Zona pellucida birefringence score and meiotic spindle visualization in relation to embryo development and ICSI outcomes.
The meiotic spindle and the zona pellucida exhibit molecular order when imaged with polarized optics. This study aimed to investigate possible factors contributing to the zona pellucida birefringence score and meiotic spindle visualization, and to evaluate whether these structures may predict intracytoplasmic sperm injection outcomes. Oocytes were divided into groups according to zona pellucida birefringence and meiotic spindle visualization. In addition, the cycles were split into three groups based on the zona birefringence of transferred embryos. A positive correlation was observed between zona birefringence and meiotic spindle visualization. In addition, when the meiotic spindle was observed, the fertilization rate among oocytes with high or low zona pellucida birefringence was similar. Implantation and pregnancy rates were significantly higher when embryos derived from high birefringence oocytes were exclusively transferred (P = 0.041 and P = 0.004 respectively). Furthermore, the miscarriage rate was higher when embryos derived from low birefringence oocytes were exclusively transferred. On the other hand, the total dose of FSH negatively affected meiotic spindle visualization. Results show that selection of embryos based on zona pellucida and meiotic spindle imaging can significantly improve implantation and pregnancy rates. Moreover, the dose of FSH used for ovarian stimulation may affect the organization of the oocyte meiotic spindle.
Madaschi
Camila
C
Fertility-Assisted Fertilization Centre, São Paulo, Brazil.
Aoki
Tsutomu
T
de Almeida Ferreira Braga
Daniela Paes
DP
de Cássia Sávio Figueira
Rita
R
Semião Francisco
Luciana
L
Iaconelli
Assumpto
A
Borges
Edson
E
D001718:Birefringence; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D006801:Humans; D008540:Meiosis / Q000502:physiology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D008941:Spindle Apparatus / Q000648:ultrastructure*; D016896:Treatment Outcome; D015044:Zona Pellucida / Q000648:ultrastructure*