The process of conceiving is no less than a miracle. An intricate sequence of events must be carefully orchestrated in both the man and the woman.
The Path to Pregnancy
How Fertilisation works?
Fertilisation occurs when a woman's egg and a man's sperm fuse to form a single cell. This occurs in one of the fallopian tubes. For this to happen, the egg and the sperm have to perform certain functions beforehand and once fused, the merged cells must find their way to the uterus and embed into the lining of the womb, in order for the fertilisation to become a pregnancy.
Here is a brief overview of the roles played by the female egg and the male sperm:
The Female Egg:
The exact time of the month for ovulation depends on your menstrual cycle. Taking an average menstrual cycle of 28 days, ovulation occurs on days 12-15. Day one is the first day of your period.
At ovulation, an egg is released from the ovaries. It is picked up by and travels down one of the fallopian tubes towards the uterus where , if intercourse has taken place within the last four days, it may meet sperm.
Eggs live and can be fertilised for 12-24 hours after being released. Sperm can live and stay active in your body for up to 48 hours.
Hormones prompt an increase in blood supply to the womb, in preparation for implantation. It takes up to five days for the fertilised egg to reach the womb and embed itself in the lining.
If the egg is not fertilised, or if the fertilised egg cannot attach to the womb lining, then a period begins.
The Male Sperm:
At the point of ejaculation during intercourse, a man can release up to 300 million partner’s vagina.
Only a small proportion of those make it through the neck of the womb and on to the fallopian tubes. The sperm must be actively moving, of normal appearance and of sufficient quantities to be considered normal. It must also be capable of moving through the female genital tract to reach the fallopian tube, where the egg is fertilised.
The quality of the cervical mucus in the woman’s body at the time of ovulation must be such that it allows free passage of the sperm into the uterus.
Finally, only one sperm will find its way in to fertilise an egg.
The fusion of the Female Egg and the Male Sperm:
Once the sperm penetrates the egg, the chromosomes carried by the sperm and the egg come together and the egg is fertilised. Within hours, the microscopic zygote divides over and over to produce multiple cells. Over the period of about 5 days, the fertilised egg or blastocyst now made up of about 150 cells, makes its way to the uterus or womb.
At this point, if conditions are favourable, the fertilised egg embeds itself in the lining of the womb and the female becomes pregnant
Here are the more common female fertility problems in more detail:
Ovulatory problems are the most common cause of female infertility and occur due to hormonal imbalance. This imbalance may arise either within the hypothalamus, the pituitary gland or in the ovaries. Common causes of these problems include stress, excess weight loss or weight gain, excessive production of prolactin (the hormone that stimulates milk production in the breasts) and polycystic ovarian disease.
Polycystic Ovarian Syndrome:
About 20% of women have polycystic ovaries (PCO). Many women with PCO have normal menstrual cycles and actually do not have a problem conceiving. However, some women have follicles on their ovaries which get stuck at a certain stage of development before they can get to the stage of producing an egg. This condition is known as polycystic ovarian syndrome (PCOS). PCOS is due to a hormonal imbalance, especially a raised LH, with irregular or absent periods. PCOS can very often be caused by a high glycaemic diet as many PCOS patients are also insulin resistant. It can also cause increased hair growth on the face and body inevitably-difficulty conceiving.
Symptoms of PCOS in women include irregular or no periods, often heavy and prolonged when they do arrive. The patient may be prone to being overweight and often craves mid-meal snacks, is often tired and may also complain of pelvic pain.
Treatment usually involves a practical diet and if required, the use of drugs to correct the hormonal imbalance and to stimulate ovulation. If a woman is overweight then losing excess weight, exercising and changing to a low glycaemic diet may help to improve the hormone imbalance. Medication is used to increase sensitivity to insulin and the most widely used is Metformin.
Alternatively, a laparoscopic polycystic ovarian drill, which involves putting a telescope into the tummy and inserting a needle into the ovary to disrupt it and trigger ovulation, may be performed.
Patients with PCOS are often successfully treated, though there can be the complication of either over or under stimulation of the ovaries, which has to be carefully managed by an experienced and reputable consultant.
Endometriosis is a condition that commonly affects women during their reproductive years. It occurs when endometrial cells, which are normally found only inside the womb, are found outside the uterine cavity. Some women with Endometriosis are without symptoms, but others suffer painful periods and pain during intercourse.
Endometriosis can appear as spots or patches called implants or as cysts on the ovaries and in severe cases can affect surrounding tissue causing adhesions or scar tissue. Unlike the lining of the uterus, endometrial tissue located outside the womb is trapped and does not have a way to leave the body. This can cause inflammation near the implants and if nerve tissue is affected, pelvic pain may result.
The diagnosis of Endometriosis cannot be made from symptoms alone as some women have no symptoms as there may be other reasons for pelvic pain.
Surgery or Laparoscopy is the only definitive way to diagnose endometriosis. Laparoscopy allows direct visualisation and ideally biopsy of areas suspected of being endometriosis. It is carried out by inserting a small telescope through an incision close to the naval.
Endometriosis can be managed quite simply and IVF is an appropriate treatment for associated infertility where other methods have failed.
During laparoscopy, the surgeon can also clarify if the tubes are open. This is where liquid is flushed through the neck of the womb. This flushing with liquid is similar to Saline Infusion Hysterosonography which is carried out on all female patients pre-IVF at Womens Center.
Many women who have Endometriosis can conceive without any difficulty however some women do have difficulty getting pregnant.
IVF is an appropriate treatment for infertility associated with Endometriosis where other methods have failed.
Tubal factor infertility accounts for up to one quarter of all cases of infertility. This includes cases where both the fallopian tubes are blocked, or one is blocked, or one (or both) are scarred. It is usually caused by pelvic infection (e.g. pelvic inflammatory disease (PID) or appendicitis), by pelvic endometriosis, or by scar tissue that forms after pelvic surgery.
In cases of relatively minor tubal damage it can be difficult to be certain if it is solely responsible for the infertility – or simply an additional factor in addition to other significant contributing causes. From a practical point of view, the presumptive diagnosis is of tubal factor unless the degree of scarring is very minimal. In this event, and if no other cause of infertility is found, then a diagnosis of unexplained infertility may be warranted.
The diagnosis can be made in a number of ways. Your doctor may suggest a laparoscopy and hydrotubation. A camera is placed through your belly button (usually) to inspect the pelvis. This is especially useful if other features are present e.g. pain which might suggest endometriosis (often treated at the same time). Dye is passed through the tubes and patency (or blockage or swelling) confirmed. The most common cause of blocked tubes is infection (PID) of which the most common infection is chlamydia. About 70% of women who have blocked tubes have had a chlamydia infection although it is often silent and they will not have even been aware of it.
A less invasive test still carried out in some hospitals is called a hysterosalpingogram. It is a useful test but is being superseded in many parts of the world by HyCoSy or saline sonography. These do not require X-Ray technology but rather vaginal ultrasound (like you may have when being monitored for fertility treatment). HyCoSy uses a special contrast dye while the saline test uses sterile salty water (saline). These are much less invasive than the older tests and may themselves be overtaken by three-dimensional ultrasound in years to come.
Anti-Mullerian Hormone (AMH):
Knowledge of how you will respond to hormone injections during an IVF treatment cycle is a very important part of fertility treatment.Depending on your own individual characteristics, you may fall into the extremes of response – an excessive response or and inadequate response. A recently developed test allows us to modify our approach, resulting in a reduced incidence of both of these extremes.
It has now been established that the hormone AMH, which is made by the ovarian follicle containing the egg, can accurately predict how your ovaries will respond to fertility drugs. This is sometimes called the ovarian reserve. Armed with this information, our consultant can make better decisions from the outset as to how to best proceed with your assisted reproduction cycle.
AMH involves a single blood test which can be performed at any stage in the menstrual cycle. At Womens Center , we can analyse your AMH levels in our own dedicated laboratory. Other relevant hormones may be measured in parallel with AMH, these are thyroid stimulation hormone (TSH) and Prolactin. Together these are known as the AMH profile.
Male Fertility Problems:
Male infertility occurs when a man does not produce enough sperm, known as a low sperm count, or the sperm are not of a sufficiently high quality to fertilise the egg.
It is also possible that there are problems with the tubes that carry sperm resulting in no sperm in the ejaculate (azoospermia). A man may also find it difficult to get an rection, or have trouble ejaculating, therefore, sperm may not reach his partner's vagina.
Abnormalities in semen production can cause male fertility problems. The initial screening for men is a semen analysis. A normal assessment should show a sperm count of more than 20 million sperm per ml with at least 50% of the sperm actively motile and more than 35% of the sperm with a normal shape.
The sperm should be able to survive in the female genital tract for a period of 24-48 hours so that they are able to reach the site of fertilisation in the fallopian tubes.
Abnormalities in the semen are primarily due to a defect in sperm production by the testicles. The cause of this is usually unknown but may be associated with previous infections or surgery including undescended testis or hernia. Abnormalities may also be caused by excessive drinking.
Certain drugs, radiation and radiotherapy may have a detrimental effect on the production of the sperm. The presence of a varicocele, a condition where there is an increase in the blood flow around the testicles due to dilated veins, may lead to a rise in the temperature around the testicles, which may adversely affect sperm production and motility.
Absence of sperm in the ejaculate (azoospermia) may due to an obstruction at the level of the vas deferens, epididymis, or even at the level of the testes. It may also be due to bilateral congenital absence of the vas. Some men may have testicular failure which is failure of production of the spermatozoa. This may be the result of a chromosomal disorder or previous infections such as mumps. It may also be associated with the history of failure of descent of the testes into the scrotum.
On rare occasions there may be anti-sperm antibodies in the sperm which impair their motility. This may occur following a reversal of a vasectomy or other surgery on the male genitals and may also be related to previous infections or injury. Your semen sample will be tested for sperm antibodies during the analysis.
Until recently, there has been no effective treatment for male infertility. Drugs have rarely improved sperm counts. However, since the introduction of micro manipulative techniques, in particular Intracytoplasmic Sperm Injection (ICSI), the success rates for couples with male problems have markedly improved.
ICSI bypasses the natural process involved in a sperm penetrating an egg and is therefore used when there are problems that make it difficult to achieve fertilisation naturally or with conventional IVF.
Sperm DNA fragmentation testing:
Sperm DNA is packaged by nature in a different way compared to that of other cells in the body. In sperm cells, DNA is arranged in very tight organised loops so that it can be carried safely to its final destination – the egg.
Semen protects sperm from several hazards along the journey. DNA fragmentation occurs when particular reactive oxygen species damage the sperm DNA. If damaged sperm is accepted into an egg for fertilisation, poor quality embryos or miscarriage can result.
There is a test that can assess this problem. The sperm chromatin structure assasy (SCSA) can measure a DNA fragmentation index (DFI). This test may reveal high susceptibility toward DNA damage or actual DNA fragmentation already present in the sperm.
Treatment includes maintaining appropriate temperature for the scrotum, giving up smoking, reducing your weight and ensuring that any medication that you are on does not cause DNA fragmentation.