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Flashcards in Contraception Deck (15)
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What is the mode of action of the combined oral contraceptive pill?

  • Suppresses ovulation.
  • Reduces sperm pentrability of cervical mucus. 
  • Alters endometrium to reduce the likelihood of implantation.


What to do in the event of a missed pill?

  • It takes 7 consecutive pills to ensure that ovulation has been suppressed.
  • Follicular activity can begin to return towards the end of the 7 day break, therefore avoid lengthening the 'sugar pill' period beyond 7 days.
  • If greater than 12 hours late with 1 or more pills then take today's pill as soon as possible. 
  • Consider emergency contraception.
  • Use additional measures such as condoms for 7 days. 
  • If there are less than 7 pills left then continue straight on with the next packet and omit the pill-free week.


What are the considerations for the combined oral contraceptive pill and women approaching menopause?

  • The COCP will mask the menopause due to normal levels of oestrogen and regular bleeds. This effect disappears after 6 weeks. 
  • If COCP is stopped before age of 50, presume loss of fertility after 2 years of amenorrhoea. 
  • If COCP is stopper after age of 50, presume loss of fertility after just 1 year of amenorrhoea. 


What are the advantages and disadvantages of the combined oral contraceptive pill?



  • high efficacy (failure rate of 0.1 to 3 per 100 woman years)
  • reversible (may be a delay of up to 1 year)
  • not related to intercourse
  • reduced menstrual blood flow
  • reduced dysmenorrhoea
  • increased predictability of menses
  • reduced PMS
  • reduced PID
  • reduced ectopic pregnancy
  • reduced benign breast disease
  • reduced ovarian cancer
  • reduced endometrial cancer
  • reduced functional ovarian cysts
  • increased cardiovascular morbidity (VTE, IHD, CVA, HT)
  • increased breast cancer
  • increased cervical cancer
  • increased liver adenomas
  • cholestasis
  • gallstones


What is the significant of migraine with aura in regards to the combined oral contraceptive pill?

  • Increases the risk of ischaemic stroke. 


When should the Depo-Provera be commenced?

  • Day 1 to 5 of the menstrual cycle. 
  • Day of abortion or miscarriage. 
  • 6 weeks postpartum. 
  • Day of last pill of POP/COCP if switching. 


What is the mechanism of action of the Depo-Provera?

  • Progesterone-only. 
  • Suppresses the hypothalamopituitary axis resulting in consistent inhibition of ovulation. 
  • Reduced oestrogen levels compared to the POP, Implanon and Mirena. 


What are the advantages and disadvantages of injectable progesterones (eg. Depo-Provera)?



  • good for poorly compliant or travelling patients
  • improves endometriosis
  • improves dysmenorrhoea
  • improves menorrhagia
  • reduces iron deficiency anaemia
  • improves PMS
  • reduces epileptic seizures
  • no CVS effects (eg. HT, IHD, CVA, VTE)
  • menstrual disturbance (amenorrhoea in the long term)
  • headaches and dizziness (3-19%)
  • breast tenderness
  • mood changes
  • depression
  • weigh gain (2kg in first year)
  • delay in return of fertility (70% conceive in the first year)
  • reduced oestrogen levels (?adverse effect on bone density)
  • small risk of breast cancer (similar to COCP)



What is the mechanism of action of the progesterone implant (eg. Implanon)?

  • Inhibits ovulation by preventing the LH surge. 
  • Blockade of cervical mucus. 
  • Suppression of oestrogen-induced cyclical maturation of endometrium. 
  • Endogenous oestrogen is synthesised normally. 


When is the appropriate time to insert an Implanon?

  • Day 1 to 5 of cycle.
  • Can be inserted immediately postpartum. 


What are the advantages and disadvantages of the Implanon?



  • rapid return of ovulation on removal
  • 2 year continuation rate is 69%
  • no increased risk of CVS or VTE problems
  • variable bleeding pattern
  • headaches
  • acne
  • breast pain
  • weight gain
  • chloasma




What is the mechanism of action of the levonorgestral intrauterine system (eg. Mirena)?

  • Mirena results in profound endometrial atrophy, decidualisation and foreign body reaction. 
  • Changes in cervical mucus. 
  • Ovulation is not suppressed. 


When should the Mirena be inserted?

  • Before day 7.


What are the advantages and disadvantages of the Mirena?



  • safe
  • highly effective
  • long-acting
  • failure rate is 0.3 per 100 women years
  • no delay in return of fertility on removal
  • insert before day 7
  • risk of perforation 1 in 1000
  • risk of expulsion 5 per 100 women years
  • incidence of ectopic pregnancy 0.02 per 100 women years


What is the effect of progestogen-only injectables on bone mineral density?

  • There appears to be an initial small loss of bone density that returns when DMPA is discontinued. 
  • Those women on DMPA suffer an initial loss of bone density but, unlike other women, menopause does not incur further loss in bone strength.