Contraception and HRT Flashcards
List 3 ways by which contraception prevents pregnancy.
1 - Preventing ovulation.
2 - Preventing fertilisation.
3 - Preventing implantation.
Which event marks the beginning of pregnancy?
Implantation.
What is the PEARL index?
The failure rate of a contraceptive per 100 years of use.
List 4 contraceptives with no potential for user failure.
1 - Intrauterine devices such as copper coils.
2 - Intrauterine systems such as levonorgestrel.
3 - Hormone implants.
4 - Sterilisation.
List 3 contraceptives with potential for user failure.
1 - Barrier contraceptives.
2 - Hormonal drugs.
3 - Lactational amenorrhoea.
How do levels of oestrogen and progesterone differ between pregnancy and the combined contraceptive pill?
- In pregnancy, oestrogen and progesterone increase until delivery.
- With the combined pill, oestrogen and progesterone stay at a constant level.
What is the typical failure rate of male condoms?
How does this compare to the failure rate with perfect use?
- Male condoms have a 17% failure rate with typical use.
- Male condoms have a 2% failure rate with perfect use.
What is the typical failure rate of female condoms?
How does this compare to the failure rate with perfect use?
- Female condoms have a 21% failure rate with typical use.
- Female condoms have a 5% failure rate with perfect use.
List 2 barrier methods other than condoms.
How are they used?
1 - Diaphragms.
2 - Caps.
- They are inserted into the cervix and used in combination with spermicides.
What does LARC stand for?
List 4 advantages of LARCs.
- Long-acting reversible contraception.
1 - Effectiveness doesn’t depend on memory or use.
2 - More effective than other forms of contraception.
3 - Cost-effective.
List 4 LARCs.
1 - Intrauterine systems.
2 - Intrauterine devices.
3 - Implants.
4 - Progesterone only injection.
What are intrauterine systems?
Describe the mechanism of action of intrauterine systems.
- Intrauterine systems are small, plastic T-shaped devices that are inserted into the uterus.
- They gradually release levonorgestrel, a progesterone analogue. This causes:
1 - Thinning of the endometrium.
2 - Thickening of the cervical mucus.
3 - Inhibition of ovulation by negative feedback of FSH and LH.
What is the failure rate of intrauterine systems?
<1%.
What are intrauterine devices?
Describe the mechanism of action of intrauterine devices.
- Intrauterine devices are small, plastic T-shaped devices with copper on the stem / arms that are inserted into the uterus.
- They are directly toxic to both the sperm and the egg.
- If fertilisation occurs, they prevent implantation by inducing a foreign body reaction.
What is the failure rate of intrauterine systems?
<1%.
Describe the mechanism of action of implants.
They release etonogestrel, a progesterone analogue, to:
1 - Prevent ovulation by negative feedback of FSH and LH.
2 - Thicken cervical mucus.
What is the failure rate of implants?
<1%.
What is the main injectable contraceptive?
Which drug does it contain?
- Depo-provera is the main injectable contraceptive.
- It contains medroxyprogesterone acetate, a progesterone analogue.
List 2 injectable contraceptives other than Depo-provera.
1 - Sayana Press.
2 - Norethisterone enanthate.
List 3 combined hormonal contraceptives.
1 - Combined pill.
2 - Patch.
3 - Vaginal ring.
List the mechanisms of action by which hormonal contraceptives prevent pregnancy.
- Primary mechanism: prevent ovulation by negative feedback of FSH and LH.
- Secondary mechanism: thickens cervical mucus and thins endometrium.
Which hormones are contained in combined pills?
Oestrogen and progesterone.
What is a hormone-free gap?
The period in which a person taking a combined pill stops taking the medication to allow for withdrawal bleeding.
List the drugs contained in combined vaginal rings.
1 - An oestrogen analogue.
2 - Etonogestrel, a progesterone analogue.
