Live birth rate per transfer is not impacted by the proportion of smooth endoplasmatic reticulum aggregates oocytes.

Background: Despite the data published to date, prognostic factors and the clinical impact of ICSI cycles with smooth endoplasmatic reticulum aggregates (SERa) positive oocytes remain unclear.

Objective: Are the clinical outcomes of an ICSI cycle impacted by the proportion of oocytes with SERa?

Materials And Methods: Retrospective study (2016-2019), including data from 2468 ovum pick-ups, performed in a tertiary university hospital. Cases are categorised based on the rate of SERa positive oocytes compared to the total number of MII oocytes: 0% (n=2097), <30% (n=262) and ≥30% (n=109).

Assisted oocyte activation does not overcome recurrent embryo developmental problems.

Study Question: Can recurrent embryo developmental problems after ICSI be overcome by assisted oocyte activation (AOA)?

Summary Answer: AOA did not improve blastocyst formation in our patient cohort with recurrent embryo developmental problems after ICSI.

What Is Known Already: The use of AOA to artificially induce calcium (Ca2+) rises by using Ca2+ ionophores (mainly calcimycin and ionomycin) has been reported as very effective in overcoming fertilization failure after ICSI, especially in patients whose Ca2+ dynamics during fertilization are deficient. However, there is only scarce and contradictory literature on the use of AOA to overcome embryo developmental problems after ICSI, and it is not clear whether abnormal Ca2+ patterns during fertilization disturb human preimplantation embryo development.

No difference in cumulative live birth rates between cleavage versus blastocyst transfer in patients with four or fewer zygotes: results from a retrospective study.

Study Question: Is the cumulative live birth rate (CLBR) per oocyte collection cycle (OCC) comparable after cleavage-stage or blastocyst-stage transfer in combination with supernumerary blastocyst vitrification on Day 5 (D5) in patients with four or fewer zygotes on Day 1?

Summary Answer: The CLBR in a fresh blastocyst-transfer or cleavage-stage transfer policy followed by vitrification on D5 is comparable in patients with four or fewer zygotes.

What Is Known Already: Blastocyst transfer enhances the self-selection of the embryo and shortens the time to pregnancy in patients with normal or high ovarian response. Whether these advantages are also present in patients with a low ovarian response and/or a limited number of available zygotes is a continuous debate.

Machine learning for prediction of euploidy in human embryos: in search of the best-performing model and predictive features.

Objective: To assess the best-performing machine learning (ML) model and features to predict euploidy in human embryos.

Design: Retrospective cohort analysis.

Setting: Department for reproductive medicine in a university hospital.

Low feasibility of in vitro matured oocytes originating from cumulus complexes found during ovarian tissue preparation at the moment of gender confirmation surgery and during testosterone treatment for fertility preservation in transgender men.

Objective: To study the feasibility of in vitro maturation of ovarian tissue oocytes for fertility preservation in transgender men on testosterone treatment.

Design: Cross-sectional study SETTING: University hospital PATIENT(S): Eighty-three transgender men enrolled from November 2015 to January 2019 INTERVENTION(S): In vitro maturation of cumulus-oocyte complexes (COCs) harvested at the time of gender confirmation surgery, and fertilization through intracytoplasmic sperm injection.

Main Outcome Measure(s): In vitro maturation, fertilization, and blastulation rates; comparison of morphokinetics with vitrified-warmed oocytes; and analysis of the genetic profiles of embryos.