Contraception Flashcards
What are the properties of the ideal contraceptive?
•100% reversible •100% effective •100% unrelated to intercourse •100% free of adverse side-effects •100% protective against STIs •Non-contraceptive benefits •Low maintenance, no ongoing medical input •Male and female options
Are any MOC reversible?
All except sterilisation - only delay in reversal are injectables
Are any MOC completely effective?
None - best vasectomy followed by implant
Are any MOC unrelated to intercourse?
All except condoms
Are any MOC free from side-effects?
None
Are any MOC completely protective against STIs?
Not even condoms
Do any MOC have non-contraceptive benefits?
Particularly CHC and IUS
Are any MOC low-maintenance?
Implant or IUT
Do any MOC have male and female options?
Males can only use condoms or vasectomy
What is the Pearl Index?
The number of contraceptive failures per 100 women-years of exposure
What information does the Pearl Index use?
It looks at the total months or cycles of exposure from the initiation of the product to the end of the study
What does the Life Table Analysis provide?
The contraceptive failure rate over a specified time-frame and can provide a cumulative failure rate for any specific length of exposure
What is LARC?
Long-Acting Reversible Contraception
What is a “method failure” of contraception?
Pregnancy despite correct use of method by user
What is a “user failure” of contraception?
Pregnancy because method not used correctly by user
How does LARC minimise user failure rates?
Minimises user input
When does ovulation tend to occur on a 26-32 day cycle?
Day 12-18 (2 weeks before period)
How long does the egg serve for?
24 hours
How long does the sperm survive for within the female?
Most sperm survive less than 4 days (5% may survive 7 days)
So, when is the highest chance of pregnancy from sex?
- Day 8-19
* But sperm survival and ovulation is variable so natural methods can fail even if abstain/barrier on most fertile days
In which forms does combined hormonal contraception come?
Pill, patch and vaginal ring
What is CHC a combination of?
- 2 hormones
- Ethinyl estradiol (EE)
- Synthetic progesterone (progestogen)
(basically oestrogen and progesterone)
How does CHC act?
- Stops ovulation
* Affects cervical mucus and endometrium
What is the standard regime for CHC?
21 days with a hormone-free week
What are tailored CHC regimes and why are they useful?
- Tricycling/continuous use
* No need for uncomfortable inconvenient withdrawal bleed, avoids forgetting to restart after break
When is the CHC pill taken?
Daily - not good if frequent GI upset
When is the CHC patch (EVRA) changed?
Weekly - <5% have skin reaction
When is the CHC ring (Nuvaring) changed?
- Changed every 3 weeks
* Can take out for 3 hrs in 24 so may prefer to take out for sex
What are the non-contraceptive benefits of CHC?
- Regulate/reduce bleeding - help heavy or painful natural periods
- Stop ovulation - may help premenstrual syndrome
- Reduction in functional ovarian cysts
- 50% reduction in ovarian and endometrial cancer
- Improve acne/hirsutism
- Reduction in benign breast disease, rheumatoid arthritis, colon cancer and osteoporosis
What are the troublesome side-effects of CHC?
- Breast tenderness
- Nausea
- Headache
- Irregular bleeding first 3 months
- Mood? Causal or other life events
- Weight gain - not causal
What are the serious risks associated with CHC?
- Increased risk venous thrombosis - DVT, PE
- Increased risk arterial thrombosis - MI/ischaemic stroke
- Avoid if active gall bladder disease or previous liver tumour
- Increased risk cervical cancer - but data predates HPV vaccine
- Increased risk breast cancer - back to normal after 10 years off Rx
- No overall increased cancer risk for CHC users
What are risk factors for venous thrombosis with CHC?
- BMI >34, previous VTE
- 1st degree relative VTE under 45
- Thrombophilis e.g. systemic lupus erythematosus
- Reduced mobility
What are risk factors for arterial thrombosis with CHC?
- Smokers >35
- Personal history arterial thrombosis
- Focal migraine
- Age>50
- Hypertension>140/90
What is the POP?
Progesterone only pill