Chromosomal abnormalities in infertile men and preimplantation embryos

Since 1979, studies have stated that the prevalence of chromosomal abnormalities increases with decreasing sperm quality. In 1992 it became possible to conceive a pregnancy with sperm from infertile men using IVF-ICSI. This raised concerns of an increased number of children born with congenital anomalies. The national guideline issued that a chromosomal analysis was a prerequisite in all men eligible for ICSI. The number of chromosomal abnormalities found in these men was relatively low, while a chromosomal analysis is costly and time-consuming. We studied which subgroup of infertile men carried the highest risk of chromosomal abnormalities, and in which men one can refrain from performing a chromosomal analysis.Preimplantation genetic diagnosis (PGD) is used in couples with an increased risk of an embryo with a genetic abnormality. Only non-afflicted embryos are used to conceive a pregnancy. The analysis is performed on 1 cell of the embryo, presuming that all cells in the embryo have the same genetic make-up. This is not the case in chromosomal mosaicism. There are indications that this phenomenon is influenced by the environmental conditions during embryo culture. We studied whether the rate of mosaicism was influenced by the oxygen concentration during embryo culture.In carriers of a specific type of chromosomal abnormalities, so-called reciprocal translocations, the chance of embryos with an abnormal chromosomal make-up is strikingly high. We studied whether cytogenetic characteristics of these translocations could predict a couple’s chance of a successful PGD-procedure.

Dissertation: http://hdl.handle.net/11370/2838b70b-14c2-4e75-b514-d889f99d8d04