Contraception Flashcards
UKMEC 2 criteria for COCP
Age >40
Partially breastfeeding >6weeks and <6months
Smoking if <35 or aged >35 and stopped smoking >1 year ago
BMI 30-34
FHx VTE in 1st degree relative
Major surgery without prolonged immobilisation
Migraine without aura
HIV/AIDS
Diabetes
Gall bladder disease
RANZCOG Q:
A 23 year old nulliparous woman consults you to obtain contraception. She wants to know about lifestyle and health issues.
a.What relevant issues might you discuss? (4 marks)
Menstrual history: cycles, regularity of menses, length of menses, heaviness of menses, clots, dyschezia/dysuria/dysparenunia
• Androgenic symptoms e.g. acne
• Current BMI, if BMI >25 give advice on weight loss, exercise and healthy eating
• Smoking, if current smoker give advice on quitting
• Alcohol intake
• HPV vaccination
• Past medical history: any cardiovascular disease, VTE, migraines, diabetes
• Family history: family history of VTE, autoimmune or thrombogenic conditions
• Previous contraception used: if this worked well or didn’t, and for what reasons
• Need for condoms to protect against STIs and offer STI screening
• Most recent cervical smear and cervical smear history
• Fertility and pregnancy planning- what type of contraception would suit her best?
UKMEC 4 criteria for COCP
Breastfeeding <6/52 PP Smoking- >35 and >15 a day BMI >40 CVD with multiple risk factors for arterial disease Personal hx of VTE Personal hx of IHD Major surgery with prolonged immobilisation Stroke Migraine with aura Current breast ca Liver disease e.g. hepatitis
Following discussion she is undecided between the combined oral contraceptive pill and a progesterone-only subdermal implant (Implanon®).
b. Outline two advantages and two disadvantages for each of these forms of contraception. (8 marks)
c. Specify 6 situations in which you would not prescribe the combined oral contraceptive pill to this woman. (3 marks)
Advantages COC :
Reversible, can be stopped anytime with an immediate return to fertility
Non-invasive
Can be effective in other gynaecological conditions for treatment e.g. menorrhagia and can treat symptoms of androgen excess e.g. acne Requires daily pill taking- higher user failure rate
Disadvantages COC:
Can interact with other medications e.g. enzyme inducers
Cost
Limited by some conditions
Raised risk of VTE from baseline by 3-4x
Implanon Advantages:
Long-acting contraception
Reliable contraception failure rate 0.05/100 in the first year
Suitable for those for whom the COC is contraindicated
Disadvantages:
Minor surgery to remove
Abnormal and irregular uterine bleeding
Possible migration and difficult extraction
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
No method
- No method T&P: 85
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Fertility awareness-based methods
- Fertility awareness-based methods T: 24 P:0.4–5
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Male condom
- Male condom T: 18 P: 2
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Combined hormonal contraception
- Combined hormonal contraception (CHC)* T: 9 P: 0.3
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Progestogen-only pill
- Progestogen-only pill (POP) T: 9 P: 0.3
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Progestogen-only injectable
- Progestogen-only injectable (DMPA) T: 6 P: 0.2
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Copper-bearing intrauterine device
- Copper-bearing intrauterine device (Cu-IUD) T: 0.8 P: 0.6
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
- Levonorgestrel-releasing intrauterine system
- Levonorgestrel-releasing intrauterine system (LNGIUS) T: 0.2 P: 0.2
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Progestogen-only implant
- Progestogen-only implant (IMP) T: 0.05 P:0.05
Percentage of women experiencing an unintended pregnancy within the first year of use with typical use and perfect use (%) for:
Female sterilisation
Vasectomy
- Female sterilisation T: 0.5 P: 0.5
- Vasectomy T: 0.15 P: 0.1
Dosage of ethinyl estradiol in first generation COCP and example
50mcg
Components of second generation COCP
20-40mcg of ethinyl estradiol
Progestin: Northinedorne and its derivatives (e.g. levonorgestrol)
More androgenic
Components of third generation COCP
Contain the progestins desogestrel and gestodene - formulated to be less androgenic than the second-generation progestins
Components of fourth generation COCP
fourth generation contraceptive pills include, among others, the progestin drospirenone, which is derived from spironolactone and has anti-androgenic activity
How does the dose of oestrogen affect VTE risk
- Doses >50mcg ethinyl estradiol increase VTE risk
- Limited evidence but potential that doses lower than 50mcg may not have as high risk
- Using any oestrogen increases VTE risk compared to progesterone alone
How does the dose of progesterone affect VTE risk
3rd generation COCP (containing desogestrol) increase risk of VTE when compared to second generation
May be the same with 4th generation but evidence re effect of type of progesterone is debatable
Some studies have found an increased risk with 3rd and 4th but others haven’t.
International Active Surveillance Study of Women Taking Oral Contraceptives did not find a difference in VTE rates among different progestins
Overall advice- increased risk of VTE with 3rd generation but that increase in risk is small (10-15 per 10,000 vs 8 per 10,000 with levonorgestrel)
Risk factors for VTE with COCP use
tobacco use,
age (>35 years),
obesity,
presence of hereditary thrombophilias e.g. factor V Leiden mutation, prothrombin mutation and protein C, protein S, or antithrombin deficiency
RANZCOG Q:
A 42 year old woman sees you requesting a second opinion regarding options for contraception. She has previously experienced weight gain on a combined oral contraceptive pill (COCP) containing norethisterone and Yasmin COCP (30 mcg ethinylestrodiol, 3 mg drosperinone) has been recommended as an alternative. She has heard in the media, however, that Yasmin is more likely to be associated with venous thromboembolism (VTE).
a. What are the possible mechanisms by which the individual chemical components of Yasmin may increase the risk of VTE? (2 marks)
Ethinylestrodiol- use of oestrogen increases VTE risk. Risk is highest in preparations >50mcg but any use of oestrogen increases risk. Debatable whether this is dose dependent when <50mcg.
Progesterone- Drosperinone is a fourth generation progestin and may carry an increased risk of VTE when compared to second generation (e.g. levonorgesterol). Evidence comparing 4th versus second is not very strong and unclear whether there is an actual increased risk.
Drosperinone is an antimineralocorticoid- may reduce aldosterone levels (higher levels decrease coagulobility) and thus cause coagulability
What are 8 risk factors relevant for VTE when assessing this woman’s suitability for the COCP? (4 marks)
- Smoker
- BMI>35
- Age>40
- Personal history of VTE
- Known thrombophilia e.g. protein C/S deficiency
- History of VTE in first degree relative
- Recent major surgery with immobility
- Postpartum<6 weeks
- Exclusive breastfeeding <6 months postpartum
- Active cancer
c. i) List 2 unique pharmacological effects that are specific to drosperinone (a fourth generation progestogen)?
AND
List 2 positive clinical effects associated with each pharmacological effect. (Total 6 marks) You may wish to use a table to answer this part (c) of the question.
Weak diuretic due to antimineralocorticoid properties therefore:
- Less bloating with cycles
- Decreased breast tenderness
- Lowered blood pressure
Anti-androgenic progesterone
- Reduces acne
- Reduces hirsuitism