A suggestion originated in the early 2000s that the high hormone levels derived from a stimulated IVF cycle would encourage a non-receptive, out-of-phase endometrium, the concept arose that adopting a freeze-all approach would not only minimize the risk of ovarian hyper response syndrome, but maybe even improve pregnancy rates in the general IVF population.

The latest clinical meta-analysis of fresh vs frozen transfers, now involving 5379 eligible subjects and 11 trials, found eFET associated with a higher live birth rate only in hyper-responders. There was no outcome difference between fresh and frozen in normal responders, nor in the cumulative live birth rate of the two overall groups. Now, here is where it gets complicated. 

The CDC described the increase in the number of elective FET cycles between 2007 and 2016 as ‘dramatic’, rising steeply from almost zero to more than 60,000 cycles per year. In its summary of US activity for 2016 the CDC seems unequivocal – at least, based on its observational registry data – that rates of pregnancy and live birth are higher after frozen transfers than after fresh. Yet the (published, peer reviewed or randomized clinical trial) so far has not shown a large difference. It seems to be a case where the clinical trials have not caught up with clinical practice, and because there is clear evidence that for hyper responders outcomes are better, many clinics are now relying on a freeze all strategy to reduce this poor outcome.   

Don’t choose your clinic based solely on insurance coverage. Base your decision on the performance of the individual clinic. Clinics that have higher volumes will naturally have embryologists who get to participate in a lot of procedures. Fertilization rates should be above 70% and 40-50% of fertilized eggs should make it to the blastocyst stage. 

Weigh the cost of the treatments with the CDC success rates. Good clinics with high success rates may cost more up front but may get you pregnant faster and at a lower cost in the long run instead of paying for multiple treatments.

Consider inquiring about the technologies the clinic uses. Do they use an EMR? Does it have a patient Portal for easy communication? Is there an electronic consenting process? Does the lab have state of the art cryo-storage monitoring systems? Does the lab use “electronic witnessing”?