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.
Of those fertilised eggs, around 15% will be lost before implantation begins. Of those which begin to implant, only about half will implant successfully. Of the half which do implant successfully (as shown by detectable HCG in the woman's urine), between one third and one half will be lost at the time of the menses.
How common is failed implantation? Failed embryo implantation is complex and more common than you may think. In a natural pregnancy, it's believed that somewhere between 40 to 60% of embryos are lost during the period between fertilization and birth [3].
An estimated 70% to 75% of human conceptions fail to survive to birth. That number includes both embryos that are reabsorbed into the parent's body before anyone knows an egg has been fertilized and miscarriages that happen later in the pregnancy.
As a general rule of thumb, at RMA New Jersey, which has one of the best embryology labs in the country (as evidenced by the clinic's high success rates), about 80 percent of eggs will fertilize (day 1 success), and of those, about 30-50 percent will make it to the blastocyst stage (day 5 or 6).
Of the mature eggs that are successfully fertilized, about 80% of them will make it to the day 3 embryo stage.
Women under 35 have the highest success rates in all of the “egg number” groups. Women under 38 in our IVF program have acceptable live birth rates even with only 3 – 6 eggs, do better with more than 6 eggs, and do best with more than 10 eggs.
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.
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.
Not every egg leads to a baby, no matter how young you are.
Because a certain percentage of our eggs are abnormal at any age, and because fertilization has to happen within a narrow window after ovulation occurs, even a young, healthy woman trying to get pregnant has only about a 25% chance each month.
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.
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.
The lining of the uterus is receptive to the embryo for only a brief time, called the Window of Implantation. It is possible that a perfectly normal embryo might not implant because the lining was not ready for it. In natural cycles, the window may be 4-5d wide, but in our treatments in can be only 12-48h long.
Once the embryo reaches the blastocyst stage, approximately five to six days after fertilization, it hatches out of its zona pellucida and begins the process of implantation in the uterus. In nature, 50 percent of all fertilized eggs are lost before a woman's missed menses.
In spontaneous conception it is estimated that 30% of pregnancies are lost before implantation and 10% are clinical pregnancy losses [15]. It is also important to note that spontaneous pregnancy is only achieved in around 30% of normal fertile couples on the first try, and many succeed on subsequent efforts [16].
Contraceptive implant: more than 99% effective with perfect use. They work for 3 years, but can be taken out earlier. Fewer than 1 in 100 women using the implant will get pregnant in a year.
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.
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.
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.
Around half of all fertilized eggs die and are lost (aborted) spontaneously, usually before the woman knows she is pregnant. Among women who know they are pregnant, about 10% to 25% will have a miscarriage.
A blighted ovum, also known as an anembryonic pregnancy, occurs when a fertilized egg implants and a gestational (embryonic) sac forms and grows, but the embryo fails to develop. A blighted ovum is the single leading cause of miscarriage.
In humans, a fertilized egg is no guarantee of reproductive success. Most embryos stop developing and perish within days of fertilization, usually because they have an abnormal number of chromosomes.
In general, an average of 8 to 14 eggs are typically retrieved from a woman's ovaries with IVF; however, its ultimately not the number of eggs that matter but the quality. 1 high quality egg is better than 20 poor quality eggs when it comes to success rates.
A single embryo transfer during IVF is the standard of care for the majority of people trying to conceive. The CDC, American Society for Reproductive Medicine, and the Society for Assisted Reproductive Technology all recommend one embryo transfers for most IVF patients. Why is that?
SET-IVF allows for the transfer of only one embryo at a time. This drastically decreases the chance of twins (or more) from being conceived, as well as complications that may arise from higher-risk pregnancies and births.