A boy or a girl: can I choose my baby’s gender?

Whilst it is technically possible to choose a child’s gender using pre-implantation genetic diagnosis, Spanish law prohibits selecting a baby’s sex, except with a view to avoiding the transmission of genetic diseases associated with the X chromosome. Such is the case, for example, of haemophilia A.
Law 14/2006 indicates that pre-implantation genetic diagnosis may only be used in order to detect serious genetic diseases or those which compromise the viability of an embryo. Therefore, this technique may not be used in order to select a future baby’s gender. Any other use of this technique is a serious offence which is punishable by law. […]

Cytomegalovirus (CMV): What is it? How is it transmitted? What are its symptoms? How can it be treated?

Cytomegalovirus (CMV) is a virus from the family Herpesviridae. We also find the chickenpox virus, herpes simplex and the mononucleosis virus in this family.
Infection with CMV is very common since it is present worldwide and can affect anyone. On the whole, it is an infection which does not usually cause any serious health issues. Once the virus has infected a person, it will remain in that person’s body for the remainder of his or her life. In fact, it is usually inactive or latent for a long time and it does not tend to reactivate unless the person’s defence system (immune system) is affected. Most people who are infected by the virus and who do not have serious health issues do not, on the whole, have any symptoms which might cause them to believe that they are infected with CMV. People who do develop some symptoms may suffer from a high temperature, swollen lymph glands, muscle pain or tiredness.
However, in the case of babies infected with the virus during pregnancy or childbirth and in people with a weak immune system, it is considered to be a significant public health problem since it can cause serious illnesses. […]

Techniques for obtaining spermatozoa

There are currently many different solutions when spermatozoa are not present in ejaculate. Access to a trained urologist increases chances of achieving spermatozoa in greater quantities and with improved quality.
What is TESA (Testicular Sperm Aspiration)?
This is a question which many couples ask themselves as they turn to assisted reproduction treatment when the issue is an absence of spermatozoa in semen (azoospermia) with the aim of obtaining sperm. TESA (Testicular Sperm Aspiration) is a technique used for obtaining spermatozoa by testicular puncture.
Modern-day urology means that spermatozoa can be obtained for use in assisted reproduction techniques using different means. Over the last 10 years, we have improved the chances of achieving good results whilst reducing the invasive nature of the process and improving the quality of samples obtained in cases in which this was not previously possible. Men who have undergone a vasectomy, cases in which the sperm duct is obstructed or patients with cystic fibrosis are common examples in which adequate spermatozoa may be obtained through a simple testicular puncture under local anaesthetic. Different types of biopsy are also prescribed in certain cases. The differences between them are as follows: […]

By |26 de August de 2016|Fertility, News, Reproductive biology, Urology|0 Comments

Why does embryonic arrest sometimes happen during in vitro development?

Many factors can intervene in arrest processes during embryo development which mean cell division is detained and, therefore, it is not possible to implant the embryo in the mother’s uterus and bring about a pregnancy.
In the first instance, the conditions for development are essential.  Embryos that develop in vitro are subjected to a number of artificial conditions that do not exist in vivo and which will always be less than optimum. Embryos which were apparently viable can suffer embryonic arrest. Huge efforts have been made over the last few years to try and mimic what happens inside the mother and replicate those conditions in laboratory processes.  Most of all, the concentration of oxygen in incubators has been reduced, going from 20% down to 5%. The composition of the culture means has also been improved. This, along with exhaustive monitoring of pH and osmotic concentration, means that we can routinely carry out prolonged embryo development up to blastocyst stage in order to achieve improved embryo selection and increase pregnancy rates. […]

Can I choose the sex of my embryos when I undergo embryo transfer?

The human genome consists of 46 chromosomes: 23 of these are inherited from our father and the other 23 are inherited from our mother. Our organism’s entire genetic make-up is stored in these chromosomes. The 23 pairs are organised as follows: 22 pairs, known as autosomes, and one pair of sex chromosomes (X and Y) which differentiate the two sexes (XY for males and XX for females).
From a technical point of view, using pre-implantation genetic diagnosis, we have the means of analysing an embryo’s entire chromosomal make-up. This technique, which is known as CCS (Comprehensive Chromosome Screening), means additional or a lack of any chromosomes in the embryo can be detected. Therefore, we can use CCS to analyse the entire make-up of the embryo and determine that there are neither DNA excesses nor deficiencies which will stop the embryo from developing properly. But, if we focus on the sex chromosomes, we can also determine if the analysed embryo has two X chromosomes and will, therefore, be a girl (XX) or one X chromosome and one Y chromosome (XY) and will be a boy. […]

Beta hCG (β-hCG) result table

β-hCG (human chorionic gonadotropin) is a glycoprotein that is initially secreted by trophoblast cells in the embryo shortly after it implants in the uterus. The rapid increase in serum levels of hCG following conception means it is an excellent early indicator of pregnancy. It’s also a parameter which is widely used for monitoring that a pregnancy is progressing correctly.
On a physiological level, hCG triggers the corpus luteum and thus facilitates progesterone and oestrogen synthesis. Progesterone stimulates the maturing of blood and capillary vessels that help the foetus to develop correctly.
hCG levels can be measured in blood or in urine.
Urine tests have a detection limit of 20 to 100 mUI/ml depending on the brand. If the measurement is to be taken in urine, a sample of the first urine of the day is recommended. This is particularly true during the early days of pregnancy because, if the urine is too diluted, the test can return incorrect negative results.
hCG levels in blood can be used to detect levels as low as 5 mUI/ml and the concentration levels of the hormone can therefore be calculated.
hCG levels in multiple pregnancies are 30-50 % higher than in pregnancies where there is only one foetus. However, a multiple pregnancy should be confirmed by means of an ultrasound.

Embryo transfer on day 3 or day 5. The pros and cons.

Determining the ideal day for embryo transfer has always been a controversial issue and there are, even today, still a number of doubts surrounding this issue.
Embryo culture is, basically, a selection process. Each embryo’s progress is evaluated throughout and a decision is taken on which is most likely to implant successfully. […]

Obesity and embryo implantation failure

It has long been known that patients who are overweight face increased reproduction and pregnancy loss issues.
Issues achieving a successful pregnancy are even greater if, as well as being obese, the patient also has illnesses such as diabetes, thyroid issues or other metabolic disorders (refer to further information on endocrinology and pregnancy).
However, little was known about the direct effect of obesity on endometrial receptivity and successful or unsuccessful embryo implantation. […]

Recurrent pregnancy loss: an issue that does have a solution

Clearly one of the most difficult situations a couple trying for children may have to face is pregnancy loss. Suffering is even greater when, prior to this, the couple has gone through fertility treatment such as in vitro fertilisation, insemination or egg donation.
Pregnancy loss is not always the result of an illness or underlying abnormality. It can be the response nature provides in order to block the development of an abnormal embryo. In fact, when the tissue from the pregnancy loss is examined, a large number of chromosomal abnormalities can be detected. […]

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. […]