L41 Contraception

Question 1

What is the UK MEC?

Answer 1

UK Medical Eligibility Criteria for contraceptive USE - It is a method to classify conditions and whether a particular contraceptive is appropriate.

Question 2

Give an account of the combined pill:

• How does it work?
• How is it taken?
• Failure rate?
• Side effects?

Answer 2

• Has a dose of oestrogen and progesterone. The combined pill gives people a total combined oestrogen and progesterone well above the normal level. There is therefore no fluctuations in levels and so there is no LH or FSH surge and so no ovulation.
  
  • The pill is taken 21 days out of 28 (in the other days you will have a bleed helping to keep track of periods. The hormones still have effect on the lining and you will still bleed).
  • It leads to cervical mucus thickening and reduces endometrial receptivity - the efficiency of accepting the egg if it were released
  • It is very effective - failure rate is 0.3-9%
  • There is a wide range because it relies on people taking it. The most common reason for getting pregnant on the pill is due to forgetting the pill - breaking the window of high oestrogen levels.
  • It can lead to severe acne and emotional changes due to high hormone levels. Caution with smoking and obesity as they increase the risk of blood clots in the legs and lungs. Oestrogen causes blood to be more viscous and increases the chance of clots (hence why at pregnancy, you have the increased risk of clots. Cautioned in people with a history or family history of clots.

Question 3

Give an account of the Evra contraceptive patch:

• How does it work?
• How is it taken?
• Failure rate?

Answer 3

• Not as common - not quite as convenient or as known as the pill. Also it is visible and so there is a connotation with it.
  
  • It has a lower failure rate as it takes away the human element to it 0.3-9%
  • Worn 21 out of 28 days. Must rotate the site of attachment.
  • Has a dose of oestrogen and progesterone. The combined pill gives people a total combined oestrogen and progesterone well above the normal level. There is therefore no fluctuations in levels and so there is no LH or FSH surge and so no ovulation.

Question 4

Give an account of the Nuvaring Combined ring:

• How does it work?
• How is it taken?
• Failure rate?

Answer 4

• Has a dose of oestrogen and progesterone. The combined pill gives people a total combined oestrogen and progesterone well above the normal level. There is therefore no fluctuations in levels and so there is no LH or FSH surge and so no ovulation.
  
  • It has a low failure rate as you do not remember to take a pill 0.3-9%
  • It is a vaginal ring that is flexible and easy to insert and remove
  • The ring is worn for 21 days and then discarded - another ring is inserted on day 28

Question 5

Give an account of the progesterone only pill:

• How does it work?
• How is it taken?
• Failure rate?

Answer 5

• Sometimes call the mini pill
  
  • Take one pill a day - there is no pill free week. It does not thick the endometrial lining as much due to the loss of oestrogen and so there is no need for that withdrawal bleed
  • Generally works buy thickening cervical mucus. To a lesser degree, it suppresses ovulation.
  • It has more effect on the endometrium
  • There is a short window you must take it within everyday
    Can lead to irregular bleeding as it keeps the endometrium thin compared to the combined pill when you know when you will have your period.
    
    • Failure rate is 0.3-9%

Question 6

Give an account of the progesterone injection:

• How does it work?
• How is it taken?
• Failure rate?
• Side effects?

Answer 6

Progesterone injectables

- An injection every few months - given a large dose of progesterone and so generally you will not have any periods, there may be irregular spotting. This generally prevents ovulation due to the very high dose.
- Very low failure rate - removes away the element of adherence 0.2-6%
- Quite a painful injection into a thick muscle 
- Other side effects: mood changes, irritable etc. due to the massive dose of hormones. May also get weight gain. 
- It thickens cervical mucus and reduces endometrial receptivity.

Question 7

Give an account of the implant:

• How does it work?
• How is it taken?
• Failure rate?

Answer 7

The Implant

- An implant under the skin. 
- The failure rate is very low - 0.05%. It lasts for 3 years.
- It prevents ovulation by thickening cervical mucus and reduces endometrial receptivity.  May lead to irregular bleeding pattern.

Question 8

Give an account of a IUS:

• How does it work?
• How is it taken?
• Failure rate?

Answer 8

• A fine T shaped piece of plastic is placed at the top of the uterus. It secretes progesterone slowly.
  
  • It generally thickens cervical mucus and causes endometrial lining to thin. Since there is something in the uterus, it prevents the egg being implanted by causing a little bit of inflammation
  • Lasts 5 years
  • It stops periods - it is the only licensed treatment for heavy menstrual bleeding
  • Does not tend to have the mood swings as it acts more local - since in the uterus, the hormone does not need to travel far in the blood
  • Very low failure rate (0.02%)

Question 9

Give an account of an IUD:

• How does it work?
• How is it taken?
• Failure rate?

Answer 9

• It contains no hormones at all
  
  • A copper coil. Copper is spermicidal, it’s main mechanism is by preventing fertilisation by direct effect on sperm. It also causes a foreign body environment - it causes a bit of inflammation and a hostile environment for implantation but not harmful in the long run.
  • Lasts 5-10 years.
  • Can cause heaver periods as there is no hormonal component to regulate the periods. It has heavier periods due to the inflammation etc. Beneficial in those who do not want to take a hormone e.g. from bad reaction, or do not want the acne or weight gain.
  • Failure rate (0.6-08%) is not as good as the implant as it does require people to check that the threads are in the right place. You should be able to see the thread, you therefore must check it throughout its life span. The failure rate is associated with it falling out and people not knowing or it being misplaced.

Question 10

Give an account of condoms.

Answer 10

• Not a very good form of contraceptive due to men are particular bad at using condoms - may not be put on in time. Therefore high failure rate.
  
  • You can get female condoms - usually made of latex which is a common allergy - though there are non-latex condoms
    “Double Dutch” - since condoms are not very effectively, you should use it alongside another method

Question 11

Give an account of caps and diaphragms:

• How does it work?
• How is it taken?
• Failure rate?

Answer 11

• Have quite a high failure rate, but lower than condoms.
  
  • Used by women.
  • Made out of latex
  • Can be used with spermicide - usually left in for 6 hours
  • Offer some protection against STI’s
    They cover the entrance to the uterus - cover the cervix and put spermicide around it

Question 12

Give an account of emergency oral contraceptives:

• How does it work?
• How is it taken?
• Failure rate?

Answer 12

• Common on the market: Ulipristal and Levonorgestrel
  
  • Contain large doses of progesterone; work by delaying ovulation.
  • Prevent ovulation so you do not release an egg at the same time of intercourse
  • The large dose of progesterone prevents the LH/FSH surge to prevent ovulation
  • Very effective
  • If you have intercourse after ovulation, they may still be effective as they may change the endometrial lining and the thickness of the cervical sperm. But as they won’t prevent ovulation.
    The only other method is the IUD as the IUD causes irritation and disrupts implantation. Even if the egg was fertilised, it would not implant and so the individual would not become pregnant. It is also a suitable method for ongoing contraception.

Question 13

Give an account of the sterilisation.

Answer 13

Involves cutting tubes. There is a slight failure rate as the tubes can recanalize but this is very rare. Sometimes after the vasectomy you need to provide samples to show that sperm is not present and if you do not, you may not be sterile.

Male - Vasectomy 
Some bruising, but very quick and easy.

Female - Tubal occlusion/ligation Involves an operation. Puts clips to occlude the tube. One on each side to pass the egg passing through.

Question 14

What are non-contraceptive benefits of contraception?

Answer 14

• Reduction in risk of endometrial and ovarian cancer - 40% risk as some cancers are driven by oestrogen primarily. There is the break without endometrial activation through oestrogen. Things that prevent oestrogen effects will be beneficial in reducing cancer such as the Mirena coil. Early stages of endometrial cancers may be treated with the coil.
  
  • Decrease benign breast tissue
  • Reduces iron-deficiency due to the reduction of periods
  • Treats pelvic pain caused by endometriosis - the Mirena coil is particularly good for this and pills will also work. You will effectively treat the endometriosis which is driven by hormones, and the hormones are being regulated.

Question 15

What are risks of contraception?

Answer 15

• Failure - ectopic pregnancy is higher with Mirena coil for example with the coil in situ as the coil prevents implantation in situ.
  
  • Increased thickening of blood due to oestrogen and increased risk of clots/heart disease/stroke - do not start if you have an increased risk already
  • Pain during operative sterilisation/indwelling devices