Temperature Decline in Embryological Culture Dishes outside Incubator

In embryological culture dishes, there is a temperature decline when removed outside incubators. This study aimed at investigating this decline within a certain time frame and type of 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.

The temperature of four types of polystyrene dishes (50mm ICSI, 35mm, 60mm, 90mm), with culture medium and oil, was recorded for a period of 10 minutes outside the incubator. Temperature was measured with an infrared thermographic camera. The reference temperature was 37oC. Four parameters were analyzed: type of dishes, air flow, heating stage at 37oC and 38.5oC.

There was a time-dependant significant temperature decline outside the incubator in any type of dish and any type of experimental conditions. Under air flow, temperature decline increased. The use of a heating stage, at 37oC or 38.5oC, slightly improved the situation in most cases. Three minutes out of the incubator: without a heating stage and air flow, the temperature was <34oC; with air flow and without a heating stage, the temperature was <33oC. When a heating stage was used, the temperature was <36oC, except ICSI dishes. ICSI dishes, on a heating stage, maintained a temperature close to 37oC, with or without air flow. In all experimental conditions, the highest decline was recorded with 90mm dishes.

Time is crucial for temperature decline. Under air laminar flow, the heat loss is greater; with a heating stage at 37oC or better at 38.5oC this loss is lower but still exists. ICSI flat bottom dishes give the best results, when heated stages are used. Bottom flat dishes maintain the temperature efficiently. In our opinion, the use of flat bottom dishes should be generalized in IVF.