Andrology and Endocrinology

Fertility treatments - Andrology and Endocrinology


All too often, male issues are overlooked when discussing fertility. This is a mistake, of course, because an egg cannot be fertilised without a good-quality sperm cell. This is why we pay as much attention to the male factor as the female factor at our fertility centre. For this, we work very closely with an expert in this area: Dr Frank Comhaire, professor emeritus, andrologist and endocrinologist.


Endocrinology is the study of the endocrine system or the hormonal system. The fact is that many fertility problems are caused by hormonal imbalances. This mainly involves the hormones that directly determine the condition and functioning of the sex organs.

The woman's hormonal cycle is determined by the follicle-stimulating hormone (FSH), luteinising hormone (LH), progesterone and, of course, oestrogen. At the beginning of a woman's cycle, an excess of FSH is produced so that a follicle (from which an egg is released) can mature. This follicle in turn produces oestrogen, which will ensure that a lining forms in the womb. Once the follicle is completely mature, the pituitary gland (a gland in the brain that excretes hormones) gets the signal to produce an LH peak. This LH peak triggers ovulation, after which the follicle ruptures and turns into a corpus luteum. The corpus luteum is a temporary hormonal structure that produces progesterone to be able to turn the womb lining into a receptive endometrium. This makes implantation of an embryo possible.

It goes without saying that the slightest hitch in this delicate female hormonal system will mean that either a disruption may occur in folliculogenesis (it is not possible for egg cells to mature properly) or that implantation cannot occur. What is more, disorders in other endocrine systems, such as the thyroid, adrenal gland, pituitary etc. can have a great influence on the reproductive hormone system and even block it.

Likewise in men, the formation of active sperm cells is controlled by a hormonal system comparable to that of women. All men also produce female hormones and vice versa. The proportion of male and female hormones should always correspond, however, because otherwise huge problems with sperm quality can occur. In some cases, the development of female sexual characteristics (feminisation) can even occur in the man, for example with breasts starting to form etc. Conversely, if a woman has male hormones in excessive quantities, this will clearly disrupt her cycle, but may also lead to androgenisation (e.g. acne, increased hairiness, greasy hair or seborrhoea etc.) caused by an imbalance in the proportion of female and male hormones.
All this therefore makes it clear that a thorough analysis of the hormonal situation of both the woman and the man, and possible correction of it, are essential elements of fertility treatment.


In medicine, andrology is more or less the counterpart to reproductive medicine, in the sense that andrology is the branch of medicine occupied with the male sex organs, their functioning and possible disorders. There is a certain amount of overlap with both endocrinology, given that the functioning of the sex organs is mainly controlled by hormones, and medical urology.

There is no doubt that during initial evaluations of a couple, a sperm analysis and a thorough andrological examination are as essential as the woman's fertility status. Studies have shown that a moderate to serious male fertility factor can be demonstrated in 30% to 50% of couples (depending on the study) experiencing fertility problems. Sometimes no cause can be found for male sterility issues (ideopathic andrological sterility issues), but in an increasing number of cases today, we are able to trace the causes. In many of these cases, the sterility issue can be corrected, at least partially. Examples are varicoceles, chronic prostatitis, hormonal disorders etc.