Contraception Flashcards
(36 cards)
What would make the ideal contraceptive?
100% reversible - all except sterilisation.
100% effective - None
100% unrelated to intercourse - all except condoms
110% free of adverse side effects- None
100% protective against STIs - None
Non-contraceptive benefits - Combined pill and IUS
Low maintenance, no ongoing medical input - Implant or IUT
Male and female options - only condoms/vasectomy for men.
What is the Pearl index?
The number of contraceptive failures per 100 women years of exposure. It looks at the total months or cycles of exposure from the initiation of the product to the end of the study.
What is life table analysis?
Provides the contraceptive failure rate over a specified time-frame and can provide a cumulative failure rate for any specific length of exposure.
What is a method failure?
Pregnancy despite correct use of method by user.
What is a user failure?
Pregnancy because method not used correctly by the user.
What can minimise user failure rates?
Long-Acting Reversible Contraception (LARC) minimises user input so subsequently minimises user failure rates.
When can sex cause pregnancy?
Likely to ovulate day 12-18 of cycle.
Egg survives 24hours
Most sperm survive less than 4 days
So highest chance of pregnancy is between day 8-19.
What are some characteristics of Combined Hormonal Contraception?
Can come in pill, patch or vaginal ring form.
Combination of 2 hormones - ethinyl estradiol and synthetic progesterone.
Stops ovulation and also effects cervical mucus and endometrium.
Standard regime is 21 days with a hormone free week.
How long does the CHC pill, patch and ring last respectively?
Pill taken daily
Patch changed weekly
Ring changed every 3 weeks (can take it out for 3/24hrs).
What are some non-contraceptive benefits of combined hormonal contraception?
Regulate and reduce heavy bleeding.
Stop ovulation - may help premenstrual syndrome.
Reduction in functional ovarian cysts.
50% reduction in ovarian and endometrial cancer.
Improve acne and hirsutism.
Reduction in benign breast disease, rhematoid arthritis, colon cancer and osteoporosis.
What are some side effects of Combined Hormonal Contraception?
Breast tenderness Nausea Headache Irregular bleeding for first 3 months. Mood? Weight gain?
What are some serious risks associated with CHC use?
Increased risk of venous thrombosis - DVT, PE. Avoid if BMI > 34, previous Hx, 1st degree relative Hx under 45, thrombophilis.
Increased risk of arterial thrombosis - MI, ischaemic stroke. Avoid in smokers >35yrs, personal Hx arterial thrombosis, focal migraine, age >50, hypertension > 140/90.
Avoid if active gallbladder disease or previous liver tumour.
Increased risk of cervical cancer - data predates HPV vaccine.
Increased risk of breast cancer - back to normal after 10yrs off CHC.
What are some characteristics of the Progestogen-only pill (POP) ‘mini pill’?
Take at same time each day without a pill free interval.
Desogestrel pill - 12hr window period. Nearly all cycles are anovulant and it also affects cervical mucus.
Traditional LNG NET pills - 3hr window period, 1/3 anovulant, 2/3 rely on cervical mucus effect. 1/3 bleed free, 1/3 irregular, 1/3 regular periods.
Oestrogen free so very few contraindications.
What are some Progestogenic side effects?
Appetite increase Hair loss/gain Mood change Bloating or fluid retention Headache Ance Avoid if current breast cancer or liver tumour past/present.
What are some characteristics of the injectable progestogen?
Aqueous solution of the progestogen depomedroxyprogesterone acetate Depoprovera.
150mg 1ml deep intramuscular injection not the upper outer quadrant of the buttock every 13 weeks.
Newer 0.6ml subcutaneous version for self administration, Sayana press.
Prevents ovulation
Alters cervical mucus making it hostile to sperm
Makes endometrium unsuitable for implantation.
Oestrogen free so few contraindications.
How long does the injectable progestogen last?
Needs updated 12 weeks.
70% women amenorrheic after 3 doses.
What are some side effects to the injectable progestogen?
Delay in return to fertility - av. 9 months.
Reversible reduction in bone density .
Problematic bleeding especially first 2 doses.
Weight gain - 2/3 women gain 2-3kgs.
What is the implant?
Small plastic rod measuring 4cm in length and 2mm cross sectional diameter. It contains 68mg of progestogen etonogestrel dispersed in a matrix of ethinylvinylacetate (EVA). The rod is also covered in a rate controlling membrane made from EVA.
What are some characteristics of the implant?
Inhibition of ovulation and effect on cervical mucus.
Can last 3 years or be removed at any time.
No user input needed.
No causal effect on weight.
What are some side effects of the implant?
60% are almost bleed free but 30% have prolonged, frequent bleeding.
May cause mood change more often than other progesterone only methods.
What are some characteristics of intrauterine contraception?
Little user input after fitting - neither woman or partner should be aware of the device.
Can be fitted at any age or parity.
Effects/side effects are immediately reversed when removed.
Small infection risk within first 3 weeks - offer STI testing.
Fitting takes 10minutes - usually done by GP or at SH clinic.
If conceives then may be ectopic but method is so effective that ectopic risk is lower than that for condoms.
How do Copper IUDs work and how long do they last?
Copper is toxic to sperm so prevents them from reaching egg and can sometimes prevent implantation of fertilised egg.
Hormone free
Can last 5-10years depending on type.
May make periods heavier/crampier.
How do levonorgestrel IUS work and how long do they last for?
Affect cervical mucus and endometrium, most women still ovulate.
Stop fertilisation of the egg and may stop implantation.
Slow release progestogen on stem.
Lower levels of circulating progestogen compared with pill/implant/injection.
Reduce menstrual bleeding after up to 4months.
3years Jaydess and 5 years Mirena and Kyleena.
What are some examples of emergency contraception?
Copper IUD (most effective)
Levonogestrel pill “levenelle”
Ulipristal pill “ellaone”
