The menstrual cycle is controlled by the hypothalamic-pituitary-ovarian axis (see Figure 3.1).

As one of the three basic fertility factors is that the ‘right number of fertile sperm should be deposited into the vagina’, investigating the male partner’s semen quality is important and is one of the first investigations when a couple have a fertility problem. In fact, one-third of cases of subfertility are thought to be due to a male factor.

In this first chapter, we will outline the necessary steps to achieve pregnancy. These include the three primary requirements that have to be fulfilled for an embryo to be produced, and the process for that embryo to implant and grow within the womb (uterus).

Couples who do not have a barrier to conception and have unexplained subfertility sometimes conceive when they stop trying, adopt a child, embark on a new career or go on holiday. It is postulated that in this situation the couple have stopped focusing on achieving pregnancy and, if psychological factors are involved, this may have solved the problem. Psychologists say that women who have a subconscious conflict between motherhood and career may experience this.

Chapter 1 explained that one of the three requirements for conception to happen is that the passages, the womb (uterus) and tubes (Fallopian tubes) have to be open and normal to allow the passage of sperm up, sweep the ovulated egg from the ovary into the funnel-like end of the Fallopian tube (the ampulla) and then transport the resulting embryo (after fertilisation) down the tubes into the uterus, where the embryo implants to establish a pregnancy (see Figure 4.1). As part of fertility investigations, it is important to exclude tubal damage, although tubal function cannot be assessed and must be implied from appearances. If the tubes are totally blocked, then this would explain the infertility. When the tubes are open but damaged, it is not possible to assess the chance of conception.

The couple who has read this book should now be better informed about how pregnancy occurs and have a better understanding of the various aspects of ART. They also should understand that, in the twenty-first century, there are many ways of parenting and several possibilities for kinship. We have got used to couples divorcing and re-coupling, and of having stepparents and stepchildren.

As described in Chapter 4, the tubes (Fallopian tubes) are intricate structures, which are easily damaged. Although tubal microsurgery was introduced into gynaecology in the 1970s, the results of operating on damaged tubes were disappointing. This is understandable because of their intricate structure. Even when blocked tubes were reopened (i.e. patency was restored), the tubes still sometimes did not work normally. Other strategies were therefore called for. With the developments in organ transplantation, attempts were made to transplant healthy Fallopian tubes from a donor who did not wish to have children to someone whose damaged tube would be removed and replaced by the normal tube. This, however, required lifelong immunosuppression to avoid rejection, and was not feasible, and the one reported attempt did not work. Another ‘out-of-the-box’ solution that was attempted was to cover the ovaries in a plastic envelope and drain these with artificial tubes into the uterine cavity. Again, and not surprisingly because of the intricate function of the Fallopian tubes, this attempt did not work. Consequently, another solution was needed.

The human clinical practice of sperm freezing, storing and thawing was developed using the techniques transferred from animal husbandry. The first human births using sperm frozen were reported in 1954. This soon became accepted practice, and sperm freezing and banking became widely used clinical tools. It was also recognised that the use of chemotherapy and radiotherapy would often cause subsequent male infertility (azoospermia), and that the technology used for sperm banking could be used to preserve the fertility of such men by storing their sperm before treatment. Clinics started to store semen before cancer treatment in the 1970s, and the service is readily available in most cities.

Chapter 1 explained that the basic fertility factors were the right number of sperm, in the right place, at the right time, along with release of oocytes (eggs) and normal passages (the tubes and uterus). However, all these factors can appear adequate in some couples, yet no pregnancy results. These couples are said to have ’unexplained subfertility’, the medical term being ‘idiopathic subfertility’.