The clinical procedure until the transfer of the embryos can be controlled. However , after the embryo transfer , it is impossible to predict what will happen inside the uterus. Implantation is a biological process, and involves the complex cross talk between the molecules produced by the embryo and the endometrium. It is beyond medical control .
We know from genetic analysis that most embryos fail to implant because they have intrinsic genetic defects. Research shows that over 90% of embryos from women over 40 years of age are aneuploid
( genetically abnormal, because of an abnormal number of chromosomes) . This is why they fail to implant. This is Nature's defense mechanism, to prevent the birth of an abnormal baby. This is why the pregnancy rate even with surrogacy for older women is so poor.
Today's technology is still limited, and lots of these defects still cannot be accurately diagnosed. Human reproduction is inefficient and patients need to come to terms with this.
Need help in making sense of a failed IVF cycle ? Please send me your medical details by filling in the form at www.drmalpani.com/malpaniform.htm so that I can guide you better !