Reversible and non-reversible contraception Flashcards
Hormonal contraceptive methods (reversible) - list
- COCP
- Vaginal ring
- POP
- Depot medroxyprogesterone acetate
- Progestogen implants
Non-hormonal contraception (reversible) - list (3)
- Intrauterine devices
- Barrier methods
- Natural family planning
Permanent contraception (irreversible) - list (2)
- Vasectomy
2. Tubal occlusion
COCP - overview
- E+P
- Taken daily
- P is the primary contraceptive hormone - suppresses LH surge and prevents ovulation. Also thickens cervical mucus (impedes sperm penetration) and makes the endometrium less suitable for implantation
- E adds to contraceptive effect by preventing follicular maturation. Main purpose is to stabilise endometrium, so that irregular bleeding occurs less frequently
- Perfect use efficacy 99.7%, typical use efficacy 92%
COCP - benefits
- Positive effects on menstrual cycle and bleeding (3 - reduction in premenstrual symptoms, less heavy/painful menstrual bleeding, predictable bleeding pattern)
- Improvement in skin condition in acne vulgaris
- Decreased risk of benign ovarian tumours
- 50% reduction in incidence of PID
- 50-60% reduction in ovarian and endometrial cancer risk
COCP - risks
- VTE
- Stroke (esp for smokers >35y and those with pre-existing migraine with aura)
- Cardiovascular disease (why?)
- Small increase in breast cancer risk
- Very small increase in risk of cervical cancer
COCP - side effects
- Breakthrough bleeding (esp in first 3mo - need to consider missed pills, STIs and pregnancy)
- Headache
- Breast tenderness
- Nausea
- Disappear within 3mo of starting
COCP - contraindications
- Pregnancy
- IHD, previous stroke
- VTE
- > 35y + smoking
- Severe liver disease
- Breast cancer
- Migraine with aura
- Breastfeeding (in mothers with infants 35
- Undiagnosed genital tract bleeding
COCP - how to take
- 7 inactive tablets, tablet taken every day. Take at same time each day to get into habit of using COCP
- If starting with active tablet on day 1-5 of menstrual cycle (i.e. starting with period), there is immediate contraceptive cover. If starting after day 5, need additional contraceptive cover (e.g. condom/avoidance of penetrative sex) until taken at least 7 active tablets. 7d rule for missed pills also appliies if pt has vomiting, diarrhoea or is on antibiotics
- Must continue to use condoms to protect against viral STIs
- Earlier unprotected sex in cycle or prior use of emergency contraception - should not preclude starting pill, bc pre-existing pregnancy can be confirmed by urine pregnancy test at end of first pill pack. Hormones have no adverse effect on early pregnancy
- Withdrawal bleed when no active tablets taken. Can choose to avoid this by continuing active pills. Not dangerous, no risk to future fertility. But may have break-through bleeding over time
COCP - missed tablets
- Missed one tablet - take it as soon as you remember (even if it means taking two at once) - no loss of contraceptive cover
- Missed two or more tablets (i.e. last pill >48hrs ago), last two tablets should be taken together, but also need additional precautions for another week (condoms/abstinence) to maintain contraceptive cover
- Missed two or more tablets in last week (before placebo) - skip placebo and continue to active tablets + extra contraceptive cover for a week
Vaginal ring - overview
- 54mm diameter ring placed by user within the vagina. Alternative system for delivering combined hormonal contraception. Equivalent efficacy to COCP
- Constant dose of both ethinylestradiol and etonorgestrel delivered to vessels underlying vaginal skin
- Each ring contains sufficient hormones for 3 weeks’ use, after which it is removed for a week before a new ring is inserted. During this ‘no-ring’ week, the woman experiences withdrawal bleeding similar to that which occurs on the COCP
- Advantages over oral bc avoids first-pass metabolism of hormones by the liver
- Lower daily hormone dose and constant delivery system -> may result in fewer side effects for the user
Progestogen-only pill (POP) or minipill - overview
- No estrogen, only a small dose of progestogen. One tablet per day at the same time. Used when COCP contraindicated - during lactation, sickle cell disease, SLE and other autoimmune diseases (?)
- All tablets are active and contain either 30mcg levonorgestrel or 350mcg norethisterone. Both these hormones have variable effects on ovulation and achieve their contraceptive effect primarily through effects on cervical mucus and the endometrium
- Maintaining adequate hormone levels is critical for efficacy - if a tablet is taken >3hrs late, additional contraception must be used until two further tablets are taken
- Although the theoretical efficacy of POPs is the same as that of the combined pill, the typical failure rate tends to be higher
- Side effects = menstrual disturbance (regular, irregular or amenorrhoea), headaches, nausea, mood swings, abdominal bloating and breast tenderness - subside after a few months. Very unpredictable bleeding pattern bc no scheduled withdrawal bleeds. Some women experience no bleeding at all, while others report almost constant vaginal spotting
Depo provera (depot medroxyprogesterone acetate [DMPA] - overview (may need more on contraindications)
- Depot medroxyprogesterone acetate (DMPA), 150mg
- Very effective contraception; efficacy 99.7% perfect use and 97% typical use
- Administered by IM injection (into buttock or upper arm every 12 weeks (10-16)
- Benefits = useful option for women in whom estrogen is contraindicated and for those who have difficulty committing to a daily contraceptive method
- Irregular bleeding (common problem), average delay of 8mo in return of ovulation after cessation of DMPA (not suitable for women wanting to achieve pregnancy in short term), weight gain of 2-3kg in first year (appetite stimulation), may cause reduced bone density in long term use (avoid in those with pre-existing RFs for osteoporosis)
Progestogen implants (implanon NXT) - overview
- Single rod system releases etonorgestrel over 3y period, supplied in a pre-loaded inserter
- Implant placed superficially under the skin of the upper, inner, non-dominant arm. Initially, 60mcg of etonorgestrel is released per day, but this declines to 30mcg per day by the 3rd year
- Method of action? Efficacy around 99.9%
- Implants are rapidly reversible, with most women ovulating within one month of the device being removed
- Side effects = disruption of normal menstrual cycle inevitable. 1/4 of women have the implant removed within 12mo bc of unacceptable bleeding. Bleeding pattern should stabilise by 4-5mo (encourage to persist until this time). Hormonal side effects (e.g. weight gain, breast tenderness, headache) - uncommon bc low hormone dose.
Intrauterine devices - types (3 - available in Australia)
- Copper-containing
- Progesterone-releasing
- Inert (no longer used in most Western countries)
(4. Frameless - not available in Australia)
IUDs - contraindications
- Pre-existing pregnancy
- Undiagnosed suspicious vaginal bleeding
- Cervical cancer awaiting treatment, endometrial cancer
- Marked distortion of the uterine cavity
- Current cervicitis or PID
Copper IUDs - overview
- Copper ions are extremely toxic to sperm, preventing fertilisation from occurring in the first place and providing
- Efficacy of >99%
- Secondary anti-implantation effect is still utilised when a copper IUD is used for emergency contraception
- Expected 50% increase in menstrual bleeding after insertion
- Two copper IUDs are available in Australia at present - Copper-TT380 (effective for 10y) and Multiload-Cu375 (effective for 5y)
Copper IUD - complications
- Irregular PV bleeding, especially first 3–6mths
- Risk of infection: screen for Chlamydia prior to insertion
- IUD expulsion: most common in the first 3mths after insertion
- Perforation: poor insertion technique or
IUD - timing of insertion
- Exclude pregnancy
- Insert any time during cycle
- Post-partum: safe to insert IUCD from 4wks after delivery
- Following TOP: insert within first 48h after termination
- Switching from other contraception: any time as long as not pregnant
Mirena (the only progestogen-releasing IUD available in AUstralia) - overview
- Progestogen thickens the cervical mucus plug and alters the composition of endometrial fluid, greatly impeding the transit of sperm through the uterus. Also thins the endometrium, making it unsuitable for implantation
- Releases 20mcg of levonorgestrel daily over 5y. Failure rate of 0.2%
- 80% reduction in menstrual bleedingl can be used to tx heavy periods. At 6mo after insertion, 50% of women fitted with a hormonal IUD report no menstrual bleeding, and in almost all wearers, bleeding is markedly reduced
- Particularly useful when estrogen contraindicated. May be used in pts with hx of breast cancer - if no disease after 5y and after consultation with breast surgeon
- Breast feeding - can be inserted >4wks post partum
Mirena - side effects
- Irregular PV bleeding common in 3-4mo; amenorrhoea in up to 30% by 1yr
Hormonal symptoms
- Nausea
- Headache
- Breast tenderness
- Bloating
Barrier methods - types
- Condoms - male and female
2. Diaphragms and spermicides
Male condoms - overview
- Perfect efficacy of 98% but falls to 85% in typical use
- For maximal effectiveness, the condom should be carefully removed from its cover and applied to the erect penis before there is any genital contact
- If condom has teat at the end, this should be pressed together with the fingers just before use so that air is not trapped at the end of the condom
- After ejaculation, the penis should be withdrawn from the vagina before the erection is lost
- Routine use of lubricant reduces the risk of friction and condom failure. Only use water-based lubricants with latex condoms (because oils can cause the rubber to deteriorate within minutes); both oil and water-based lubricants are safe to use with polyurethane condoms
Female condoms - overview
- Can only be purchased in Australia from specialty suppliers or via the internet
- Made from polyurethane. Larger than male condom and have a flexible ring at each end
- The loose ring within the device is used to place the end of the female condom into the upper vagina
- The larger, thinner ring at the open end remains outside the vagina during intercourse and partially covers the vulva
- Slightly higher failure rate than male condoms. Typical use efficacy 80%