[26] Contraception - Progesterone Only Flashcards
What does progesterone only hormonal contraception use?
The female steroid hormone progesterone
What is the failure rate of progesterone only contraceptives with perfect use?
0.3%
What is the typical failure rate of progesterone only contraceptives?
9%
What are the different types of progesterone only contraceptives?
- Pill (POCP)
- Implant
- Injection
What are the types of POCP currently available in the UK?
- Femulen
- Norgeston
- Noriday
- Micronor
- Cerazette
What is the primary mechanism of action of POCP?
Thicken cervical mucus due to high levels of progesterone, which prevents the entry of sperm and therefore fertilisation of the oocyte
What are the secondary mechanisms of POCP?
- Suppression of ovulation (to varying degrees)
- Thinning of endometrium, inhibiting implantation
What does the degree to which the POCP suppresses ovulation vary based on?
The form of progesterone given
What are the advantages of the POCP?
- More effective than barrier methods when taken correctly
- Sex doesn’t need to be interrupted to use contraception
- Can be used in many patients for whom the COCP is contraindicated
- May reduce risk of endometrial cancer
What are the disadvantages of the POCP?
- User dependant, and has to be taken at same time every day
- Can produce irregular menstruation or amenorrhoea
- Some adverse effects
- Increased risk of ovarian cysts
- Small increased risk of breast cancer
What proportion of women taking the POCP experience irregular mensuration?
4 in 10
What proportion of women taking the POCP experience amenorrhoea?
2 in 10
What are the adverse effects of POCP?
- Headaches
- Breast tenderness
- Skin changes
By how much does POCP increase risk of ovarian cysts?
30%
What are the contraindications to POCP?
- Current or past history of breast cancer
- Liver cirrhosis or tumours
- Stroke or coronary heart disease
In whom does the POCP have a lower efficacy?
Women over 70kg
What is the brand name for the progesterone only implant linseed for use in the UK?
Nexplanon
What is the progesterone only implant?
A small, flexible tube about 40mm long that is inserted into the upper arm
What does the progesterone only implant contain?
68mg steroidal progestin
How long does the progesterone only implant last?
3 years
What is the failure rate of the progesterone only implant with perfect use?
0.05%
What is the typical failure rate of the progesterone only implant?
0.05%
What is the main mechanism of action of the progesterone only implant?
Inhibition of ovulation
What are the additional mechanisms of action of the progesterone only implant?
- Causes thinking of cervical mucus, which inhibits the passage of sperm
- Causes thinning of endometrium, preventing implantation if the egg were fertilised
What are the advantages of the progesterone only implant?
- Extremely effective
- Can be used in some women for whom the COCP is contraindicated
- Users don’t have to think about contraception for 3 years
- Can be used when breastfeeding
- Normal fertility returns as soon as implant is removed
- Effective in woman of all BMIs
- May reduce risk of endometrial cancer
What is recommended in women using the progesterone only implant with a high BMI?
Earlier replacement
What are the disadvantages of the progesterone only implant?
- About 50% of women experience changes in menstrual bleeding
- Fitting and removing the implant may cause pain, bruising, and irritation
- Small increased risk of breast cancer
- Implant can break or bend in situ
Are bleeding patterns likely to remain irregular if a woman with the progesterone only implant experiences changes in menstrual bleeding?
Yes
What are the contraindications to the progesterone only implant?
- Pregnancy
- Unexplained vaginal bleeding
- Liver cirrhosis or tumours
- History of breast cancer
- Stroke or transient ischaemic attacks whilst using implant
What is the progesterone only injectable contraceptive?
A long lasting contraception where synthetic progesterone is slowly release into the systemic circulation
How does the progesterone only injectable contraceptive administered?
IM or IV
What are the currently available progesterone only injectable contraceptive in the UK?
- Depo-Provera
- SAYANA PRESS
- Noristerat
What is the most commonly used progesterone only injectable contraceptive in the UK?
Depo-Provera
Is Depo-Provera licensed for long-term use?
Yes
How often is Depo-Provera given?
Every 12 weeks
How is Depo-Provera administered?
IM injection
Is SAYANA PRESS licensed for long-term use?
Yes
How often is SAYANA PRESS given?
Every 13 weeks
Is Noristerat licensed for long term use?
No, only 2 sets of injections
How often is Noristerat given?
Every 8 weeks
How is Noristerat administered?
Deep IM injection
What is the failure rate of the progesterone only injectable contraceptive with perfect use?
0.2%
What is the typical failure rate of the progesterone only injectable contraceptive?
6%
What is the mechanism of action of progesterone only injectable contraceptive?
- Inhibition of ovulation
- Thickening of cervical mucus
- Thinning of endometrium, making it unfavourable for implantation if fertilisation was to occur
What are the advantages of progesterone only injectable contraceptive?
- Very effective
- Users don’t have to think about contraception for as long as the injection lasts
- No known interactions with any drugs
- Can be used when hormonal contraceptives are not recommended, such as in women with migraine or who are breastfeeding
- Can be used in women <35
- May reduce risk of endometrial cancer
What are the disadvantages of progesterone only injectable contraceptive?
- Not rapidly reversible
- Up to 50% of women stop using within a year
- Increase in body weight
- May be slightly increased risk of breast cancer
- Loss of bone mineral density with long-term use
How long does it take for fertility to return with progesterone only injectable contraceptive?
Up to a year
How long does it take for menstruation to return to normal with progesterone only injectable contraceptive?
Several months
Why do 50% of women stop using the progesterone only injectable contraceptive within a year?
Due to altered bleeding patterns, including persistent bleeding
How much can body weight increase with progesterone only injectable contraceptive?
2-3kg/year
What constitutes long term use with progesterone only injectable contraceptive?
Over a year
Does the loss of bone mineral density with progesterone only injectable contraceptive increase the risk of fracture?
No evidence for this
What are the contraindications to progesterone only injectable contraceptive?
- Breast cancer within past 5 years, or currently
- History of severe arterial disease or very high risk factors
- Pregnancy
- Diabetes with any vascular disease, e.g. retinopathy
- People who will want to return to fertility in the near future