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)
Examples of POPs
-Norethisterone
- Ethynodiol diacetate
- Levonorgestrel
- Norgestrel
Where does progesterone act?
- anterior pituitary and hypothalamus
-on endometrium
-on the fallopian tubes
-on cervical mucus
POP basic principles
- Delivery method is user choice
- Systemic side effects (e.g. headache / bloating / acne) depend
upon systemic absorption - Effect on cervical mucous and endometrium highly reliable
- Effect on HPO suppression less reliable – some women
ovulate! - Irregular bleeding is potential issue for ALL methods
Why Desogestrel is taking over the world:
- As effective as COCP
- No oestrogen – CIs e.g. breastfeeding
- Favourable side effect profile vs older POPS
- Bleeding as predictable as COCP – probably not quite as good!!
- 12 hour window
IUCDs
Copper bearing intrauterine contraceptive devices are inserted
into the uterus by suitably trained practitioners and may be left
in situ long term and act by
* 1. Destroying spermatozoa
* 2. Preventing implantation – Inflammatory reaction and
prostaglandin secretion as well as a mechanical effect.
IUCDs types?
- copper bearing
-Ortho T 380 – 8 -12yr
- Multiload 375 – 5yr
- Multiload 250 – 5yr - Hormone bearing:
-Mirena (IUS) – 5yr
-Jaydess – 3 years
-Kyleena IUS (4 years)
IUCDs Benefits
- Non user dependent
- Immediately and retrospectively effective
- Immediately reversible
- Can be used long term
- Extremely reliable
- Unrelated to coitus
- Free from serious medical dangers
IUCD disadvantages
- Has to be fitted by trained medical personnel
- Fitting may cause pain or discomfort Periods may become
heavier & painful – what have they just stopped using??? - It does not offer protection against infection
- Threads may be felt by the male
IUCDs risks
- May be expelled
- The uterus may be perforated – very rare
- Miscarriage if left in situ if a pregnancy
- ? ectopics
IUCDs absolute contrindications
- Current pelvic inflammatory disease
- Suspected or known pregnancy
- Unexplained vaginal bleeding
- Abnormalities of the uterine cavity
IUCDs relative contraindications?
- Nulliparity
- Past history of pelvic inflammatory disease
- Not in mutually monogamous relationship
- Menorrhagia / Dysmenorrhoea
- Small uterine fibroids
=> NO
Condom advantages: females
- Woman in control
- Protects against STIs
- Can be put in in
advance and left
inside after erection
lost - Not dependent on
male erection to work
condom advantages: males
- Man in control
- Protects against STIs
- No serious health
risks - Easily available (free
at Family Planning
clinics)
Condom disadvantages: female
- Obtrusive
- Expensive
- Messy
- Rustles during sex
- Uncertain failure rate
Condoms disadvantages: males
- Last minute use
- Needs to be taught
- May cause allergies
- May cause psycho sexual difficulties
- Higher failure rate among some couples
- Oily preparations rot rubber
Caps
- Diaphragm
-* Made of latex
* Fit across vagina
* Sizes 55 – 95mm in 5mm jumps
* Must be used with spermicide
and left in at least 6 hours
after sexual intercourse - suction (cervical) caps
* Made of plastic
* Suction to cervix or vaginal vault
* Different sizes
* Must be used with spermicide and left in 6 hours or more.
Fertility awareness
- Prediction of ovulation ? 14/7 before period
- Sperm can survive 5 days in female tract
- Ova can survive 24 hours
- Ova are fertilised in the fallopian tube and take 4 days to reach the uterus and implant
- Cervical mucus is receptive to sperm around the time of ovulation
- Use Periodic Abstinence/alternative contraception to avoid pregnancy
- Time intercourse to pre-ovulatory phase to conceive
Natural (contraception) family planning
- Temperature
- Rhythm
- Cervix position
- Cervical mucus- thicker
- Persona - natural method of contraception that works by monitoring hormone changes in a woman’s urine to identify the days of her menstrual cycle when she is most likely to get pregnant.
- Lactational amenorrhoea (LAM) - unlikely to get your period when you breastfeed, so women use this as a natural form of contraception
Fertility awareness advantages:
- Non medical
- Can be used in 3rd world
- Allowed by Catholic church
- Can result in closeness of
understanding between
partners
fertility awareness disadvantages:
- Failure rate heavily user
dependent - Requires skilled teaching
- May require cooperation between
partners - May involve limiting sexual activity
- Can cause strain
postcoital pills
- Up to 72 hours after unprotected sexual intercourse (UPSI)
- Act by postponing ovulation in 1st part of the cycle – So beware!
- Act by preventing implantation in 2nd part of the cycle
- Schering PC4 – prevents 3 out of 4 pregnancies which would have occurred
- Levonelle – prevents 7 out of 8 pregnancies
- ellaOne (ulipristal)– similar
=> even if ovulated endometrium is altered so implantation wont take place.
Copper bearing IUCDs
- Up to 5 days after presumed
ovulation or 5 days after one single episode of UPSI at any time of the cycle - Failure extremely rare
- Copper kills sperm in 1st part of the
cycle - Device prevents implantation in 2nd
part of the cycle
Levonelle 2
-consists 2 tablets each containing 750 microgram of levonorgestrel
-1.5mg one dose
-lower failure rate in 1st 24hrs
-very little nausea
-only contrained in women taking very potent liver enzyme medication (anti TB)
PC4 (no longer available but people still self administer)
- Lower failure rate in 1st 24
hours. - Causes nausea & vomiting in
many women - Contraindicated during focal
Migraine attack
ellaOne - ullipristal acetate
- New selective progestagen receptor modulator (SPeRM)
- Up to 120 hours
- Similar rates of pregnancy vs Levonelle
- Possible slightly higher side effect profile – GI symptoms mainly
Levonelle 2 effectiveness
Up to 24hrs – 95%
25 – 48 hrs - 85%
49 – 72 hrs- 58%
Schering PC4 effectiveness
Up to 24 hrs – 77%
25 – 48 hrs – 36%
49 – 72 hrs – 31%
