women should continue with contraception until their first period post-procedure unless advised otherwise.
There is greater risk of complication in female sterilisations than male.
This method is particularly suitable for women needing treatment for menorrhagia, although altered bleeding patterns are common.