Research IB: Chromosomal differences between eggs from advance age patients and eggs from young age egg donors

When a couple makes the decision of having a child, one of their main concerns is that the pregnancy goes to term and of course the child is born healthy. A miscarriage occurs in about 10-15% of pregnancies and their origin is diverse, but the most common causes are chromosomal abnormalities in the embryo.

 

Chromosomal abnormalities in the embryo come, almost exclusively, from alterations in the male or female gamete. At the paper accepted for oral presentation at the “British Congress of Fertility”, we have analyzed the female contribution to embryonic chromosomal alterations and, for this we have studied the gametes in a group of fertile and young patients, the egg donors.

 

The chromosomal abnormalities (aneuploidy) rate in eggs from our egg donors is lower than the ones detected in embryos from egg donation cycles. Sperm aneuploidy explains the rest of alterations described. We have also identified the most frequent alterations in eggs and we have compared them with those detected in embryos.

 

The aneuploidy in eggs increases with the maternal age and in parallel to the embryonic chromosomal alterations rate. The CCS or “Complete Chromosomal Screening” allows the reduction of miscarriages and increases the chances of a successful pregnancy in this group of patients, allowing transferring only chromosomally normal embryos.

 

Incidence of aneuploidy in oocytes from egg donation cycles. JA. Ortiz, H. Blanca, R. Morales.; B. Lledó; J. Guerrero, J. Ll. Aparicio, R. Bernabeu. Oral Presentation. BFS Annual Meeting 2015. Birmingham, UK. January 2015