I’m going to start by saying that for every single IVF treatment cycle two main parameters lead to a successful cycle. 80% of it has to do with embryo quality, and 20% of it has to do with endometrial receptivity. When it comes to the embryo quality, the best way that we can possibly assess embryos is once we fertilize them in the lab to culture them to the day-5 stage. I know that there’s a lot of clinics and doctors that say let’s transfer the embryos on day-2 or day-3, but if we transfer them so early on, we don’t know their final assessment. We don’t know if the embryos can implant. For an embryo to be able to implant it needs to get to the blastocyst stage. There’s a fear there what happens if they don’t last in the lab and they don’t develop into blastocysts. We have the technology to be able to create a blastocyst. If any number a woman produces is going to survive in the lab and we have the good culture media, technology and the knowledge, so I don’t think that’s an excuse not to take embryos to day- 5. We as a clinic, take every single cycle to the last stage at the moment. Even in natural cycles, where we only get one egg. It is the best way to have a final assessment and find out reasons why certain treatment cycles don’t even reach the transfer. I think it’s good for the patient if they don’t have a proper embryo to transfer, not to perform a transfer. I think when we’re performing a treatment cycle, we also need to give answers to patients. We need to explain to them why it failed. Is it the egg’s fault, is it the sperms fault, do we see something in the lab? Things like this can be shown in the lab. For example, the paternal gene in the sperm, the effect of this gene on the embryo kicks in on day-3. If you transfer the embryo on day-3 they may be perfect, but they may stop developing after day three. So we definitely need to take the embryos to the day five-stage. A possible reason why we have repeated failures in IVF cycles may be chromosome abnormalities in some women. Many of the embryos that they have despite they look nice on day-5 may be abnormal. This is something that, unfortunately, we cannot change. It’s something we have to face as older women. But at least taking them to the day five-stage we allow nature filters to stop certain chromosome abnormalities, so we’re transferring healthy embryos on day five. The other reason for implantation failures may be poor quality not just genetically but how the embryo looks like morphologically in the lab. We see this sometimes. 20% of the success has to do with endometrial activity. Certain women also have a problem with receiving and accepting an embryo. Nowadays in certain cases, we also suggest that specific tests are performed. One of these is called the endometrial receptivity assay, and by performing this assay we can see if an endometrial lining is receptive but also the time the embryo is most likely to take to the lining. It gives us information that’s very important for a future cycle or when we’re performing a frozen embryo transfer. It’s not for everybody, as I said. We have to individualize every single case.