Contraception and Fertility control Flashcards
Natural oestrogen
Estradiol valerate
Most common form of synthetic oestrogen used in contraception
Ethinyl estradiol
Normal starting dose of oestrogen in contraception for a healthy woman
15-30 micrograms
Effect of higher and lower than normal doses of oestrogen in contraceptive pills
Higher: much higher increased risk of arterial and venous thrombosis
Lower: poorer cycle control
What is cyproterone acetate and what are indications for its use?
An anti-androgen progestin
Indicated for treatment of acne and hisutism but not contracpetion
In a combined preparation: Dianette
Absolute contraindications for use of the COCP (13)
Breastfeeding less than 6 weeks postpartum Smoking over the age of 35 Multiple risk factors for CVD HTN: SBP 160, DBP 100 History of DVT or PE Major surgery with prolonged immobilisation Known thrombogenic mutations History of IHD or stroke Complicated valvular heart disease Migraine with aura, or without aura if over 35 Current breast cancer Active viral hepatitis Severe liver disease
Common side effects of COCP (13)
CNS: - depressed mood - mood swings - headaches - loss of libido GI: - nausea - perceived weight gain - bloatedness Reproductive system: - breakthrough bleeding - increased vaginal discharge - breast pain and enlargement Miscellaneous: - chloasma - fluid retention - change in contact lens wearing
What is chloasma
AKA melasma or mask of pregnancy
Facial pigmentation which worsens with continued oestrogen exposure, and spontaneously resolved after exposure is ceased (e.g. COCP, HRT, pregnancy)
Benefits of COCP
Contraception
Light, pain-free, regular bleeds (thus suitable to treat heavy or painful periods)
Reduced risk of PID
improved premenstrual syndrome
Long-term protection against ovarian and endometrial cancers
Improvement of acne
Failure rate of contraception of the COCP
0.1-1 per 100 woman years (i.e. 1/100 women will become pregnant on the pill each year)
What to do if miss one pill (COCP)
Take most recent pills when remember and continue taking remaining pills daily at the usual time
Do not require any additional contraception or emergency contraception
What to do if miss 2 pills (COCP)
Take most recent pills as soon as remembers
Continue taking remaining pills at usual time
Use condoms or abstain from intercourse until have taken pills for 7 days in a row
IF MISSED IN WEEK 1: emergency contraception if unprotected sex in pill-free interval or week 1
IF MISSED IN WEEK 3:
continue pills as normal and then start neck pack, skipping pill-free interval
Failure rate of combined hormonal vaginal ring or patch
0.3% perfect use
9% typical use
How to use a contraceptive combined hormonal patch
Wear patch for 1 week for 3 weeks, followed by 1 week without patch
How to use a combined hormonal vaginal ring for contraception
Insert and leave in for 3 weeks, remove for 1 week before re-inserting a new ring
Additional contraception required for 7 days if ring removed for more than 3 hours outside of ring-free interval
How progestogen only contraceptives work
Local action on:
- Cervical mucus - makes cervical canal hostile to ascending sperm
- Endometrium - makes thin and atrophic preventing implantation and sperm transport
Higher doses of progestogen also act centrally and inhibit ovulation
Side effects of progestogen only contraceptives
Erratic, or absent menstrual bleeding Simple, functional ovarian cysts breast tenderness Acne Weight gain Loss of bone mineral density (due to drop in oestrogen) Emotional lability
Failure rate of minipill (POP)
1-3%
+ slightly higher risk of ectopic pregnancy if does fail
Must be taken daily within 3 hour time frame
how long does Depo-provera (DPMA) last
12 weeks with 2 week grace period
Cons of depo-provera in relation to other progestogen only methods of contraception
Delay in return of fertility - can take up to 6 months longer to conceive compared to a woman who stops the COCP
If intolerable, cannot remove
How long does implanon last
Up to 3 years (re-insert around 2.5 years)
Failure rate of implanon
0.05-0.1% - equivalent to female sterilisation
Failure rate of Depo provera
0.2% with perfect use
6% with typical use
Side effects of intrauterine contraceptive devices
Copper: periods can become heavier and painful with more days of spotting but nil hormonal side effects
Mirena: irregular but lighter periods (often become amenorrhoeic), erratic spotting initially often settles, greasier skin and acne, breast tenderness, mood swings (hormonal side effects often settle with time)
Slightly increased risk of ectopic pregnancy if failure
failure rate of intrauterine devices
Copper: 0.8%
Mirena: 0.1%
Contraindications to use of a intrauterine contraceptive device
Current STI or PID
Malignant trophoblastic disease
Unexplained vaginal bleeding
Endometrial or Cervical cancer (not yet treated)
Known malformation of the uterus or distortion of the cavity (e.g. fibroids)
Copper allergy (can still use mirena)
How does a copper intrauterine contraceptive device work?
Toxic effect on both sperm and egg before fertilisation occurs
How does a mirena work?
Local release of levonorgestrel has local effect on cervical mucus (making cervix more hostile for ascending sperm) and on endometrium (atrophy - prevents implantation and sperm motility)
Failure rates for condoms
Perfect use 2%
Typical use 18%
failure rates for withdrawal method
Perfect use 4%
Typical use 22%
Methods used to calculate fertile period in natural family planning
changes in basal body temperature
changes in cervical mucus
tracking cycle days
combined approaches
Contraceptive protection of full breast feeding postpartum
Over 98%
AKA lactational amenorrhoea method
failure rates of natural family planning
perfect use 0.4-5%
Typical use 24%
When should emergency contraception be used?
After unprotected intercourse if there has either been failure of barrier method or a dose of hormonal contraception has been forgotten
Options for emergency contraception
Hormonal: single dose levonorgestrel 1.5mg
OR
Copper IUD
Use of hormonal emergency contraception
Must be used within 72 hours of unprotected intercourse
More effective if taken earlier
No contraindications to use (does not cause an abortion or harm an existing pregnancy)
Mechanism of action of hormonal emergency contraception
Unknown, likely disruption of ovulation or corpus luteal function depending on time in cycle that it is taken
prevents approx 75% of pregnancies
Use of copper IUD as emergency contraception
Can be inserted up to 5 days after single episode of unprotected intercourse at any stage in cycle OR 5 days after calculated earliest day of ovulation covering multiple episodes of intercourse
Give antibiotic cover if there is a risk of STI
Can remain in situ for ongoing contraception or removed once next menstrual period begins
same contraindications for general IUD contraception
Mechanism of action of copper IUD as an emergency contraception
prevention of implantation + copper ions exert embryotoxic effect
Failure rate of female sterilisation
Approx 0.1%
Options of female sterilisation
Tubal ligation (laparoscopic tube tying) - most common OR Tubal occlusion (Essure procedure - coiling)
Procedure of laparoscopic tubal ligation
Requires general anaesthesia (usually a day case though)
Small cut near umbilicus to insert laparoscope, used to close clips over the uterine tubes
Side effects of tubal ligation
+/- discomfort (often need a few days off work)
+/- pain under diaphragm or shoulder or abdomen immediately after procedure
How soon does tubal ligation offer contraception
immediately
Reversibility of tubal ligation
potentially reversible
50% chance of having a child after reversal but the high cost not covered by Medicare
Procedure involved in tubal occlusion
Sedation of woman
Hysteroscope passed through cervix, through which tiny metal coils are passed into each uterine tube
Tissue grows into the coil over about 3 months to permanently block the tubes
x-ray 3 months later to confirm complete occlusion
Sometimes a hysterosalpingogram is required to confirm success
Disadvantages of tubal occlusion
- Takes 3 months to work (additional contraception required)
- Unable to be performed successfully in 5% of cases
- Irreversible
- Cramping and pain after procedure
- Some bleeding or spotting for a few days after procedure
How long does it take for tubal occlusion to work as a successful contraceptive method
At least 3 months - additional contraception required until confirmed to be successful
How common is a vasectomy
1/4 men over the age of 40 have had it performed
Procedure of vasectomy
takes 15-20 minutes
Performed under general or local anaesthetic
Small cut made on each side of the scrotum - vas deferens is cut and small piece removed + ends of vas sealed with a stitch or diathermy
Semen analysis 12 weeks later to ensure no live sperm - re-check every 1-2 months until clear
Expected side effects of vasectomy
small amount of bruising and mild discomfort for a few days, relieved by OTC analgesics, ice packs and supportive underwear
Risks of vasectomy
Less than 1/20
- Infection
- Bleeding
- long-term scrotal pain (30% at 12 weeks, 6-8% at 12 months)
- Pain with ejaculation
(medications or [rarely] surgery can help with pain)
- Sperm antibodies (4/5 men) may affect sperm motility if reverse procedure
- Sperm granulomas - small lumps at cut end of vas due to local inflammation may need surgical excision
Failure rates of vasectomy
1/500
recanalization can develop to bypass vasectomy site months-years later
How long does it take for vasectomy to offer effective contraception
3 months - sperm needs to clear out of ducts - will be sped up with regular ejaculation
Other methods of contraception required until no live sperm are seen in semen
Vasectomy reversal success rates
Succeeds technically in 60-90% (only 40-70% will result in pregnancy after 3 years though)
Lower rates of success if: long time between vasectomy and reversal (e.g. 10-15 years), large amount of vas deferens removed or cut near epididymis, other blockages have developed in the epididymis
Suitable contraception for a woman with epilepsy
IF ON ENZYME INDUCING AGENTS
COCP - 50mcg AT LEAST of oestrogen (increase to 80-100 if breakthrough bleeding)
Depo Provera: suitable, but need to give 10-weekly rather than 12 weekly
IMPLANON IS NOT RELIABLE
If on lamotrigine with COCP, may need to increase lamotrigine dose as oestrogen reduces plasma concentration
