Objective: Hydroxyethyl piperazine ethane sulfonic acid (HEPES)-buffered media have long been employed in assisted reproductive technology (ART) procedures; however, concerns persist regarding the impact of zwitterionic buffers on intrinsic cellular mechanisms. Limited studies have compared ART outcomes using bicarbonate media versus HEPES-buffered media during intracytoplasmic sperm injection (ICSI). This study compared the efficacy of two media used in ICSI: bicarbonate medium (one-step) and HEPES-buffered medium (SynVitro Flush). Methods: This retrospective study analyzed data from 200 ICSI cycles performed in 2023. Metaphase II oocytes were allocated to a bicarbonate medium (SAGE 1-STEP; Origio) or a HEPES-buffered medium (SynVitro Flush) during the ICSI procedure. Outcomes including fertilization rate, embryo quality and development, implantation rate, clinical pregnancy rate, miscarriage rate, and live birth rate were compared between the two groups. Results: The fertilization rate was significantly higher in the one-step medium (89.04%) than in the SynVitro medium (82.30%; p<0.001). The one-step medium also yielded more cleaved embryos and higher-quality blastocysts (class A/B; p<0.05). Consequently, more embryos were frozen in the one-step group (264 vs. 151), and higher embryo utilization rates were observed. Clinical pregnancy and live birth rates were significantly higher in the one-step group (p<0.05). No significant differences were found in chemical pregnancy rates or live birth rates among cycles utilizing frozen embryos (p>0.05). Additionally, there were no differences observed in miscarriage rates or multiple pregnancy rates. Conclusion The one-step bicarbonate medium improved cycle efficiency during the ICSI procedure compared to the SynVitro Flush medium. This finding underscores the importance of selecting an appropriate medium.

OBJECTIVES: Most of the studies on the effect of heat stress on preterm birth (PTB) are conducted in temperate climates. Evidence on this effect in hot and arid countries with low and middle income is limited. This paper describes the short-term effect of exposure to the hot and cold environment on a daily number of PTB in Iran. METHODS: The daily number of PTB was obtained from all hospitals of the city. Meteorological and air pollution data from 2011 to 2017 were obtained from a metrological station in the city. A semi-parametric generalized additive model following a quasi-Poisson distribution with the distributed lag non-linear model was selected as a modeling framework for time-series analysis to simultaneously model the short-term and lagged effect of heat stress on PTB in the Sabzevar city. RESULTS: The minimum and maximum daily temperature were - 11.2 and 45.4 °C respectively. The highest risk estimate at extreme cold temperature was found for apparent temperature (relative risk (RR) 1.83; 95% CI 1.61: 2.09). This pattern was seen for both models. For extreme hot temperatures, the model with mean temperature showed the highest risk increase for both the main model and air pollution adjusted model (RR 1.36; 95% CI 1.25: 1.49). The lowest risk estimate in extremely cold conditions was found in the model with mean temperature. However, for extremely hot temperature conditions, the lowest risk estimate was found for both maximum and apparent temperature. CONCLUSION Obstetricians working in semi-arid areas should be aware of the influence of environmental extreme temperature on the incidence of PTB.
Air Pollutants ; analysis ; Climate ; Cold Temperature ; adverse effects ; Environmental Exposure ; adverse effects ; Environmental Monitoring ; methods ; Female ; Hospital Records ; Hot Temperature ; adverse effects ; Humans ; Infant, Newborn ; Iran ; epidemiology ; Poisson Distribution ; Pregnancy ; Premature Birth ; etiology ; Risk Factors