Contraception

Question 1

Problems with coitus interrupt us and rhythm method?

Answer 1

Coitus interruptus
-get sperm in pre-ejaculate produced by bulbourethral glands

Rhythm method

• need a regular cycle
• assume sperm survives 7 days and ovum for 1 day so in a regular 28 day cycle with ovulation on day 14/15, fertile period is days 7-16

Question 2

What happens in a vasectomy?

Answer 2

Vas deferens are divided bilaterally

Question 3

What needs to be checked before relying on a vasectomy?

Answer 3

That the ejaculate is free of sperm

Question 4

Barrier methods of contraception?

Answer 4

Condoms
Diaphragm
Cervical cap

Question 5

Where does the diaphragm go and how does it work?

Answer 5

Lies diagonally across cervix

Holds sleep in acid environment, reducing survival time

Question 6

Problems with the diaphragm?

Answer 6

Does not completely occlude passage of sperm

Question 7

Different hormonal contraception methods?

Answer 7

Combined OCP
Depot progesterone
Progesterone-only pill
Progesterone implant

Question 8

How does the combined OCP work?

Answer 8

Contains oestrogen and progesterone
Get negative feedback to the hypothalamus/pituitary, inhibiting follicular development
Progesterone causes loss of positive feedback by oestrogen so get no LH surge and ovulation
Makes cervical mucus thick and hostile
Inhibits implantation

Question 9

How does depot progesterone work?

Answer 9

3 monthly injection of progesterone
Negative feedback inhibits ovulation
Makes cervical mucus thick and hostile
Inhibits implantation

Question 10

How does the progesterone-only pill work?

Answer 10

Inhibits implantation
Causes cervical mucus to become thick and hostile (main action)
May inhibit ovulation by negative feedback to hypothalamus and pituitary

Question 11

How does the progesterone implant work?

Answer 11

Causes cervical mucus to be thick and hostile, preventing sperm from passing through the cervix (main mode of action)
Inhibits implantation

Question 12

How can the Fallopian tubes be occluded? Rate of recanalisation?

Answer 12

Clips, rings, ligation

1:300-500

Question 13

How does hormonal contraception inhibit implantation?

Answer 13

Affects receptivity of endometrium

Absence of corpus luteum prevents preparation of the endometrium for implantation

Question 14

How does post-coital contraception work?

Answer 14

Combine oestrogen and progesterone at a high dose or progesterone only
Can be given up to 72hrs after intercourse
May disrupt ovulation and block implantation
May impair luteal function

Question 15

How does the intra-uterine device work?

Answer 15

It can be copper, inert or progesterone impregnated
Copper interferes with endometrial enzymes and sperm transport into Fallopian tubes
Also affects implantation

Can be used as post-coital contraception up to 5 days after ovulation

Question 16

Methods of natural contraception?

Answer 16

Abstinence
Coitus interrupt us
Rhythm method