contraception Flashcards
Why use contraception?
-reduce termination rates
-for family planning
-reduce maternal mortality rate (as contraception became more common maternal mortality rate decreased)
-to regulate periods and balance hormones
the perfect contraception
- 100% Reliable
- 100% Safe
- Non User Dependent
- Unrelated to Coitus
- Visible to the Woman
- No ongoing Medical Input
- Completely reversible within 24 hours
- No Discomfort
Why do men not take the pill?
-women take it because they have control over it, and they can chose to take it
-men may not be trustworthy, may not take it leaving women with the consequences
contraception methods that require ongoing action:
- Oral Contraception
- Vaginal contraception - female diaphragm
- Barrier Methods
- Fertility awareness - know when you are less fertile, reduced risk
- Coitus interruptus- man removes his penis before ejaculation
- Oral Emergency contraception - after pill
contraception methods which prevent conception
by default:
- IUD
- Progesterone
implant/IUS/injection - Male Sterilisation
- Female sterilisation
what are limitations of ongoing contraception
=> take them correctly
=> take them at the right time so reduce risk of pregnancy
=> need to actively do things and can’t forget
reliability of different contraception methods
-100 women using that method of contraception
-without contraception use 85% get pregnant
-condoms typical use pregnancy risk is 18% and perfect use is 2% so it isnt full proof
UK medical eligibility for contraception 2016
- A condition for which there is no restriction of the method = always useable
- A condition in which the advantages of using the method generally outweigh the theoretical or proven risks = broadly useable
3.A condition where the theoretical or proven risks generally outweigh the advantages of using the method, use of method not generally recommended unless more appropriate methods not acceptable or available = counsel/caution - A condition which represents an unacceptable health risk if the contraceptive method is used = Do not use.
=> if there are no other methods then use 3/4 but try to avoid it if you can use 1/2
=> other medical conditions can affect risk
Combined oral contraception
-oestrogen and progestoGEN
1. oestrogen = ethinyloestradiol - 20, 30, 35, 50 micrograms (synthetic oestrogen)
2. progestogens
-older -2nd gen- Norethisterone (Norethindrone) & Levonorgestrel
-Newer (3rd gen) - Desogestrel, Gestodene & Norgestimate (Noregestromin)
- latest (derived from spironolactone)- Drospirenone
=> often the difference is the progestogen component and people get side effects due to the progetogen, so you can change the pill if side effects are bad to a different progestogen pill.
How does combined oral work?
- Oestrogen levels:
two major physiological effects of oestrogen:
-more than what you produce in menstrual cycle, high levels = negative feedback = not enough FSH/LH so you don’t have the follicular phase and don’t release the oocyte => no egg fertilised. - Higher progestogen levels
-negative feedback = block ovulation = also instead of having cyclical change, having high levels at all times causes endometrium to witch off = so you have thin endometrium so can’t get pregnant, the cilia action doesn’t work so sperm doesn’t get in, progestogens thicken the cervical mucus, acts as a physical barrier to stop sperm getting in.
=> just oestrogen you get proliferation of the endometrium (gets thicker) and progestogen causes atrophy (gets thinner) so giving the COC in low oestrogen ratio to high progestogen ratio so the net effect is the endometrium to become thin.
basic principles of COC
-supra-physiological levels of pregnancy
-“pseudo-pregnancy” because all these hormonal and endometrial changes happens when a women is pregnant so the body thinks you’re pregnant - so no more periods too.
-suppression of the HPO axis
in reality : pharmacokinetics, highly variable
-individual serum levels vary
-suppression may not be absolute
-follicular activity possible in some
-breakthrough bleeding in some
=> some women have high pharmacokinetic activity so the pill is broken down very quickly, so the suppression of the HPO axis is removed and folliculogenesis occurs but still no pregnancy bc of other changes like thickened mucous, thin endometrium.
Benefits of COC
- Reliable
- Safe
- Unrelated to coitus
- Woman in control
- Rapidly reversible
- Halve ovarian cancer risks bc endometrium has not been proliferating in a long time
- Halve endometrium cancer
- Helps endometriosis, premenstrual syndrome,
dysmenorrhoea, menorrhagia - bc you have no cycle going on so all period symptoms go - Can stop periods if taken continuously
Risks of COC
- Cardiovascular
- Arterial – Progestogen , HBP, smoking (>35)
- Venous – Oestrogen-VTE-clotting disorders
(DVT,PE, Migraine) - Neoplastic - Breast - no, Cervix – no , Liver cancer
- Gastrointestinal – COH/insulin resistance , Weight gain?
- Hepatic – hormone metabolisms, congenital non-haemolytic jaundices, gall stones.
- Dermatological – Chloasma, acne, erythema multiforme
- Psychological – Mood swings, depression, Libido
=> can affect all over the body bc oestrogen receptors are found all over the body
Contraindications of oestrogen and progesterone
=>Breast cancer; undiagnosed genital bleeding; pregnancy; <3 weeks post partum; breast feeding; hypertension; PH
thrombosis; migraine with aura; active liver disease;
thrombophilia; systemic lupus erythematosus; thrombotic thrombocytopenic purpura; smoking >15 and age >35
=>Relative contraindications: BMI>35;migraine without aura; hypertension; diabetes; hyperprolactinoma;
Drugs which induce liver metabolism and
reduce hormone levels
- Griseofulvin
- Barbiturates
- Lamogitrine
- Topiramate
- Carbamazepine
- Oxcarbazepine
- Phenytoin
- Primidone
- Rifampicin
- Modafinil
- Certain antiretrovirals
=> they all induce enzyme cytochrome P60 complex which will break down the drug
pill rule : how to take it?
- Start 1st packet 1st day of a menstrual period
- Take 21 pills and stop for 7 day break (PFI)
- Restart each new packet on 8th day (same)
- Do not start new packets late keep going
- If late or missed pills in 1st 7 days, condoms
- If missed pills in last 7 days no PFI
combined vaginal contraceptive
-same as COCP except vaginal delivery (ring) for 21 days, ring has oestrogen and progestogen
-remove for 7 days - to bleed so you know you’re pregnant
-advantage -don’t have to take every day
-disadvantage - don’t have to take every day
Progestogen only methods
- default methods
- user dependent methods
- implants : Nexplanon(ETN), Norplant(LNG)
- hormone releasing IUCD: Mirena IUS (LNG), Jaydess IUS(3 years), Kyleena IUS(4 years)
- injectables - Depo Provera (MPA)
