The Advanced Age of the Father May Be a Risk Factor in Anomalies of the Foetus

A team of researchers at the Universitat Autònoma de Barcelona, co-ordinated by Professors Josep Egozcue and Cristina Templado, has shown for the first time that the older a man is, the more probable it is that his spermatozoa will present chromosome anomalies. This is the first time that a lineal relationship has been established with precision between these two factors. The conclusions of this study, published in the European Journal of Human Genetics, increase the importance of the father’s age in evaluating the risk of the foetus suffering from chromosomal anomalies.

The advanced age of the mother is one of the greatest risk factors in the foetus suffering from anomalies in the number of chromosomes, which leads to miscarriages and the birth of babies with physical and mental handicaps. The evaluation of the influence of the father’s age in the appearance of these anomalies, however, has always been pending. There are studies that point towards this relationship, but it has always been difficult to clearly assign the role of the father in cases with anomalies in the number of chromosomes.

A team of researchers in the Cellular Biology, Physiology and Immunology Department at the Universitat Autònoma de Barcelona, co-ordinated by Dr Josep Egozcue and Dr Cristina Templado, has looked at the research from another perspective – that of investigating the relationship between the father’s age and the chromosomes in his sperm. The objective was to thereby deduce the relationship between the father’s age and foetus anomalies.

In the most comprehensive study that has ever been carried out in this field, on a total of 200,000 spermatozoids from 18 donors aged between 24 and 74 years old, the UAB researchers have discovered that the older a man is, the more probable it is that his spermatozoa will present anomalies in the number of chromosomes. They also noticed for the first time that the relationship between these two factors is lineal.

The scientists at the UAB have determined that the percentage of spermatozoids with all chromosomes (karyotype) doubled (a phenomenon known as diploid) increases by 17% for each increase of ten years in age. Moreover, the researchers determined that the probability of chromosome 6 appearing twice (instead of once) in the same spermatozoid is 5.9% greater every ten years, 11.5% greater for the same anomaly in chromosome 21 (responsible for Down’s Syndrome) and 8.6% greater for sexual chromosomes.

The research, co-ordinated by professors Josep Egozcue and Cristina Templado at the Cellular Biology, Physiology and Immunology Department at the UAB has been published in the periodical European Journal of Human Genetics, which belongs to the Nature group of scientific publications. Also participating in the project were the UAB Researchers Mercè Bosch and Olga Martínez-Pasarell, and Osvaldo Rajmil, researcher at the Andrology Department in the Puigvert Foundation.