Temperature Decline in Embryological Culture Dishes outside Incubator.

BACKGROUND

In embryological culture dishes, there is a temperature decline when they are removed outside incubators. This study aimed at investigating the effects of this temperature decline within a certain time frame, the type of culture dish with or without the use of laminar air flow and whether it is possible to achieve a sufficient thermal control with the use of a heating stage.

MATERIALS AND METHODS

In this experimental study, the temperatures of four different types of polystyrene dishes [50 mm intracytoplasmic sperm injection (ICSI), 35 mm, 60 mm, 90 mm], filled with culture medium and oil were recorded for a period of 10 minutes outside the incubator. Temperature was measured with an infrared thermographic camera. The reference temperature was 37°C. Four parameters were analyzed: the type of dishes, air flow, a heating stage at 37°C and 38.5°C.

RESULTS

There was a time-dependant significant temperature decline outside the incubator in all types of dishes and under all experimental conditions. Under air flow temperature decline increased compared to the no air flow condition. The use of a heating stage at either 37°C or 38.5°C slightly improved the situation in most cases. After three minutes out of the incubator without a heating stage and air flow, the temperature was <34°C; with air flow and without a heating stage the temperature was <33°C. When a heating stage was used, the temperature was <36°C, except when using ICSI dishes. When ICSI dishes were on a heating stage they maintained a temperature close to 37°C with or without air flow. In all experimental conditions the highest decline was recorded with the 90 mm dishes.

CONCLUSION

Time is crucial for managing the temperature decline in culture dishes when out of the incubator. Under air laminar flow, the heat loss is greater, when with a heating stage at 37°C or better at 38.5°C this loss decreases but still exists. ICSI flat bottom dishes give the best results when heated stages are used. Flat bottom dishes maintain the temperature rather efficiently. Based on our findings, the use of flat bottom dishes should become a universal practice in fertilization (IVF).