Lecture 11: Contraception Flashcards
What is contraception and why is it important
A method of preventing pregnancy via interference with ovulation, fertilisation or implantation
Important bc allows active choice of pregnancy
- higher survival rates mean more children survive
- ability to prevent diseases in baby - eg. folic acid
- societal, mental, financial health impacts of unplanned pregnancy
At what age can contraception be prescribed and what is the age of consent
Legal age of consent is 16, but contraceptives are able to be prescribed to person under 16yo without parental consent if they have competence to give fully informed consent =
understanding and maturity to fully comprehend the proposed treatment
What is the mechanism of COCP (levonorgestrel and ethinyl estradiol)
- Suppress ovulation
- Reduce sperm transport in fallopian tubes
- Change endometrium making implantation less likely
- Thicken cervical mucus as a barrier against sperm travel
What are the contraceptives that have a form of progesterone - levonorgestrel or others and what is their mechanism of action - compared between different contraceptives
Jadelle, Mirena IUS, Mini-pill (POP) and Depo-provera have a form of Progesterone
All of them have a physical barrier function to sperm by thickening cervical mucus.
- All of them except for Depo-provera cause 50% of women have some suppression of hormones responsible for ovulation (Mini-pill at middle dose= 97%).
Depo-provera suppresses ovulation and can cause amenorrhoea.
Jadelle and Mirena has prevention of implantation as a 3rd mechanism- changing the endometrial lining. Mirena also has additional sperm impairment.
What are the advantages and disadvantages of the COCP
advantages
- convenient, familiar- most requested
- reversible
- lighter less painful periods
- lower risk of ovarian and colorectal cancer
Disadvantages
- headaches: mainly in the pill free interval.
- increased risk of Venous thromboembolism (lower absolute risk bc in pregnancy this is high)
- increased CV events, BP
- increased breast cancer risk which is low and decreases to baseline 10yrs after stopping
- requires careful risk assessment of pros vs cons
(no evidence for weight gain or depression)
What does MEC4 mean and what conditions does it apply for when prescribing the COCP
MEC4 is 4th medical eligibility criteria where there is a clear serious risk of prescribing the medicine for a certain condition that it outweighs any benefit.
For COCP MEC4 applies for patients that have focal migraines, BMI >35, high BP, poorly controlled diabetes, smoking (but depends on years and age to determine) due to increased CVS risk
As well as on other meds like enzyme inducers, epileptics.
What is the most effective and safe way to take the COCP
Continuously, only having a progesterone withdrawal bleed for max 3-4 days to reset when there is break through spotting.
This is bc during the pill free interval there are side effects: headaches, and if the next packet is started late, this may allow FSH levels (+LH) to increase high enough to stimulate follicles to develop
What are the advantages and disadvantages of the POP (minipill)
Advantage:
-Useful if unable to take COCP or if breastfeeding- less contraindications
-No pill free interval
Disadvantage
-Progesterone SE: breast tenderness, headache, nausea - tolerance can be developed by 3 mo
- 3 hr window (on subsidised pill) around the time you can allow to miss before taking the next pill otherwise the effect has to be reset which takes 48hrs to wait before its safe again
- Irregular bleeding is common- less so with non subsidised one
What is the definition of a LARC and what is one of the nz barriers to getting one when they are generally more effective
Long acting reversible Contraceptive administered less than once a month.
Barriers can be training or insertion and accessibility of LARCS as device may be subsidised but insertion is not
What are the advantages and disadvantages of Depo-provera
Advantages:
- Estrogen free so less contra-indications
Disadvantages
- Prolonged amenorrhoea/irregular bleeding –> delayed return to fertility
- Reversible decline in bone density
- weight gain in some ~2kg
- Progestogenic SE
- requires monthly recall systm
What are the advantages and disadvantages/ contra indications of the contraceptive implant: Jadelle
Advantages
- 5yr life span
- high satisfaction rate
Disadvantages
- irregular bleeding causing 14% discontinual
- Progestogenic SE
- Contra-indications for breast cancer, allergy, undiagnosed vaginal bleeding
- enzyme inducing drugs interfere eg. St Johns Wort
- minor surgical procedure to insert with LA
What is the mechanism of the Copper IUD
- It is spermicidal: impairing motility of sperm
2. creates a hostile intra uterine environment for implantation
What are the advantages and disadvantages of the Copper IUD
Advantages:
- hormone free
- lasts 10yrs and can stay in until menopause
- very low infection risk during insertion
- gold standard emergency contraception
Disadvantages:
- Periods may be heavier, longer or more painful as it is an irritant
- 5% of devices are expulsed. perforation in 0.1%
- Pregnancy risk is 0.8% but if it does occur there is a higher risk for ectopic pregnancy
What is the indications for Mirena IUS
Indications:
- heavy menstrual bleeding: patients with dysmenorrhoea
- contraception
- Endometrial protection with Menopausal hormone therapy: patients with endometriosis, hyperplasia, POI
What are the advantages and disadvantages of the Mirena IUS
Advantages
- lasts 5yrs
- 90% decrease in menstrual bleeding at 1yr with 95% satisfaction
Disadvantages
- expulsion in 5%, perforation in 0.1%
- irregular bleeding in the first 3-6 mo
- Prostogenic SE
- Pregnancy risk is 0.2 but if occurs higher risk of ectopics
