8 Chapter 1 INFERTILITY The inability to conceive within 12 months of unprotected intercourse is referred to as infertility, a disease of the female and/or male reproductive system (1, 2). In 2010 the total amount of couples facing infertility was estimated to be 48.5 million couples worldwide (3) which translates to an estimated prevalence of one in six couples trying to conceive (4). More recently, the trend of the prevalence of infertility was modelled based on data from the Global Burden of Disease Study 2017 (5), showing a gradual increase in infertility over time (6). Couples facing infertility can be referred for fertility work-up, a cluster of diagnostic tests investigating the possible causes of infertility in both the female and male partner. The results of the fertility work-up are used to determine the best strategy to fulfil their wish to conceive (7, 8). Causes of female infertility can be categorized as ovulation disorders, diminished ovarian reserve, uterine, ovarian and/ – or tubal pathology. The respective prevalences of these causes vary depending on the studied population (4, 9). Male factor infertility refers to an impaired number of motile spermatozoa which can have a congenital or acquired cause (10). The diagnosis of ‘unexplained infertility’ is made when no abnormalities are found in both the female and male partner during the fertility work-up (7, 8). FERTILITY WORK-UP The first medical step for couples facing infertility is the fertility work-up (see figure 1). Fertility work-up starts with an extensive medical history of both partners to identify risk factors potentially contributing to infertility such as congenital disorders, acquired diseases or surgical interventions. General blood testing is usually performed in women to check the overall health and to screen for a past infection with Chlamydia trachomatis using a Chlamydia trachomatis Antibody Test (CAT). An infection with this sexually transmittable pathogen can go unnoticed in women or manifest itself as clinical pelvic inflammatory disease (PID). A positive CAT has been associated with the occurrence of tubal pathology and intra-abdominal adhesions, however, CAT has a low positive predictive value for tubal factor infertility (11, 12). Other events in the medical history that may indicate a risk for tubal pathology are a history of PID, a complicated appendicitis, pelvic surgery, endometriosis and ectopic pregnancy (13). Gynaecological examination combined with transvaginal ultrasound is performed to rule out gynaecological abnormalities such as congenital uterine anomalies, uterine and adnexal pathology, endometriosis and to assess the ovarian reserve.
RkJQdWJsaXNoZXIy MTk4NDMw