Impact of chromosomal abnormalities on preimplantation embryo development.
OBJECTIVE
To evaluate the influence of numerical chromosomal abnormalities on preimplantation embryo development.


METHODS
This study includes 6936 embryos from 1245 women undergoing preimplantation genetic diagnosis (PGD). Indications for aneuploidy screening were: recurrent miscarriages, implantation failure, severe male factor, advanced maternal age, and mixed causes. Embryo biopsy was performed on day 3, and embryos were co-cultured until day 5, when embryo transfer was performed.


RESULTS
In the aneuploidy screening regimen, normal euploid embryos showed significantly higher blastocyst rates (68.2%) compared to chromosomally abnormal (42.8%, p < 0.0001) and mosaic (53.7%, p < 0.0001) embryos. Among aneuploid embryos for autosomes, higher blastocyst rates were observed in trisomies than monosomies, although only statistically significant in patients over 36 years of age (50.8 vs 38.9%; p < 0.0001). In contrast, in embryos with sex chromosomes aneuploidy, similar blastocyst rates were observed between trisomies and monosomy X.


CONCLUSIONS
Embryos with certain types of chromosomal abnormalities were negatively selected during preimplantation embryo development. Despite this selection, a remarkable percentage of chromosomally abnormal embryos can develop normally to blastocyst stage with high probability of implantation and pregnancy.
Rubio
Carmen
C
Instituto Valenciano de Infertilidad, Universidad de Valencia, Valencia, Spain. c.rubio@ivi.es
Rodrigo
Lorena
L
Mercader
Amparo
A
Mateu
Emilia
E
Buendía
Pilar
P
Pehlivan
Tugce
T
Viloria
Thamara
T
De los Santos
Ma José
MJ
Simón
Carlos
C
Remohí
José
J
Pellicer
Antonio
A
D000328:Adult; D000782:Aneuploidy; D001755:Blastocyst / Q000502:physiology*; D041321:Chromosomes, Human, X; D046508:Culture Techniques / Q000379:methods; D010064:Embryo Implantation / Q000235:genetics*; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D005307:Fertilization in Vitro; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008423:Maternal Age; D009030:Mosaicism; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D014314:Trisomy