5.12 Contraception Flashcards
Describe briefly with mention to hormones how pregnancy starts
The hormone FSH stimulates an egg in one of the ovaries to develop and after around 2 weeks the hormone LH triggers the release of that egg, which we call ovulation. It then passes along the adjacent fallopian tube and at this point it could combine with a sperm cell to form a fertilised egg. If it did, this fertilised egg would continue along the fallopian tube to the uterus where it would implant into the wall and slowly develop into a foetus.
What 2 hormones do hormonal methods of contraception release?
- Oestrogen
- Progesterone
How does the release of oestrogen reduce the chance of pregnancy?
Inhibits FSH production, so that eggs can’t mature.
How does the release of progesterone reduce chance of pregnancy? (3)
- Stimulates the production of thick cervical mucus (at the entrance to the uterus) making it less likely that any sperm will get through and reach an egg.
- Thins the lining of the uterus to reduce the chance of a fertilised egg implanting.
- Prevents ovulation by inhibiting the production of FSH and LH (not true for all types of mini-pill).
Describe the 4 different types of contraceptive methods that involve only progesterone
- Injection: effective for up to 3 months
- Implant: inserted beneath the skin of the arm. Effective for 3 years.
- Intrauterine system (IUS): a T-shaped piece of plastic inserted into the uterus Effective for 3-5 years.
- Mini-pill (aka progesterone-only pill) - has to be taken every day.
Describe the 2 different types of contraceptive methods that involve progesterone and oestrogen
- Combined pill: taken in a ‘21 day pill, 7 days no pill’ cycle
- Patch: worn on the skin in a 4-week cycle (repeated once a week for 3 weeks, then no patch worn for a week)
What types of contraceptives are the mini-pill and the combined pill classed as?
Oral contraceptives
What are 2 side effects of the combined pill?
- Headaches
- Nausea
What are the 4 non-hormonal methods of contraception?
- Barrier methods
- Intrauterine devices
- ‘Natural’ methods
- Sterilisation
Describe the 3 different types of barrier methods
- Condom (98% effective): worn over the penis during intercourse to prevent sperm entering the vagina.
- Female condom (95% effective): worn inside the vagina during intercourse.
- Diaphragm (92-96% effective): fits over the cervix (opening of the uterus) to stop sperm from meeting the egg. Has to be fitted by a GP/nurse the first time it’s used and has to be used with a spermicide (a chemical that kills sperm).
Describe the 4 types of non-hormonal contraceptive methods
- Barrier methods - these try to stop the egg and sperm meeting.
- Intrauterine devices (IUDs): T-shaped devices that contain copper. They’re inserted into the uterus and prevent sperm from surviving. They also alter the lining of the womb so that fertilised eggs can’t implant. They’re more than 99% effective and can be kept in for more than ten years.
- ‘Natural’ methods: they refer to basically just not having sexual intercourse when the woman is most fertile (the period around ovulation) or ‘withdrawal’ (the man pulling the penis out before ejaculation). These methods are the least effective at preventing pregnancy as they rely on getting the timing exactly right.
- Sterilisation: involves a surgical procedure to cut or tie tubes in the reproductive system. In women, the procedure means eggs are prevented from travelling from the ovaries to the uterus. In men, it prevents sperm from being ejaculated. The methods are over 99% effective.
In an exam, you may have to evaluate hormonal and non-hormonal methods of contraception. What 5 things would you have to think about?
1) Side effects - hormonal methods can have unpleasant side-effects, e.g. heavy or irregular periods, acne, headaches, mood changes.
2) Possibility of ‘doing it wrong’ - barrier methods and ‘natural’ methods have to be done properly each time a couple have intercourse. If, for example, a condom splits or a man doesn’t withdraw soon enough, then the methods won’t work. The same is true with some hormonal methods, e.g. if a women doesn’t take her pills correctly or replace her patch at the same time, the methods won’t work properly.
3) Medical input - many methods involve at least one trip to a nurse or doctor (e.g. to get a prescription for pills or to have a device inserted). Although these methods tend to be more effective than barrier or ‘natural’ methods, people may feel uncomfortable about the procedures involved..
4) Length of action - long-lasting methods (i.e. those that last several months or years) may be preferable over having to think about contraception everyday or every time intercourse is on the cards.
5) Sexually transmitted infections (STIs) - these are infections that are passed from person to person during sexual intercourse. The only method of contraception that can protect against them is condoms (male or female types).
What is sterilisation in women?
It involves a surgical procedure to cut or tie the fallopian tubes which connect the ovaries to the uterus. If they are cut, the ovaries won’t be able to pass from the ovaries to the uterus.
What is sterilisation in men?
It involves a surgical procedure to cut and tie the sperm ducts.
What is contraception?
A method or device used to prevent pregnancy
