Lecture 18: Avoiding pregnancy contraception

Question 1

Methods available in NZ?

Answer 1

Jadelle - 2x rod implant

Condoms

IUD

Merina

Contraceptive pill

Question 2

UK MEC?

Answer 2

Medical eligibility criteria

Very extensive criteria giving a 1-4(do not use) grading of wether or not to use.

Question 3

Different classifications of uses?

Answer 3

Perfect use and typical use

Perfect is what you would get in the laboratory and typical use what you get in real life. The difference between these two is higher in methods that require large amounts of patient control (condom and combined pill) versus methods that don’t (Implants)

Question 4

COC mechanism of action?

Answer 4

Combined oral contraceptive pill

1. Supresses ovulation (no egg = no baby)
2. thickens cervical mucus
3. changes endometrium making implantation less likely
4. Reduces sperm transport in upper genital tract

Question 5

COC: advantages, disadvantages?

Answer 5

Advantages:

• Available basically everywhere
• Been around a long time
• Can be stopped whenever you want
• reduced ovarian and endometrial cancer

Disadvantages:

• 9% failure rate
• complicated to take (missed pill rules)
• Is a large number of eligibility criteria
• Slight increased risk of breast cancer (esp in older women when their background risk kicks in)

Question 6

Purpose of pill free interval (PFI)?

Answer 6

Don’t bother aye, waste of time

Question 7

Why not tricycle?

Answer 7

Focal migranes with aura are a common sensory symptom

(they wave their hand in front of them describing the blurr)

Question 8

Starting the OCP?

Answer 8

• D1-5 of the cycle - protected straight away
• Later in the cycle (and sure they are not pregnant) - 7 days’ precautions
• NO interaction with antibiotics (except rifampicin for TB, rarely encountered)

Question 9

POP?

Answer 9

Progesterone only pill

1. Mainly thickens cervical mucus
2. maximal 48h after starting POP
3. oral barrier contraceptive
4. taken within 3-4 hours every day to be effective

Unfunded cerazette has a much lower failure rate due to supression of ovulation (95% compared to 85%) and also has a 12h window to be taken.

• started at any time as long as not pregnant

Question 10

LARC?

Answer 10

Long Acting Reversible Contraception

• requires administration less than once a month
• Cost effective even after 1 year of use
• NZ related issue - training and accessibility including COST

Question 11

Depo - Provera?? Mechanism?

Answer 11

12 weekly injection

Prolonged amenorrhoea and weight gain (av. 2kg) as well as delayed return of fertility

Oestrogen free - fewer restrictions than the OCP

• Supresses hormones responsible for ovulation
• thickens cervical mucus to block sperm

Question 12

Jadelle?

Answer 12

Two rods inserted in upper arm lasting 5 years

Bleeding:

• 14% have removed for bleeding
• Can be reduced by taking the pill as well

1. prevents ovulation
2. makes endmetrium very thin
3. thickens cervical musus (progesterone)

Can have contraindications with enzyme inducers (like st johns wart)

Question 13

Merina? mechanism?

Answer 13

Unfunded in NZ unless special criteria met: diagnosis of menorrhagia + feratin or Hb low (undunded cost about $450)

1. Creates an unfavourable environment for sperm in the uterus and fillopian tubes
2. Makes the endometriun thinner
3. Makes the cervical mucus thicker

Other uses:

• Dysmenorrhoea
• endometriosis
• Endometrial hyperplasia

Question 14

Emergency contraception?

Answer 14

• Levonelle - up to 72h following UPSI
• Efficacy decreases with time (85% at 72h)
• Main action is to postpone/prevent ovulation
• Copper IUD - implanted up to D19 of a 28D cycle
• 99% efficacy
• Anit-implantation and (primarily) anti fertilisation effects
• Can be used if there have been multiple episodes of UPSI in a cycle - Can provide ongoing protection.
• can cause increased bleeding + pain so screen for already high bleeding