The relationship between controlled ovarian stimulation protocol, meiotic spindle visibility, position of the meiotic spindle relative to the polar body in the human oocyte, and clinical outcomes following ICSI.

Purpose: To investigate the effects of different controlled ovarian stimulation (COS) protocols, including the progestin-primed ovarian stimulation (PPOS), long, short, and the gonadotropin-releasing hormone antagonist protocols, on meiotic spindle visibility and position within the oocyte and clinical outcomes following ICSI.

Methods: Before ICSI, spindle position () just below the polar body (PB) was defined as 0° and categorized as follows:  = 0°, 0° <  ≤ 30°, 30° <  ≤ 60°, 60° <  ≤ 90°, 90° <  ≤ 180°, between the PB and the oolemma, and nonvisible. The clinical outcomes after ICSI were retrospectively analyzed.

The migration speed of nucleolar precursor bodies in pronuclei affects in vitro fertilization-derived human embryo ploidy status and live birth.

Purpose: To study the relationship between clinical outcomes after assisted reproduction and the migration speed of nucleolus precursor bodies (NPBs) in male and female pronuclei (mPN; fPN).

Methods: NPB migration speed, embryo ploidy status, and live birth (LB) were retrospectively analyzed in IVF-derived zygotes. The central coordinates of the mPN, fPN, and NPBs were noted at multiple timepoints.

Association of follicular fluid volume with membrane stretchability of human metaphase II oocytes following the gonadotropin-releasing hormone agonist protocol during intracytoplasmic sperm injection.

Purpose: The authors previously revealed the association of the follicular fluid (FF) volume with oolemma stretchability following the gonadotropin-releasing hormone (GnRH) antagonist protocol during intracytoplasmic sperm injection (ICSI). However, the impact of the GnRH agonist protocol on oolemma stretchability remains unclear.

Methods: Data that were obtained from 74 ICSI cycles were reviewed retrospectively.