Conclusion:

Use of TLI incubators appears to increase the cumulative live birth rates in IVF providing additional reassuring data about the safety and effectiveness of TLI incubators for clinical practice in IVF. The fact that this effect on cumulative live birth rate has been seen with single-step culture medium and not with sequential culture medium (explored in our previous study) adds additional strength to our hypothesis that TLI incubators do not affect embryo selection alone but improve embryo quality through the uninterrupted culture conditions. This forces a rethink of the interrelationships between the type of incubator systems and type of the culture medium used in the clinical laboratory. Research studies such as meta-analyses exploring the impact of incubator systems should consider the type of culture medium used. Further research is being undertaken at our unit to assess the impact of not opening the incubator doors on day 3 in SC incubators to assess whether this adaptation might confer some of the benefits of TLI systems to SC incubators.