Contraception Flashcards
What methods of contraception are there?
Natural Barrier Hormonal control Prevention of implantation Sterilisation Emergency contraception
Is any contraception 100% effective?
No
When deciding type of contraception, what should you balance?
Patient preference with patient safety
What natural options are there?
Abstinence!
Withdrawal method - withdrawing before ejaculation
Fertility awareness methods
Lactational amenorrhoea
What are the disadvantages with the withdrawal method?
Some sperm may be released in the pre ejaculate
No protection from STIs
What are fertility awareness methods?
Use of fertility indicators to identify fertile and infertile points of menstrual cycle e.g apps
Advantages: no hormones/ contraindications
Disadvantages: unreliable, no STI protection
What does lactational amenorrhoea mean?
Breastfeeding delays return of ovulation after childbirth
- suckling stimulus disrupts release of GnRH
- affects feedback cycle of HPG axis
Lactational amenorrhoea is only effective for how long after giving birth?
6 months
It is 98% effective providing the woman is fully breast feeding, amenorrhoeic and less than 6 months post partum
What are the advantages and disadvantages of lactational amenorrhoea as contraception?
Advantages: no hormones/ contraindications
Disadvantages: unreliable, no STI protection, only for 6 months after childbirth and relies on exclusive breastfeeding
What barrier methods are there?
Male/ female condoms
Diaphragm/ caps
Physical barriers - prevent entrance of sperm into cervix
What are the advantages and disadvantages of barrier protection?
Advantages:
Reliable- 98% effective if used correctly
Protection from STIs
Male condoms widely available
Disadvantages:
“Reduced sexual pleasure”
Danger of expiring
Allergy/ sensitivity to latex or spermicide
What hormonal control options are there?
Combined oestrogen and progestogen
Progesterone depot
Progesterone implant
Low dose progestogen
What is progestogen?
Synthetic form of progesterone
How is the combined oral contraceptive pill taken?
Taken daily for 21 days, followed by 7 days break or placebo pill
How does the COCP work?
It prevents ovulation
(As if in luteal phase - reduced LH and FSH secretion and no LH surge)
Also: thickens cervical mucus, thins endometrium, so reduced chance of implantation
Low oestrogen levels inhibit follicular development and ovulation - negative feedback on HPG. Also oestrogen levels never high enough to make endometrium thick.
The progesterone also causes negative feedback on HPG and additionally, makes the cervical mucus thicker
How effective is the COCP?
98% if taken correctly
What are the additional advantages of COCP?
Can relieve menstrual disorders - reduce HMB and pain, more regular
Reduced risk of ovarian, endometrial and colorectal cancers
Contraceptive effects reversible upon stopping
May reduce ovarian cysts, benign breast disease, acne vulgaris, osteoporosis
Reduces size of fibroids (they grow due to high oestrogen)
What are the disadvantages of the COCP?
User dependent Interaction with other medications Adverse effects: nausea and abdominal pain, headache, breast tenderness, irregular bleeding (up to 20%), mood changes Also: HTN, changes in lipid metabolism No STI protection Increased risk of: breast and cervical cancer Increased risk of: VTE, MI, stroke Less effective than LARCs
What are the contraindications for the COCP?
Absolute:
More than 35 and smoking more than 15 cigarettes per day
Migraine with aura at any age
Current or past VTE history
History of stroke, TIA or IHD
Valvular heart disease, cardiomyopathy with impaired cardiac function
Uncontrolled HTN (systolic above 160, diastolic above 100)
Current breast cancer, liver cirrhosis, liver tumours
Major surgery with prolonged immobilisation
Positive anti phospholipid antibodies
Known thromobogenic mutations
Less than 6 weeks post partum and breast feeding
Relative (UKMEC 3):
More than 35 and smoking less than 15 cigarettes per day
BMI > or equal to 35
FH thromboembolic disease in first degree relative less than 45
Controlled HTN
Immobility e.g wheelchair use
History of breast cancer, carrier of breast cancer mutations
Current gallbladder disease
Migraine without aura at any age
Enzyme inducing drugs
When should the COCP be taken?
Start on the first day of the cycle (or within 5 days of start for no need of additional contraception)
If started at another point in cycle then alternative contraception should be used for first 7 days
Should the COCP be taken at the same time every day?
Yes
When might the efficacy of the COCP be reduced?
If vomiting within 2 hours of taking pill
Medication that induces diarrhoea or vomiting may reduce effectiveness of oral contraception
Taking liver enzyme inducing drugs e.g carbamazepine, rifampicin, phenytoin, topiramate, griseofulvin, sulphonylureas, st Johns worts
When taking antibiotics with the COCP, do precautions need to be taken?
No unless they are enzyme inducing e.g rifampicin
Why is there an increased risk of cervical cancer with the COCP?
Most people do not use condoms if on the pill, so more chance of STIs
What should be done if one COCP pill is missed (at any time in cycle)?
Take the last pill even if it means taking 2 pills in one day and then continue taking pills daily
No additional contraception protection needed
What should be done if 2 or more COCP pills missed?
Take the last pill even if it means taking 2 pills in one day, leave any earlier missed pills and continue taking daily pills
- should use condoms or abstain until taken pills for 7 days in a row
If pills missed in week 1: emergency contraceptive considered if unprotected sex in pill free interval or in week 1
If pills missed in week 2: after 7 days of taking pill, no need for emergency contraception
If pills missed week 3: finish pills in current pack and start new pack next day, this omitting pill free interval
What is the only COC patch licensed in the UK?
The evra patch
How is the evra patch used?
The cycle lasts 4 weeks
For first 3 weeks patch worn everyday and needs to be changed each week
During fourth week patch not worn and there will be a withdrawal bleed
Why is there an increased risk of breast cancer associated with the COCP?
Due to the proliferative effects of oestrogen
What high dose progestogen options are there?
Progestogen injection - depo provera (or self injectable version: Sayana Press SC)
Progestogen implant
How is the depo provera given?
IM injection
Every 12 weeks
How does the depo provera work?
Principle action: prevents ovulation
Secondary: thickens cervical mucus to inhibit penetration of sperm
Prevents endometrial proliferation
What are the advantages of the depo provera?
If used correctly, more than 99% effective
Eliminates risk of user failure
Does not disrupt sexual intercourse
Can be used for women who cannot use contraception that contains oestrogen
Safe in breastfeeding
Stops periods for most people
Not reduced by enzyme inducing medication - useful in those taking a lot of medication, with chronic diseases e.g HIV
What are the disadvantages of the depo provera?
Appointment needed every 12 weeks
Delay in fertility returning - can be up to year
No STI protection
People with low weight - osteoporosis risk due to loss of bone mineral density
Weight gain (3kg per year)
Periods - stop, irregular or longer
Not to be used if current breast cancer