Is it always possible to get pregnant after embryo transfer? This is not necessarily the case, the whole process of pregnancy is the result of a combination of factors, let’s take a closer look. First, let’s look at what pregnancy is. Pregnancy is called “gestation” in medical terminology. The beginning of the process of pregnancy is called “implantation”. This is the process by which the early embryo unites with the uterine wall of the mother’s uterus, thereby establishing a structural connection between mother and child that allows for the exchange of material. In layman’s terms, this means that the “seed” baby has found the right “soil” in the mother’s uterus and has taken root. This process is not instantaneous, but takes time and is gradual. What is the process of embryo transfer? The process of embryo transfer, as depicted in the picture above, involves the transfer of high quality embryos that have been cultured in a laboratory for 3-6 days, screened by embryologists, and artificially delivered to the mother’s uterus through the operation of a surgeon. As we said before, after the transfer, you won’t know right away if the embryos have latched on or not, and the surgeon will ask patients to take a pregnancy test after 14 days or so. Some patients refer to these 14 days as the “crazy 14 days”. But in fact, during this seemingly long period of time, the embryo is also struggling. Ü Day 0 1-2 Day 3-6 embryos are transferred. Ü Day 1-3 Fertilized eggs continue to develop in the mother’s body from the cleavage stage embryo or blastocyst state, with rapid cell division and gradual hatching and overflow from the blastocyst cavity in preparation for implantation. Ü Day 4 The fertilized egg adheres to the uterine lining in preparation for implantation, which is called “localization” in medical terms. Ü Day 5 The fertilized egg produces a proteolytic enzyme that dissolves the lining of the uterus with which it comes into contact. The fertilized egg slowly buries itself in the functional layer of the endometrium and the process of implantation begins. Ü Day 6 The fertilized egg is embedded in the lining of the uterus and is completely covered, completing the implantation process. The fertilized egg grows rapidly and the syncytiotrophoblasts develop and extend into the endometrial muscle layer and blood vessels with a number of uniformly chorionic cell projections. The trophoblast cells secrete more and more HCG as the fertilized egg develops. Ü Day 7-9 At the place where the fertilized egg implants, the earliest placental tissue is formed, and blood from the mother’s circulatory system begins to circulate within the placenta, exchanging substances with the embryo. Ü Day 10-14 At this point, HCG in the mother’s blood and urine has risen to a certain level, and thus a double bar can mostly be seen with a pregnancy test. So, a successful embryo transfer does not necessarily lead to pregnancy, the little embryos still need to go through such a series of efforts. Mothers-to-be should not be too careful, give the “babies” enough time to grow, and believe that they will be able to get pregnant!