What is a spermatid?

Spermatozoa production takes place in the testicular seminiferous tubules and the process is known as spermatogenesis.  At the end of this process, a germ cell generates 4 mature spermatozoa which will survive in the human body for between 62 and 75 days.  The final stage in spermatogenesis, known as spermiogenesis, is a cell differentiation and maturation process consisting of the change from spermatids to spermatozoa.  As can be seen in the picture, the spermatids develop from secondary spermatocites and have already undergone Meiosis I and II division. They have a normal set of chromosomes (haploid) which means that fertilisation of a mature egg can take place. Therefore, and despite the fact that they are immature cells, they can be used in assisted reproduction techniques using ICSI when there are no mature sperm in samples taken from the ejaculate or testicles. […]

Asthenozoospermia: What is it? How can it be detected? What course of treatment can be used in order to get pregnant?

Asthenozoospermia is a decrease in the percentage of motile sperm in a sperm sample and it is identified by means of a seminogram or semen analysis.
Nowadays, seminograms are a basic tool which provide us with information in order to evaluate a man’s fertility and they are very useful when determining personalised treatment for the couple concerned. The analysis can be used to evaluate numerous factors such as the concentration, motility and morphology of sperm present in the ejaculate, amongst others.
According to the criteria included in the 5th edition of the World Health Organisation (WHO) (2010) manual, a man has asthenozoospermia when less than 32% of sperm in the ejaculate have progressive motility (sperm which move around) or when there it less than 40% total motile sperm (motile sperm which do and do not move around). […]

Teratozoospermia and male infertility

Teratozoospermia is an increase in the percentage of abnormal sperm in a sperm sample and it is identified by means of a seminogram or semen analysis.
According to the criteria in the 5th edition of the World Health Organisation (WHO), 2010 manual, a man has teratozoospermia when the percentage of normal spermatozoa in the ejaculate is below 4%.
Defects in sperm […]

Oligozoospermia: What is it? How can it be detected? What course of treatment can be used in order to get pregnant? What about criptozoospermia?

Oligozoospermia is the presence of an abnormally low number of sperm in a semen sample.
According to the criteria in the 5th edition of the World Health Organisation (WHO) manual, normal sperm content in a sample of semen should be equal to or above 15 million per millimetre. If a sperm count gives a result below this figure, this is known as oligozoospermia and it may be associated with fertility issues. More than one sample will need to be evaluated in order to confirm this.
The diagnosis method consists of a spermogram which, amongst other things, gives a sperm count per millimetre of semen. […]

The endometrial receptivity array (ERA) test

Embryo implantation is the least well known phase of reproduction within the field of reproductive medicine. This fact is of special relevance if we also take into account that the human embryo is not very efficient when compared to other closely-related species in the evolution timeline.
We currently know that pregnancy is based upon three basic pillars: the embryo, the endometrium and the tolerance of the mother’s immune system. Not only is it essential that all three function correctly, but there needs to be optimum interaction between them. We have already covered the role of the embryo and the immune system in detail. Therefore, we will now concentrate on the endometrium and, more specifically, on studying endometrial receptivity. […]

What does embryo biopsy involve?

Preimplantation Genetic Diagnosis (PGD) is a tool designed to “get to know” the embryos genetically before they are transferred into the mother’s uterus. Thanks to this technique, we can study their chromosome count and find out if they are carriers of a hereditary disease. This information helps us to select the embryos that will produce healthy babies. Yet, how can we find that information?
Today, the only way to find genetic information about embryos is by performing an embryo biopsy. What does embryo biopsy involve?
To explain the biopsy procedure we should keep in mind that our point of departure is EMBRYOS. Embryos are retrieved after performing an assisted reproduction cycle, preferably by Intracytoplasmic Sperm Injection (ICSI), and their development is assessed during the culture period until day 3 or day 5. […]

Why does Comprehensive Chromosome Screening (CCS) by array-CGH reduce miscarriage rates?

Miscarriage rates in the general population with no fertility problems range around 15-20%. In other words, one out of every five couples who achieve pregnancy suffers a spontaneous miscarriage, and 5% of these couples suffer it more than once. Even when pregnancy is achieved with the help of assisted reproduction techniques, miscarriage rates do not vary. For this reason, it is important when couples come to our clinic seeking reproductive counselling to perform comprehensive testing and design an adequate protocol for their case to secure the best result, which is a healthy baby at home, minimising the chances of miscarriage. In order to do that, one should know that miscarriages and pregnancy losses are caused by different reasons (uterine problems, immunological problems, and so on), and yet in half the cases there are chromosomal abnormalities in the embryo that prevent pregnancies to progress, hence causing miscarriages. Normal embryos have two copies of each chromosome, one inherited from the father and the other from the mother, and the chromosomal anomalies they may suffer involve a change in the number of copies, producing an imbalance in their genetic load which might block embryo development. […]

Choosing a fertilisation technique when oocyte counts are poor. IVF or ICSI?

A low ovarian response is an increasingly common situation for clinicians. It is mainly associated with delayed motherhood and, accordingly, with lower ovarian reserves. In this type of patients, the number of oocytes retrieved after puncture is normally limited. In this situation, choosing the most adequate fertilisation technique, conventional IVF or Intracytoplasmic Sperm Injection (ICSI), may stir a little controversy (of course, provided that the sperm quality and the medical history lead us to consider conventional IVF as a reasonable option). […]

The male factor in infertility

In contrast with the old-fashioned belief that reproduction issues are a female thing, current figures are clear: 47% of infertility cases in a couple are down to an issue with the man. Therefore, when a couple has infertility issues and they seek the help of a clinic specialising in assisted reproduction, the tests and analyses are carried out on both members of the couple. This practice of looking into both the female factor and the male factor is now common and carried out by all experts in the field, but there is still a lack of understanding of the fertility issues which men can have. What are they? What solutions do leading assisted reproduction clinics offer nowadays?
The most common issues amongst men are “changes in the sperm count with no apparent cause”, explains Instituto Bernabeu in Alicante. That is, a low number of sperm, poor sperm mobility or abnormal morphology. Additionally, there may be more concrete and identifiable reasons for changes in sperm such as obstruction issues, infection, diseases or genetic reasons which impede egg fertilisation or which affect embryo quality. […]

Egg Donation, solidarity and life

Solidarity can be carried out in very different areas of life and society: supporting initiatives of NGOs or associations, or dedicating some of our time to community service in our neighbourhood or town or simply carrying out daily routines to improve the lives of those around us. It is basically making a gesture or devoting some of our time to make a little effort towards others. […]