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Zita West’s Guide to Getting Pregnant
If you think back to GCSE biology, you will remember the term ‘secondary sex characteristics’, which are the outward, visible signs of puberty and the onset of a woman’s fertile life. In a woman, increasing levels of FSH (follicle – stimulating hormone) and LH (luteinizing hormone) and the beginnings of oestrogen and progesterone production lead to the development of breast tissue, pubic and underarm hair, and a different distribution of body fat, all of which are designed to create a body capable of nourishing a growing baby, both before and after birth. These changes begin before the first menstrual period occurs, and can happen slowly over a couple of years, or relatively quickly. Again, this depends in part on genetics, and a mother’s experience of puberty will give some insight into what her daughter might expect.
Remember how you were warned in your sex education classes at school that sex inevitably led to pregnancy? Remember, too, all the efforts you took in the past not to get pregnant, not to mention all those false alarms? So it may feel a bit of a mystery as to why getting pregnant is now so elusive. This chapter is designed to help you understand your own fertility cycle, and how to work with it to achieve pregnancy.
Understanding Your Own Fertility
With so much misinformation about how, where, why and when, it’s always best to start with the basics. Once you are informed and familiar with your own body’s fertility indicators, you will feel more confident about managing to get pregnant.
And there is a lot of confusion out there! According to research carried out by Unipath (who produce Persona – the personal hormone-monitoring system), while 92 per cent of women accurately described ovulation, a third of them thought it occurred during a period! Out of six European countries covered in the research, the UK women surveyed had the worst knowledge of when their fertile days were: 21 per cent thought they were fertile for more than 21 days a month. And while 72 per cent of women knew that the fertile time was mid – cycle, one – third thought it possible to get pregnant at any time during their cycle.
It is essential to remember that every woman is different. Although the basic principles remain the same, what is true of your friend is unlikely to be true of you – from your cycle length to how your body indicates its fertility, to how you react physically and emotionally. This is why it is so useful to understand your own fertility.
Most women seldom think about their fertility, or menstrual cycles, but most women – when they do stop and think about it – are aware of cyclical changes to their skin, appetite, mood – all of which are indicators of their individual cycle.
The Menstrual Cycle
Most of us have learned to live with certain symptoms in our cycle, but it’s also important to remember that our fertility cycle is controlled by the pituitary gland, located deep within the brain and influenced by all activity there. Hormones, which are chemical messengers, are primarily controlled by the brain’s activity – it’s like a constant conversation that occurs between the hormones of the brain and the ovaries, sending messages back and forth (see page 8).
The pituitary gland is often referred to as the ‘master gland’ of the body, because it secretes at least nine major hormones designed to stimulate the ovaries, adrenals and thyroid, amongst others (including the testes in men), which all have a role to play in fertility. When we are producing the right amount and blend of hormones, we feel fine. When there is an imbalance, these chemical messengers can make us feel pretty lousy. We talk about having ‘hormones from hell’ when we, as women, feel imbalanced at certain times of the month. PMS is a clear indicator that hormones are out of balance. The hormones are doing their job, and the body is reacting as it should, but because the balance is out, then the effects are negative.
Each of the fertility signals that you observe when you begin to chart your own fertility corresponds to a hormonal process and the presence of hormones in your bloodstream. The hormones oestrogen and progesterone are particularly important, and both affect the body in a number of ways that are easy to note.
The menstrual cycle is a constantly changing hormonal environment, but oestrogen influences the first part of the cycle – up to ovulation – and then progesterone exerts its influence. Some women would probably prefer not to be so influenced by the ups and downs that a cycle brings, but these changing hormonal events will help you to know when your chances of conceiving are best.
Few women have a 28-day cycle, but we can say that the average length is around 28 days. For some women their normal cycle can be short (around 25 days) or long (around 35 days). Provided there is a regular pattern, this is normal for you, and you can be relatively sure that ovulation is occurring. It is when cycle length fluctuates from 25 days one month to 30 another, or 42 another, that ovulation is likely to be haphazard, or even non – existent during some cycles.
The fertility, or menstrual, cycle starts on the first day of menstruation or a ‘period’. Sometimes on medical forms women are asked to give the date of their ‘last menstrual period’ or ‘LMP’ – this would be the date on which you started to bleed.
Oestrogens are the dominant hormones during the first part of the cycle – the time before ovulation, also known as the follicular phase (see page 8) – while progesterone takes over during what is known as the luteal phase (see page 31) and also during pregnancy, should conception occur. Your cervical secretions are linked to oestrogen secretion, and can give a good indication of the availability of oestrogen.
Menstruation, or a ‘period’, is the bleeding with which every woman is familiar. It heralds the end of one cycle and the beginning of another. The hormones responsible for the activity of ovulation and womb – preparation effectively ‘take a break’ at this stage, in order to activate the next cycle. Many women are quite susceptible to the effects of this hormonal switch.
Women often ask me what’s ‘normal’ for a period: how long it should last and how much blood should be lost. The average period lasts for between 3 and 5 days, and the total blood loss is between 30 and 80 ml (6 to 16 teaspoons). However, this is only the average; each woman’s experience of her period will be unique to her. Some women seem to have a lot of abdominal cramping (caused by contractions in the womb) when they have a period, or back pain, while others have none. For some, the bleeding happens in a flood at the beginning, while for others it’s a slow, continuous bleed.
Hormones and the Phases of Your Cycle
A question I get asked all the time is, ‘How do I know if my hormones are balanced?’ Hormone balance is such an important part of a woman’s fertility, and so easily influenced by poor diet, stress, lack of sleep and environmental factors, that assessing a woman’s hormone levels – and addressing any rebalancing that needs to be done to help her achieve optimum fertility – are important aspects of the work I do. And although there are sometimes quite clear indicators of hormone imbalance, often a bit of detective work is needed.
The one major thing that will help balance hormones is a well-balanced lifestyle – which seems to be increasingly difficult for many of us to achieve these days.
A well – balanced lifestyle is important for hormonal balance because all hormone activity is an interplay between different hormones, which are the body’s chemical messengers: for example, secretion of fertility hormones will be affected if the body is producing too many stress hormones. Understanding the inter – relationship between all the hormones in the body is the first step towards achieving a positive balance.
Like all hormones, oestrogen and progesterone operate as chemical messengers, in this case controlling the length of a cycle, and ovulation, while also having an impact on other body systems. When in perfect balance, their effects are hardly noticeable, but most women have a degree of hormonal imbalance within the normal range, which makes these hormonal fluctuations more noticeable. Although the effects can vary – not just between women but also from month to month in the same woman – knowing about them and recognizing your own emotional and physical response to them are helpful when you are trying to understand your own cycle.
The Follicular (pre – ovulation) Phase
On Day 1 of the cycle, which is the first day of a period, the brain releases GnRH (gonadotrophin – releasing hormone) from the hypothalamus, which in turn tells the pituitary gland to release FSH (follicle – stimulating hormone). The levels of FSH in the bloodstream build over the next couple of weeks, stimulating follicles in the ovaries to start growing.
The follicle grows and starts to secrete oestrogen from the granulosa cells. It is the rising level of oestrogen that inhibits the secretion of FSH, while also causing ovulation. At this point, LH (luteinizing hormone) is secreted.
This first part of the cycle, the follicular or pre – ovulation phase, can vary in length. This explains why some women have longer cycles than others, and also why their cycles can sometimes be irregular.
The interplay of hormones throughout a woman’s fertile life forms the basis of her cycle. Not only do these hormones have a crucial role to play in fertility, they also have other effects on the body, which can be extremely useful when trying to define and assess your own levels of fertility. For example, progesterone has an effect on body temperature (as it’s designed to keep a fertilized egg warm in the incubator of the womb), while oestrogen has an effect on cervical secretions, which are so essential to helping achieve pregnancy.
Looking at oestrogen and progesterone individually, and also at how the subtle interplay between them and other hormones affects fertility, is the first step to understanding what is necessary for a pregnancy to happen.
Oestrogen
During the first part of the menstrual cycle, when the levels of oestrogen are rising, endorphins are also released, which are your body’s natural painkillers and ‘feel – good’ hormones, elevating mood. Many women say they feel very energized and creative during this phase.
While oestrogen has an effect on the internal reproductive organs, making the womb receptive to a fertilized egg, bringing the top of the Fallopian tube closer to the ovary and increasing its contractions to help the egg move down towards the womb, it also has other effects.
There are highly specialized cells in the cervix, for example, which produce cervical secretions, and their increased activity is directly caused by increased oestrogen. (The importance of these secretions and their role in conception is crucial, and is explained in more detail on page 18.)
Oestrogen also has an effect on libido, your sex drive. As oestrogen levels rise, so does libido – nature’s way of ensuring that sexual intercourse is welcomed close to ovulation. And when an animal is in oestrus, i.e. fertile, we refer to them as being ‘on heat’. This recognition of a link between oestrogen and heat comes partly from the effect of oestrogen on the blood vessels, causing a degree of dilation and increasing the flow of blood and its heat.
A good blood supply helps the organs of the body function properly, as nutrients are brought to cells and waste products removed. The transportation of oxygen in the blood is also important to developing cells, not least the maturing egg in the ovary. This blood supply also keeps tissues plump and supple, whether in the vagina or the tissues of the face. It is this effect that is lost after the menopause, when the lack of oestrogen causes the thinning of the skin and other tissues.
A good blood flow is beneficial to other organs, too, including the brain. Some women’s experience of increased productivity and creativity around ovulation may be explained as their own particular response to oestrogen. On the other hand, for some women this same effect provokes feelings of irritation. It just depends on how your body reacts to and copes with this powerful hormone.
Oestrogen is also essential for maintaining strong bones, as it provides the chemical ‘bridge’ that allows calcium from the diet to be used by the bones, keeping them dense and reducing porosity.
Oestrogen and Signs of Fertility
The term ‘oestrogen’ actually refers to a group of hormones that stimulate growth and strengthen tissues. Oestrogen is needed to build up the lining of the uterus so that it can nourish and sustain the fertilized egg, ensuring implantation – a crucial part of conception. When we are talking about fertility, the kind of oestrogen we are referring to is called oestradiol. Oestrogen is produced by the developing ovarian follicles and later, in increasing amounts, by the dominant follicle before the egg is released at ovulation.
Oestrogen has many roles:
• It signals the release of LH (luteinizing hormone), needed to trigger ovulation.
• It is needed to build up the endometrium (lining of the womb) so that a fertilized egg can find nourishment and implant successfully.
• It stimulates the production of cervical secretions, which are essential for the sperm to travel through the cervix to the Fallopian tube where an egg may be fertilized.
• It causes the cervix to soften and open, making it easier for the sperm to enter the womb and reach the Fallopian tube for possible fertilization of an egg.
Some of the signs of increased oestrogen levels, such as the amount and quality of cervical secretions, and cervical position, can be easily noticed. These signs offer some of the best indicators of your fertility status. Observing and recording your cervical secretions are vital to assessing fertility, and the optimum time for intercourse, in order to conceive (see page 21).
Factors That Can Affect Oestrogen Production
I often get asked how you can tell if your body is producing enough oestrogen, and what might make you oestrogen – deficient:
• body weight 15–20 per cent below your optimum can cause menstruation to stop, and levels of oestrogen to drop
• an excess of fibre in the diet
• antibiotics – though occasional use is OK
• excessive exercise
• smoking.
Modern women aren’t actually making more oestrogen; it’s just that today’s diet and lifestyle encourage higher levels of the hormone in the body. This is in part due to environmental oestrogens, delaying childbirth and breastfeeding, and an over – refined diet. The methods used to clear ‘old’ oestrogens from the body involve optimum digestive and liver function, which are often compromised by a poor diet and stressful lifestyle. Changing to a low – fat and nutrient – rich diet with adequate (but not too much) fibre can significantly influence the balance of hormones and help to optimize the conditions for getting pregnant.
Equally, an excess of oestrogen can be counter – productive to conception. But take heart: there are ways round these issues – we’ll be taking a look at them in the Nutrition chapter.
The Ovulation Phase
The rising oestrogen level makes the hypothalamus reduce the secretion of GnRH and FSH. As the FSH decreases, oestrogen levels from the maturing follicle rise abruptly. Only then will the pituitary gland secrete LH (luteinizing hormone), which allows just one mature follicle to release an egg – ovulation.
The Magnificent Egg
The ovum, or egg, is the largest cell in the body – 550 times bigger than the sperm. As it matures within its fluid – filled follicle prior to ovulation, it needs a lot of energy, which is supplied by the granulosa cells (specialized cells in the ovary). These cells have two functions: to secrete oestrogen (to help the egg mature) and to nourish and feed the egg as it grows.
The maturing egg is now suspended in a fluid – filled cavity (sometimes referred to as the graafian follicle, after the scientist who first discovered it). This follicle measures about 18–23mm just prior to ovulation, and when ovulation – the release of the egg – occurs, the follicle bursts and the mature egg is released into the Fallopian tube.
There are an estimated 7 million granulosa cells packed around an egg, greatly increasing the availability of energy. When the egg is eventually released, it takes with it a mass of these cells, giving it a ‘sunburst’ appearance. These cells also serve to protect and nourish the egg on its journey, and will provide a barrier against all but the one sperm that will fertilize it.
The hormonal stimulus for ovulation is the rise of oestrogen, and the primary factor that determines when you will ovulate is the level of oestrogen getting to a certain threshold, which creates a surge in luteinizing hormone (LH), responsible for the rupture of the follicle and release of the egg. So anything that depletes oestrogen will keep it from reaching the necessary level, and ovulation will not take place.
Ovulation also won’t occur unless the optimum level of oestrogen is maintained for the correct length of time. The timing of ovulation is quite exact, occurring about 36 hours after the surge in LH. Only a mature egg, once fertilized, will result in conception. Immature eggs are unlikely to be capable of being fertilized, and even if they are they tend to produce an abnormal embryo that won’t implant or develop properly, resulting in an early miscarriage (before 12 weeks). So it’s very important that the level of oestrogen produced accurately reflects the egg’s maturity. It’s a delicate feedback process, and the timing is crucial. A mature egg is necessary for fertilization because only then will it have chromosomes at the right stage for further development, allowing one sperm in and blocking the rest, and ensuring that the egg and sperm fuse properly.
At the same time, just before ovulation the follicle generates a rapid rise in the hormone progesterone. The rise in progesterone also keeps the FSH secretion going just long enough to allow full maturation of the follicle. As the hypothalamus is shutting down on FSH secretion, it is releasing prostaglandins to the follicle just before it ruptures. It is thought that these prostaglandins may help to expel the egg by breaking down the follicle wall.
Once the egg is released, the resulting cavity and the remaining granulosa cells start to produce more progesterone. These cells also stain the ruptured follicle an orangey – yellow colour, giving rise to the name corpus luteum, from the Latin for ‘yellow body’.
The egg is at its most susceptible to nutrient deficiency during this phase of the menstrual cycle, leading up to ovulation where the egg is maturing, and during early embryonic life (the first 30 days after conception). Research shows that a 70 per cent increase in sensitivity to toxins, alcohol and smoke occurs between 11.30 a.m. and 7 p.m. on the day preceding ovulation. In the five days prior to ovulation a good diet and as few toxins as possible are particularly important for achieving pregnancy. Also, it is not wise to drink heavily during this phase of your cycle. If the diet is too low in proteins, for example, too few eggs may ripen, while a vitamin B1 deficiency can inhibit ovulation. Because it can be difficult to gauge exactly when ovulation occurs, however, it is always wise to maintain good nutrition throughout your cycle.
Lifespan of the Egg
Having managed to ovulate a mature, functioning egg and, with all other things working to advantage, the lifespan of the egg is only estimated to be around 8 to 12 hours. This is further complicated by the difficulty in knowing exactly when ovulation occurs. For example, if you ovulate at 3 a.m. but don’t have intercourse until the following evening, chances are that the egg is no longer capable of being fertilized. Now, I wouldn’t want any woman reading this to start lying awake at night worrying that she might be ovulating then and there – this won’t help you or your partner in the long run! – but this is why regular and frequent sex is an essential feature of successful conception. Keep in mind that sperm deposited in a woman’s vagina stay alive, on average, for between two and three days (and in some cases for up to a week), so if you are having sex every day or every couple of days around the most fertile time of your cycle, the chances of conception are increased dramatically. Research shows that most pregnancies occur within a ‘fertile window’ of six days before ovulation and one day after. If there are live, potent sperm in the Fallopian tubes when ovulation occurs, then conception is much more likely than if sex occurs sometime after ovulation.
Why Cycle Length Matters
The length of the menstrual cycle is measured from the first day of menstruation (first day of fresh bleeding) up to the day before the next period starts. The time you are fertile will vary according to the length of your cycle. The time from ovulation to the next period is likely to be constant – approximately 10 to 16 days – whereas the time before you ovulate can be more variable.
The fertile time in a woman’s cycle is identified by two different approaches:
1. by looking at the length of your cycle and making calculations based on observing your secretions (see page 22)
2. by a combination of recording your temperature and knowing the position of your cervix (see page 22) – though I don’t usually encourage women to use these measures, as trying to do so can be confusing and stressful.
Understanding that the post – ovulation phase remains constant at around 14 days, while the pre – ovulation phase is the one that’s variable, is essential because this will help you to work out, roughly, when you are ovulating. Once you have a rough idea of what’s normal for you, working out the other indicators of fertility becomes easier.
Only if a woman’s cycle is a regular 28 days does she ovulate mid – cycle, around day 14. If her regular cycle is 25 days, then ovulation occurs around day 11; a cycle of 35 days means ovulation around day 21; and for a very long cycle of 42 days, ovulation occurs around day 28.
Many women mistakenly believe that ovulation occurs ‘mid – cycle’, then wonder why they are getting their calculations wrong. Everywhere this myth continues to be perpetuated, and it can really hamper couples’ attempts to conceive. For example, if you thought the middle of your 35-day cycle was when you were ovulating, you’d think this was day 17 – when in fact, it’s day 21 – and would thereby make a crucial error when it came to timing sexual intercourse to coincide with your fertile time.
If you don’t have an understanding of this basic information about the two phases of the menstrual cycle, all the other indicators of fertility you are trying to evaluate just won’t ‘add up’.
Case History: Christine
Christine, who was 34, had had one child with IVF. Two further attempts at IVF had been unsuccessful. She came along to our clinic to see what she could do to improve her chances. Having looked through her questionnaire, apart from the fact that she was tired from coping with a toddler, and also a little bit underweight, there were no obvious lifestyle factors that might be affecting her chances. I went back to basics with her and asked about her cycles and sex, and suggested that, as she had irregular cycles, a session of fertility awareness would benefit her. I could tell she thought that this would be a total waste of time, as she’d been told that she wasn’t ovulating.