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.