Contraception Flashcards
what axis controls the menstrual cycle?
hypothalamic-pituitary-ovarian axis
- hypothalamus produces GnRH
- pituitary releases LH and FSH
- ovary produces oestrogen and progesterone
what % of pregnancies in the UK are unplanned?
40
what contraception methods prevent ovulation?
most hormonal methods (inc emergency contraception)
*work by suppressing FSH and LH
what contraception methods work by preventing fertilisation?
condoms, diaphragm + spermicide, female and male sterilisation, intrauterine devices, hormonal methods (cervical mucous effect)
*work by creating a mechanical or surgical barrier or by direct toxicity
what contraception methods work by preventing implantation?
intrauterine devices (esp copper coil when used as emergency contraception), hormonal methods
*works by creating hostile endometrium or direct toxicity
what are the hormonal methods of contraception?
combined pill, ring, patch and “minipill”
DMPA injection and contraceptive implant (nexplanon)
what are the barrier methods of contraception?
male and female condoms
diaphragm or cervical cap (plus spermicide)
what are the intrauterine methods of contraception?
intrauterine device (copper coil) intrauterine system (hormone coil)
what are permanent methods of contraception?
female sterilisation male sterilisation (vasectomy)
what are fertility awareness methods of contraception?
basal temperature, calendar and cervical secretion monitoring methods
what are emergency methods of contraception?
emergency IUD emergency pills (ulipristal acetate or levonorgestrel)
what are the window periods for STI risk?
NAAT CT/GC = 2 weeks
HIV / syphilis = 4 weeks
HepB/C = 12 weeks
what are the non-contraceptive benefits of hormonal contraception?
decreased period pain decreased heavy menstrual bleeding decreased irregular bleeding decreased ovulation pain (mittelschmerz) decreased PMS decreased cyclical breast tenderness decreased ovarian cysts decreased endometriosis decreased ovarian cancer decreased acne or hirsutism (CHC only)
how long do hormonal and copper coils last?
LARC between 3-10 years, depending on device
*<1% failure rate
copper and hormonal coils are non-invasive options - true or false?
false - invasive
quick but open painful (3/10 for parous women and 5/10 for nulliparous women)
*small risk of perforation, PID, malposition/expulsion
what condition is hormonal and copper coils unsuitable for?
submucosal fibroids etc
what type of coil can be used as emergency contraception?
copper (IUD)
what effects does the IUD have on periods?
often makes them heavier, longer and more painful especially during first 3/12 post insertion
*NSAIDs like ibuprofen can help with both pain and bleeding
IUD might be the only reliable method for women after what illness?
breast cancer
what is more effective - IUD or IUS?
IUS
what four main IUS devices are in the market?
mirena, levosert and kyleena (5 years)
jaydess (3 years)
what other things is the mirena licensed to treat?
heavy periods
can be part of HRT
has other therapeutic uses (endometriosis, hyperplasia etc)
what is a common side effect of IUS in the weeks or months after insertion?
spotting
*50% of amenorrhoea on mirena at 6/12
hormonal side effects are often a problem in IUS - true or false?
false - rarely a problem due to systemic hormone levels
what is the most effective of all contraceptive methods?
subdermal contraceptive implant - nexplanon
how long does the SDI last?
3 years
what hormone does the SDI contain?
progestogen
*low and stable level of hormones so less hormonal side effects
what is the main side effect of SDI?
prolonged PV bleeding
*often controlled by CHC taken additionally if not contraindicated
what is the rough guide for the UK medical eligibility criteria for contraceptive use?
1 = always useable (no increased risk due to condition)
2 = broadly useable (advantages > risk, consider close follow up)
3 = counsel / caution (risks due to condition > advantage of method - expert opinion or specialist referral required)
4 = do not use (method contraindicated due to condition - do not prescribe)
what is the failure rate of combined hormonal contraception?
perfect use = 0.3%
typical = 9%
how should COC be took?
start in first 5 days of period or at any time in cycle plus condoms for 7 days
take daily for 21 days followed by 7 day break
what factors may affect the effectiveness of CHC?
impaired absorption - GI conditions
increased metabolism - liver enzyme induction, drug interaction
forgetting
what are the risks of CHC?
venous thrombosis
arterial thrombosis
adverse effects on some cancers
what has a higher risk of VTE - being on pill & not pregnant OR during and post pregnancy?
being on pill and not pregnant
what unwanted circulatory effect can come with COC?
systemic hypertension
*must check initially, at 3 months then annually
arterial disease
*MI and ischaemic stroke
in what individuals is CHC use contraindicated due to increased risk of ischaemic stroke?
migraine with aura
CHC can cause increased risk of what cancers?
breast
cervical (small increase with long term use but reduces to baseline 10 years after stopping, discussing HPV/condom use, check up to date with cervical screening)
what examination should you do before prescribing CHC?
record BP and BMI before first prescription
check smear status if relevant
what type of cancers do CHC protect against?
ovarian and endometrial
what conditions can CHC help improve?
premenstrual syndrome
PCOS
what are side effects of CHC?
nausea
spots
bleeding
breast tenderness
how do you take / start progestogen only methods of contraception (POP, subdermal implant, DMPA)?
start on day 1-5 of period
or
anytime if reasonably certain not pregnant plus condoms for 7 (2 for POP) days
when should progestogen only contraception not be given?
current breast cancer
how do injectable forms of contraception work?
depo provera = lowers estradiol
sayana press = suppress FSH
what are the different techniques of vasectomy?
local or general anaesthetic
no-scalpel technique
what are the complications of vasectomy?
anaesthetic pain infection bleeding / haematoma failure - early (non-compliance)
