1: Contraception Flashcards
What do contraceptives do?
Prevent pregnancy
Why do women choose to use contraceptives?
Family planning - no. of children and timing; to avoid unplanned pregnancy
For non-contraceptive reasons
How many babies are born every two seconds?
Six babies every two seconds
The prevalence of contraceptive use is higher in (high / low) income countries.
high income countries
What are some non-contraceptive reasons for using contraception?
Heavy, irregular or painful periods
Premenstrual syndrome (abdo pain, bloating, cravings…)
Endometriosis
Menstrual migraine
Acne
Contraceptive use is described in terms of perfect use and typical use.
What’s the difference between these two?
Perfect use - 100% compliance, never forgetting
Typical use - allows for occasional omission
Obviously effectiveness is less for typical use, but it’s more realistic
How long can sperm live in the female reproductive tract for?
5 days
How long does an egg survive in the female reproductive tract once released from the ovaries?
12 - 24 hours
For the greatest chance of conceiving, when in the menstrual cycle should a woman have sex?
Days preceding and following ovulation
Ovulation occurs at roughly Day 14, so Days 8 - 18 ish
What measurement is used to describe the effectiveness of contraceptive methods?
Pearl index
What does the Pearl index describe?
No. of contraceptive failures per 100 women per year
How is the Pearl index calculated?
(Number of accidental pregnancies) x 1200 / Total number of months using contraceptive
How long do
a) sperm
b) eggs
survive in the female reproductive tract?
a) 5 days
b) 12 - 24 hours
The Pearl index describes the number of ___ pregnancies experienced per ___ women per year.
accidental pregnancies per 100 women per year
It’s a measure of how effective a contraceptive method is
How does body temperature change around the time of ovulation?
Basal body temperature increases by around 1 degree Celsius
From 36 to 37 degrees Celsius, supports the sperm and eggs
How does the position of the cervix change around ovulation?
Cervix rises up into vagina and the internal + external os open up
What are the properties of cervical mucus around the time of ovulation?
Thin and slippery
So the sperm can swim through it easier
Sorry for the imagery
What are two natural methods of contraception?
Withdrawal method - man pulls out before he ejaculates
Lactational amenorrhoea - post-natal state that lasts for up to 6 months
What is the Pearl index for no contraception use in a sexually active woman?
85
i.e 85 out of 100 sexually active women would fall pregnant each year if they didn’t use contraception
What is the Pearl index for the withdrawal method?
Why?
22 i.e 22 out of 100 women will fall pregnant each year if the man uses the withdrawal method
Because there’s no barrier to sperm entry and it all relies on the man’s reflexes, plus a large proportion of sperm are contained in the initial ejaculate so he has to be quick
What are the three criteria for lactational amenorrhoea to be an effective state of natural contraception?
1. Woman is exclusively breastfeeding
2. Less than 6 months post-birth
3. Woman isn’t have periods
What is the most commonly used contraceptive method in the UK?
Combined hormonal contraception (CHC)
i.e the oestrogen/progrestrogen contraceptive pill
The CHC stops ___.
stops ovulation
The CHC is (short / long)-acting.
short acting
has to be taken daily
What is the Pearl index of the CHC?
0.2
i.e 0.2 per 100 women getting pregnant per year, very effective
Apart from the CHC, which other hormonal tablet is used for contraception?
Progesterone only pill / Desogestel / “Mini pill”
The mini pill contains a progesterone precursor called ___.
desogestel
Apart from tablets, what are other medical methods of contraception?
Barriers - male and female condoms, diaphragms and caps
Contraceptive implant
Contraceptive injection
Intrauterine system (IUS)
Intrauterine device (IUD)
Male and female sterilisation
What are three adaptations the female reproductive tract makes around the time of ovulation to increase the likelihood of pregnancy?
Basal body temperature increases
Cervical mucus becomes thin and “slippery”
Cervix rises and internal + external os open
For how long does the average contraceptive implant last?
3 years
What is the mode of Depo-Povera contraception?
Injection
What does the contraceptive injection contain?
Progesterone
Stops ovulation
How often must the contraceptive injection be given?
Every 13 weeks
Because it lasts for 14 weeks
What is the difference between an intrauterine system and intrauterine device?
System - releases progestrogen, rendering endometrium poor for implantation of fertilised egg
Device - releases copper, which acts as a spermicide and inflames the endometrium, stopping implantation
How long are
a) intrauterine devices
b) intrauterine systems
effective for?
a) 5 - 10 years
b) 3 - 5 years
Which substances actually cause the contraception in
a) intrauterine devices
b) intrauterine systems?
a) Copper
b) Progestrogen
What short-acting method of contraception is easy to use and provides some protection against STIs?
Barriers
i.e condoms for men
internal condoms, diaphragms and caps for women
What is a diaphragm / cap?
Barrier method of contraception which covers the os (entrance to the cervix), preventing fertilisation
Diaphragms or caps should be used alongside ___.
spermicide
to ensure sperm aren’t getting past it to fertilise an egg
What are the permanent methods of contraception for
a) men
b) women?
a) Vasectomy
b) Tubal occlusion
Which structures are cut, blocked or tied off in
a) female
b) male
sterilisation?
a) Fallopian tubes
b) Vas deferens
bilaterally
Does sterilisation have 100% effectiveness in preventing pregnancy?
No, small chance tubes could reform so Pearl index isn’t 0
Contraception should be used when the ___ outweigh the ___.
advantages outweight the risks
Which document tells you whether or not certain forms of contraception are contraindicated in certain patients?
UKMEC
Scale goes from 1 (fine to use) to 4 (contraindicated)
Which measurements and examinations should be carried out on a patient before prescribing them contraception?
BP
BMI
PV exam
bare minimum
To exclude pregnancy, when should contraception be started?
Menstruation
What exists in case a woman forgets to use contraception or her contraception fails?
Emergency contraception
WHEN should emergency contraception be used?
Within 5 days of unprotected sexual intercourse
Within 5 days of expected ovulation
What are the two forms of emergency contraception?
Copper intrauterine device
Emergency contraceptive pill
What is the most effective form of emergency contraception?
Copper intrauterine device
What are the two forms of emergency contraceptive pill?
Levonorgestrel
Ulipristal acetate
Which emergency contraceptive pill is effective within
a) 72h
b) 120h
of unprotected sexual intercourse?
a) Levonorgestrel
b) Ulipristal acetate
In relation to the LH surge which triggers ovulation, when is
a) levonorgestrel
b) ulipristal acetate
effective?
a) Before the LH surge
b) Before and during the LH surge
Do emergency contraceptive tablets work after ovulation?
No
Do emergency contraceptives cause abortion?
No
Stop sperm passage, fertilisation and implantation
So they’re looked upon as “family planning” by the Catholic church, not abortion
Ulipristal acetate is contraindicated in which patients?
Asthmatics
Exacerbates severe asthma
What are some non-contraceptive reasons for using contraception?
Heavy, irregular or painful periods
Abdominal pain assoc. with premenstrual syndrome, endometriosis
Menstrual migraine
Acne
How does contraception affect menstrual bleeding?
Affects menstruation and so bleeding becomes INFREQUENT and/or LIGHTER
Except for the IUD - inflammation causes menorrhagia
To be fully protected, when ideally should you start the combined contraceptive pill?
Menstruation or thereabouts
If you start oral contraception outwith five days of your period, what should you do for the next week to be fully protected?
Abstain or use barrier protection
How is the combined oral contraceptive pill taken?
21 days on, 7 days off (to let withdrawal bleed occur)
Which co-existing medical conditions can affect the absorption of contraceptive tablets?
Malabsorption - IBD, short bowel, gastroenteritis
Liver disease
Problems with which organ can affect the metabolism of contraceptive drugs?
Liver
Which type of drug can affect the metabolism of contraceptive drugs?
Enzyme inducers
anti-epileptics, anti-retrovirals, St John’s Wart, rifampicin
Which enzyme family is induced by antiepileptics, anti-retrovirals etc. and can affect the metabolism of contraceptive drugs?
Cytochrome P450
What may patients do which affects the effectiveness of contraceptive drugs?
Forget to take them
The combined oral contraceptive is known to increase your chances of which cardiovascular disease?
Venous thromboembolism
usually DVT leading to PE, MI, stroke
The combined contraceptive pill comes with a (large / small) increase in a patient’s DVT risk.
small
risk while on oral contraceptives is far less than risk due to being pregnant and immobile regardless
Which genetic condition can present with recurrent miscarriages?
Anti phospholipid syndrome
Apart from increased risk of VTE (venous thromboembolsim), what other cardiovascular condition is linked to oral contraceptives?
Systemic hypertension
The combined contraceptive pill is contraindicated in patients who have migraine with aura.
Why?
Study showed link between contraceptive use, these patients and ischaemic stroke
Which cancers are linked to the combined contraceptive pill?
Breast cancer
Cervical cancer
Which cancers are protected against by the combined contraceptive pill?
Ovarian and endometrial cancer
The risks for which cancers are
a) increased
b) reduced
affected by the combined contraceptive pill?
a) Breast and cervical cancers
b) Ovarian and endometrial cancers
