7. Contraception (lecture)

Question 1

what is the effect of oestrogen in early / middle follicular phase (before ovulation) on HPG axis?

Answer 1

negative feedback on anterior pituitary and hypothalamus (inhibit GnRH, LH, FSH)

Question 2

effects of oestrogen on HPG axis at ovulation?

Answer 2

positive feedback on anterior pituitary (LH surge) and hypothalamus (GnRH)

Question 3

effect of progesterone on HPG axis at lower doses?

Answer 3

progesterone doesn’t inhibit LH surge, ovulation still likely
progesterone will THICKEN cervical mucus

Question 4

what happens at moderate / high dose of progesterone at ovulation?

Answer 4

(corpus luteum release progesterone, HIGH oestrogen)

progesterone inhibits the positive feedback of oestrogen –> NO LH surge, NO ovulation

Question 5

what happens at moderate / high dose of progesterone on the HPG axis at early / mi-follicular phase? (before ovulation)

Answer 5

progesterone enhances NEGATIVE feedback of natural oestrogen - reducing LH and FSH secretion
(low oestrogen, negative feedback)

Question 6

what are common methods of contraception?

Answer 6

natural
barrier
prevention of ovulation
inhibition of sperm transport
inhibition of implantation
sterilisation (permanent)

Question 7

what are the natural methods of contraception?

Answer 7

fertility awareness methods

lactational amenorrhoea method

Question 8

what is fertility awareness method of contraception? (natural)

Answer 8

use of fertility indicators to identify fertile and infertile points of the menstrual cycle. using:
cervical secretions
basal body temperature (higher post ovulation)
length of menstrual cycle (when day 14 is approx.)

Question 9

what are the advantages of using natural methods of contraception?

Answer 9

no hormones
no contraindications (no drug harms)

Question 10

what are the disadvantages of using natural methods of contraception?

Answer 10

not as effective

unreliable

Question 11

what is the lactational amenorrhoea method of contraception? (natural)

Answer 11

breastfeeding delays the return of ovulation after childbirth

Question 12

how long is the lactational amenorrhoea method of contraception effective for? (natural)

Answer 12

only effective up to 6 months after birth

Question 13

what are the barrier methods of contraception?

Answer 13

male / female condoms

female diaphragm / cap

Question 14

what is the mechanism of action male / female condoms? (barrier)

Answer 14

prevents entrance of sperm into the cervix

Question 15

what is female diaphragm / cap also used with? (barrier)

Answer 15

diaphragm / cap also used with spermicide so additional CHEMICAL barrier

Question 16

advantages of barrier contraception?

Answer 16

can help prevent STIs

can be inserted anytime before intercourse

Question 17

disadvantages of male condom (barrier contraception)?

Answer 17

sensitivity / allergy to latex

Question 18

disadvantages of female condom (barrier contraception)?

Answer 18

not as widely available

Question 19

what is a disadvantage of barrier contraception?

Answer 19

need to use with spermicide (can cause a local reaction)

Question 20

what are the different pills used for prevention of ovulation?

Answer 20

combined oral contraceptive pill (COCP)
progesterone depot
progesterone implant

Question 21

why do progesterone pills work as a contraception?

Answer 21

at moderate / high doses, progesterone inhibits the positive feedback of oestrogen - no LH surge, no ovulation
(lower doses progesterone thickens cervical mucus, so progesterone needs to be high enough)

Question 22

what is progestogen?

Answer 22

synthetic form of progesterone

Question 23

what is the principle action of combine oral contraceptive pill (COCP)?

Answer 23

prevents ovulation

Question 24

what are the secondary actions of COCP?

Answer 24

Reduces endometrial receptivity to inhibit implantation

Thickens cervical mucus to inhibit penetration of sperm

Question 25

what are the advantages of COCP?

Answer 25

can relieve menstrual disorders | reduces risk of ovarian cysts and cancer (compared to just oestrogen)

Question 26

disadvantage of COCP?

Answer 26

user dependent

Question 27

side effect of COCP?

Answer 27

breakthrough bleeding breast tenderness mood disturbance

Question 28

what can COCP lead to increased risk of?

Answer 28

``` venous thromboembolism (clot in veins) myocardial infarction ```

Question 29

how do you take COCP?

Answer 29

taken either 21 days followed by 7 day break OR taken for 21 days with 7 days of 'dummy' pill

Question 30

what are progesterone depot AND progesterone implant's main mechanism of action?

Answer 30

prevents ovulation

Question 31

what are progesterone depot AND progesterone implant's secondary actions?

Answer 31

Reduces endometrial receptivity to inhibit implantation | Thickens cervical mucus to inhibit penetration of sperm

Question 32

what are the advantages of progesterone depot?

Answer 32

convenient | can also relieve menstrual disorder

Question 33

what are the disadvantages of progesterone depot?

Answer 33

Altered and irregular bleeding is common Delayed return of fertility for up to 1 year after stopping Not quickly reversible Small loss of bone mineral density and and possible increase in fracture risk

Question 34

what is progesterone depot?

Answer 34

synthetic progestogen

Question 35

how is progesterone depot administered?

Answer 35

via subcutaneous / IM injection, which is slowly released into systemic circulation

Question 36

how long does an injection of progesterone depot last for?

Answer 36

between 8-13 weeks

Question 37

what are the advantages of progesterone implant?

Answer 37

long duration of action convenient can also relieve menstrual disorders

Question 38

what are the disadvantages of progesterone implant?

Answer 38

small procedure required to fit and remove the implant local adverse effects can occur can cause changes in bleeding pattern

Question 39

how does progesterone implant work?

Answer 39

progestogen containing 4cm flexible rod implant which si inserted sub-dermally (under the skin) in the upper arm

Question 40

how long can progesterone implant last up to?

Answer 40

3 years