Contraception Through Combined Pills

Combined pills, containing oestrogen and progestogen, are commonly referred to simply as ‘the pill’. Worldwide there are currently 50-60 million women using the pill, and it is still the commonest method of contraception in the United Kingdom (the sheath is a close second). It is particularly popular with young women; up to seventy per cent of sexually active women in their twenties use the pill in this country.

For centuries women (and men) have been searching for an oral contraceptive. In ancient China it was recommended that the woman swallow twenty-four live tadpoles in the early spring; this was said to prevent conception for five years! All over the world primitive peoples have believed that certain plants prevent pregnancy. Some of these plants have been shown to contain oestrogens, so may have some genuine effect; others may work in a totally different way. Many others probably don’t work at all. However, the World Health Organization has a task force researching into plant products to see if any of them have usable contraceptive properties.

In the early 1900s it was conclusively shown that action of the corpus luteum in a pregnant woman prevents further pregnancies from occurring. In 1921 an Austrian doctor suggested that extracts from the ovaries of pregnant animals might prevent pregnancy in humans. It was not until the 1930s that there was sufficient understanding of when in the menstrual cycle a woman was most likely to conceive to allow work on altering that pattern to control fertility. By the late 1930s extracts from pregnant rats were being used for experimentation in humans, but they had to be given by injection because the extracts were destroyed by the digestive system.

In 1943 progesterone was produced from a product of the Mexican wild yam, and large trials began in Puerto Rico in 1956. Since the 1960s, there has been a progressive trend towards lower dosages of oestrogen and progestogen in the pills. Dosages of 100-150mcg of oestrogen and 1-10mg of progestogen were common, but levels nowadays are usually 30-40mcg of oestrogen and lmg or less of progestogen.

Contraception – How the pill works

It is rather misleading to talk of ‘the pill’, as many dozens of different brands have been tried in various parts of the world through the years, but all combined pills are based on similar ingredients and work in similar ways. Each pill contains oestrogen and progestogen (synthetic progesterone), which are very similar to the hormones produced by the woman’s body. The oestrogen works on the brain’s pituitary gland and ‘fools’ it into thinking that the woman is pregnant. Consequently the pituitary doesn’t release its normal follicle stimulating hormone (FsH) and surge of luteinising hormone (LH), which normally stimulates ovulation, so no egg is released.

In addition the oestrogen and progestogen between them make the cervical mucus virtually impenetrable to sperm, interfere somewhat with sperm capacitation, and also make the lining of the uterus inhospitable. Most types of pill regime include a 6 or 7-day pill-free ‘resting’ phase to imitate a woman’s normal menstrual cycle. During this time the thinner-than-usual lining of the uterus comes away and is discharged like a period. This bleeding is really a withdrawal reaction to stopping the oestrogen contained in the pill, and is not a true period; that is why many women on the pill find that their ‘periods’ are virtually trouble-free.


If you feel that you want to use the pill, your doctor or family planning clinician will do his or her best to ensure that you are a low risk for any of the pill’s possible dangers, and that you understand fully how to use the pill. You will be asked about your medical history, your age, and your smoking habits, and then will be weighed and have your blood-pressure taken. You will also be asked whether you have ever been pregnant, whether the pregnancy or pregnancies ended in birth, miscarriage or abortion, and whether you have ever had treatment for VD or any kind of vaginal or pelvic infection. These questions can be rather distasteful if you are still a virgin, but they are necessary for the doctor to form a complete picture of your gynaecological health.

The doctor will discuss the pill and the way it works with you, and the clinic may prefer to give you an internal examination. This is not vital, but is helpful to the clinician, especially if you are already sexually experienced, as it can help detect problems such as fibroids, ectopic pregnancy and cervical erosion. In this examination the doctor will probably do a manual check of your uterus and ovaries, and will then visually examine the vagina and cervix with the aid of an instrument known as a speculum. If you are sexually active the doctor may well take a Pap smear of the cervix to check that all is in order. Your breasts will also be examined to see if there is any abnormal growth or lumpiness.

When the doctor has made all these checks, he or she will be able to make a very accurate assessment of whether or not you are a suitable candidate for the pill. If you are not, then the doctor will discuss alternative forms of contraception with you. If you are, the doctor will select the pill brand that is best suited to you; this will generally be the lowest possible dose that can be relied upon to prevent ovulation. The doctor will ensure that you know exactly how to take that particular type of pill, and will probably give you only three months’ supply to begin with. This is to ensure that you return for a full check-up so that your progress, health and satisfaction with the method can be monitored.

Taking the pill

There are several different types of basic combined pill; some of these require slightly different routines.

The most common pill-taking regime is ’21 days on, 7 days off’. Pills of this kind come arranged in a circuit of 21 pills to a packet. Each one is marked with a day of the week, but as each pill contains exactly the same balance of hormones it doesn’t matter which you start with. The days are marked only to make it obvious if you have missed a pill. When you have taken pills 21 days in succession, and finished the packet, then you stop for 7 days. During this time you will get a period-like withdrawal bleeding. You are still protected from conceiving during this 7 days, as the hormone levels in your body are still high enough to continue stopping ovulation. On day 8, you begin a new packet of pills, and so on in a 21 days of pill, 7 pill-free cycle. Some pills modify this cycle slightly, and have 22 days on and 6 off. This is simply so that you stop and start your pills on the same day of the week — and it can act as a memory jogger for the forgetful.

For the very forgetful, or those who live such an active life that they can lose track of where they are in the cycle, there are 28 day pills. In these packs, 7 of the pills are ‘dummies’ — they do not contain hormones. These pill systems work just like the basic ’21 day on, 7 days off’ system, described above, with withdrawal bleeding during the 7 days of taking the dummy tablets. The advantage is that a pill is taken every day, so the woman doesn’t need to keep track of when she should be stopping or starting again. The disadvantage is that she has to be careful to start the pack in the right place, otherwise she could take the dummy pills instead of the real ones. The packs are clearly marked to show which is which. Another type of pill is the ‘phased’ kind. Biphasic pill packs have two different mixtures of hormones for two parts of the monthly cycle. Triphasic pill packs have three different mixtures. These phased pills are intended to imitate the normal menstrual cycle more exactly; because they do this, the dosages of oestrogen and progestogen can be the bare minimum through the month to keep the woman from conceiving. Because they are closer to the normal sequence of hormone rise and fall, the woman’s withdrawal bleeds are more like normal periods, and may still have accompanying pre-menstrual tension and pain (these are usually absent with ordinary pills). Of course with phased pills it is extremely important that you take the pills in the correct order. Because the dosage of hormones is so low, there is a very much reduced margin of error if the pills are taken in the wrong order or if one is forgotten. These pills should not be used to change the timing of your period, which can be done with ordinary combined pills.

Some pill-taking women prefer what is known as the ‘tricycle’ system (not the same as the triphasic pill). This involves taking four packs of pills in a row without a break, then having a 7-day break. This means that withdrawal bleeding occurs only once every three months. However, it also means that the woman takes significantly more hormones over any given year, and so some doctors advise against this system.

Starting the pill

There are two main ways of starting the combined pill. The traditional way is to begin with the first pill on day 5 of your cycle (remember day 1 is the first day of your period). It doesn’t matter whether or not your period has stopped by then. If you use this way of starting, you will not be protected against conception for the first 14 days, as the hormones are still reaching the correct level. If you are already married, you should use an alternative contraception, or abstinence, for these 14 days. If you are going on the pill prior to getting married, then make sure that you get over this 14 day phase before your wedding! A newer way to take the pill is to start on day 1 of your cycle (the first day of your period). This gives complete contraceptive protection straight away, and you do not need an alternative method. This can cause a little more ‘breakthrough’ bleeding in the middle of your first cycle as the hormones adjust. It also means that your first withdrawal bleed will be 21 days after your last period began, so your first cycle will be extra-short. From then on, of course, you will experience a normal monthly pill cycle.

You may want to start the pill after a pregnancy. You are usually sterile for four weeks after a normal birth, so if you are bottle-feeding you can start the pill towards the end of the fourth week, although some doctors recommend a longer wait. The pill can be started immediately after a miscarriage or a suction abortion, but some doctors prefer to wait for a month or so, so will recommend an alternative method for that time.

Timing the pill

You should always aim to be consistent in the time you take your pill. If you always take them roughly twenty-four hours apart, then the body should always contain a high enough level of hormones to prevent ovulation. Some doctors recommend that you take your pill last thing at night, but if your routine is too varied to make that feasible, then taking the pill in the mornings will probably suit you better. Consistent pill-taking is very important; if you decide to use the pill then you should be committed to taking it every day that it is necessary. The Health Provider’s Guide to Contraception states that ‘the efficacy of the method relies entirely on the woman’s consistency in pill-taking’.

Naturally, everyone is human and there is bound to be at least one occasion when you forget to take your pill. The rules here apply only to ordinary combined pills; other types of pill (progestogen-only, phased pills) do not have such a large margin for error. If less than twelve hours has elapsed since your proper time for taking the pill, simply take the missed pill as soon as you remember it and carry on as usual. You will still be protected against conception. However, if more than twelve hours has elapsed, take your pill anyway (and carry on taking subsequent ones in your normal regime), but use a back-up method of contraception for the next 14 days. This is very important. It is extremely likely that ‘breakthrough’ ovulation will occur if your hormone level suddenly drops during your normal pill-taking days, and many of the pregnancies that occur in women on the pill occur in this way.

Stomach upsets can also play havoc with the body’s absorption of the pill. If you are sick after three hours of taking a pill, don’t worry—the pill will already have passed into your system. If you are sick within three hours, take another pill from a spare pack. If it happens again within three hours, then try again with another one; as long as you can keep one pill down for three hours you will be all right. If you can’t, or don’t feel like trying, within twelve hours of your usual pill time, then again you will need a back-up contraceptive for the next 14 days (or longer if you miss pills for more than one day). The same is true if you have diarrhoea; the pill is likely to have been passed through your digestion before it has had time to be absorbed. In this case also you will need extra protection for 14 days (or more, if the diarrhoea lasts for more than one day). Antibiotics can also prevent full absorption of the pill, and therefore an alternative method may need to be used while on a course of antibiotics, up until your next withdrawal bleed.