Dr Sarah Brewer graduated from Cambridge University as a Natural Scientist in 1980. She went on to study medicine at Cambridge Clinical School, where she qualified as a doctor in 1983. Although her first love is medicine, her major passion is writing. She is pursuing a career in medical journalism to successfully combine the two.
Sarah writes regularly for a wide variety of newspapers and magazines including Marie Clare, Prime, The Lady and The Daily Express. She has written numerous books including: The Daily Telegraph Encyclopedia of Vitamins, Minerals and Herbal Supplements (Constable & Robinson), Eat to Beat I.B.S. (Thorsons), Total Detox Plan (Carlton Books) and Pregnancy the Natural Way (Souvenir Press Ltd).
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First published in the United Kingdom in 1995 by Optima
First published in 1998 by Vermilion
This revised edition published in the United Kingdom in 2004 by Vermilion
an imprint of Ebury Press
Random House Group Ltd
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ISBN 9780091898489 (from January 2007)
ISBN 009189848X
Contents
Introduction
Part
I
For future mums
1
The female reproductive system
2
Contraception
3
Pre-conceptual care and a healthy diet
4
Vitamins and pre-conceptual care
5
Minerals and trace elements
6
Antioxidants and free radicals
7
Healthy eating for vegetarians and vegans
8
Body weight and pre-conceptual care
9
Exercise
10
General health screening during pre-conceptual care
11
Female genital infections
12
Other harmful infections
13
Smoking, alcohol and drugs
14
Environmental and work-related toxins
15
Pre-conceptual genetic counselling
Part
II
For future dads
16
Sperm and male reproductive health
17
Factors that significantly affect sperm formation
18
General male health
Part
III
Conception
19
Trying to conceive
20
Antenatal tests
21
Miscarriage
Appendix
Useful addresses
Introduction
Deciding to start a family is a time of great joy, adventure and hope. It is also a time of apprehension. Are we fertile? How long will I take to conceive? When should we make love? What dietary changes should we make? Question after question is raised – of which perhaps the most important is – will I be able to produce a healthy baby?
It’s estimated that between 60 and 70 per cent of babies born in the Western world are planned, allowing plenty of opportunity for advanced preparation. By following a pre-conceptual care programme, and ensuring both you and your partner are in the peak of health, you can maximise your chances of success.
The most critical time of a baby’s development is the first four weeks of gestation – often before the mother is even aware that she is pregnant. Recent studies suggest the development of coronary heart disease, stroke or diabetes in later years is linked to growth failure in the first few weeks of life. If a baby is under-nourished at this critical time, it may become programmed to develop high blood pressure, blood clotting disorders, or abnormal glucose, insulin and cholesterol metabolism in middle age.
You can never adopt a healthy diet and lifestyle too soon where pregnancy and your future offspring are concerned. You should start at least three months – and preferably six – before you try to conceive.
Research shows that following a pre-conceptual care programme greatly increases the chance of successfully conceiving a healthy baby, especially if a women takes pre-conceptual folic acid supplements and avoids cigarette smoking (active or passive) and excessive alcohol intake.
Pre-conceptual care is just as important for the future father as it is for the mother. It takes 100 days to produce a sperm, from the first division of its primitive germ cell until ejaculation. That’s 100 crucial days in which, if properly nurtured, sperm will flourish. Dietary and lifestyle carelessness can cause irreparable damage that may project into future generations.
More women are now having babies in their thirties than in their twenties, mostly through choice in delaying motherhood and establishing their career first. Female fertility naturally decreases with age, however, and it will take an average of six months (and sometimes as long as two years) to conceive at the age of 35 compared with two to three months at the age of 25.
I first wrote Planning a Baby as a means of researching pre-conceptual care before starting a family myself. I was amazed at how much information was available in the medical literature, but how little was available for the general public. Since writing the first edition of this book, pre-conceptual care has come on in leaps and bounds, with folic acid supplements now routinely recommended, and many GP surgeries and hospitals offering pre-conceptual counselling. I followed the information in my book myself and was thrilled to become pregnant the first time round, at the age of 38, during the first month of trying. It took six months to conceive my second pregnancy, at the age of 41, but I was delighted to discover I was expecting twins. One of the advantages (?!) of postponing motherhood into later life is that the chance of twins does increase.
Best of luck with starting your own family – one of the most exciting adventures on which any couple can embark.
Dr Sarah Brewer
PART I
For future mums
1
The female reproductive system
The female menstrual cycle
The hormonal fluctuations that occur throughout a female’s menstrual cycle trigger changes in the ovaries, uterus (womb) and cervix. Understanding these changes is important during the pre-conceptual programme. They can be used to:
Follow the natural fertility awareness method of contraception while preparing for future pregnancy (see pages 16–20).
Maximise your chances of conception once you’ve decided it’s time to try.
The uterine cycle
The female menstrual cycle is the periodic preparation of the endometrium (womb lining) for implantation of a fertilised egg.
The length of the menstrual cycle is variable. In some women it lasts 21 days or less; in others, 35 days between the start of each period is normal. A regular 28-day cycle, usually considered the ‘norm’, is in fact enjoyed by only 12 per cent of females. Menstruation itself usually lasts from one to eight days, with the majority of women experiencing bleeding for three to five days.
The most fertile time of the month lasts for the six days up to, and including, the day of ovulation. The time of ovulation varies, although it is usually said to occur around 14 days before your next period is due. New research shows that the timing of ovulation is highly unpredictable, however, even in women whose cycles are regular. When around 700 menstrual cycles were assessed among 221 women trying to conceive, only 30 per cent had their fertile phase entirely between day 10 and day 17 of the cycle (the first day of the last period is counted as day 1). Most women reached their fertile window earlier, and others much later. At least 10 per cent of women were fertile on any given day between days 6 and 21, and up to 6 per cent were potentially fertile even on the day their next period was due.
Control of the menstrual cycle
Cervical mucus changes, the waxing and waning of the endometrium and the development of the ovarian follicle are all synchronised by the female hormones.
The key to the cycle is the corpus luteum – the collapsed follicle from which the egg was recently released. If pregnancy occurs, this remains functional (by receiving feedback hormones from the developing placenta), the endometrium is maintained and menstruation prevented. If pregnancy does not occur, the corpus luteum stops making oestrogen and progesterone. This triggers menstruation and also the release of FSH (follicle stimulating hormone) and LH (luteinising hormone) from the pituitary gland. These in turn trigger the development of a new batch of ovarian follicles (eggs). As ovarian follicles start to develop under the influence of pituitary hormones (see page 10) they secrete oestrogen.
Oestrogen from the developing follicles stimulates the endometrium, which then thickens. Endometrial glands become elongated and straight and grow rapidly during the first two weeks of the menstrual cycle. This is called the proliferative (or follicular) phase. After ovulation, blood vessels rapidly grow into the thickened endometrium. It becomes soft and spongy under the influence of the hormone progesterone, which, along with oestrogen, is secreted by the empty ovarian follicle (corpus luteum).
The endometrium reaches a maximum thickness of around 5 mm. Its glands become coiled and tortuous and start to secrete a clear, nourishing fluid, which will provide the fertilised egg with nutrients before and after its implants. This part of the menstrual cycle is therefore called the secretory phase.
If pregnancy occurs, the empty ovarian follicle (corpus luteum) is triggered to continue secreting oestrogen and progesterone by HCG (human chorionic gonadotrophin) from the developing placenta. This prevents further shedding of the endometrium until after the baby is born.
If pregnancy does not occur, the corpus luteum deteriorates after ten days and stops making hormones around four days before the next period starts.
Arteries supplying the endometrium with blood go into spasm and the lining thins and starts to disintegrate. The outer two thirds of the endometrium are then shed as a menstrual period – almost exactly fourteen days after ovulation occurred. All but the deep layers of the endometrium are cast off and a new cycle now begins.
Anovulatory cycles
In some cycles, ovulation fails. This is most common during the first eighteen months of puberty and again as the menopause approaches.
When ovulation fails, there is no corpus luteum to secrete the progesterone necessary for the secretory phase of the menstrual cycle. Oestrogens from the ovary continue to cause growth, however, and the proliferative phase of the cycle carries on.
Soon, the endometrium becomes thick enough to outgrow its blood supply and it starts to break down, triggering a menstrual bleed. The time it takes for bleeding to occur is variable but is usually less than 28 days from the onset of the previous period. Bleeding also varies from scanty to profuse.
Cervical mucus cycle
Throughout a normal menstrual cycle, changes occur in mucus secreted by the cervix. During the proliferative phase of the cycle, the hormone oestrogen encourages the production of mucus which is thin and alkaline (non acidic). This type of mucus is ideal for the survival and easy penetration of sperm. Mucus becomes increasingly fluid, slippery and elastic until ovulation occurs. At this time, a drop of cervical mucus can be stretched into a long, thin thread up to 15 cm (6 inches) long. The molecules in the mucus are well aligned and it is easy for sperm to swim through. (See also page 17.)
Within a day of ovulation, the cervical mucus suddenly changes in character under the influence of the hormone progesterone. It becomes thick, sticky, scant and hostile to sperm. It is inelastic and the molecules within are entangled like a tight mesh, making it difficult for sperm to swim through.
Similar hormone-related changes affect saliva, and examining these changes through a pocket-sized microscope (Calista, see page 19) is the latest method for predicting ovulation.
Oogenesis
The female reproductive cells, the ova or eggs, are made in a process known as oogenesis. This differs from the formation of sperm (spermatogenesis) in several important ways:
Unlike the male, in whom spermatogenesis starts at puberty, the major part of oogenesis occurs in the female foetus before birth. The final stage of the development of each egg only occurs just before it is released during ovulation.
Each primitive germ cell (spermatogonium) in the male continues dividing and can produce as many as 512 sperm. Each primitive germ cell (oogonium) in the female only produces two eggs as a result of two unequal divisions. The smaller product of each division is cast off and absorbed as waste.
It takes around 380 cell divisions to form a sperm, but only 23 to make an egg.
Each human female is born with her full complement of eggs. Unlike the male, who continues making new sperm for the rest of his life, the female cannot make new eggs after she is born.
After puberty, women release eggs at a rate of one (occasionally more) per month. The male releases millions of sperm per ejaculation.
Sperm production continues into advanced old age. The monthly release of eggs stops once a female reaches the menopause.
These differences have important consequences for pre-conceptual care. As it takes around 100 days to make a batch of sperm, a man can follow a careful pre-conceptual care programme for at least three months before trying for a baby. By providing optimal conditions for his sperm to grow, he can be fairly confident they are present in peak quality and quantity (see page 185).
By the time a woman wants to start a family, her eggs may already be 16 to 48 years old. As eggs get older, the risk of deterioration increases. That’s the main reason why increasing maternal age is associated with an increased risk of having offspring with genetic abnormalities such as Down’s Syndrome (see page 259). So pre-conceptual care for the future mother is aimed more at improving her general health for the nine months of pregnancy ahead, rather than dramatically improving the quality of released eggs.
Even so, it is useful to understand how eggs are released each month. By seeing how this fits into the menstrual cycle, it’s possible to calculate the most fertile part of the month.
How the ovaries and eggs develop
The ovaries start developing during the first few weeks of foetal life. The outer layer of the ovary (cortex) contains primitive germ cells called oogonia. These are equivalent to the spermatogonia from which the male’s sperm arise.
The oogonia rapidly mature and develop. By the third month after conception, they undergo a series of normal divisions and multiply to form around seven million primary oocytes. Each primary oocyte has the same number of genes, divided into 46 chromosomes, as every other cell in the body.
The oocytes now enter a specialised form of cell division (meiosis) in which half the usual number of chromosomes – 23 – go to each daughter cell.
Meiosis is a two-stage process. During the first stage, the chromosomes double up and pair off. The chromosomes exchange random blocks of genes within each pair. After exchanging genetic material, the paired chromosomes separate to either end of the cell ready for the oocyte to divide again.
At this stage, development of the egg suddenly stops before this division is complete. The egg is virtually frozen in time and will not complete this division until just before ovulation – some 10 to 50 years after the process was started.
In the female oocytes (unlike a male’s spermatocytes) this division, when it does finally occur just before ovulation, is unequal. One daughter cell gets most of the cell material (cytoplasm) of the parent cell. The smaller offspring cell (called the first polar body) fragments and disappears.
After ovulation, the new daughter oocyte now contains a different mix of genes, arranged in a different order on the 46 chromosomes, than are found in the woman’s other body cells. It immediately enters the second stage of meiosis.
The chromosomes split and half of each one separates to either end of the cell. The egg now starts to divide unequally again. This time, one daughter cell takes half the usual number of chromosomes (23 instead of 46) and most of the cell material. The other product of division, containing half the genetic material and very little cytoplasm, will again be cast off as waste. This final division, like the first, is frozen just before completion and is only properly finished when a sperm penetrates the egg. At this stage, the unwanted half of genetic material is cast off as the second polar body and the fertilised egg proceeds to develop into a new individual.
Meiosis
As a result of the swapping and splitting up of genes that occurs during meiosis, each egg contains a unique set of genes – a random half selection from the primitive parent cell from which it originated. Some eggs may have a similar selection of genes to other eggs – accounting for family similarities between future brothers and sisters – but no two will ever be identical.
Ovarian follicles
The eight million primary oocytes within the ovarian cortex are each surrounded by a single layer of flattened cells. These cells plus the immature egg inside are known as the primordial follicles.
The cells surrounding each follicle are also important and are known as granulosa cells. They are full of tiny granules rich in cholesterol which will eventually be converted into female hormones.
During the fifth and sixth months of foetal life, many primordial follicles start to break up. A five-month-old female foetus contains about seven million eggs. By the time of birth, this number falls to two million and by the time of puberty, only 40,000 to 400,000 primordial follicles remain. The rest have slowly degenerated and become re-absorbed.
No new eggs are ever formed after birth – when we talk about making eggs, we mean maturation of egg cells (primary oocytes) already present in the ovary.
Ovarian changes at puberty
At puberty, the ovaries are switched on by two hormones secreted in the pituitary gland at the base of the brain. These hormones are follicle stimulating hormone (FSH) and luteinising hormone (LH). They are the same hormones that, in the male, trigger the production of sperm in the testicles.
In the female, FSH triggers the production and development of several ovarian follicles at the start of each cycle. As well as growing in size, the granulosa cells surrounding the follicle start to secrete oestrogen hormone. Blood levels of oestrogen start to rise.
In humans, one follicle starts to grow more rapidly on about the sixth day of development and continues to outpace the rest. It produces increasing amounts of oestrogen which has a dampening effect on the production of hormones in the pituitary gland in the brain. As a result, blood levels of FSH fall slightly. When this happens, the non-dominant follicles stop growing and start to regress. Only the dominant follicle continues to grow because it has matured enough to respond to the falling levels of FSH.
It is not yet known how this follicle is singled out for development. If women are given highly purified pituitary hormones (FSH and LH) as a fertility treatment, many follicles continue to develop, hence the increased incidence of a multiple pregnancy.
The maturing follicle
As a follicle starts to mature, a fluid-filled cavity forms around the egg cell inside. The egg becomes suspended at the top of a hillock of cells within the fluid and the follicle continues to swell. It is now known as a Graafian follicle after the scientist who first described it.
By the time of ovulation after 10 to 14 days of growth, the Graafian follicle measures 1.8–2.6 cm across and bulges from the surface of the ovary. During this process, the immature egg inside the follicle also enlarges. Granulosa cells secrete a thick protective coating around the egg – rather like chunky egg white – which will form a future barrier against sperm so that only one can successfully penetrate the egg.
In the few hours before ovulation, the chromosomes within the egg cell that first started to divide during the third month of foetal life are finally arranged correctly within the nucleus. The egg now immediately enters its second meiotic division and then stops, almost frozen in time. This division will only be completed upon fertilisation by a sperm. At that time, as already described above, an unequal division occurs and half the genetic material is extruded as the second polar body.
At ovulation, the follicle ruptures and a blob of jelly containing the egg oozes out. Some women notice mid-cycle pain (known as Mittelschmertz) at around this time due to pressure within the swollen egg follicle. The empty follicle now collapses and forms a yellow cyst known as the corpus luteum. This secretes the female hormones oestrogen and progesterone. Progesterone prevents menstruation and the development of other ovarian follicles during the remainder of the monthly cycle. For the next 10 days, the corpus luteum swells and becomes as large as 2 cm across.
If a pregnancy occurs, the corpus luteum continues its secretory role and maintains early pregnancy by preventing menstruation. After the third month of pregnancy, the placenta takes over all hormone production and the corpus luteum fades away. If pregnancy doesn’t occur, the corpus luteum degenerates after about 10 days. This triggers menstruation and the start of a new cycle.
The maturing follicle
It is estimated that only 300 to 500 ovarian follicles come to full maturity and release eggs during a woman’s reproductive life. If she uses a hormonal method of contraception such as the combined oral contraceptive pill, ovulation is suppressed and a woman may release fewer than 100 eggs during her lifetime.
The released egg
As a rule, only one egg is released each month in humans. Contrary to popular belief, an egg is not released from each ovary on alternate months. There doesn’t seem to be a pattern and eggs are released from the two ovaries in an irregular and unpredictable sequence. Some women regularly ovulate two or more eggs, which increases the chance of twins, triplets or higher multiple births. Interestingly, egg cells seem to become less receptive in later life to the signals telling them to stop developing, so that two or more eggs may continue maturing and are released at ovulation. As a result, women who conceive in their forties are more likely to produce twins because of this phenomenon.
Immediately after ovulation, the fresh egg is sucked into the end of a Fallopian tube. This is wrapped round the ovary at the site of follicular rupture. The inside surface of the Fallopian tube is covered with tiny hair-like projections (cilia), which beat rapidly to set up eddy currents. These suck the newly released egg into the tube and then carry it downwards on what has been described as the ciliary escalator. Fluid currents and contraction of the muscular walls of the Fallopian tubes also contribute to the egg’s downward journey.
It’s not known how long the egg remains fertilisable within the tube – but it is probably for only a short period of around one day. If fertilisation does not occur while the egg is within the upper end of the Fallopian tube, it starts to degenerate.
2
Contraception
Family planning is an essential part of reproductive health and pre-conceptual care. In ideal circumstances, effective contraception allows women to choose whether to have children, how many and when. You will need to decide:
Whether to continue with your current method of contraception.
If discontinuing your current method, when to do so.
Whether to switch to a natural family planning technique.
Whether to switch to a barrier method of contraception.
When to come off the Pill – probably the most commonly asked question.
If pre-conceptual care is to be most effective, it is essential that the future parents can rely on their chosen method of contraception. It must be:
Safe – both for them and their future offspring.
Effective.
Reliable.
Readily reversible.
Easy to use.
It must not interfere too much with the spontaneity and pleasure of making love.
Most women who are currently using a hormonal method of contraception or the coil (IUCD – intra-uterine contraceptive device) will wish to change either to natural, fertility awareness methods of contraception or to a barrier method. Only you can choose which method is right for you. Personal advice is available from your doctor or a family planning specialist. Useful addresses are included in the back of the book.
In order to answer most of your questions, the following chapter provides information on:
The various methods of contraception available.
How they are used and how they work.
Whether they are suitable during pre-conceptual care.
Failure rates of various methods
Most contraception failures are caused by human error such as forgetting to take a Pill, tearing a condom or removing a diaphragm too early.
The following table shows how effective various methods of contraception are, giving the typical pregnancy rates during the first year of use. The figures given are failures per 100 women, which in effect is the same as a percentage failure rate.
Typical
Method
failure rate
No contraception
85
Withdrawal
19
Natural fertility awareness methods
Up to 23
Fertility awareness computer (Persona)
6 or more
Diaphragm/cap
Up to 18
Spermicides alone
25
Male condom
Up to 15
Female condom
Up to 15
Coil (IUCD)
1 to 2
Progestogen coil (intra-uterine system)
<1
Progestogen implant
<1
Depot progestogen injection
<1
Combined Pill
<1–3 or more
Mini Pill
<1–4 or more
Contraceptive patch
<1
Female sterilisation
<1
Male sterilisation
<1
Emergency contraceptive Pill
Up to 4
Emergency contraceptive IUCD
Up to 2
Natural family planning methods
Withdrawal
The withdrawal method is undoubtedly the oldest method of contraception.
If practised carefully, it is surprisingly effective. Some studies show no difference in failure rates between the withdrawal method and barrier methods such as the diaphragm. Although there are many better methods of contraception available, withdrawal is better than nothing and may be the method of choice for some couples during the pre-conceptual care period.
Fertility awareness
Fertility awareness or ‘natural’ methods of contraception involve monitoring physical changes that occur throughout the menstrual cycle to predict the most fertile period. Unprotected sex is then avoided during this time, and you may either abstain from sex or use another method of contraception such as a condom. It requires proper training and a thorough understanding of the method, as recent research suggests that the timing of ovulation is not as predictable as previously thought. At least 10 per cent of women seem to be fertile on any given day between days 6 and 21 of their cycle, and up to 6 per cent are potentially fertile even on the day their next period was due. Fertility awareness can be as effective as barrier methods of contraception with careful use – failure rates are usually quoted as ranging from 2 per cent to 20 per cent. A large population study in the US, however, found that 9 to 16 per cent of married women and 21 to 23 per cent of single women using natural birth control became pregnant within a year even though they did not intend to. Because no chemicals are involved, because it is a ‘natural’ method that helps you predict when you are more fertile once you are ready to start a family, this is a popular contraceptive choice during the pre-conceptual period.
Fertility awareness involves monitoring body changes that help you predict when ovulation has occurred. As some women seem to ovulate at different times in each cycle, and as a few women seem to ovulate more than once in a cycle, its reliability is difficult to assess.
The changes that may be monitored include:
Body temperature: Immediately after ovulation, body temperature drops slightly and then rises by 0.2–0.4 degrees Centigrade. It then stays high until the next period starts. Women are advised to take their core body temperature using a special fertility (expanded-scale) thermometer on waking and before getting out of bed. Results are plotted daily on a chart.
Cervical mucus: Before ovulation, cervical mucus becomes increasingly fluid and slippery due to the effects of oestrogen hormone. It has a consistency similar to egg white and may be drawn between two fingers to a length of several centimetres. The alignment of mucus molecules allows sperm to swim through it easily and survive for a relatively long time (see page 6). Immediately after ovulation, cervical mucus becomes thick and sticky under the influence of progesterone hormone. It then becomes more hostile to sperm and, because the mucus molecules are entangled, sperm cannot swim through as easily. The quantity, fluidity, glossiness, transparency and elasticity of cervical mucus is observed on each visit to the bathroom. You can either insert a finger into the vagina to assess dryness or moistness, or wipe yourself with toilet tissue and examine the mucus you collect.
Typical ovulatory temperature chart
Saliva: Is affected by the presence of oestrogen and luteinising hormone during the fertile days of your cycle. By examining dried saliva under a pocket microscope (sold as Calista) you can time when you make love either as a form of contraception, or to maximise your chances of conception. Calista consists of a powerful, pocket-sized, backlit microscope through which you examine a sample of saliva. You just place a little saliva on the optical block and wait for it to dry. Your dried saliva will show a dotted pattern on non-ovulating days, or a clear fern-like pattern that indicates ovulation is imminent and you have reached your fertile peak. Clinical trials show that Calista is 98 per cent accurate and – unlike urine-based ovulation predictor kits – can be used month after month for over two years, making it a less expensive method to use. It is available from most pharmacies, and from www.ecobrands.co.uk.
The position and texture of the cervix: As the fertile phase approaches, the cervix becomes softer, pouts open and rises higher in the vagina. During the infertile phase, the cervix sits lower in the vagina and feels firm, rubbery and dry with a closed opening. These changes are less easy to detect once you have had a child.
Mood changes.
Mid-cycle spotting of blood.
Mid-cycle pain occurring 24–48 hours before ovulation (Mittelschmertz): This is due to distension of the ovarian capsule.
Breast sensitivity.
Acne and other skin changes.
Natural methods require commitment by both partners. Those choosing this method must receive personal training as the techniques and calculations involved are complex and need to be fully understood if the method is to work as effectively as possible. Monitoring must occur throughout the menstrual cycle, and you must be careful not to confuse cervical mucus with semen or spermicide so the wrong characteristics are noticed.
Persona
Persona makes natural fertility awareness more effective. It involves dip-testing your urine on eight days of your monthly cycle (16 days in the first month) and inserting the test stick into a small, hand-held analyser. This measures levels of natural hormones in your urine to assess when you are most at risk of pregnancy. Failure rates are around 6 per cent or greater depending on how properly it is used, and how rigorously you avoid unsafe sex on unsafe days.
The diaphragm
The diaphragm covers the cervix and upper vagina, acting as a female barrier contraceptive. It is kept in place by the action of the vaginal muscles, the pubic bone and by a spring within its rim. Sizes range from 5 to 10 cm in diameter.
Fitting by a trained family planning specialist is required. If a woman’s weight changes by more than half a stone (3 kg) it is essential that the diaphragm’s fit is rechecked. A diaphragm can be inserted either way up, but maintains the correct position more readily if inserted dome upwards.
As the upper third of the vagina balloons during intercourse, semen often gets past and spermicidal agents are essential. Failure rates when used with a spermicide range from 2 to 15 per cent.
A diaphragm should not be left in place for longer than 24 hours. This both encourages infection and gives a theoretical risk of pressure damage to vaginal walls.
The cap
The cap is smaller than a diaphragm. It looks rather like a thimble and fits directly over the cervix. The new silicone version (Oves) is most popular today.
Spermicides
Spermicides are substances which physically or chemically immobilise or destroy sperm on prolonged contact. They are available as aerosol foams, jellies, creams, impregnated films, pessaries or sponges which are inserted into the vagina before making love.
Spermicides are not recommended for use without a barrier method of contraception, but in those studies where sole use has occurred, failure rates vary between 4 and 25 per cent.
Spermicides contain both an inert carrier base and an active agent. Water-soluble bases are preferable as mineral oil-based agents weaken the latex rubber of condoms and diaphragms by up to 95 per cent within fifteen minutes.
Active spermicidal ingredients include:
Surface-active agents, e.g. nonoxynol-9.
Enzyme inhibitors.
Some anti-bacterial agents.
Acids, e.g. lactic acid.
Local anaesthetics which affect sperm cell membranes.
Studies suggest that some spermicides are protective against sexually transmissible diseases. Nonoxynol-9 is active against Neisseria gonorrhoea, chlamydia, herpes simplex virus, human immunodeficiency virus (HIV), trichomonas vaginalis and candida (thrush).
There is no evidence that fertilisation with a sperm damaged through exposure to spermicidal agents, or inadvertent use during pregnancy, might result in a foetal abnormality.
The male condom
Male condoms are made from vulcanised latex rubber, or from polyurethane, which has the advantages of being twice as strong as latex, thinner and non-allergenic.
Condoms provide a physical barrier so that sperm do not enter the female reproductive tract. They are most effective when used with a spermicidal cream or gel. Apart from protecting against any spilled sperm, this provides extra lubrication so the condom is less likely to burst than when used dry. It is important to use only a water-based lubricant, as petroleum jelly and mineral oils such as baby oil weaken latex rubber (they do not harm polyurethane condoms, however). Condoms also help to protect against sexually transmissible infections.
Condoms are available non-lubricated, lubricated with the spermicide nonoxynol-9, or with a non-spermicidal lubricant (sk-70) for those with allergies. Condoms are available in two standard widths in the UK – 52 mm and 49 mm. The selection is broadened by the choice of several different contours to provide optimum fit and sensitivity. The table opposite acts as a guide to the different shapes to choose from.
Improving sensitivity
Many men are unaware that advances in condom technology can improve sensitivity. Shaped condoms, for example, can provide extra comfort, a feeling of roominess, or a snugger fit which many men prefer – once they’ve tried it – to the traditional straight up-and-down designs. Gel charging can also boost sensitivity to give a more natural sensation – almost as if a condom is not being used.
Gel charging involves putting a small amount of water-based lubricating gel (around one teaspoon – 5 ml) inside the condom before putting it on in the usual way. It helps to warm the tube of gel in warm water first so it isn’t too cold. During love-making, the gel warms further and liquefies to provide extra stimulation.
Gel charging should only be tried with a shaped condom – contoured or flared – which retains the gel more easily and makes slipping less likely during use.
Protection against infections
Using a condom can reduce the risk of catching gonorrhoea, NSU (chlamydia), trichomonas, herpes, hepatitis or HIV if your partner is infected, but are not foolproof. The spermicide nonoxynol-9 adds to the protection as it can kill some infections in the same way that it kills sperm. By reducing the risk of sexually transmitted infections, using condoms also reduces the risk of pelvic inflammatory disease in women and may reduce the risk of cervical cancer.
Straight
Same width up and down.
For men who are used to the traditional shape.
Flared
Wide head, tapered at tip.
For extra comfort; condom feels larger and less restrictive; useful for men who usually find condoms too tight.
Contoured: wide head and neck
Anatomically shaped for a better fit – flared over glans and snug below.
For improved sensitivity and comfort; helps to prevent slippage; excellent starter condom.
Contoured: wide head and smaller neck
Anatomically shaped for better fit over glans. Width at base of penis 49 mm for a closer fit.
Helps to prevent slippage; a closer and firmer fit for those who require it.
Textured
Condoms possess ribs or dots.
Designed for increased friction and heightened sensation. Use with water-based lubricant to prevent soreness. Not suitable for oral sex.
Ultra-thin
Slightly thinner latex.
For greater sensitivity; only for experienced users.
Super-strong
Thicker latex (e.g. 50% thicker than normal).
For extra-vigorous sex.
Non-spermicide lubricant
For use if either partner is allergic to spermicides.
With integral applicator
For those who prefer a no-touch technique, who have difficulty applying a normal condom, or who regularly burst condoms on opening the packet or donning the condom.
Polyurethane
For improved sensitivity and for those who are allergic to latex.
When used correctly, condoms have a method failure rate of 2 to 5 per cent per year. However, incorrect use, and the risk of bursting or coming off, increase the typical failure rate to between 11 and 15 per cent.
The female condom
The female condom is a pre-lubricated, loose-fitting, disposable polyurethane sheath measuring 17 cm by 8 cm.
It contains two flexible rings, one of which is attached and remains outside the vagina. The smaller, inner ring sits loosely inside the sheath in position beyond the pubic bone. The outer ring may dangle between the legs initially, but lies flat against the female during sex.
What puts most women off at first glance is the female condom’s size. In fact, this is an advantage as it gently lines the vagina, allowing comfort and sensitivity during use.
Trials involving over 1,700 women using 30,000 female condoms suggest they are as effective as other barrier methods of contraception. When used carefully, failure rates may be as low as 2 per cent but can be as high as 15 per cent. The chance of a female condom bursting is only 0.1 per cent compared to the male condom’s 8 to 12 per cent chance of breaking.
It is important that women who have just switched to using the female condom should continue with their usual method of contraception (e.g. Pill, male condom) until they are confident in its use. Inadvertent slipping of the device, or the placing of the penis between the female condom and the vaginal wall are more common during the first few times of use.
The coil (IUCD – intra-uterine contraceptive device)
Modern coils are made from polyethylene and copper.
The coil is inserted into the womb using a technique which carries a small risk of introducing an infection into the womb. Two monofilament threads hang down into the vagina to help removal and to allow checking that the device is still in place. Coils can be inserted immediately following childbirth or Caesarean section, but there is an increased risk of expulsion. They are usually fitted six weeks after delivery.
The recommended life span of many coils is from three to five years. Failure rates are 0.3 to 4 per cent.
Coils work in several ways to prevent pregnancy:
Physical interference with implantation.
Low-grade inflammation of the endometrium with infiltration of white pus cells (leucocytes), causing inflammation.
Stimulation of hormone-like prostaglandin production.
Copper ions are toxic to ova and spermatozoa.
Interference with transportation of sperm and egg within the Fallopian tubes.
Removal of the coil is usually a simple matter of a doctor grasping the coil strings with a sterile instrument and gently pulling the coil out. In some cases, a coil can be difficult to remove and may need operative recovery under a general anaesthetic, although this is rare.
If the coil is to be removed, and you are not having another inserted, use condoms or another method of contraception for seven days before removal if you don’t want to get pregnant.
Side effects
IUCDs may increase blood loss during menstruation, and as many as half of women fitted with a coil report heavier, more painful periods, which are the most common reason given for stopping using this method of contraception. The coil is also associated with an increased risk of ectopic pregnancy and an increased risk of pelvic inflammatory disease – especially during the first 20 days after insertion, presumably because insertion encourages the spread of infection into the female tract. As pelvic inflammatory disease can affect future fertility, an IUCD is not usually recommended for women who are at a high risk of sexually transmitted infection, or those with a previous history of ectopic pregnancy.
All these are good reasons for a woman wishing to start a family to have her coil removed at least three months before attempting conception.
The Mirena Intra-uterine System (IUS)
The intra-uterine system (IUS, or Mirena) is a hormonal method of contraception that delivers a progestogen hormone (levonorgestrel) directly into the uterus via a device similar to a coil. It consists of a plain, plastic T-frame whose vertical stem is surrounded by a hormone sleeve containing levonorgestrel which is slowly released into the uterine cavity.
The IUS acts as a contraceptive by:
Changing cervical mucus to inhibit the passage of sperm.