methods of contraception

Question 1

list the major classes of contraceptive drugs

Answer 1

• hormonal
• barrier
• IUDs
• permanent
• natural

Question 2

how does progesterone exhibit its actions?

Answer 2

• mimics the high levels of hormones during the luteal phase exhibiting negative feedback on the HPG axis
• constant exposure to P suppresses ovulation
• causes thickening of cervical mucus decreasing endometrial receptivity further reducing the likelihood of pregnancy

Question 3

how does oestrogen increase the effects of progesterone?

Answer 3

• exerts additional negative feedback and induces Progesterone receptor expression
• also aims to improve the cycle control decreasing episodes of irregular bleeding

Question 4

how does Mifepristone work?

Answer 4

• selective progesterone receptor antagonist

Question 5

why does the barrier method have a higher rate of failure than hormonal methods?

Answer 5

• due to design
• human error
• more effective if taken in combination with other therapies

Question 6

what is a condom?

Answer 6

• most common and effective when used properly
• effectiveness 85-98%
• prevention of pregnancy and STIs
• both female /male

Question 7

what is the effectiveness of the cap?

Answer 7

84-94%

Question 8

what are intrauterine devices?

Answer 8

• placed within uterus –> copper (spermicidal)
• lasts 5-12 yrs -LARC
• extremely effective without using hormones 99%

Question 9

how do IUDs exhibit contraceptive action?

Answer 9

• increase release of leukocytes and PGs by endometrium which are hostile to both sperm and embryos
• presence of copper increases spermicidal effects
• post fertilisation mechanisms also contribute to their effectiveness

Question 10

how does mirena IUS work?

Answer 10

• acts as an IUD
• continuously releases small amounts of progestin of which leads to atrophy and bleeding of endometrium
• thickening of cervical mucus suppressing ovulation

Question 11

what current permanent methods are in use?

Answer 11

• permanent sterilisation
• female -> uterine tubes
• male-> vasectomy (vas deferens)

Question 12

natural methods include

Answer 12

• the rhythm method (menstrual cycle)
• fertility awareness method (monitoring temp, cervical mucus production)
• natural cycles app
• coitus (withdrawal)
• prolactin suppresses the HPG axis
• abstinence