Women's reproductive system

Producing fertile eggs (oocytes)
Every woman is born with a certain number of immature eggs already in their ovaries. Each month, between puberty and menopause, one egg (usually) fully matures and starts its journey down the fallopian tubes (The Fallopian tubes are two small muscular structures extending from a point near the ovary to the uterus. (Cohen, 2005, p. 363)) in the anticipation of fertilisation.

Menstrual cycle
There are three stages to a woman's menstrual cycle. On average, this cycle lasts 28 days. 

• Stage one: follicular phase
  The first stage of the cycle lasts for about two weeks. During this stage, the secretion of FSH rises, stimulating the development of an egg-containing follicle and the maturation of the egg within it. The growing follicle secretes increasing amounts of the female hormone, oestrogen, which triggers changes in the lining of the uterus (endometrium) and cervical mucus. The cervical mucus thins to allow sperm to pass through and the endometrium thickens making it ideal for the implantation of a fertilised egg.
  

   

• Stage two: ovulation
  About one day before an egg is ready to be released, the amount of oestrogen produced by the follicle sharply increases, causing a spike in the secretion of LH by the pituitary gland. This surge in LH production causes ovulation. The matured egg bursts out of the follicle and travels down the fallopian tube.
  

   

• Stage three: luteal phase
  The remains of the follicle become a corpus luteum, which secretes a second female hormone, progesterone. This helps maintain the best conditions for pregnancy should the egg be fertilised. If the egg is not fertilised within about 72 hours, the corpus luteum eventually degenerates and the egg is expelled from the uterus along with the lining, leading to menstruation approximately 14 days later.
  (Cohen, 2005, pp. 366 - 367)

Men's reproductive system

Sperm production
LH is responsible for the production of the male hormone testosterone, which along with FSH is responsible for stimulating sperm production in the testicles.
Sperm production, spermatogenesis, is a continuous process. Spermatogenesis is most efficient at a temperature of 3°C below normal body temperature (Waugh A, 2007, pp. 453). It is vulnerable to increases in temperature. 

Sperm cells
A sperm cell consists of two main parts: 

• the head which has the crucial role of clinging to an egg and penetrating its outer membrane, taking with it its genetic information
• the tail, which enables the sperm cell to "swim" the length of the female reproductive tract to reach an egg.

Problems affecting any of these components will affect the fertilising power of the sperm cell.

Best time for conception

Becoming pregnant is not always straightforward even for people without fertility problems.

Generally sperm can only live for a maximum of 3 days in the female reproductive tract and the egg needs to be fertilised within 72 hours (Cohen, 2005, p. 361) following ovulation, leaving a narrow window for fertilisation. Thus, the best time for conception is around the middle of the menstrual cycle just before ovulation occurs.

Pregnancy

Under normal circumstances only a few hundred of the 200 million sperm or more (Cohen, 2005, pp. 360) deposited naturally (via ejaculation – release of sperm) into the vagina during intercourse, are able to reach the end of the fallopian tube where the egg can be fertilised.

After one sperm has successfully fertilised an egg, cell division begins and the fused cells become an embryo. Migration of the embryo happens at the same time and about a week following ovulation, the embryo finds itself in the uterus and implants itself into the endometrium. Successful implantation prevents the corpus luteum and endometrium from breaking down, therefore menstruation does not happen.

At this point, a third gonadotrophin, the human chorionic gonadotrophin (hCG), is produced by the placenta which develops upon implantation. The hCG plays an important role in maintaining the pregnancy. It stimulates the corpus luteum to continue to produce high levels of oestrogen and progesterone.

Causes of Infertility

The complex nature of the processes and interactions involved in egg/sperm production and fertilisation means that something can go wrong at various stages of the process.

Infertility
Infertility is regarded as the inability of a couple to conceive after one year of unprotected intercourse. However, women over 35 or those with certain medical conditions, such as diabetes, should only wait six months.
(TF Kruger, 2007, pp. 317 - 331)

Female factors can include but are not limited to:

• Hormonal / ovulation:
  Hormonal problems affect follicular development as well as ovulation. Problems with ovulation account for a large number of all cases. 
  
  
• Tubal problems:
  Damage to the fallopian tubes is another common reason for infertility, preventing the egg from travelling down, affecting fertilisation or passage to the uterus. 
  
  
• Uterine problems:
  Such as Endometriosis, which occurs when developing cells from the endometrium break away and stick to the ovaries and fallopian tubes affecting the way they function. Other conditions such as fibroids (Fibroids are firm masses of smooth muscle encapsulated in compressed muscle fibres and they vary greatly in size. ) (Waugh A, 2007, pp. 459))in the uterus, can also cause problems with fertility.
   
• Cervix / vaginal problems:
  Structural abnormalities of the vagina or cervix can affect fertility as can the physical characteristics of the cervical mucus. The mucus can be hostile to sperm, perhaps containing antibodies or it becomes so thick it blocks the movement of the sperm. (TF Kruger, 2007, pp. 317 - 325)
  
  
• Hyperprolactinaemia:
  This is a condition where excess levels of the hormone prolactin are found in the blood. This can cause irregular or absent menstrual cycles, infertility and increased production of breast milk. (TF Kruger, 2007, pp. 298 - 299)  

Male factors can include but are not limited to: 

• Sperm potency:
  The vast majority of cases of male infertility are due to a low sperm count, which is generally associated with a high rate of sperm defects (size, shape and movement). 
  
  
• Hormonal imbalances:
  Hormonal imbalances related to FSH and LH do occur in men but are not very common. 
  
  
• Testicular failure:
  Some men are found to have no sperm in their semen. This could be due to a failure to ejaculate or a failure of the testes to produce sperm. 
  
  
• Tubal blockage:
  Damage as a result of infections can prevent the sperm from getting into the semen. Occasionally the ejaculate of some men is diverted into the bladder. 
  
  
• Sperm antibodies:
  A small group of men actually produce antibodies against their own sperm. (TF Kruger, 2007, p. 330)  

Joint infertility problems
Of the number of cases of infertility where the problem lies with both partners, some of the causes may be straightforward and quite simple to remedy. As the window of opportunity to fertilise an egg is quite limited in a woman's monthly cycle, the frequency and timing of intercourse may be contributing factors.

Fertility is also reduced with increasing age, especially in women. In men, testosterone levels can decline with age but not in the dramatic manner seen in women. Men continue to produce sperm but their motility and quality are reduced with advancing age. (TF Kruger, 2007, pp. 317 - 331)

Treating Infertility

A variety of options are now available to help identify the cause(s) of infertility and ultimately provide couples with the highest chance of realising their dream of having a baby.

Ferring has been helping couples to conceive for more than a decade with a portfolio of high quality products that work in the same way as the body's natural hormones. By correcting hormonal imbalances and stimulating ovulation, these products help to achieve a high pregnancy success rate.   

Treatment options
The procedures and treatments available from infertility clinics can be divided into four main categories: 

• Hormonal and anti-oestrogen therapy (includes induction of ovulation)
• Artificial insemination (AI) procedures
• Surgery
• Assisted reproductive technology (ART)

The infertility specialist is likely to start with the simplest treatment that is suitable for the cause of infertility in a particular couple. Where a pregnancy is not achieved after a few cycles of treatment another procedure will be selected. (TF Kruger, 2007, pp. 317 - 331) Please discuss the various treatment options available with your treating Reproductive Health Specialist.

Hormonal therapy
Its objective is to replace, or enhance, the hormones produced naturally by the body. Gonadotrophin treatment is also used to stimulate "super-ovulation" for assisted conception procedures, including in-vitro fertilisation (IVF). (TF Kruger, 2007, pp. 317 - 331)

Ovulation induction
Ovulation induction can be used as a treatment on its own or in combination with another infertility treatment such as artificial insemination or IVF.
The treatment stimulates ovulation in women with infrequent or irregular periods, or in those whose menstrual cycles have stopped due to polycystic ovaries. Care must be taken in patients who suffer from Polycystic Ovarian Syndrome (PCOS), as they are at a higher risk for hyperstimulation. Although successful for many women, it carries a high risk of multiple pregnancies. (TF Kruger, 2007, pp. 317 - 331) 

Artificial insemination
Most often used in cases of infertility due to low sperm count or reduced motility, the procedure can also be used in cases where the woman has hostile cervical mucus, or produces antibodies against sperm. The sperm cells are collected, processed and washed and then inserted directly into the uterus, cervical canal or vagina. (TF Kruger, 2007, pp. 317 - 331)

Surgery
Surgery can be used to correct anatomical abnormalities of the reproductive system in either the woman or the man. (TF Kruger, 2007, pp. 317 - 331) 

Assisted Reproductive Technology
ART is a general term covering a range of advanced procedures, including micro-manipulation of sperm, to aid fertilisation and implantation. The procedures all have one thing in common: they require the collection of multiple mature eggs (oocytes), which is achieved by hormonal stimulation of the ovaries often described as "super-ovulation".

The main ART procedures include: 

• In-vitro fertilisation (IVF)
• Intracytoplasmic sperm injection (ICSI) - for male infertility
• Gamete intrafallopian tube transfer (GIFT)
• Zygote intrafallopian transfer (ZIFT)
• Blastocyst transfer (BT) (TF Kruger, 2007, pp. 317 - 331)

References

Cohen, B.J & Taylor, J. (2005). Memmler's Structure and Function of the Human Body. Lippincott Wiliams & Wilkins. 

Kruger, TF & Bothe, M. (2007). Clinical Gynaecology (3rd ed.). Juta.

Waugh, A. & Grant, A. (2007). Ross and Wilson Anatomy and Physiology in Health and Illness (10th ed.). Churchill Livingstone Elsevier.

Introduction

Obstetrics is the branch of medicine related to pregnancy, giving birth, and the recovery period following birth. Most women have uneventful pregnancies with no complications, but some pregnancies will require further care and attention. Part of obstetric care is to try to identify and prevent problems occurring during pregnancy, labour, and following the birth of the baby that could affect the health of both mother and baby.

To learn more about the areas of obstetrics where Ferring is involved, please select one of the below topics:

Induction of Labour

For many pregnant women, the onset of labour occurs spontaneously and without complications. However in some cases, labour is initiated or induced by obstetricians when it is considered in the best interests of the mother and child to do so.

The reasons for inducing labour include (but are not limited to):

• Post-dates pregnancy: pregnancy that continues beyond 41 weeks¹ (this is the most common reason and occurs in about 10% of cases²)
• Pre-eclampsia: a syndrome involving several body systems that is characterised by the onset of hypertension (high blood pressure) in thesecond half of the pregnancy³. It occurs in 3 – 5% of all pregnancies³.
• Maternal medical problems e.g. Type 1 Diabetes⁴

Labour induction involves stimulating the uterus to contract prior to the onset of natural labour⁴. Various methods can be used to achieve this. Before inducing contractions, the patient’s cervix needs to be favourable – i.e. the cervix should be softening, dilating (opening) and effacing (stretching)⁵. This process is also called ‘ripening’.

The naturally-occurring hormone oxytocin drives the uterus to contract, pushing the baby down towards the cervix⁶. Prostaglandins, which also occur naturally in the human body, are also released in preparation for childbirth, and set in motion the processes that soften the cervix. Prostaglandins cause the cervix to become thinner and to dilate (open), making it ready for the baby to pass through⁵.

When labour is induced with an unfavourable, or unripe cervix, complications can occur (such as an assisted vaginal delivery, or a need for a caesarean section⁷). It is therefore necessary to prepare the cervix for labour prior to stimulating the uterus to contract⁴. The most widely-used agent for ripening the cervix is Prostaglandin E₂, administered into the vagina or into the cervix². Prostaglandins can also be used for the induction of labour, as they play a role in the contraction of the uterus⁵.

References

¹ WHO recommendations for induction of labour. WHO Press (2011)

² Saeed GA et al. Misoprostol for term labor induction: A randomized controlled trial. Taiwanese Journal of Obstetrics and Gynecology  (2011) 50:15-19

³ Pettit F & Brown MA. The management of pre-eclampsia: what we think we know. European Journal of Obstetrics and Gynecology and Reproductive Biology (2012) 160:6-12

⁴ McCarthy FP & Kenny LC. Induction of Labour. Obstetrics, Gynaecology and Reproductive Medicine (2011) 12(1):1-6

⁵ Hawkins JS & Wing DA. Current pharmacotherapy options for labor induction. Expert Opin. Pharmacother. (2012) 13(14):2005-2014

⁶ Waugh A & Grant A. Ross and Wilson Anatomy and Physiology in Health and Illness. Churchill Livingstone (2007)

⁷ Triglia MT et al. A randomized controlled trial of 24-hour vaginal dinoprostone pessary compared to gel for induction of labor in term pregnancies with a Bishop score ≤ 4. Acta Obstreticia et Gynecologia. Early Online:1-7 (2010)