Combined oral contraceptive pill (COCP)

The Pill contains low doses of 2 hormones – an oestrogen and a progestogen. These are similar to the hormones naturally produced in the female body.

There are many combined pills available. They differ in the type and dose of the 2 hormones they contain.

It works by:

• preventing ovulation (egg release from the ovary)
• thickening the mucous in the cervix to prevent the sperm entering the uterus (womb)
• thinning the lining in the uterus, making it unsuitable for pregnancy

The Pill is 99% effective when taken correctly. This means that if 100 women take the Pill, 1 woman could become pregnant in a year, but it is less effective than this if not taken according to instructions. The typical effectiveness rate in studies of women using the Pill is 91%. This rate reflects the fact that the Pill may not always be taken consistently.

The Pill has few side effects. Some side effects tend to settle within 2 or 3 months of starting the Pill. During this time some women may experience:

• nausea
• breast tenderness or enlargement
• mood changes
• breakthrough bleeding
• headache

Other possible side effects that may occur over time include:

• Skin changes including acne or chloasma (brown discoloration on the face)
• Change is sexual response
• Weight gain: studies suggest this is not related to the pill

While serious risks are extremely rare in healthy women taking the Pill, it is important to note the following: Thrombosis is a rare but very serious complication which occurs when blood clots form in major blood vessels. This can occur spontaneously, after an operation or accident, on the COCP, during and after pregnancy. Warning signs of a thrombosis are severe sudden chest pain, shortness of breath, severe pain or swelling in one leg, sudden blurred vision or loss of sight, or sudden severe headache. If you have any of these symptoms contact your doctor or go to your nearest emergency department immediately.

It is important to understand how big the risk is for you. The information below shows the risk in women in different situations, from women who are not pregnant and not taking the pill (two women in every 10,000 in one year) to the highest level of risk, for women after they have had a baby (200 times more than the lowest level, and 60 times more than the lowest risk level for a woman on the pill).

For every 10,000 women in one year, thrombosis occurs in:

• 2 women not using the Pill/ring and who are not pregnant
• 6-12 women using the vaginal ring
• 29 women during pregnancy
• 300-400 women soon after having a baby

For the COCP, the risk of thrombosis varies with the type of progesterone:

• 5-7 women using 1st generation pills (the pills that have been in use for the longest time – containing levonorgestrel or norethisterone
• 9-12 women using other pills

If blood clots are a specific concern for you, visit your doctor who can assess your particular risk based on your personal and family health history, as there are specific blood disorders that might increase the risk of thrombosis.

• Very effective method of contraception when taken every day
• Readily accessible by most women
• Fertility returns soon after stopping the pill
• Control over bleeding so that it can be predictable

• Must be taken on a daily basis
• Efficacy depends on the reliability of the woman in taking it as directed
• Needs to see a doctor for review and prescriptions
• The cost of the pill varies with the type
• The pill gives no protection against sexually transmitted infections (STIs)
• Some rare but potentially serious side effects
• Some risks associated with Pill use in a number of health conditions, limiting its safety and ability to be used in these situations

• Lighter periods
• Less period pains
• Can improve acne
• Useful for gynaecological conditions: premenstrual syndrome, endometriosis, recurrent ovarian cysts
• Can reduce or assist with symptoms of the perimenopause and polycystic ovarian syndrome
• Reduced risk of cancer of the uterus, bowel and ovary
• May decrease the odds of developing bacterial vaginosis (imbalance of natural organisms in the vagina and vulva potentially leading to symptoms)

Most women can safely take the Pill. Your doctor will review the suitability of the method with you before prescribing the pill. Your doctor will ask about your own and your family history:

• A history of blood clots or current health conditions and inherited conditions that might increase your chance of a blood clot
• Certain types of migraine
• A history of stroke or heart problems or risk factors for a cardiovascular problem: smoking, overweight, high blood pressure, high cholesterol
• Gall bladder or liver disease
• Diabetes
• Breast cancer
• Unexplained vaginal bleeding - this must be investigated before starting the pill
• Cervical cancer screening status
• History of polycystic ovarian syndrome
• Medications – prescribed and over-the-counter
• The possibility of current pregnancy and past pregnancies and their outcomes
• Breast feeding
• Plans for future pregnancies

After the review by your doctor, you will be able to fill your prescription. Australian pill packets contain both hormonal 'active' pills and 'inactive' pills. ‘Inactive’ pills are sometimes called the ‘sugar pills’. Your doctor will explain starting the Pill with you, based on the particular Pill being prescribed for you, as all packages look different. Key points:

• If you start on an 'active' pill on any of the first 5 days of your cycle (day 1 of the cycle is the day your period starts) then you are protected against pregnancy immediately
• Starting the first packet of the Pill at any other time in your menstrual cycle, you will be protected from pregnancy only after you have taken 7 hormone 'active' pills

The Pill needs to be taken at a regular time every day. It can be useful to link pill taking with other activities that are part of your daily routine. A monthly bleed occurs during the 'inactive’ pills and many women prefer to have this regular period. However, if you do not want to have a monthly bleed, you can safely take the hormone pills continuously – missing out the ‘sugar’ pills of each pack. The pill can be stopped for a ‘period’ at any time of your choosing. If you decide to take the pill continuously, without a break, and you start to bleed, then stop the pill for 3 days and then restart the pill. To renew your pill prescription you will need to see a doctor at least once a year.

The pill may not be effective if:

• Your pill is late
• Vomiting occurs within 2-3 hours of taking the pill
• Severe diarrhea occurs
• Other medications are taken
• Some non-prescribed medications, for example St John’s wort (hypericum), can interfere with the action of the pill

For some medications, you cannot rely on the Pill for prevention of pregnancy while on the medication and then for the next 7-28 days of ‘active’ hormone pills. Check with your doctor for any of these issues.

Emergency Contraception may be required if you miss pills and sexual activity occurs without a condom being used. Emergency Contraception should particularly be considered for pills missed in the first week of ‘active’ pills, ie, the first 7 hormone pills taken after the 7 day break on the ‘inactive’ pills.

Emergency Contraception is most effective when taken within 24 hours, but may be taken up to 120 hours (5 days) after unprotected sexual intercourse. It is available without a prescription from pharmacies, general practitioners (GPs), Sexual Health or True clinics.