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.
However, as many other studies have shown, the chance of success began to decline after 20 eggs were retrieved. A new study from the USA has also found that the chances of pregnancy and live birth do increase significantly with every extra fertilised egg available.
The likelihood of childbirth after in vitro fertilization (IVF) treatment increases if 18 to 20 eggs are stimulated to mature in a woman's ovaries, new research shows. That is more eggs than the number aimed at in today's IVF treatments.
An average of ten to 20 eggs are usually retrieved for IVF, but the number can be higher or lower.
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).
Blastocyst stage (days 4–8) division results in monochorionic-diamniotic twins. Division at the 8–12-day stage results in monochorionic-monoamniotic twins, and division after day 12 leads to conjoined twins [1, 2].
The biggest reason those little embryos take a breather and stop growing comes back to both the quality of the eggs and the sperm. You need good fuel packs (the mitochondria) in the sperm and eggs to provide the energy needed for the intense DNA division needed to move from 2 cells to 100s of cells or a Day 5 embryo.
Optimal Number of Eggs
Researchers analyzed thousands of IVF cycles between 1991 and 2008 and created a model based on age, the number of eggs retrieved, and success rates. They found that 15 was the magic number.
There is one egg per follicle; In a normal menstrual cycle one follicle will grow that contains one egg. So you may see the term 'follicles' used synonymously with eggs.
Research has shown that a woman's fertility levels return to normal one to two months after donation. However, in the one to two months immediately following donation, fertility levels are actually heightened.
Anywhere from 60-80% of all fertilized eggs make it to Day 3, which is when they are about 8-10 cells in size.
An ideal IVF follicle size for egg retrieval is typically around 15 to 22 millimeters in size, which falls right in line with the ideal size for an IVF trigger shot. Your fertility team will closely monitor the size of your follicles, and time everything out accordingly.
A number of studies (1, 2) published recently suggest that cumulative live IVF birth rates increase significantly with the number of eggs retrieved. This association is not evident in the initial fresh cycle of treatment, where birth rates might be even inferior when a high number of oocytes is obtained (1, 3).
IVF success rates depend on many factors, such as age and the reasons for infertility. Overall, first-time IVF success rates often fall between 25-30% for most intended parents. However, this probability tends to increase after multiple IVF cycles.
Irregular period cycle and difficulty conceiving
If you are facing issues conceiving and have not been able to conceive for a while now, it could be one of the signs of bad egg quality.
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. Women 38-40 and 41-42 years old have low live birth rates with low egg numbers. Success rates are much better when relatively high egg numbers are obtained.
Levels of CoQ10 decrease as you age. Taking CoQ10 supplements can increase blood and tissue CoQ10 levels. CoQ10 supplementation has been shown to improve egg quality, sperm quality, and pregnancy rates.
The average woman gets about 12 eggs at an egg retrieval. Of these, about 10 eggs are expected to be mature. Only mature eggs can go on to embryo formation after being fertilized with sperm, and only 80% of mature eggs fertilize. So now about eight of the 10 mature eggs become embryos.
However, as to the question of how many eggs are in a follicle, the answer is: just one. This is the scientific process behind ovulation, which generally occurs monthly for most women between puberty and menopause.
This, and the fact that the eggs which remain also decline in quality, explains why fertility reduces as we get older. Here is the range of what you could expect by age of a normal antral follicle count (AFC): Age 25 to 34, AFC from 10 to 13. Age 35 to 40, AFC from 10 to 8.
If the reason behind your repeated IVF failures is the age or quality of your eggs, a donor egg program is the best option to go for. There are many young women aged 21 to 34 who have healthier eggs and are intending to donate their eggs anonymously.
There is tremendous attrition from egg numbers to blastocysts for transfer or freezing. Typically, it goes something like this: 10 eggs, 8 mature eggs, 6 fertilized embryos, 4 eight cell embryos, 2 to 3 blastocysts.
The major reason why an IVF cycle is not successful is embryo quality. Many embryos are not able to implant after transfer to the uterus because they are flawed in some way. Even embryos that look good in the lab may have defects that cause them to die instead of growing.