T2 L5 Fertility Control Flashcards
What mechanisms will create temporary, reversible infertility in a female?
Stopping ovulation
Stopping LH surge
Why are levels of progesterone high during pregnancy?
They stop LH surge to stop ovulation. Prevents you getting pregnant again
What are the effects of giving progestogens?
Prevent ovulation by stopping LH surge
Thicken cervical mucus
Hostile endometrium
Why does giving progestogens cause a hostile endometrium?
Progesterone causes thickening of the endometrium to cease and not become secretory.
If the endometrium remains very thin it will be hostile
What is the risk of pregnancy with a progesterone-only contraception?
5%
What is the risk of pregnancy if using no contraception?
80% in the first year
What is the risk of pregnancy with the combined oral contraceptive pill?
0.03% per year provided it is taken correctly
What happens during the 7 pill free days?
The thin endometrium breaks down causing a withdrawal bleed
What is the purpose of the withdrawal bleed?
Acts as a pregnancy test
Thought that it would help prevent endometrial cancer but there the evidence for this is slim
What happens if you miss a pill when taking COCP?
If the pill is missed in the middle of the pack, chances of pregnancy are very low
If the pill is missed at the start or end there is an increased risk of pregnancy
Why does missing a pill at the start / end increase the risk of pregnancy?
You’ll have 9 or 10 drug-free days so Graafian follicles can develop and the ovum starts to mature causing risk of ovulation
Give some examples of progesterone-only oral contraceptives
Norethisterone
Levonorgestrel
Desogestrel
Describe how progesterone-only oral contraceptives work
Inhibit ovulation by suppressing LH surge
Thicken cervical mucus and render the endometrium hostile
What are the adverse effects of progesterone-only oral contraceptives?
Menstrual irregularities Nausea Vomiting Headache Breast discomfort Weight changes Changes in libido
Describe how COCP works
Mixture of oestrogen and progesterone
Oestrogen prevents follicular development by suppression of FSH
Progesterone inhibits ovulation by suppressing LH surge, thickening cervical mucus and rendering endometrium hostile
What are the adverse effects of combined-oral contraceptives?
Nausea Vomiting Abdominal cramps Fluid retention Changes in body weight Hepatic impairment Cardiovascular changes Breast tenderness Cervical erosion Exacerbation of migraine Chloasma Mood changes
Describe intrauterine non-hormonal contraception
Piece of plastic that causes local sterile inflammatory response so the fertilised ovum can’t implant into the uterus
IUDs are the most effective form of contraception
IUS is an IUD that releases progestogen into the uterus
Describe implants
Solid rings that release progestogen
Inserted under the skin
Release progestogen over a period of 3 years
No drug-free period
Very reliable method and there are no issues with drug absorption
Describe vaginal contraception
Silicon ring that releases hormones
Left in for 21 days, taken out for 7 days for a withdrawal bleed then put back in
Can be taken out for up to 3 hours
What are the 2 types of emergency contraception?
Levo-norgestrel
Ulipristal
Describe the use of levo-norgestrel
Take for 2 days which blocks LH surge
70-80% effective depending on the day used
-if ovulation has already occurred then it is too late
-won’t prevent a pregnancy if ovulation has occurred so if intercourse has taken place in day 12-16. However, they can disrupt implantation
Describe the use of ulipristal
Blocks progesterone receptor but has slight agonist properties (partial agonist)
More effective as it prevents the endometrium from developing
What drug is used to induce abortion?
Mifepristone
Describe the use of mifepristone
Progesterone antagonist which means the endometrium can’t support pregnancy so the pregnancy is terminated
What mechanisms will create temporary, reversible infertility in a male?
Block sperm production
Give testosterone to block FSH and LH
Give oestrogen or progesterone to block LH which stops production of testosterone
How long will a drug that blocks testosterone take to stop sperm production?
3 months as sperm takes 3 months to develop
It’ll take 3 months after stopping treatment for sperm production to return to normal
What can happen if you give progesterone to men?
It will block LH and testosterone so it can cause loss of male secondary sexual characteristics:
- male pattern pubic hair
- muscle development
- sperm production
How can male secondary sexual characteristics be conserved when giving progesterone?
Also give testosterone to make up for the loss of endogenous testosterone
