Lecture 11: Contraception

Question 1

What is the definition of contraception:

Answer 1

A method of preventing pregnancy via interference with ovulation, fertilisation or implantation.

Question 2

Why is contraception important?

Answer 2

50% pregnancies are unplanned

NZ has 21.3 per 1000 teenagers having kids… unplanned

Question 3

Whats the law around informed consent and competence? - with regards to contraception

Answer 3

The law: There is no restriction on prescribing contraception to under 16s without parental consent

Informed consent relies on an assessment of competence

Question 4

What are the theoretical ways of contraception:

Answer 4

1. Physical barrier
2. Sperm impairment
3. Prevent ovulation
4. Prevent implantation

Question 5

Compare and contrast perfect vs typical use of contraceptions:

Answer 5

18% failure rate of condoms with typical use of condoms and 2% with perfect use

Combined oral pill 9% typical use and 0.3% perfect use.

Question 6

What are the UK Medical Eligibility Criteria:

Answer 6

MEC-1 No restriction on use.
MEC-2 Advantages outweigh disadvantages
MEC-3 Disadvantages outweight advantages
MEC-4 Do not use.

Question 7

What is the mechanism of action for the combined oral contraception:

Answer 7

COC: Estrogen + Progesterone.

• Suppress ovulation
• Reduce sperm transport in upper genital tract (FT)
• Change in endometrium making implantation less likely

Mainly: Thicken cervical mucus (preventing sperm penetration

Question 8

How many COC formulations are there?

Answer 8

29 different formulations

• Find the one with least side effects

Question 9

What are the combined OCP advantages?

Answer 9

• Convenient
• Familiar
• Reversible
• Lighter, less painful periods
• Lower risk of ovarian and colorectal cancer
• In reality this is what most women know, and so it is what they request.

Question 10

What are the OCP side effects and risks?

Answer 10

• NO EVIDENCE weight gain or depression
• Headaches - mainly pill free interval
• Increase risk of venous thromboembolism
• Increased CVA
• Increased hypertension
• Increased risk of breast cancer
• (CAREful risk assessment required)

Question 11

What are some medical conditions that are to consider when prescribing combined OCP:

Answer 11

• Focal migraines (MEC4)
• Smoking status
• Weight (BMI 35+ is MEC3)
• Blood pressure
• Poorly controlled diabetes

Question 12

Why bother with the pill free interval?

Answer 12

• Its not a real period
• Sleeping ovaries awake, FSH rise…
• Cant start next late….
• Side effects more common during this time i.e headache

Question 13

What are the 3 ways to take the pill:

Answer 13

Period each month (7 days non-hormone pills)

Have period every few months (just have 7 non-hormone pills when you want to have period)

Not have period, take hormone pills continuously

Question 14

What is the POP?

Answer 14

Progesterone Only Pill

Question 15

How does the POP work?

Answer 15

Mainly by thickening cervical mucous 
- Withint 48hrs
Ovulation supression may occur
- Depends on dose conc.
No PFI (hormone free period- which only came about cus of religion)

Useful if unable to take the OCP, or if breast feeding

Question 16

Noriday and cerazette are two types of POP, decrease them:

Answer 16

Noriday

• Mini pill
• Relies on cervical mucous effect
• 3h window

Cerazette

• Cervical mucus effect
• Higher rate of suppression of ovulation
• 12h window

Question 17

What are the side effects of POP?

Answer 17

Progesterone effects: Breast, tenderness, headaches, nausea

Irregular bleeding is common, less so with cerazette

Few contraindications compared with OCP

Question 18

What are LARCs? how do they work?

Answer 18

Long acting reversible contraception

• Administered once month
• Cost effective after one year use
• Main choice of youth
• Training and accessibility i.e cost are issues

Question 19

How does the depo provera work?

Answer 19

Suppresses hormones responsible for ovulation

Thickens cervical mucus to block sperm

Question 20

What are the benefits, risk and side effects of depo provera:

Answer 20

12 weekly injections

Prolonged amenorrhoea / irregular bleeding
Progestogenic side effects

Weight gain in some
Reversible dec in bone density
Delayed return to fertility (av six months)

Estrogen free - fewer restrictions than OCP

Question 21

How does jadelle work?

Answer 21

Prevents implantation

Question 22

Describe the benefits, risks and side effects of jadelle?

Answer 22

5y lifespan
irregular bleeding
Progestogenic side effects
CI- Breast cancer, allergy to jadelle, undiagnosed vaginal bleeding

Enyme inducing drugs i.e st john wort

Question 23

How does the copper IUD work?

Answer 23

Sperm impairment

Prevents implantation

Question 24

What are the benefits, risks and side effects of the copper IUD:

Answer 24

Hormone free
Lasts ten years
Infection risk exceptionally low
Gold standard emergency contraception
Periods may be heavier, longer or more painful
Expulsion ~5%, perforation 0.1%
Increased risk of ectopic (minor)

Can be used as emergency contraception (copper one only)

Question 25

How does the mirena IUS work?

Answer 25

Sperm impairment

Question 26

What are the mirena indications?

Answer 26

• Heavy menstural bleeding
• Contraception
• Endometrial protection with MHT

OTher uses (not indications)

• Dysmenorrhea
• Endometriosis
• Endometrial hyperplasia

Question 27

What are the benefits, risks, and side effects of the mirena IUS?

Answer 27

• last 5 years
• 90% decrease in menstural bleeding at one year with 95% satisfaction.
• Irregular bleeding 3-6 months
• Progestogenic SEs
• Expulsion ~5%, perforation 0.1%
• Increased risk of ectopic (minor)

Question 28

How does the emergency contraceptive pill work:

Answer 28

• Use within 72hrs
• Delays ovulation
• Efficacy decreases over time.
• Must change dose with weight

Question 29

How does copper IUD work as an emergency contraceptive?

Answer 29

• Use up to five days after ovulation
• 99.9% efficacy
• Weight not a factor
• Primarily anti fertilisation, but also ant implantation effect