What is an oral contraceptive pill?
A birth control pill (‘The Pill’) is taken by mouth with the objective of preventing pregnancy. Currently birth control pills are taken by women only.
The following short video explains the effects of the hormones used in the pill relate to the menstrual cycle.
In 1921 it was suggested that extracts from ovaries could be used as birth controls. Diosgenin was first extracted from the Mexican yam in 1941 and this continues to provide a source for the production of sex steroids including norethisterone (norethindrone in the USA) and progesterone (Progest progesterone and progestogen in PMS; progesterone replacement therapy) and Crinone (progesterone and progestogen in PMS).
Video: The Pill – Benefits Including reduced mortality.
How popular are birth control pills?
A birth control was first used in a clinical trial in 1956. The pill became available in the USA in 1960 and in the UK in 1961. By 1986, 95% of sexually active women in the UK under the age of 30 had used the combined birth control pill at some time and by 1991 almost half the women aged 20 years in the UK were taking it.
A survey in 1995 found that 25% of the 13 million women in the UK aged 16-49 were currently using the combined birth control pill. The peak age group was 20-24 with 48% of all women and 70% of contraceptive users choosing this method. The use of the various methods of contraception varies from country to country. In Japan less than 2% of women use the combined birth control pill whereas in Holland 40% of sexually active women do so.
What are the benefits of birth control pills?
The combined birth control pill suppresses the natural hormone cycle providing:
- one of the most effective contraceptive methods available (Pearl Index).
- less painful periods .
- less heavy periods.
- treatment of ovulation pain – Mittelschmerz
- improvement of premenstrual tension.
- regular cycles for those with irregular periods.
The additional benefits include:
- improvement of acne ).
- oestrogen for those with amenorrhoea (absent periods) and low oestrogen levels.
- reduction of excess body hair.
- reduced incidence of functional ovarian cysts
- improvement in endometriosis.
- reduction in the incidence of cancer of the ovary and endometrium.
The four-weekly bleeds that occur whilst taking the combined birth control pill are not periods (menstruation) but withdrawal bleeds. Menstruation is a bleed that occurs each month spontaneously and not in women who are taking hormonal treatment such as the combined birth control pill.
Will the birth pill improve my periods?
The majority of patients report reduced flow and less period pain. There are occasional exceptions so that a few ladies with light periods find their menstrual flow increased by the combined birth control pill. During early pill cycles in particular there may be some breakthrough bleeding. Some women do not have a withdrawal bleed during the combined oral contraceptive pill-free interval. If this happens for two consecutive cycles a pregnancy test should be considered. Absence of the withdrawal bleed is not detrimental to health. When the combined oral contraceptive pill is discontinued, the periods may take a few months to return to normal. Premenstrual syndrome is less common whilst taking the combined oral contraceptive pill although there may still be some symptoms for the last few days of the cycle.
Could the birth pill alter my libido?
Relieved of the stress of possible unwanted pregnancy, some women report increased initiation of sexual activity. Others find their libido reduced, perhaps as there is some sub-conscious wish to have a child. If libido is reduced, vaginal discomfort due to infection should be excluded. Otherwise a change to a less progestogenic pill may help.
What are the risks of taking the birth pill?
Thromboembolism (blood clots): The early combined oral contraceptive pills contained 150 mg of the oestrogen mestranol together with norethynodrel which is a progestogen. The first report of thromboembolism (a blood clot forming in a vein within the leg or pelvis and then travelling to the lungs) in association with the combined oral contraceptive pill came soon after the combined oral contraceptive pills were introduced. The pharmaceutical industry has made enormous efforts to reduce the risks associated with the oral contraceptive pills whilst maintaining their contraceptive effectiveness. Essentially there have been two avenues that have been explored. Firstly, the amount of oestrogen in the combined oral contraceptive pill has been reduced and secondly newer progestogens have been developed.
The oestrogen in the combined oral contraceptive pill reduces LH and FSH production and therefore suppresses follicular development and ovulation (Q 2.3). There has been concern that reducing the amount of oestrogen in the combined oral contraceptive pills could lead to contraceptive failure. Over the years it has been found that the lowest dose of oestrogen that remains effective is much lower than originally contemplated. The original 150 mg was reduced to 100mg then 50mg. The majority of pills prescribed today have less than 50mg of ethinyl oestradiol and two have just 20mg (Loestrin 20 – Parke Davis; Mercilon – Organon). At this level, the oestrogen content is only a little more than that found in hormone replacement therapy (HRT). HRT does not suppress follicular development or ovulation and it therefore follows that the 20mg oestrogen pills will be the minimum effective dose.
Mortality risks are negligible.
What side effects could I have whilst taking the birth pill?
The vast majority of patients taking the combined oral contraceptive pill feel very well but, as with any medicine that has benefits, some minor side effects are occasionally reported. These include:
- altered body weight (some gain a few pounds and others lose a little).
- nausea (feeling sick) and vomiting.
- mastalgia (breast tenderness).
- headaches (the combined oral contraceptive pill should be stopped if they become severe).
- altered libido with many women noticing an increase and others a reduction.
- reduced or absent menstrual flow.
These side effects usually settle within two or three months.
What is the effect of birth pills on body weight?
All of us are intermittently gaining or losing weight.
Inevitably some patients find that they gain weight around the time of starting the combined oral contraceptive pill but others observe a weight loss.
In a personal computer search of the medical literature from 1966 to date I found exactly fifty papers (articles in medical journals) where weight change in relation to the combined oral contraceptive pill had been studied.
- Thirty-six papers indicated no change, eleven found an increase varying from 0.3kg to 2.4Kg.
- Three papers found weight loss with the combined oral contraceptive pill for women who were overweight or who had polycystic ovaries.
Will the birth pill increase my vaginal discharge?
Cervical ectopy (erosion – cervical erosion) appears to be more common in women taking the combined oral contraceptive pill although the newer lower dose pill seem to cause this less frequently. Cervical ectopy only requires treatment if there are persistent significant symptoms after excluding other problems such as infection. Contrary to popular belief, there is no evidence that the combined oral contraceptive pill increases the incidence of candida (thrush).
Does the birth pill increase my chance of pelvic infections?
There is no increase in the incidence of Candida infection in pill users. The incidence is the same as in women with intrauterine devices and those using no contraception. Bacterial infections that gain entry to the pelvis through the cervix are less common in pill users as the progestogen makes the cervical mucus thick. However, there is no protection against viruses or chlamydia.
What is the relationship between the birth pill and fibroids?
Surprisingly, studies show that the combined oral contraceptive pill reduces the chance of fibroid development. It is a surprise because both oestrogen and progesterone are factors in fibroid development so fibroids shrink after the menopause (HRT-Add-Back). The current presumption is that the total of these hormones provided by the combined oral contraceptive pill in a month must be less than the natural hormone output by the ovaries.
Will the birth pill increase my blood pressure?
For the majority of women, the blood pressure increases on the combined oral contraceptive pill by an average of 1mm Hg (a tiny amount). An increase of 5-10mm Hg may be of clinical importance but 1mm really does not matter. This is an example of a statistical (mathematical) proven increase that has no consequence from the medical point of view.
The international recommendation is that the combined oral contraceptive pill should not be started or continued if your blood pressure is 160/100 or higher. High blood pressure can be a factor in heart disease and strokes and as a few women (about 1%) may develop clinically significant raised blood pressure, checks should be carried out periodically. Your blood pressure should be measured before you start the combined oral contraceptive pill and three months later. If your blood pressure is normal it should be reviewed at six months intervals and after two years it can be reviewed annually.
Does the birth pill have any effect on the blood?
All chemicals in the blood are eventually removed and eliminated from the body. The liver plays a key role in this process and this is true for oestrogens and progestogens. The oestrogen and progestogens in the combined oral contraceptive pill results in a slight alteration in the fat chemistry of the blood. There is a rise in low-density cholesterol (Q 27.4) and triglycerides and a reduction of high-density cholesterol. These changes have been reduced by the more modern pills.
When we cut ourselves a blood clot forms to seal the wound and stop the bleeding.
- This involves a cascade of chemical reactions in the blood that lead to the clot forming.
- Some people are particularly prone to inappropriate blood clots, which occur within the veins usually in the legs or pelvis.
- If such a blood clot, which is called a deep venous thrombosis, becomes dislodged it can travel to the lungs and causes a pulmonary embolism, which is a serious life threatening condition.
- The combined oral contraceptive pills do have a slight adverse effect on the clotting mechanism. Again, the new low oestrogen dose preparations are less likely to lead to problems.
What is the relationship between the birth pill and thromboembolism (blood clots)?
Deep venous thrombosis and pulmonary embolism are uncommon if you are young (Figure 15.1). There is a slight increased risk of these problems if you are taking a combined oral contraceptive pill and the risk is further increased for those who are overweight or who smoke. The newer and lower oestrogen dose pills probably cause fewer problems. To put the risk in context, a woman taking the combined oral contraceptive pill is more likely to be hospitalised as a result of an accident than from a complication associated with her pill.
A study by the World Health Organisation (WHO) published in 1995 provided evidence that the newer pills with their lower oestrogen content are associated with lower incidence of thromboembolism than the earlier higher oestrogen dose pills. This study also brought attention to the relationship between the progestogen in the combined oral contraceptive pill and thromboembolism.
There have been three “generations” of progestogens used in oral contraceptives. The WHO study found that the second generation progestogen, levonorgestrel, was only half as likely to be associated with thromboembolism compared to the third generation progestogens desogestrel and gestodene. Essentially, the WHO study demonstrated that the second generation progestogens were associated with a lower incidence of thromboembolism than had been previously believed. The third generation progestogens were not found to be associated with higher risks than anticipated.
In October 1995, the Committee on Safety of Medicines issued an alert to doctors and the media recommending that women taking third generation combined oral contraceptive pills should change to second generation preparations.
- The presentation of the information was such that many women were inappropriately led to believe that the combined oral contraceptive pill was associated with high risk of mortality.
- There was a 10,000 increase in the number of pregnancy terminations in the next nine months. Some Hospitals reported a 25% increase in births in July and August of 1996.
- There are risks of mortality with pregnancy termination and with childbirth. The emotional trauma of pregnancy termination is not easilyQuantified.
Table 15.1 puts the risk of deaths from thromboembolism in perspective.
Table 15. 1 Deaths per million women.
|Risk||Deaths per million women|
|Second generation pill||approximately 2|
|Third generation pill||approximately 3|
|Pregnancy and childbirth||60|
|Road traffic accidents||80|
|Smoker (aged 35)||1670|
A change from a third generation pill to a second generation would be expected to prevent the death of one women in every million taking the combined oral contraceptive pill. There are risks in most aspects of life. We cannot be complacent but every effort should be made to ensure that when clinical information is presented to the public, it is presented in perspective. One death in a million is a tiny risk but for any family (and doctor) involved it is a disaster of the most enormous proportion. There has been an indication that third generation progestogens may have been safer in relation to heart disease.
The latest evaluation of the third generation of the combined oral contraceptive pill has concluded that these pills can be prescribed as a first choice preparation. There are a number of factors to be taken into account when assessing risk and the tiny risks involved probably make it virtually impossible to distinguish risks between second and third generation pills.
What is the relationship between the combined oral contraceptive pill and heart attacks?
The combined oral contraceptive pill has slight adverse effects on the lipids (“fat” chemicals) in the blood and these changes are known risk factors for heart disease. Heart attacks before the menopause are rare. Studies of patients on the early high dose preparations of the combined oral contraceptive pill found a five-fold increase in the incidence of heart attacks. Further studies demonstrated that there are usually confounding (additional) factors contributing to the attacks. In particular, smoking increases the risks. With the more modern low dose pills the risks are probably lower. The latest evidence suggests that there is no increased risk of heart attacks for oral contraceptive users.
The current recommended advice is that smokers should discontinue the combined oral contraceptive pill at the age of 35years. The best advice is that smokers should stop smoking.
What is the relationship between the birth pill and strokes?
Strokes are uncommon in young women but there is a marginal statistical increase in those who have taken the combined oral contraceptive pill. Strokes may involve haemorrhage (bleeding) within the brain or reduced blood supply (ischaemia) to part of the brain. In young women it is the bleed variety of stroke that is the more common. One study in Europe found no significant increase in the chance of the bleed variety of stroke in association with the combined oral contraceptive pill. Smoking and high blood pressure are more important risk factors and these confuse any analysis of the risks of the combined oral contraceptive pill.
Related Medical Abstracts – Click on the paper title:-
Does the birth pill affect the breasts?
Many women find that their breasts are slightly larger when taking the combined oral contraceptive pill. Breast discomfort (mastalgia) may respond to vitamin B 6 (pyridoxine) 50 mg once or twice daily. Otherwise a change of pill should be considered. Should milk production occur (galactorrhoea) investigation of the prolactin hormone level is indicated (hyperprolactinaemia). Benign breast disease (Q 27.16) tends to improve when the combined oral contraceptive pill is taken.
Could I feel depressed as a result of taking the birth pill?
A few women describe a little depression when taking the combined oral contraceptive pill. The pill does not cause severe depression. If a change of pill does not solve the problem, pyridoxine (Vitamin B6) 50mg daily may be beneficial but it can take up to two months to be effective.
What is the relationship between the birth pill and cancer of the ovary?
Several studies have provided convincing evidence that ovarian cancer is less likely to occur in women who have taken the combined oral contraceptive pill. Your risk of ovarian cancer is reduced by about 50% if you have taken the combined oral contraceptive pill for at least five years. The protection continues for about 15 to 20 years after you stop taking the combined oral contraceptive pill. This protection appears to be independent of the brand of pill used. It is likely that the combined oral contraceptive pill needs to have been taken for a minimum of two years to achieve this protection. The incidence of ovarian cancer seems to be falling and this is likely to be related to this benefit of the combined oral contraceptive pill.
What is the relationship between the combined oral contraceptive pill and cancer of the uterus?
Progesterone and progestogens protect against endometrial (lining of the womb) cancer. The combined oral contraceptive pill provides progestogen for 21 days each month. Studies indicate a 40% reduction in the incidence of endometrial cancer when the combined oral contraceptive pill has been taken for more than five years. Protection continues for more than fifteen years after the combined oral contraceptive pill is discontinued.
What is the relationship between the combined oral contraceptive pill and cancer of the cervix?
Sexual activity and number of partners are the factors that have large impacts on the incidence of pre-malignant and malignant conditions of the cervix (neck of the womb – Q32.16). The sheath (condom) provides mechanical protection not only against pregnancy but also against sexually transmitted disease. It prevents transmission of the human papilloma virus believed to be responsible for cervical cancer. It may be that the early studies suggesting that the combined oral contraceptive pill increased the risk were only reflecting the prevention of transmission of the virus with the barrier method.
There has been a suggestion that the combined oral contraceptive pill may increase the chance of pre-malignant conditions of the cervix developing in women at risk but this remains an area of debate requiring more data. There is no reason to stop the combined oral contraceptive pill if you have been found to have an abnormal smear test provided appropriate investigations and treatment are undertaken (Pap Test).
What is the relationship between the birth pill and cancer of the breast?
What are the different types of birth pills?
All combined oral contraceptive pills contain oestrogen and progestogen (Tables 16.1 and 16.2). Pills may be either fixed dose or phasic. All phasic pills have varying amounts of progestogen and the oestrogen content may also change during the course. With the exception of two pills, which have mestranol as the oestrogens, all combined pills in the UK contain ethinyl oestradiol as the oestrogen. There are a variety of progestogens that have been developed and we have three ?generations? of the combined oral contraceptive pill. In 2002 a new pill called ‘Yasmin‘ has been launched in the UK. This is the first combined pill to contain a new progestin called drospirenone that affects the salt and water balance in your body. It has been claimed that this new pill is even less likely to affect your weight than its predecessors.
The pill is generally taken for twenty-one days with a seven day gap between courses. Some ?every day pills? are marketed with seven placebo (blank) pills. These packages are not popular in the UK as the placebo may be taken at the incorrect time occasionally resulting in pill failure but in some countries the majority of packages are of the every day variety.
Yasmin:Drospirenone 3mg with ethinylestradiol 20microg (Yasmin) is a low-dose combined oral contraceptive (COC) administered in a regimen of 24 days of active tablets followed by a short hormone-free interval (4 days; 24/4 regimen).
Drospirenone, unlike other synthetic progestogens used in COCs, is a 17alpha-spirolactone derivative and a 17alpha-spironolactone analogue with antimineralocorticoid and antiandrogenic properties.
This means that it is not associated with water retention and it counters male hormone (testosterone) effects.
Yasmin is approved in the US for:
- prevention of pregnancy in women,
- treatment of the symptoms of premenstrual dysphoric disorder (PMDD)
- treatment of moderate acne vulgaris in women who wish to use an oral contraceptive for contraception.
The same treatment regimen over three treatment cycles also significantly improved the emotional and physical symptoms associated with PMDD,0701, 0801and improved moderate acne vulgaris over six treatment cycles in double-blind trials. It was generally well tolerated, with adverse events generally typical of those experienced with other COCs and which were most likely to occur in the first few cycles. Clinical trials indicate that drospirenone/ethinylestradiol 3mg/20microg (24/4) is a good long-term contraceptive option, and additionally offers relief of symptoms that characterise PMDD and has a favourable effect on moderate acne vulgaris.0802
What are the benefits and problems of the phasic oral contraceptive pills?
Phasic pills (Table 16.2) claim to provide better cycle control than monophasic pills providing the same amount of hormone each month.
Great care is needed to ensure that each pill is taken on the correct day. Some women report premenstrual syndrome like symptoms as the hormone levels change. Phasic pills do not readily lend themselves to postponing the withdrawal bleed or omitting the combined oral contraceptive pill-free interval. This problem can be overcome when required by moving on to a monophasic pill with the same hormone content as the last part of the phasic pill (e.g. Binovum to Norimin).
Deciding on the best pill oral contraceptive pill.
The objective is to choose an effective pill, with the lowest side effects and the lowest possible hormone content. A pill with 30 or 35mg ethinyl oestradiol is now the usual first choice. A 50mg pill may be recommended for women on some anti-epileptic drugs .
If a friend has recommended her brand of pill to you there is unlikely to be a reason why you should not try it. Similarly, if you are about to recommence oral contraception and have been happy with one preparation in the past, it would seem reasonable for you to try it again.
Whilst I am taking the combined oral contraceptive pill, what monitoring should I receive?
Medical opinion varies as to how often patients on the combined oral contraceptive pill should be checked.
At your first visit the doctor will need to review your medical history and to undertake a general and pelvic examination.
A further review will be undertaken about three months later to ensure that the chosen pill is acceptable.
Many family planning clinics have specialist nurses to undertake some of these routine assessments.
The blood pressure is checked at each subsequent visit to the clinic, which will probably be at three to six monthly intervals. A persistent blood pressure of 160/100mm Hg or more would be an indication to stop the combined oral contraceptive pill and to consider medication to reduce your blood pressure.
Pelvic examination and cervical smears every three years are probably adequate unless you develop symptoms. More frequent monitoring may be indicated for those with risk factors.
Product information for oral contraceptives currently includes the recommendation that all women should have breast and pelvic examination before starting the combined oral contraceptive pill and at regular intervals whilst taking it.
The Committee on Safety of Medicines and the Faculty of Family Planning and Reproductive Health Care in the UK now believe that it is unnecessary for all women taking the combined oral contraceptive pill to have routine breast and pelvic examinations either before or whilst taking the combined oral contraceptive pill.
Blood pressure should always be measured but other physical examination should only be performed if considered appropriate by the clinician.
One of my family has had a blood clot (thromboembolism). Should I have any special tests?
Thromboembolism may occur during immobilisation particularly after a major operation. If your relative had a thromboembolism in such circumstances we would not anticipate that you are at increased risk.
Some families have disorders of the blood clotting mechanism, which predisposes them to thrombosis (thrombophilia). If several of your relatives have been affected, particularly when the blood clots have occurred spontaneously without an obvious cause, we would need to consider thrombophilia. There are blood tests that may detect these abnormalities but they are extremely expensive. In these circumstances, it may be appropriate to seek advice from a haematologist (blood disorder specialist).
Does an aeroplane journey increase the risks of taking the combined oral contraceptive pill?
Modern commercial aeroplanes are pressurised. The increased risks of venous and arterial thrombosis associated with high altitude are therefore eliminated.
There have been reports of circulatory complications after a flight but this is equally true for those not taking the combined oral contraceptive pill. Underlying dehydration, following sunbathing, alcohol or a gastro-intestinal upset increases the risk.
Many airline stewardesses take the combined oral contraceptive pill. They know the importance of ensuring adequate fluid intake and they will take a little walk every hour or so to keep their circulation going.
It has been suggested that Aspirin 75mg daily should be considered before the flight and for a few days afterwards.
There is one concern about flights for women taking the combined oral contraceptive pill particularly if they are travelling West as they may inadvertently take a pill late. It may be prudent to keep one watch set at the time of your home and use this to guide you on when you should be taking your pills.
Are there times when the combined oral contraceptive pill should be prescribed only with special caution?
Yes, there are times when a patient has medical problems such that the combined oral contraceptive pill can be prescribed but only with special caution. More careful monitoring is required. Examples are:
- moderately elevated blood pressure (hypertension) requiring medication (patients with a history of high blood pressure in pregnancy can be given the combined oral contraceptive pill but again the blood pressure should be checked more frequently).
- obesity (greater than 50% above ideal weight for height) is a reason for caution. Calorie control and exercise should be encouraged with a view to ensuring weight loss.
- hormones may, on occasion, aggravate depression.
- sickle cell disease (an inherited cause of anaemia found generally in people of Afro-Caribbean origin); this was regarded as a contraindication for the combined oral contraceptive pill as there is an increased risk of thrombosis; some authorities now suggest that the combined oral contraceptive pill can be given with caution. It may be prudent to discontinue the combined oral contraceptive pill during any episodes of immobilisation.
- some medical conditions when they are mild but not if they are severe. Examples are diabetes, systemic lupus (SLE), Crohn’s disease and renal disease.Varicose vein problems are not a contraindication for the combined oral contraceptive pill. Varicose veins are more frequently found in association with obesity and this would be a reason for caution. The pill should be stopped if you need injection treatment.The more common contraindications to the combined oral contraceptive pill include:-
- a history of arterial or venous thrombosis.
- cardiomyopathy (an inflammatory condition of the heart).
- ischaemic heart disease (heart attacks or angina).
- familial conditions associated with thrombosis.
- severe migraine.
- liver diseases.
- gall stones (the combined oral contraceptive pill can be taken after surgical removal of the gall bladder).
- porphyria (an inherited condition affecting the break down process of red blood cells)
- very high blood pressure.
- smoking at age 35 years or more.
- severe systemic lupus (SLE) requiring steroid treatment.
- cancer of the breast or uterus.
As with any medication, your doctor will check to see if there is any specific medical reason contraindicating the combined oral contraceptive pill.
- When a woman has a medical problem that may be affected by the combined oral contraceptive pill, the doctors involved in her care will usually liaise to ensure consistency of advice. Ultimately it is for the doctors caring for the woman to provide her with the information that she requires to make an informed choice.
On which day of my menstrual cycle should I start my first course of the combined oral contraceptive pill?
Nowadays, we recommend that it should be started on thefirst day of a period as this provides immediate contraceptive cover. The next period will occur after 23 days but subsequent periods will be at 28 day intervals.
Following childbirth, the combined pill can be taken if the baby is not being breast-fed; breast feeding combined with progestogen-only pills provides excellent contraception. During pregnancy and for the first two weeks after childbirth there is an increased risk of thromboembolism (blood clot problems – surgery risks) and this may be further increased by the combined oral contraceptive pill.
- The pill should be commenced no earlier than 21 days after childbirth.
- If there has been a high blood pressure problem associated with pregnancy or there is a tendency to obesity, the combined oral contraceptive pill should be further delayed.
- If the combined oral contraceptive pill is commenced more than 21 days after childbirth, additional contraceptive precautions are required for the first seven days. The combined oral contraceptive pill can be commenced immediately after early miscarriage or pregnancy termination.
If periods are absent or infrequent, and this problem has been appropriately investigated (Q6.6), a course of progestogen tablets will usually provide a withdrawal bleed and the combined oral contraceptive pill can be commenced on the first day of bleeding.
Can I start the combined oral contraceptive pill whilst I am breast-feeding?
The combined oral contraceptive pill is likely to reduce the quantity and quality of your milk which will contain a relatively large amount of hormones. If oral contraception is required the combination of a progestogen-only pill with breast-feeding will provide highly effective contraception for you.
Can I take the combined oral contraceptive pill if I have had episodes when I did not see my periods (amenorrhoea)?
- The amenorrhoea should be investigated, before the combined oral contraceptive pill is prescribed, and treated if a specific cause is found .
- If pregnancy has been excluded there is no reason why the combined oral contraceptive pill cannot be prescribed.
- When the combined oral contraceptive pill is subsequently discontinued the menstrual cycle will return to the pattern that would have occurred if the combined oral contraceptive pill had not been taken.
This means that the amenorrhoea may recur and fertility medication may be required if a pregnancy is planned.
Can I start the combined oral contraceptive pill if I am not currently seeing my periods?
Absence of periods (amenorrhoea) needs to be investigated (Q6.6). Provided that both pregnancy and a problem requiring treatment have been excluded, amenorrhoea is not a contraindication to the combined oral contraceptive pill.
Does it matter if I do not see a period whilst taking the combined oral contraceptive pill?
A withdrawal bleed (‘period’ whilst taking the combined oral contraceptive pill) does not have to occur with every pill-free interval.
Provided you have taken the combined oral contraceptive pill correctly, a pregnancy is very unlikely.
If you do not see a withdrawal bleed it usually means that the lining of your womb is not building up sufficiently to result in a bleed. This reflects the way that the womb is responding to the combined oral contraceptive pill and does not indicate what will happen when the combined oral contraceptive pill is stopped if you wish to have a baby.
From the medical point of view there is no reason to change the combined oral contraceptive pill if the problem continues and there is no need to run any tests.
If you are unhappy that you do not see a withdrawal bleed, a different pill may suit you better. One of the phasic pills could be tried if you are on a monophasic variety
A girl of 13 had extremely heavy and painful periods which were controlled for two years with a monophasic pill (Microgynon). At the age of sixteen she returned to my clinic as she kept missing withdrawal bleeds. She had not started sexual activity but was worried that she would lose her fertility. We reassured her that medically there was no anxiety. After discussion she was started on a phasic pill (Trinovum) and withdrawal bleeds occurred.
Some women find that when they stop the combined oral contraceptive pill they do not see their periods. Until twenty years ago this was called ‘post-pill amenorrhoea’. Research then showed that, with few exceptions, patients with amenorrhoea after discontinuing the combined oral contraceptive pill had infrequent or absent periods before they commenced the combined oral contraceptive pill. The pill had simply masked an underlying problem and was not the cause.
What is the advice when my changing combined oral contraceptive pill preparation?
The simplest guide is that the current combined oral contraceptive pill should be taken until the course is completed and the new pill should commence on the first day of the withdrawal bleed; no additional contraception is required but the first cycle on the new pill will be just 23 days.
What should be done if breakthrough bleeding occurs whilst I am taking the combined oral contraceptive pill?
The first course of action is to check that there is no cause for the bleeding other than the combined oral contraceptive pill preparation. A missed pill, antibiotics or gastro-intestinal upset may have occurred. There may be a local cause such as vaginitis (inflammation of the vagina), a cervical polyp (cervical polyps) or other cervical disease. These can be assessed by medical examination. A bleed early in pregnancy can be mistaken for break-through bleeding.
Light breakthrough bleeding may be acceptable for perhaps three months and is likely to settle. Otherwise a change of pill preparation is appropriate. If the oestrogen content is very low increasing this may be the first line of approach. Increasing the progestogen content (Table 16.1) or changing from a monophasic to a bi-phasic or tri-phasic pill (Table 16. 2) are other possible remedies.
Can my combined oral contraceptive pill withdrawal bleed be planned to avoid weekends?
If a pill packet is commenced on a Sunday, the withdrawal bleed should occur on weekdays. When starting the combined oral contraceptive pill for the first time, if you delay to the next Sunday rather than commence on the first day of the period, additional contraception is required for the first seven days. For those on monophasic pills (Table 16.1) who wish to convert to a Sunday start, it is probably best to take two packets back-to-back and then finish the second packet on the Saturday. The third packet is commenced on the following Sunday. The other option would be to continue taking the combined oral contraceptive pill from a spare pack until the next Sunday. This spare packet can be kept in reserve for similar cycle adjustments when required.
Table 16. 1 Monophasic combined oral contraceptive pills:
|Preparation||Ethinyl Oestradiol (mg)||mg / Progestogen||Manufacturer|
|Loestrin 20||20||1 norethisterone acetate||Parke Davis|
|Loestrin 30||30||1.5 norethisterone acetate||Parke Davis|
|BrevinorOvysmen||3535||0.5 norethisterone0.5 norethisterone||SearleJannsen-Cilag|
|Norinyl -1Ortho-Novin 1/50||50 (mestranol)||1 norethisterone||SearleJanssen-Cilag|
|Microgynon 30 Ovranette?||3030||levonorgestrel0.15 levonorgestrel||ScheringWyeth|
|Eugynon 30Ovran 30||3030||levonorgestrel0.25 levonorgestrel||ScheringWyeth|
|YasminEvra Patch||30(see 16-01a-)||3 drospirenone||ScheringJanssen-Cilag|
Table 16. 2 Phasic combined oral contraceptive pills:
|Preparation||Ethinyl Oestradiol (mg)||mg / Progestogen||Manufacturer|
Can I take the combined oral contraceptive pill without a seven-day pill-free gap?
From the medical point of view, there is no benefit in having the gap, and if you are taking a fixed, rather than a phasic pill, you can take the combined oral contraceptive pill back-to-back without pill free days. This may avoid a bleed during a social event or a vacation.
The bleed that occurs during the gap we call a withdrawal bleed and not a period. The pharmaceutical companies produce the packaging with the combined oral contraceptive pill-free interval as women understandably feel that it is normal to have a monthly bleed. The only real advantage is that it provides an indication that there is no pregnancy. The phasic pills do not readily lend themselves to a pill-free interval although your doctor can usually provide appropriate advice (2)
If a pill is missed less than seven days before the combined oral contraceptive pill-free interval, the combined oral contraceptive pill-free interval should be avoided (18).
The pill-free interval can be avoided for social convenience such as a vacation.
Some women have cyclical symptoms around the time of the combined oral contraceptive pill-free interval. If there are problems with headaches, heavy or painful periods the combined oral contraceptive pill can be taken back-to-back. We generally recommend three packets at a time leading to a withdrawal bleed every ten weeks. The combined oral contraceptive pill is a treatment option for endometriosis and we may recommend avoiding the combined oral contraceptive pill-free interval for several months (21).
What should be done if a pill is missed?
If a pill is taken more than 12 hours late we regard it as missed. The missed pill can be taken and the course continued at the appropriate time. Additional precautions (usually condoms) should be used for the next seven days. If there are less than seven pills remaining in the course, the next packet should be commenced without a seven-day gap; if you are on an ED (every day) regimen, the seven inactive pills should be omitted. The risks of pregnancy are highest when the missed pill is at the beginning or end of a cycle.
Could I conceive whilst I am taking the combined oral contraceptive pill?
There are few failures associated with the combined oral contraceptive pill provided that the combined oral contraceptive pill has been taken correctly.
Ideally, the combined oral contraceptive pill should be taken at the same time each day.
There is a maximum safety limit of 12 hours.
If the combined oral contraceptive pill is taken more than 12 hours late additional precautions are essential (18). The seven pill-free days allow the natural hormone cycle to begin.
If the gap is inadvertently increased, ovulation (egg release) can occur and pregnancy may ensue.
During a gastro-intestinal upset (vomiting or severe diarrhoea) the combined oral contraceptive pill may not be absorbed and additional precautions are required. The additional precautions should be continued for at least seven days after the bowel has settled. Similarly, some antibiotics reduce the absorption of the combined oral contraceptive pill and the same precautions would apply.
Can combined oral contraceptive pills interact with other medication?
Some medications, such as those used in the treatment of epilepsy, increase the rate that the liver breaks down chemicals including the oestrogen and progestogen in the combined oral contraceptive pill.
Rifampicin, used for a short course for those at risk of meningococcal meningitis, is so powerful at speeding up chemical breakdown pathways that although given for only 2 days, its effects may last for 4 weeks; additional contraceptive precautions are advisable to cover this. Rifampicin may also be prescribed for several months during treatment of tuberculosis. This may make the lower dose pills in particular less effective and breakthrough bleeding more likely. Higher dose pills (e.g. 50mg ethinyl oestradiol), in these circumstances, achieve similar hormone levels to lower dose pills taken by women not taking the anti-epileptic treatment.
Some broad-spectrum antibiotics (effective against a wide variety of bacteria) can reduce the absorption of oestrogen. Break-through bleeding may occur if the hormone levels fall below a threshold. For those on long-term broad spectrum antibiotics (e.g. for treatment of acne) the bacteria in the intestine become resistant to the antibiotic and after the first two weeks there is no need for additional contraception.
The combined oral contraceptive pills may interfere with treatment for diabetes, depression and high blood pressure; appropriate adjustments may be required.
Can The combined oral contraceptive pill affect future fertility?
The short answer is no.
At one time it was thought that the combined oral contraceptive pill could cause ‘post-pill amenorrhoea (absent periods after stopping the combined oral contraceptive pill ) and this was associated with anovulatory (failure of egg release) infertility. Subsequent studies showed that those who developed post-pill amenorrhoea had similar cycle problems before commencing the combined oral contraceptive pill. The pill was not the cause but it had been masking the underlying problem.
It seems likely that, if anything, the combined oral contraceptive pill may conserve fertility by reducing the incidence of pelvic inflammatory disease (Q 20.2) and endometriosis (Q9.11). Pregnancy termination (abortion), which should be prevented by the combined oral contraceptive pill, can have complications leading to infertility (Q19.14).
Modern contraceptive methods are extremely effective. There is a danger that one can assume that when the combined oral contraceptive pill is discontinued a pregnancy will occur quickly. With increasing age, fertility decreases if you want a child, you should not leave it too long.
Taking breaks from the combined oral contraceptive pill.
There is no medical advantage in taking a break from the combined oral contraceptive pill. All too frequently, an unplanned pregnancy will occur. The concept that the combined oral contraceptive pill should only be taken for five or ten years at a time is based in mythology.
Surgery and the combined oral contraceptive pill.
One of the potential complications following an operation is a blood clot in one of the veins in the legs or pelvis (surgery risks) and we surgeons try to reduce the risk as far as possible.
As the combined pill is also associated with a tiny risk of blood clot problems (Q15.14) we need to consider whether the combined oral contraceptive pill should be stopped before we operate.
Ideally, the combined oral contraceptive pill should be discontinued four weeks before major surgery or any operation on the legs.
The pill can be recommenced on the first day of the next period provided that this occurs at least 14 days after the operation.
If there is need for a major operation when the combined oral contraceptive pill has not been discontinued, your surgeon may recommend injections of heparin for a few days to thin the blood a little.
There is no reason to discontinue the combined oral contraceptive pill for minor operations or intermediate operations such as laparoscopy.
There is no recommendation to stop progestogen-only pills or other progestogen contraception for surgery.
The third generation combined oral contraceptive pill.
The latest evidence is that third generation combined oral contraceptive pills are safe and may be offered as a first choice. This subject is discussed in Q15.6
Until what age can I take the combined oral contraceptive pill?
The official recommendation for women with no risk factors is that there is no upper age limit for taking the combined oral contraceptive pill.
Women who smoke should stop the combined oral contraceptive pill by the age of 35 years as they are at increased risk of heart disease. The best medical advice is to stop smoking.
As we get older the risks of heart disease increase and fertility falls. If you are taking the combined pill and wish to continue with oral contraception, it is probably advisable to change to a progestogen-only pill at the age of 50.
The combined oral contraceptive pill and the menopause.
The pill does not change the time of the menopause. Each egg appears to behave as if it has a timer which determines when it will go into an active phase (Q 2.3). If the hormone environment is not appropriate, the active phase is cut short and that egg fails to develop. One of the important ways that the combined oral contraceptive pill works is that it creates a hormone environment that prevents further development of the eggs that are going into the active phase. The pill does not stop eggs from going into the early active phase (otherwise the menopause would be delayed in pill users).
I am taking the combined oral contraceptive pill. How will I know if I have reached my menopause?
As you approach the age of 50 there is an increasing chance that you will be reaching your menopause but withdrawal bleeds will continue for however long the combined oral contraceptive pill is taken. There is no test that can absolutely define when the menopause has occurred even for a woman who is not taking the combined oral contraceptive pill and seems to have stopped her periods although a blood test for FSH and oestradiol levels (14) can be a useful guide. If you want to know if you are likely to have reached your menopause, the blood test should be scheduled for the last day of the combined oral contraceptive pill-free interval.
In what circumstances should the combined oral contraceptive pill be stopped immediately?
The pill should be discontinued and urgent medical advice sought if any of the following occur:-
- Severe headache accompanied by visual disturbance.
- Sudden visual disturbance or difficulty with speech.
- Weakness or numbness in one part of the body.
- Severe pain in a calf.
- Unexplained shortness of breath.
- Severe chest or abdominal pain.
What symptoms are commonly associated with taking the oral contraceptive pill?
Many women experience mild symptoms that are a nuisance or inconvenience although they are not damaging to their general health.
Many of these symptoms occur frequently amongst non-pill takers so the combined oral contraceptive pill may not be responsible. Anxiety that the combined oral contraceptive pill may be causing major problems frequently leads the patient back to her doctor.
The more common symptoms include
- breast discomfort,
- vaginal discharge,
- aches in the legs and
- weight change.
After checking that all is well, your doctor will probably only need to reassure you. frequent change of pill prescription is rarely indicated.
Should the combined oral contraceptive pill be discontinued if I develop headaches?
Migraine involves a headache with visual disturbance. If severe migraine starts, the combined oral contraceptive pill should be stopped immediately and not recommenced. The progestogen-only pill is not contraindicated. If mild migraine occurs, the combined oral contraceptive pill should be stopped but it may be tried again later with careful monitoring and advice from your doctor.
Headaches by themselves are not a contraindication to the combined oral contraceptive pill. If they occur around the time of the combined oral contraceptive pill-free interval, the combined oral contraceptive pill may be taken for nine weeks without a break before a pill-free interval reducing the symptom from 13 to 5 times each year.
Varicose veins and the combined oral contraceptive pill.
Varicose veins are not a contraindication against taking the combined oral contraceptive pill.
Vomiting and diarrhoea. How does this affect my oral contraceptive pill taking?
If you have taken a pill within two hours and you do not think that another will stay down, you should recommence the combined oral contraceptive pill as soon as possible and use additional contraception until seven days after the vomiting has settled. The pill should be continued rather than omitted for the seven pill free days if they would occur during this time. Mild to moderate diarrhoea does not interfere with pill absorption.
Starting a pregnancy- When should I stop taking the combined oral contraceptive pill?
There is no evidence of any increased risk of abnormality for the baby in women who conceive soon after stopping the combined oral contraceptive pill. The underlying risk of congenital abnormality (a structural defect of one or more parts of the body present at birth) is 2% of all babies. Even when pregnancy occurs accidentally in women taking the combined oral contraceptive pill, the risk of congenital abnormality is not increased above this 2% level.
At one time, one of the most common problems facing obstetricians was determination of the duration of pregnancy.
- Only if the menstrual cycle was normal and the mother was certain about the date of the first day of the last menstrual period (L. M. P.) could the obstetrician be reasonably confident about the expected time for delivery (expected date of delivery E.D.D).
- Knowing the dates is critical either when there is a possible need to induce labour, plan an elective Caesarean section or stop premature labour.
- Periods may be delayed or irregular for a few months after stopping the combined oral contraceptive pill, reducing the accuracy of determining dates in a pregnancy.
- Ultrasound, which has been available for more than thirty years, can be reasonably accurate in the first half of pregnancy in determining dates usually overcoming this potential difficulty.
There is some evidence that folic acid supplementation reduces the risk of the spina bifida group of defects when taken before pregnancy and for a few weeks after conception. We now recommend folic acid supplements to all women contemplating pregnancy.