Contraception Flashcards
What is the definition of contraception?
The deliberate use of artificial methods or other techniques to prevent pregnancy as a consequence of sexual intercourse
What is meant by birth control?
Methods or devices used to prevent pregnancy
This is also known as contraception and fertility control
what is meant by family planning?
Planning, provision and use of birth control
What % of sexually active women have used birth control at some point in their life?
99%
How many women use the pill?
100 million
What is the UK MEC?
it helps clinicians decide what contraceptives they can safely recommend based on the medical conditions of patients in their care
What is meant by category 1 in UK MEC?
A condition for which there is no restriction for the use of the method
What is meant by category 2 in UK MEC?
A condition where the advantages of using the method generally outweigh the theoretical or proven risks
What is meant by category 3 in UK MEC?
A condition where the theoretical or proven risks usually outweigh the advantages of using the method
Under which conditions may a method be used in category 3 in UK MEC?
The provision of a method requires expert clinical judgement and a referral to a specialist contraceptive provider
This method is not recommended unless other more appropriate methods are not available/acceptable
What is meant by category 4 in UK MEC?
A condition which represents an unacceptable health risk if the method is used
what are the characteristics of an ideal contraceptive?
- 100% effective
- 100% convenient - independent of intercourse, nothing to remember
- 100% reversible
- 100% safe
- cheap
- independent of the medical profession
- acceptable to every religion and culture
- having non-contraceptive benefits - control of periods, reduction in cancer etc.
What are the most effective contraceptives, with less than 1 pregnancy per 100 women in a year?
- implant
- intrauterine device
- sterilisation - in both male and female
What type of contraceptives cause 6-12 pregnancies per 100 women in a year?
- injectable contraceptives
- pill
- patch
- ring
- diaphragm
What are the least effective types of contraceptives causing 18 or more pregnancies per 100 women in a year?
- male condom
- female condom
- withdrawal during sex
- sponge
- fertility-awareness based months
- spermicide
What is the mechanism of action of combined contraceptives?
They prevent ovulation by suppressing the release of gonadotrophins
They inhibit follicular development and prevent ovulation
What does progesterone negative feedback lead to?
- decreased pulse frequency of GnRH release by hypothalamus
2. this decreases the release of FSH and LH
What is the result of decreasing levels of FSH?
It inhibits follicular development
This prevents an increase in estradiol levels and a mid-cycle LH surge
What actually prevents ovulation when using a combined contraceptive?
Inhibition of follicular development and the absence of an LH surge
How do progesterone-containing contraceptives also help to prevent pregnancy?
They inhibit sperm penetration through the cervix into the upper genital tract
They decrease the amount and increase the viscosity of cervical mucus
What is the failure rate of the combined pill?
0.3 - 9%
What is contained within the combined pill?
How does it work?
It contains oestrogen and progesterone
It prevents ovulation by suppressing LH and FSH
How often is the combined pill taken?
It is taken 21 days out of 28
There is a pill-free week every month
Other than preventing ovulation, how does the combined pill work?
It thickens cervical mucous
It reduces endometrial receptivity
What are the contraindications of the combined pill?
Caution should be taken with smoking and obesity
Also hypertension
And a personal history of thrombosis or CHD
How does the Evra contraceptive patch work?
How often is it worn?
it works like the combined pill to prevent ovulation
It is worn 21 days out of 28
What is the failure rate of the Evra contraceptive patch?
0.3-9%
Where is the placement site of the Evra contraceptive patch?
The placement site should be rotated
How does the Nuvaring combined ring work?
It works like the combined pill
The ring is worn for 3 weeks and discarded
A new ring is inserted 1 week later
What is the failure rate of the Nuvaring combined ring?
Why do people choose this method?
0.3-9%
The ring is flexible and easy to insert and remove
What does the vaginal contraceptive ring deliver whilst it is inserted into the vagina?
It delivers very low doses of ethinyl estradiol and etonogesterel
These sex hormones are delivered continuously whilst in the vagina
How is the progesterone-only pill taken?
What is the failure rate?
One pill is taken each day with no pill-free week
The failure rate is 0.3-9%
How does the progesterone only pill work?
it thickens cervical mucus
it reduces endometrial receptivity
it suppresses ovulation
What are the negative consequences of taking the progesterone only pill?
it requires accurate pill taking within hours
irregular bleeding
Which particular group of people are often advised to take the progesterone only pill?
Women over 35 and smokers
What are examples of injectable progesterone only contraceptives?
What is the failure rate?
Depo Provera, Sayana Press, Noristerat
Failure rate 0.2-6%
How do injectable progesterone only contraceptives work?
They prevent ovulation
They also thicken cervical mucus and reduce endometrial receptivity
How often are progesterone only contraceptives injected?
Either intramuscular or subcutaneous
Every 8 or 12 weeks
What are periods like when injecting progesterone only contraceptives?
There are no periods
But there may be irregular spotting
What is Implanon and what is the failure rate?
It is a progesterone only implant under the skin
The failure rate is 0.05%
How does Implanon work?
- prevents ovulation
- thickens cervical mucus
- reduces endometrial receptivity
How often does Implanon last and what is the bleeding pattern like?
it lasts 3 years
It has an irregular bleeding pattern
What is IUS?
Intrauterine system
It is a small T shaped plastic device that releases progesterone
What is the failure rate of IUS?
How long does it last?
Failure rate is 0.2%
It lasts for 5 years
How does IUS work?
It thickens cervical mucus
It leads to endometrial thickening
(It also suppresses ovulation)
How does IUS affect periods?
It reduces periods and can stop them entirely
What is IUD
Intrauterine device
It is a T-shaped plastic and copper device that releases copper
How does IUD work?
The copper prevents fertilisation by having a direct effect on sperm
It also causes endometrial changes
What is the failure rate of IUD?
How long does it last?
Failure rate is 0.6-0.8%
It lasts for 5-10 years
How does IUD affect periods?
it can cause heavy periods
What is the failure rate of condoms?
2-18%
There are both male and female condoms
What is the benefit of using condoms?
they protect against STIs
What is meant by “double dutch”?
Using both barrier contraception (e.g. condom) and an additional method
How do caps and diaphragms work?
They are latex and are left in for 6 hours
They block the uterus
They are used with spermicide
What is the failure rate of caps and diaphragms?
How do they affect contraction of STIs?
Failure rate is 6-12%
They have some protection against STIs
What is the negative consequence of using a diaphragm?
there is an increased risk of urethritis
What is the sterilisation method used for males?
Vasectomy
It involves cutting the ends of the vas deferens are sealing them
What is the failure rate for vasectomy?
0.1 - 0.15%
2 consecutive negative samples are needed to prove effectiveness
What is meant by late recanalisation after vasectomy?
The appearance of motile sperm after the vasectomy was declared a success
What are the sterilisation techniques in females?
tubal occlusion
ligation
What is tubal occlusion?
a micro-insert is placed into each of the fallopian tubes
this forms a natural barrier to prevent sperm reaching the egg
What is tubal ligation?
This involves “getting your tubes tied”
Fallopian tubes can be banded, cauterised or tied and cut
What is the failure rate for female sterilisation?
What is the risk of failure?
failure rate is 0.5%
Failures have a higher risk of ectopic pregnancy
What are the 2 oral emergency contraceptives?
Ulipristal (take within 120 hours)
and Levonorgesterel (take within 72 hours)
How do the oral emergency contraceptives work?
How effective are they?
They work by delaying ovulation
They are effective if taken promptly and are available without prescription
What is the most effective emergency contraceptive?
The copper IUD
This is also suitable for ongoing contraception
What is the main non-contraceptive benefit?
reduction in risk of endometrial and ovarian cancers by 40%
This is due to the endometrial effects and suppression of gonadotrophins
What are the other non-contraceptive benefits?
- decrease benign breast disease - fibrocystic and fibroadenoma
- reduce iron-deficiency anaemia
- treats pelvic pain caused by endometriosis
What are the risks of contraception?
- failure (this increases risk of ectopic pregnancy)
- inconvenience
- increased risk of clots, heart disease and stroke
- pain during operative sterilisation and indwelling devices
