Combined oral contraceptive pill
January 06, 2014
Usually called ‘the Pill’, the combined oral contraceptive pill is a monthly method of contraception.What is it?
The combined pill contains the hormones oestrogen and progestogen. There are many different pills available, varying in the dose of hormones used, but essentially they all work in the same way. The Pill needs to be taken every day to effectively protect against pregnancy.How do I take the Pill?
The Pill comes in monthly packages. Most brands have 21 hormone pills with 7 inactive (sugar) pills.
It is usually recommended for a woman to start taking a hormone pill on the first day of her period, that way she is protected from pregnancy straight away. However, the Pill may be started at any time in a woman’s cycle if there is no chance that she may already be pregnant. If the hormone pills are taken later than the first day of a woman’s period it is important that 7 consecutive hormone pills are taken over one week before she relies on the Pill to protect her from pregnancy.
Many women prefer to have a monthly bleed (period) to reassure them that they are not pregnant. To achieve this the Pill is taken in cycles of 21 days of hormone pills followed by a seven-day break (most pills are packaged with inactive pills to mark out the seven-day break). This break allows a bleed to occur. If you do not want to have a period you can safely take the hormone pills continuously without a break ie start a new pill packet every 21 days. It is often recommended that women have a bleed every three months - see a doctor for more information.
As the Pill needs to be taken every day it is easier to remember if you make it a part of your daily routine. However, you can take the Pill up to 24 hours after your regular time and still be protected from pregnancy.How does it work?
The Pill works by:
How effective is it?
- preventing the body from releasing an ovum (egg) every month (this is its main action)
- thickening mucus in the cervix to prevent sperm penetration
- changing the lining of the uterus (womb), making it difficult for a fertilised egg to implant.
If taken correctly the Pill is more than 99.5% effective at preventing pregnancy. If you follow all of the pill packaging instructions you are protected every day of the month - even on the days when you take an inactive pill or during the seven-day break (provided you start your next pill packet on time).Who can take the Pill?
The Pill is suitable for most women, but there may be health risks for some.
You should not take it if you:
- have ever had a deep vein thrombosis (blood clot), a stroke or a heart attack
- have hepatitis or other liver disease which is affecting liver function
- have vaginal bleeding, the cause of which has not been diagnosed
- have focal migraines (headaches preceded by visual changes, numbness in the face or hands, or other neurological symptoms)
- are over 35 and a smoker
A doctor needs to know if you:
Can I get pregnant?
- have, or have a family history of, high blood pressure, high cholesterol, gallstones, diabetes, or any blood disorder
- are breast feeding
- are a smoker (as women who smoke are more at risk of developing a blood clot)
- are over 40
- have had cancer of the breast or of the uterus
- plan to have surgery
Your chance of getting pregnant on the Pill is greater if:
- you are more than 24 hours late taking a hormone pill (see next page for more information about missed pills)
- you take other prescribed medications such as antibiotics, anti-epileptic drugs and some medications used to treat tuberculosis. Always remember to tell the doctor you are seeing
- that you are taking the Pill, and ask if any drug that is prescribed will lower its effectiveness
- you take herbal medicines such as St John’s Wort
- you have severe vomiting or diarrhoea. If you vomit within two hours of taking it or you have severe diarrhoea, the Pill may not be absorbed properly, making it less effective. Continue to take the Pill every day, but use another form of contraception (eg condoms)
The Pill will be effective again once you have taken 7 consecutive hormone pills over one week after your forgotten pills or the end of your course of antibiotics. It can take longer than this for the effect of some other medications to wear off, so check with the doctor prescribing your medication.What if I miss a pill?
Missing one pill
If you miss one hormone pill, or start taking your hormone pills up to 24 hours late after having a period/break, take the hormone pill as soon as possible, then continue taking pills as usual. Unless you miss more pills within the next seven days you will still be protected against pregnancy.“Anna takes the last inactive pill in her packet on Monday morning at 7am. On Tuesday morning she forgets to take her pill before going to work, and doesn’t take the first hormone pill in her new packet until 6pm that night. Anna is still protected against pregnancy as she was less than 24 hours late taking her pill.”
Missing more than one pill
If you miss more than one pill in a week (eg you miss two pills in a row, miss one and then are late taking the next one, or miss Monday and Thursday’s pills), or are more than 24 hours late starting a new pack after a period/break, you should do all of the following:
“Sarah usually takes her pill at 8pm. She forgets to take it on Wednesday evening, and doesn’t realise until Thursday at 10pm. Sarah has missed more than one pill and won’t be protected against pregnancy until she has taken seven consecutive hormone pills.”
- disregard the missed pills
- start taking pills as soon as you remember
- continue taking pills as usual
- abstain from intercourse or use condoms for the next seven days, as you are at risk of getting pregnant.
If you missed more than one pill in the first week after your inactive pills (or were more than 24 hours late starting your new pack after having a period/break) and had unprotected sex in the last five days you may wish to consider using emergency contraception.
The Emergency Contraceptive Pill (ECP) is available over the counter at pharmacies and is most effective at preventing pregnancy when taken within 24 hours of having sex, though there is some effectiveness for up to five days. For further information call the Sexual Health Helpline on 9227 6178 (1800 198 205 country callers), or see FPWA’s Emergency Contraception information sheet.
If the pills have been missed in the third week of hormone pill taking, finish the hormone pills in the pack and go straight to the hormone pills of the next pack - do not take the seven inactive pills. In this instance you will not have a period (but this doesn’t mean you are pregnant).What if I start to bleed?
If you have any unexpected bleeding when you are taking the hormone pills don’t stop taking the Pill. Ask for advice from a doctor or FPWA clinician. Occasionally women have some spot-bleeding, or even bleeding like a period during their first two months on the Pill, but this usually settles. Taking hormone pills continuously without a break can make this more likely.What if I don’t get a period?
If you miss a period and have followed all the pill packaging instructions, it is very unlikely that you are pregnant. However, you should take a home pregnancy test (available from pharmacies and supermarkets) and consult a doctor or FPWA clinician as soon as possible if your period is more than one week late and you think you may be pregnant.What are some advantages of taking the Pill?
What are some disadvantages of taking the Pill?
- is a very effective form of contraception if used correctly
- is available in many different varieties, meaning most women can find one that suits them
- can make periods lighter, more predictable and less painful
- allows a woman to choose the timing of her period or not to have a period at all some months
- may relieve premenstrual syndrome (PMS)
- can improve acne
- reduces the risk of developing ovarian cysts, ovarian cancer, cancer of the lining of the womb (endometrium), anaemia, serious pelvic infection and benign breast lumps
Some women experience:
- sore breasts
- spotting or bleeding like a period while taking hormone pills
- mood changes including irritability and feeling depressed
- fluid retention
These problems usually disappear after the first two or three cycles on the Pill. Some women find the problems improve if they take the Pill at exactly the same time each day. Women who experience nausea may find it helpful to take the Pill at night rather than in the morning.
Many women are concerned they may experience weight gain if taking the Pill. The reality is that weight gain, if any, is usually minimal (under 2kg), and can often be attributed to other factors such as lifestyle.
A few women taking the Pill may develop brown patches on their face (chloasma) when exposed to sunlight. Others experience a change in sex drive, though this can often take several months to develop.
If you have any concerns, discuss these with a doctor or FPWA clinician. Often a change of pill may be all that is needed.Is there anything else I need to know?
You should arrange to have your blood pressure checked at least once a year while you are taking the Pill. All women, whether they are taking the Pill or not, should have regular Pap smears.
As women taking the Pill have an increased risk of developing a blood clot in the vein, it is important to drink plenty of water and move around regularly when flying, as there is a greater risk of clotting during long flights. This is a rare but important side effect.
Although the Pill does have some side effects and possible risks, few women actually have serious health problems related to taking it. Seek medical help from a doctor or FPWA clinician at once if you develop any of the following:
- painful swelling of the calf (lower leg muscle)
- severe chest pains or abdominal pain
- a cough with blood-stained phlegm, or breathlessness
- a bad fainting attack or collapse
- an unusual, severe or persistent headache
- disturbance of speech or eyesight
- numbness or weakness of your face or of a limb
A new pill, Qlaira, is now available in Australia. Consisting of 26 hormone pills and 2 inactive pills, Qlaira works differently from other pill brands – ask a doctor for more information, and follow the instructions on the pill packaging regarding missed pills.
The Pill does not protect you from sexually transmissible infections (STIs).
SOURCE: © Family Planning Association of WA (Inc)
The information on this fact sheet is not professional medical or health advice and must not replace such advice. Health+Medicine strongly recommends consulting a health care professional. Download the PDF