Contraception Flashcards
What are the 2 types of contraception methods
- Inhibit viable sperm from coming into contact with mature ovum (e.g., barriers, prevent ovulation)
- Prevent fertilized ovum from successfully implanting in the endometrium (e.g., create unfavourable uterine environment)
What is the % pregnancy with barrier techniques compared to oral hormonal contraceptives?
Barrier (typical use): 13-21%
Oral hormonal contraceptives: 1-7%
Discuss the absolute contraindications, advantages, and disadvantages of male external condoms
Absolute CI: allergy to latex or rubber
Advantage: STD protection
Disadvantage: high user failure rate, poor acceptance, breakage
Discuss the absolute contraindications, advantages, and disadvantages of female internal condoms
Absolute CI:
- Allergy to polyurethane
- Hx of TSS
Advantage: STD protection, can be inserted ahead of time
Disadvantage: high user failure rate, dislike ring hanging outside vagina
Discuss the absolute contraindications, advantages, and disadvantages of diaphragm with spermicide and cervical cap
Absolute CI:
- Allergy to latex, rubber, or spermicide
- Recurrent UTIs
- History of TSS
- Abnormal gynecologic anatomy
Advantage: low cost, reusable
Disadvantage: high user failure rate, low STD protection, increased risk of UTI, cervical irritation
*Typically insert a few hours before intercourse, and taken out a few hours after
Hormonal contraception contains _________ or ______ only
Combination of Estrogen + Progestin, or Progestin only
What can hormonal contraception be used for?
- Prevent pregnancy
- Improve menstrual cycle regularity
- Management of perimenopause
- Management of certain conditions (like PCOS)
Describe the role of E and P in combined oral contraceptives
Estrogen:
- Suppress FSH release => suppress development of ovarian follicle => prevent ovulation
Progestin:
- Thickening of cervical mucus, prevent sperm penetration
- Slow tubal motility to delay sperm transport
- Induce endometrial atrophy (unable to successfully implant fertilized ovum in endometrium)
- Block LH surge => prevent ovulation
*P provides most of the contraceptive effect, while E stabilizes the endometrial lining and provides cycle control to ensure theres still menstruation
Lower doses of Ehinyl Estradiol (EE) are used as high doses are associated with adverse events (e.g., vascular, embolic events, cancers etc.)
List the factors favouring lower doses and higher doses respectively.
Factors favouring lower doses (20-25mcg) *default
- Adolescence
- Underweight <50kg
- Age >35yo
- Peri-menopausal
- Fewer SEs
Factors favouring higher doses (30-35mcg)
- Obesity of weight >70.5kg
- Early to mid cycle breakthrough bleeding/spotting
- Tendency to be non-adherent
Discuss the difference from 1st to 4th generation of Progestins, and name examples
Progestins have varying progestational activity + inherent androgenic effects (androgenic SEs: oily skin, acne, hirsutism)
1st to 3rd gen: have androgenic effect
- 1st gen - Norethindrone, Ethynodiol diacetate, Norgestrel, Norethindrone acetate
- 2nd gen - Levonorgestrel
- 3rd gen - Norgestimate, Desogestrel
4th gen: no/minimal androgenic effect
- Drospirenone
- Cyproterone
What are the properties of Drospirenone (effects, SEs)
Drospirenone (4th gen Progestin)
- Analogue of spironolactone (thus, mild diuretic)
- Anti-mineralcorticoid, some anti-androgenic effect (~30% of cyproterone)
- Less water retention, less acne
- SE: hyperkalemia, thromboembolism, bone loss
What are the properties of Cyproterone (effects, SEs)
What is its primary indication?
Cyproterone (4th gen Progestin)
- Antiandrogenic, antigonadotropic
- Estelle-35/Diane-35 (Cyproterone 2mg + EE 35mcg)
Primary indication:
- To treat excessive-androgen related conditions (e.g., severe acne, hirsutism)
- *SHOULD NOT be used solely for contraception (due to high risk of thromboembolism)
COC typically has lower Progestin overall (as with normal physiological cycle)
What are 2 situations in which P may be increased?
- Late cycle breakthrough bleeding
- Painful menstrual cramps (prevent endometrium build up, less bleeding, less cramps)
What are the 4 types of COC?
- Monophasic COC
- Same amount of E and P in each pill
- Multiphasic COC
- Variable amount of E and P (overall lower P, mimic physiological cycle, lesser SE)
- Conventional/Newer Formulation Cycle COC
- 21 days active pill + 7 days placebo
- 24 days active pill + 4 days placebo (reduce pill-free period to reduce hormone fluctuations between cycles)
- Extended/Continuous Cycle COC
- 84 days (3months) followed by 7 days placebo (no placebo for continuous)
Discuss the selection of COC based on the following factors:
- Hormonal content required
- Convenience
- Adherence level
- Tendency for oily skin, acne, hirsutism
- Medical conditions (e.g., premenstrual syndrome, dysmenorrhea)
- Hormonal content required
- Higher dose of E if early/mid breakthrough bleeding, higher dose of P if late breakthrough bleeding
- Higher dose of E if obesity or weight >70.5kg, non-adherence, early bleeding
- Convenience
- Extended/continuous cycle for less periods
- Adherence level
- Consider monophasic as it is less confusing
- Tendency for oily skin, acne, hirsutism
- Antiandrogenic progestin (Dropirenone, Cyproterone)
- Medical conditions - Dysmenorrhea (menstrual cramp)
- Higher dose of P
- Extended cycle (less period)
- 24 days active pills COC to keep hormone-free interval as short as possible
What are the 3 methods to initiate COC?
- First day method
- Sunday start
- Quick start
Describe the start, backup contraceptives and rationale behind:
- First day method
Start on first day of menstrual cycle
No backup contraceptives required
(unlikely to get pregnant during period, 5-6 pills alr taken)
Describe the start, backup contraceptives and rationale behind:
- Sunday start
Start on the first Sunday after period ends
Backup contraceptive for at least 7 days
Rationale: provide weekend free of menstrual periods (period start on Monday after 21 pills - assuming conventional)
Describe the start, backup contraceptives and rationale behind:
- Quick start
Start now
Backup contraceptive for at least 7 days, and potentially until next menstrual cycle begins
List the non-contraceptive benefits of oral hormonal contraceptives
- Relief from menstrual related problems
- Improvement in menstrual regularity
- Better for acne
- Premenstrual dysphoric disorder (severe PMS)
- Iron-deficient anemia (need to stop period to reduce bleeding)
- Polycystic ovary syndrome (PCOS)
- Reduced risk from ovarian and endometrial cancers (with Progestin - endometrium unable to proliferate)
- Reduced risk of ovarian cysts, ectopic pregnancy, pelvic inflammatory disease, endometriosis, uterine fibroids, benign breast disease
What are the major adverse effects of COC?
- Breast cancer
- Venous thromboembolism (VTE)
- Ischemic stroke/myocardial infarction
Explain the risk of breast cancer with COC
Who is at risk, and should avoid COC?
Risk of breast cancer increases with duration and age >40yo
After discontinuation, risk returns to that of those who never used COC
Who is at risk?
- Age >40yo [AVOID]
- Family history/risk factors of breast cancer [AVOID]
- Current/recent PMH of breast cancer, within 5 years [STOP/AVOID]
Healthy and young individuals may use COC as benefit of pregnancy prevention outweighs the risk of developing breast cancer
Explain the MOA of how COC results in Venous Thromboembolism (VTE)
Estrogen increases hepatic pdn of factor VII, factor X, and fibrinogen of coagulation cascade
New generation progestins (esp Drosperinone, Cyproterone, and Desogestrel) => unknown MOA
Explain the risk of VTE with COC
Risk of VTE is higher in normal pregnancy than in COC pill users
Risk factors for VTE:
- > 35yo
- Obesity - related to immobility
- Smoker - narrowed blood vessels, blood becomes hypercoagulable
- Family history of VTE
- Immobilization
- Cancer - blood becomes hypercoagulable
Explain the risk of ischemic stroke/myocardial infarction with COC
More associated with Estrogen than Progestins
Risk factors:
- Old age
- HTN
- Migraine headache with aura (sensory disturbances - flashing lights, tingling) => high risk of stroke [CI]
- Obesity
- Dyslipidemia
- Smoking
- Prothrombotic mutations
Given the risk factors for VTE and ischemic stroke/MI with the use of COC, what are some considerations to reduce risk? (e.g., adjust dose, change method)
- Low dose E (with older P - for VTE risk)
- Progestin-only contraceptive (POP)
- Barrier method
What are the absolute contraindications to the use of COC?
- Current breast cancer / recent history of breast cancer within 5 years
- History of DVT/PE, acute DVT/PE, pt with DVT/PE and on anticoagulant therapy
- Major surgery with prolonged immobilization
- <21 days postpartum (avoid in breastfeeding) - high risk VTE
- Thrombogenic mutations
- Migraine with aura - risk of stroke
- SBP >160mmHg, DBP >100mmHg (uncontrolled HTN)
- HTN with vascular disease
- Current/history of ischemia heart disease
- Cardiomyopathy
- Smoking >= 15 sticks/day AND age >= 35yo
- History of cerebrovascular disease
How to manage common adverse effects with COC?
Breakthrough bleeding
Early/mid cycle: Higher dose of E
Late cycle: Higher dose of P
How to manage common adverse effects with COC?
Acne
- Less androgenic Progestin (Drospirenone, Cyproterone)
- Increase E
- If on POP, change to COC
How to manage common adverse effects with COC?
Bloating
Bloating is usually due to E
- Reduce dose of E
- Change to P (Drospirenone - mild diuretic effect)
How to manage common adverse effects with COC?
Nausea/Vomiting
Nausea/Vomiting usually due to E
- Reduce dose of E
- Take pills at night
- Change to POP
How to manage common adverse effects with COC?
Headache
Headache usually due to E and P, occur during pill-free week
- Exclude migraine with aura - absolute CI
- Switch to extended cycle/continuous cycle/shorter pill-free interval
How to manage common adverse effects with COC?
Menstrual cramp
- Increase dose of P
- Switch to extended/continuous cycle => less/stop periods
How to manage common adverse effects with COC?
Breast tenderness/weight gain
E can cause breast tenderness, weight gain => reduce E
P can cause weight gain => reduce P
In general, keep both E and P doses as low as possible
How should we counsel a patient who experience adverse effects with COC?
Adverse effects tend to occur during EARLY COC use, and may improve by 3rd-4th cycle after adjusting to hormone levels
Hence, important to persevere for 2-3 months as these symptoms will improve
Unless serious adverse effects such as VTE/Stroke/Migraine with aura/MI, then STOP COC, change method
What are some DDIs with COC?
RAH
- Rifampicin
- Contraceptives are prodrugs metabolized by intestinal bacteria, and antibiotics alter the gut flora, cause less active drug
- Use additional back up contraception until Rifampicin discontinued, for at least 7 days
- Anticonvulsants (e.g., phenytoin, carbamazepine)
- Reduces free serum concentrations are both E and P
- *anticonvulsants are mostly teratogenic and cause fetal malformation, hence contraception is impt to prevent unwanted pregnancy
- HIV antiretrovirals (e.g., protease inhibitors - ritonavir, darunavir)
- Reduce effectiveness of both COC and antiretrovirals
Across all DDI, increasing dose of COC will prevent risk of interaction compromising efficacy
Counsel on the missed dose procedures for COC
- If one dose missed (less than 48h)
If one dose missed (<48h since a pill should have been taken), take the missed dose immediately and continue the rest as usual
May take 2 pills on the same day
No backup contraceptive required
Counsel on the missed dose procedures for COC
- If two or more consecutive dose missed (>48h)
If two or more consecutive dose missed (>48h), take the missed dose immediately and discard the rest of the missed doses. Continue the rest as usual.
May take 2 pills on the same day
Backup contraceptive required for at least 7 days
Counsel on the missed dose procedures for COC
- If pills were missed during last week of hormonal tablets (e.g., day 15-21)
If pills were missed during last week of hormonal tablets (e.g., day 15-21)
Finish the remaining active pills in the current pack
SKIP the hormone free interval and start a new pack the next day
Backup contraceptive required for at least 7 days
Progesterone only pill (POP) has the same effectiveness as COC (with typical use failure of ~7%)
What are the advantages of POP?
POP - e.g., Norethisterone - 28 active pills continuous (no period)
Advantages:
- Can use in breastfeeding
- Intolerance to Estrogen (e.g., due to N/V, bloating)
- Conditions that preclude estrogen (e.g., VTE, vascular disease)
*The only true CI is current/recent history of breast cancer
Discuss the initiation and missed dose procedure for POP
Initiation:
- Start within 5 days of menstrual cycle/bleeding => NO backup contraceptive
- Any other day => Backup contraceptive for 2 days
Missed dose:
- If late by >3h => Backup contraceptive for 2 days
Hormonal contraceptives are not limited to oral pills only.
What are some other options?
- Transdermal contraceptives
- Vaginal rings
- Progestin injections
- Long-acting reversible contraception (LARC): Intrauterine devices (IUD), Subdermal Progestin implants [*IUD can be hormonal/non-hormonal]
Explain the uses of transdermal contraceptives
- Typical use failure rate
- Not as effective for which group of patients
- How is it applied
- SE
Contains both E and P components
Typical use failure rate 7% (same as COC)
Not as effective in patients >90kg
Applied once weekly for 3 weeks, followed by 1 patch-free week
SE: similar to COC + application site reactions
Explain the uses of vaginal rings
- Typical use failure rate
- How is it used
- Explain placement of the ring
- SE
Contains both E and P components
Typical use failure rate 7% (same as COC)
Used for 3 weeks, then discarded
Unlike diaphragms or cervical caps, precise placement not required as hormones are absorbed (NOT a barrier)
SE: similar to COC + tissue irritation + risk of expulsion
What is one disadvantage with using transdermal patch and vaginal rings?
Continuous, higher exposure to estrogen => increased risk of VTE, higher clot risk (compared to those taking oral contraceptives)
Explain the uses of Progestin injections (Depo-Provera)
- Typical use failure rate
- Administration frequency
- Effects on fertility and period
- Added advantage
Typical use failure rate 4% < COC
IM injection every 12 weeks
Effects on fertility and period:
- Return to fertility may be delayed (since it is a depot)
- SE: Variable breakthrough bleeding especially in the first 9 months
- Amenorrhea (50% after 12 months, 70% after 2 years)
Added advantage:
- Good for after giving birth to prevent next pregnancy + helps with production of breastmilk
What are some notable adverse effects of Progestin injections?
- Weight gain
- Black box warning: Short term bone loss due to decreased bone mineral density
=> Risk-benefit analysis
- Avoid in older women
- Avoid in osteoporosis risk factors (e.g., long term steroids)
- If use for >2 years, evaluate other options (*bone loss greater with increasing duration of use)
*Recall Drospirenone causes bone loss
What is the effectiveness of LARC (IUD, implants)?
Typical use/perfect use failure rates <1%
Effects quickly reversible upon removal
However, invasive
LARC - Intrauterine devices
What is the MOA of IUD?
Who should not use IUD?
What are the risks of using IUD?
MOA: inhibit sperm migration, damage ovum, damage/disrupt transport of fertilized ovum from reaching endometrium, (if w Progestin - endometrial suppression, thicken mucus)
SHOULD NOT insert if:
- pregnant
- current STI
- undiagnosed vaginal bleeding
- malignancy of genital tract
- uterine anomalies
- uterine fibroids
General risks:
- Uterine perforation
- Expulsion
- Pelvic infection
What are the 2 types of IUDs?
- Levonorgestrel IUD
- Menstrual flow decreased
- Typical spotting, amenorrhea
- Ideal if concomitant menorrhagia
- 5 years
- Copper IUD
- Heavier menses/bleeding (compared to Levonorgestrel)
- Ideal if concomittant amenorrhea
- 10 years
- Can be used as emergency contraception
LARC - Subdermal Progestin Implants
Describe its use and common side effects
Single 4cm long implant, containing 68mg of etonogestrel (progestin)
Lasts for 3 years
Can cause irregular bleeding pattern with continued use such as:
- Amenorrhea
- Prolonged bleeding
- Spotting
- Frequent bleeding
