A complex process

Conceiving a baby may be one of the most natural things in the world but it is nevertheless a complex process that depends on everything working properly at a number of different stages. In the first instance your hormone balance must be right so that the egg develops normally.

Secondly, you must be ovulating and an egg released. Thirdly, you must have sex at the right time in your menstrual cycle. Your partner must also have an adequate sperm count and possess healthy sperm, which can penetrate the cervical mucus to reach the egg. Then the egg has to be fertilised in the fallopian tube.

Once the egg has been fertilised the embryo has to implant securely in the lining of your uterus, which needs the right levels of the hormone progesterone to maintain the pregnancy. It is not surprising therefore that when you are trying to get pregnant things may not always go to plan.

Weight

Your weight is vitally important for your fertility. If you are very underweight or overweight conception may prove difficult or impossible. Women have more body fat than men for the specific purpose of reproducing and feeding their babies. Fat is essential to fertility and it is necessary in order to ovulate. Most young girls do not start to ovulate until their bodies are composed of at least 17% fat.

Low body fat can be caused by excessive exercise or excessive dieting, and anyone with a body mass index (BMI) of less than 20 is considered to be underweight. If your bodyweight drops too low your periods may stop.

Periods cease in many women who suffer from anorexia nervosa and with so many young women suffering from 'the slimmer's disease' the long-term damage to fertility due to dramatic weight loss is well documented.

Being overweight may also affect your fertility as it can stop you ovulating. A BMI of over 25 is considered overweight. The link between excess weight and reduced fertility lies in the way your blood sugar levels (which are controlled by your diet and eating habits) affect your hormonal cycle. If blood sugar levels are not in balance then the hormones that control your fertility may not work properly either.

Research has indicated that just losing a small amount of weight, for example 10%, can be enough to increase fertility by stimulating ovulation, improving hormonal balance and making periods more regular. Your dietary intake is something you have control over and eating the right amount and type of food can be one of the most important things you can do to achieve a successful pregnancy.

Alcohol, smoking and drugs

A lot of couples are not aware that smoking and alcohol could actually stop them conceiving as it reduces their fertility. Studies show that women who drink heavily may stop ovulating and menstruating. Smoking may also reduce your chances of getting pregnant.

The good news is, however, that the negative effects are not permanent and simply stopping will significantly improve your chances of conceiving. Recreational drugs such as cocaine or heroin will not only make it harder for a woman to conceive but she is also more likely to have a stillbirth or a baby with a malformation.

Medication

If you or your partner takes any prescribed medication you should consult your doctor regarding those that are medically essential and those that are not. Some drugs have a direct effect on fertility. For example, non-steroidal anti-inflammatory drugs (NSAIDs – often used for backache or arthritis) can stop ovulation.

Medical problems

Blocked fallopian tubes
Fallopian tubes link the ovaries to the uterus and this is where the fertilised egg is for the first seven days of life as it gradually moves along the tube to the uterus where it implants in the uterine wall. If the tube is blocked the egg is unable to reach the uterus so implantation cannot take place. This is a serious problem, which usually requires surgical intervention.

Polycystic ovary syndrome
This condition, commonly known as PCOS, is the most common cause of ovulation disorders. The cause of PCOS is not fully understood but it is often familial (inherited). Women who have PCOS tend to be overweight, suffer from acne and have periods seldom or not at all.

Some develop unsightly body hair (often on the face, breasts and inside of the legs). Mood swings may be common. Diagnosis is usually made by an ultrasound or a laparoscopy where a narrow tube with a telescopic lens is inserted into the abdomen via a small incision below the navel.

Treatment usually involves weight loss, which may restore menstruation and ovulation in women with PCOS. Induction of ovulation by clomiphene (Clomid) is often the first choice when treating PCOS. Surgery is sometimes recommended if medical treatment fails.

Endometriosis
Endometriosis occurs where the lining of the uterus (the endometrium) grows in places other than the uterus. Endometrial tissue may grow in the fallopian tubes, ovaries, bowel or bladder, or even in lungs or joints. The exact cause of endometriosis is not known but it does seem to run in families.

The endometrial tissue, regardless of where it is growing, responds to the normal hormone cycle and will bleed when menstruation occurs. This condition can be extremely painful, especially if tissue has grown where there is no natural escape route for the blood. Endometriosis can cause scarring and blockage within the pelvis, which can result in infertility.

Diagnosis is by laparoscopy. Because endometriosis is influenced by the menstrual cycle medical treatment involves drugs that shut down the female hormone pattern so that menstruation does not occur.

The contraceptive pill is sometimes used to treat endometriosis but in order for the treatment to be totally effective there should be no breakthrough bleeding. Therefore, high-dosage contraceptive pills may be necessary and these can have unpleasant side effects.

The main drug used for the treatment of endometriosis is Danazol, a synthetic weak hormone that stops ovulation. Unfortunately, this drug has side effects such as nausea, dizziness and mood swings. There is also a relatively new drug that contains gonadotrophin-releasing hormone, which produces a temporary menopause and causes the endometrial tissue to shrink.

Identifying the problem

Infertility is usually defined as not being able to get pregnant despite trying for one year. However, if you are over 35 years of age you should consult your doctor if you have not conceived after six months.

Your GP will probably do a blood test to measure your progesterone levels. The 21-day test is done seven days after ovulation (14 days from the start of your period to ovulation plus seven days after that) and can indicate if you have ovulated. If your blood results are abnormal you will probably be referred to a gynaecologist for further tests.

The gynaecologist may recommend other tests such as:

• A laparoscopy, which is a diagnostic procedure whereby a laparoscope (a narrow instrument with a telescopic lens) is inserted into your abdomen via a small incision just below the navel in order to view the uterus, fallopian tubes, ovaries and other abdominal organs.

• A hysterosalpingogram (HSG), an x-ray procedure in which a special opaque dye is inserted through the cervix to see inside the uterus and to see if the fallopian tubes are patent.

• A hysteroscopy is a diagnostic procedure in which a hysteroscope (a thin, lighted telescope) is inserted through the cervix in order to view the inside of the uterus.

Fertility treatments

Drugs for inducing ovulation are often the first line of treatment if it is discovered that you are not ovulating but your fallopian tubes and your partner's sperm are normal. A variety of drugs are available that are designed to stimulate ovulation and correct the hormone balance, therefore helping to ensure the release of an egg.

Clomiphene citrate (Clomid)

This drug is used to stimulate ovulation and it is also used if you have long cycles and infrequent periods. It is taken every day for five days early in your cycle. One of the possible side effects of clomiphene treatment is multiple births.

It is advised that this drug should only be given if ultrasound monitoring of the ovaries can be done at the same time, therefore it is normally prescribed at a specialist clinic. Unpleasant side effects such as bloating, bowel upsets, headache, dizziness, hot flushes and depression may occur.

Human chorionic gonadotrophin (hCG)

This hormone is normally produced naturally in the early stages of pregnancy and works by causing the follicle to release its egg. It is given by injection and is often used in conjunction with clomiphene tablets.

Human menopausal gonadotrophin (hMG)

This is one of the most potent ovulation drugs and is often used for women who have not had any success with clomiphene. The risk of multiple births is increased so careful monitoring is required. There is the danger of hyperstimulation, where the ovaries can become enlarged and cause severe abdominal pain.

Extreme hyperstimulation can be life threatening and excessive fluid builds up in the chest and abdominal cavity. Careful monitoring is essential and treatment may be withheld if there are too many follicles present or your oestrogen level is too high.

Assisted conception techniques

Intrauterine insemination (IUI)
This is a procedure where your partner's sperm is put directly into your uterus at a much higher level than can be achieved during intercourse, which may improve the chances of fertilisation. IUI is the first procedure of choice if you have a diagnosis of unexplained infertility, you are under the age of 35 and there are no apparent medical or physical reasons why you are not conceiving.

IUI may be used if there is a problem with ovulation because ovulation-stimulating drugs can be given at the same time. If your partner is producing an anti-sperm antibody, which means that the sperm will not penetrate your cervical mucus, IUI can also be used. IUI has a good success rate if there are no medical reasons for the infertility and you are under 35 years.

In vitro fertilisation (IVF)

IVF is a technique where your egg is fertilised with your partner's sperm outside your body and then the egg is implanted back into your uterus. This is where the phrase 'test tube babies' originates. IVF may be used if a couple have unexplained infertility for a number of years.

It is often the treatment of choice for women who have damaged fallopian tubes or other problems that mean normal fertilisation cannot take place. Unfortunately the success rate for IVF remains relatively low at around 15-20% and commonly fails at the implantation stage.

Gamete intra-fallopian transfer (GIFT)

In this procedure your egg is mixed together with your partner's sperm (not fertilised) and put back into the fallopian tube so that fertilisation takes place in the natural way. GIFT can only be used if you have healthy fallopian tubes. There are no official success rates for GIFT treatment.

Intra-cytoplasmic sperm injection (ICSI)

This technique involves injecting a single sperm directly into the egg to fertilise it. The embryo is then implanted into your uterus. ICSI can be used if your partner has a low sperm count and IVF is not possible.

ICSI is an extremely delicate procedure but the success rate is 20-25%, slightly higher than that for IVF. This may be due to the fact that the sperm is injected directly into the egg and the technique is not dependant on how well fertilisation takes place