Embryo quality and impact of specific embryo characteristics on ongoing implantation in unselected embryos derived from modified natural cycle in vitro fertilization.
OBJECTIVE
To study the implantation potential of unselected embryos derived from modified natural cycle IVF according to their morphological characteristics.


METHODS
Cohort study.


METHODS
Academic department of reproductive medicine.


METHODS
A series of 449 single embryo transfers derived from modified natural cycle IVF.


METHODS
None.


METHODS
Ongoing implantation rate according to embryo characteristics.


RESULTS
The best implantation was found in embryos with 4 and 8 cells on day 2 and 3 respectively, <or=10% fragmentation, and absence of multinucleated blastomeres. In contrast to findings from other studies, we found embryos with fewer than four blastomeres on day 2 to do relatively well. Furthermore, we found the implantation potential of embryos containing multinucleated blastomeres to be less severely impaired than expected.


CONCLUSIONS
Findings from this study suggest that in currently used embryo scoring systems, the implantation potential of embryos with low numbers of blastomeres on day 2, as well as embryos containing multinucleated blastomeres, is underestimated. However, it is unclear whether the results of our study apply to embryos derived from controlled ovarian hyperstimulation cycles.
Department of Obstetrics and Gynaecology, University Medical Center Groningen, Groningen, The Netherlands.
Marie-José
MJ
Pelinck
Annemieke
A
Hoek
Arnold H M
AH
Simons
Maas Jan
MJ
Heineman
Janny
J
van Echten-Arends
Eus G J M
EG
Arts
D000328:Adult; D001755:Blastocyst / Q000166:cytology* / Q000473:pathology; D001757:Blastomeres / Q000166:cytology / Q000473:pathology; D002970:Cleavage Stage, Ovum; D015331:Cohort Studies; D016208:Databases, Factual; D046149:Embryo Culture Techniques; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000592:standards*; D015726:Giant Cells / Q000473:pathology; D006801:Humans; D007247:Infertility, Female / Q000628:therapy; D054315:Oocyte Retrieval; D010062:Ovulation Induction; D011247:Pregnancy; D012044:Regression Analysis; D056826:Single Embryo Transfer / Q000379:methods* / Q000592:standards*; D055815:Young Adult