Contraception Flashcards
Contraception: What are the advantages of contraception?
Choice
control (for personal or medical reasons)
Family spacing (and associated health concerns)
Cost
saves lives globally
What are some of the disadvantages of contraception?
Changes in sexual habits
Increased promiscuity
medical complications
cost
What are some of the key considerations in contraceptive consultation?
- Health (obesity)
- age (16 yrs and consent, vs older woman)
- desire for fertility
- social/ religious/ ethical (e.g. certain religins dictate no contraception may be used)
- education
- compliance
- cost
Contraceptive methods
Which is the least reliable?
- Natural/ physiological (generally least reliable)
- Barrier (Condoms/ female condom)
- Hormonal
- Surgical
- Overlap –> use more than one type.
Natural physiological methods of contraception?
- Rhythm method –> prevent sperm/ egg interaction
- Coitus interruptus
- Lactation –> prevent ovulation (theoretically and only with exclusive regular feeding)
Rhythm method: what is it?
Meaning in rhythm with a woman’s natural fertility
Ovum has limited period of fertility.
Avoid intercouse in the fertility window 4-5 days prior and 1-2 days after a predicted ovulation.
Rhythm method:
Advantages?
Disadvantages?
Advantages:
- Cheap/ no side effect
- no contraindications
- no religious/ ethical issues
Disadvantages:
- Limit sexual activity
- Failure rate, failure of compliance (however failure rate more recently mitigated by ovulation tests).
- Requires Education (3-6 months)
What methods may be used to predict the timing of the fertile window?
- Basal body temperature (rises post ovulation)
- Vaginal mucus (watery pre ovulation)
- Hormone levels (spike in oestrogen pre ovulation.)
Lactation: MOA?
Regular and exclusive breastfeeding:
Prolactin inhibits the secretion of FSH
suppression of the HPO axis –> no ovulation
Six months
–> risk of failure rate and miscommunication risk between dr. and patient
Coitus interruptus : MOA?
Penile withdrawal before ejaculation
Significant failure rate
Advantages and disadvantages to rhythm method: (Cheap/ no SE’s/ religious or ethical BUT Limits sexual activity, FAILURE RATE).
No STI protection
Barrier methods
What are they?
MOA?
- Condom (disadvantage –> risk of a tear)
- Diaphragm
- Cervical cap
- Plus –> spermicide
MOA –> prevents sperm/ egg interaction
Barrier method: Diaphragm/ cap
MOA
Advantages
Disadvantages
- MOA: Covers the cervix, preventing sperm egg interactions.
-
Advantages:
- Can be covered in spermicide as extra precaution
- not usually felt by partner during intercourse
- increased agency over fertility, no need for hormones
- discreet
-
Disadvantages:
- Requires professional fitting
- Needs to be left in 6 hours after sex
- requires proper education on its use
- can cause infection if it is left in for too long
- NO STI PROTECTION
Condom:
MOA
Advantages
Disadvantages
MOA: prevent sperm- egg interaction
Advantages: Cheap, readily available, STI PROTECTION
Disadvantages: Latex allergy, some sensation loss/ interruption / accidents, education requires (beware oil based lubricant).
What is LARC?
Moa?
Long acting reversible contraception (LARC), also known as intrauterine contraceptive device (ICD) or intrauterine device (IUD)
MOA: The copper IUD releases copper which is a spermacide and mechanically prevents implantation
Advantages of the LARC/ IUD?
Advantages:
- Long term (12 yrs)
- will not limit/ interrupt sexual activity
- IUCD copper no artifical hormones
- amenorrhea (no period yaaaas)
- decrease dysmenorrhea (pain during period)
- partner unaware, however strings required to know still in place, risk of pulling.
Disadvantages of LARC/IUCD?
Decreased libido
irregular bleeding
amenorrhea (may be seen as benefit)
cost
invasive
NO STI PROTECTION
When is IUCD particularly indicated for?
- Long lasting contraception needed (last 1- 12 yrs)
- When you think compliance may be an issue
- Cost effectiveness
- Older/ parous –> useful in older/ parous people (difficult to insert in preparous cervix)
- Emergency contraception if implanted within 5 days of unprotected sex (copper is embryotoxic).
Complications of IUCD?
Expulsion
perforation
infection (pelvic inflammatory disease)
Bacteria inserted via IUCD insertion may lead to fallopian tube closure, and increased risk of ectopic pregnancy
IUDC side effects?
- Copper/ inert –> bleeding (can be heavy or irregular or lighter), cramping (can be better or worse)
Terminating a pregnancy:
Legal at what stages of pregnancy?
Causes?
Used as an opportunity to?
Abortion is legal to 24/40 weeks in UK.
Due to failure of contraception or lack of contraception
Can be the last chance to educate.
Terminating a pregnancy:
Methods
Methods:
Up to 9/40 weeks –> MEDICATION:
Mifepristone/ misoprostol ( extra –> mifepristone = antiprogesterone, blocks effects of progesterone making cervix easier to open, promotes contraction of uterus when exposed to misoprostol. Misoprostol = prostaglandin analogue causes strong myometrial contractions and expulsion of tissue. )
Surgical 9-15/ 40 weeks: (up to 15 weeks)
Vaccum aspiration followed by dilation and curettage (dilation of the cervix and surgical removal of the lining of the uterus by scraping/ scooping)
Surgical sterilisation: MOA?
M and F method?
Disadvantages?
MOA -> prevent sperm egg interaction
M –> vasectomy (failure rate 0.05% possibly less)
F –> tubal ligation (failure rate 0.5%)
Disadvantages:
- Irreversible
- counselling recommended due to knock on psychological effects
- cost
- invasive
- failures
- no STI protection
Oral hormone contraceptives (steroidal contraceptives/ “the pill”)
What is the general MOA?
Two main types?
Synthetic steroid hormones that mimic the functions of oestrogens and progesterone.
1) Combined oral contraceptive pill --> oestrogen and progesterone
2) Oral mini pill contraceptive –> Progesterone only oral contraceptive pill
What are the molecular mechanisms of the oral contraceptive pill?
- Oral contraceptives act upon oestrogen and progesterone receptors which are INTRACELLULAR TRANSCRIPTION FACTORS
- ER alpha and ER beta (oestrogen); PR-A and PR-B (progesterone)
Do not need to worry about this but:
names of synthetic oestrogen
names of synthetic progesterone
Synthetic Oestrogen –> ethinylestradiol
Synthetic progesterone –> desogestrel and levonorgesterl
Pharmokinetics of the oral contraceptives/ steroid hormones?
Action IC?
- Steroid hormones diffuse across cell membranes to reach IC receptors
- Binding of hormone to latent complex receptor made up of HSP90 chaperone molecule
- Hormone binding displaces HSP90, forms dimeric active complex
- translocates into cell nucleus
- active receptor dimers then form and influence extensive gene expression
What is the primary MOA of oral contraceptives?
Primary MOA -> Suppression of ovulation
Ovulation is driven by endocrine dynamics and the relative TIMING of hormone secretion and activity
Drugs based on oestrogen/ progesterone taken at right times disrupt critical endocrine events required for ovulation
progesterone can exert additional effects that can disrupt fertilisation and implantation.
Where is progesterone produced?
How do progesterone levels change during the menstrual cycle?
Progesterone produced by the corpus luteum during menstrual cycle post ovulation.
High during the luteal phase and very low during the follicular phase.
With NO embryo implantation, the corpus luteum disintegrates, progesterone levels fall, contributing to menses. The cycle resumes.
With POSITIVE embryo implantation, the corpus luteum is sustained and progesterone levels remain HIGH -> promoting pregnancy.
In which phases of the menstrual cycle is progesterone particularly low?
In which phase is it particularly high?
High during the luteal phase –> suppresses secretion of FSH and LH (do not want follicular maturation during this phase of the cycle, preparing for pregnancy)
LH surge critical for ovulation
Progesterone Low in follicular phase –> allows FSH and LH release to mature follicles and ovulate
What is the action of progesterone alone?
Why would we use a combination of oestrogen and progesterone?
Progesterone –> negative feedback which inhibits luteinizing hormone and FSH release from the anterior pituitary gland, essentially preventing maturation and ovulation.
High doses are required but can cause significant nausea and not 100% effective.
Combination of oestrogen and progesterone augment one another, when administered at specific time achieves > 99.8% effectiveness
When is the progesterone only “mini pill” particularly indicated?
Progesterone only pill used for emergency contraception and in situations when oestrogen derived complications/ risks occur.
MOA progesterone
Progesterone acts on ant pit and hypoT in -ve feedback system
suppresses FSH and LH synthesis
High progesterone early in follicular phase lowers FSH and LH synthesis/ activity -> inhibit ovulation
Effects of progesterone on endometrium?
Asynchronous high level of progesterone:
inhibits endometrial gland development –> makes implantation less favourable
Thickens cervical mucus –> inhibits sperm motility
Common adverse effects of oral contraceptives?
Increases the risk of what conditions?
Depression, Nausea, Breakthough bleeding (Do Not Bone)
Increased risk of CV complications w oestrogen containing oral contraceptive:
HITS:
HTN
IHD
Thromboembolism
stroke
-> plus evidence of slight increase in breast CA risk w long term use
Benefits of contraception (beyond contraceptive effects)?
Relief of endometriosis, dysmenorrhoea (painful period) , menorrhagia (heavy, prolonged bleeding)
Acne control in women (oestrogen) (note can be side effect of progesterone pill)
Progestogens reduce risk of endometrial cancer (orally and with IUS)
What is an intrauterine system?
How long does it work for?
How effective is it?
what can it also treat?
Intrauterine system (e.g. mirena coil) incorporates a progestogen releasing polymer component into the intrauterine device.
Works for 3-5 yrs
Very effective contraceptive system can also treat conditions such as menorrhagia.
