If the embryo does not implant, it stops growing, because it is not able to establish a blood supply from the uterine lining. The cells dies, and are silently reabsorbed. Cells die in the body all the time, and the body reabsorbs these quietly and efficiently.
When an embryo fails to implant, there can only be two logical reasons: the embryo is not good enough (genetically abnormal), or the endometrium is not “receptive” (doesn't allow the embryo to implant) enough.
Once embryos have been frozen, they will remain viable indefinitely. You can choose to begin a frozen embryo transfer after an unsuccessful fresh in vitro fertilization (IVF) cycle if you still wish to start a family.
If the blastocyst doesn't implant in the person's endometrium, pregnancy will not occur. For implantation to occur, hormones trigger a process called hatching. The blastocyst sheds its clear outer membrane. Hatching occurs one to three days after a blastocyst enters their uterus.
Early pregnancy loss can be grouped into two different categories based on when the loss happens. Sometimes the embryo just won't implant, which is still a loss for the patient, though not technically considered a miscarriage.
Of those fertilised eggs, around 15% will be lost before implantation begins. Of those which begin to implant, only about half will implant successfully.
Generally, when implantation occurs, you may experience sensitive breasts and mild abdominal cramping. If you haven't experienced these in the weeks after your embryo transfer, it may be indicative that the implantation has failed. Additionally, you may experience vaginal bleeding.
After it is in the uterus, a fertilized egg usually attaches to (implants in) the lining of the uterus (endometrium). But not all fertilized eggs successfully implant. If the egg is not fertilized or does not implant, the woman's body sheds the egg and the endometrium.
Typically, implantation occurs between six and 10 days after the fertilization of the egg. At this time, many women experience spotting and light bleeding. However, in some cases, implantation occurs later, well after 10 days have passed. This is called late implantation and can also be characterized by bleeding.
Progesterone is what stabilizes the uterine lining and makes it “sticky” enough for an embryo to attach. Without enough progesterone, it can be more difficult for an embryo to successfully implant. Progesterone stabilizes the uterine lining and makes it “sticky” enough for an embryo to attach.
Unfortunately, even if an egg is successfully fertilized, it is possible for the embryo to fail to implant in the uterine lining. In two out of three cases, this is due to inadequate uterine receptivity.
Also, about 1% of implanting embryos will split into identical twins. As a result, even when “only” two embryos are transferred, triplet pregnancy can still occur. The risks of low birth weight and prematurity are not to be taken lightly.
Transfer of poor quality embryos at either day 3 or day 5 have a low potential for implantation, though those embryos which successfully implanted have the same potential for live birth as the embryos of fair and good quality.
Between one-third and one-half of all fertilized eggs never fully implant. A pregnancy is considered to be established only after implantation is complete. Source: American College of Obstetricans and Gynecologists.
Most fertility specialists believe that in more than 95% of IVF failures it is due to arrest of the embryos. Embryonic arrest is quite often due to chromosomal or other genetic abnormalities in those embryos that made them too “weak” to continue normal development and sustained implantation.
Mental stress can lead to an increased endogenous level of epinephrine. Excessive epinephrine level may interfere with the decidual differentiation of human endometrial stromal cells and thus affect embryo implantation.
Think lots of fresh fruits, vegetables, good quality proteins, nuts and seeds, healthy fats and whole grains. The key here is blood sugar control to support implantation and early embryo development, so limit the junk and focus on real, nutrient-dense food.
This means the implantation takes place about 7 to 8 days after fertilization of the egg. The time required for implantation in both the cases, normal pregnancy and pregnancy through IVF, is more or less the same.
Sexual activity around ovulation leads to the possibility of fertilization of a released egg by sperm. But even then, the time frame for a fertilized egg to implant can vary. And hCG isn't produced until after implantation has occurred.
In the case of fetal demise, a dead fetus that has been in the uterus for 4 weeks can cause changes in the body's clotting system. These changes can put a woman at a much higher chance of significant bleeding if she waits for a long time after the fetal demise to deliver the pregnancy.
Zygotic splitting occurs between days two and six when the zygote divides, usually into two, and each zygote then goes on to develop into an embryo, leading to identical twins (or triplets if it divides into three).
In IVF, the chance of this outcome is approximately one out of 100 transfers. Although the root cause for this is still unknown, we do know that during an IVF transfer, the blastocyst, or developing embryo, can collapse in on itself. When this happens, sometimes it can cause the inner cell mass to split into two.
You are 3- 6% more likely to have a baby boy than a girl when using IVF to conceive. IVF increases the odds of a boy from 51 in 100 when conceived naturally to 56 in 100 with IVF.