3 years ago

Morphokinetic characteristics of embryos derived from in-vitro-matured oocytes and their in-vivo-matured siblings after ovarian stimulation

Tamar Margalit, Avi Ben-haroush, Roni Garor, Naomi Kotler, Dania Shefer, Natalia Krasilnikov, Moran Tzabari, Galia Oron, Yoel Shufaro, Onit Sapir

Publication date: Available online 10 November 2018

Source: Reproductive BioMedicine Online

Author(s): Tamar Margalit, Avi Ben-Haroush, Roni Garor, Naomi Kotler, Dania Shefer, Natalia Krasilnikov, Moran Tzabari, Galia Oron, Yoel Shufaro, Onit Sapir

Research question

Does delayed maturation of aspirated metaphase I (MI) oocytes, completed in vitro, adversely affect early embryo development?


Time-lapse microscopy was used to compare morphokinetic variables between embryos derived from oocytes with delayed maturation after ovarian stimulation and from in-vivo-matured metaphase II (MII) sibling oocytes from the same IVF and intracytoplasmic sperm injection cycle.


A total of 1545 injected oocytes in 169 cycles from 149 patients were included. The in-vitro-matured oocytes had lower normal fertilization rates than the MII aspirated oocytes (50.2% versus 68.0%; P < 0.001). Early key developmental events were significantly delayed in the normally fertilized in-vitro-matured compared with in-vivo-matured oocytes (polar body extrusion: 5.4 ± 3 versus 3.9 ± 1.8 h; P < 0.001; pronuclear fading: 27.2 ± 4.7 versus 25.1 ± 4.2 h; P < 0.001, respectively) and synchrony of the second cell cycle was adversely affected. The proportions of embryos with optimal second cell cycle length and second cell cycle were similar but with fewer top-quality embryos, based on an algorithm, for the delayed in-vitro-matured oocytes compared with their in-vivo-matured sibling oocytes (14% versus 29.1%; P < 0.001).


Embryos derived from oocytes that failed to mature in-vivo in standard treatment after ovarian stimulation may show a different morphokinetic profile from their sibling oocytes aspirated at the MII stage after completing maturation in-vivo.

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