With the advancement of technology, egg freezing has become very sophisticated and is now a standard part of the IVF procedure.
Related FAQs are listed below.
What is the expected live birth rate for women undergoing egg freezing?
The rate of sustained pregnancy per transfer was the same for autologous cryopreserved and fresh eggs (38.6% and 36%, respectively, P>.05).
If you freeze your eggs at age 30 and then thaw them at age 40, the pregnancy rate will be about the same as if you had implanted at age 30.
How does age at the time of egg freezing affect the results?
Oocyte efficiency decreases with age (pregnancy rate per egg thawed is inversely proportional to age)
Pregnancy rate per thawed egg is 7.4% for women <30 years old.
The pregnancy rate per thawed egg for women aged 30-34 years is 7.0%.
The pregnancy rate per thawed egg for women aged 35-37 years is 6.5%.
The pregnancy rate per thawed egg for women aged 38-40 years is 5.21 TP3T.
For women aged 41-42, the rate was 2.4 %.
|
Age (y) |
Cycles |
Oocytes |
Children (fresh ET) |
Vitrified blastocysts |
Children (cryo ET)a |
Total children |
Children per oocyte (%) |
|---|---|---|---|---|---|---|---|
|
<30 |
2,085 |
34,017 |
1,339 |
4,484 |
1,611 |
2,950 |
8.67 |
|
30-34 |
5,715 |
83,597 |
3,257 |
10,409 |
3,601 |
6,858 |
8.20 |
|
35-37 |
4,189 |
53,794 |
2,097 |
5,404 |
1,844 |
3,941 |
7.33 |
|
38-40 |
4,148 |
46,582 |
1,573 |
2,928 |
509 |
2,082 |
4.47 |
|
41-42 |
1,831 |
18,584 |
379 |
544 |
85 |
464 |
2.49 |
|
43-44 |
778 |
7,318 |
67 |
81 |
11 |
78 |
1.06 |
Fertil Steril .2016 Feb;105(2):459-66.
Does the freezing and thawing process affect the quality of the eggs and the development of the embryos resulting from subsequent fertilization?
In terms of fertilization rate: Fresh eggs have higher fertilization rate than frozen eggs (85% vs 80%)
Ratio of high quality embryos on day 3: Fresh eggs formed more than frozen eggs (38% vs 30%)
Blastocyst rate: Fresh egg formation rate is higher than frozen egg (41% vs 36%)
Fresh embryo implantation vs. frozen embryo implantation vs. embryo implantation from thawed eggs, which is preferred?
The best pregnancy rates are for thawed implantation using frozen embryos, the next best are for embryo implantation from thawed eggs, and the worst are for fresh embryo implantation.
The main reason for this is the use of large amounts of ovulation-inducing drugs during the fresh implantation cycle, which causes early maturation of the endometrium (luteinization) and changes in the genetic expression of the endometrium, which in turn affects embryo implantation.
The endometrium is also less affected during the thawed implantation cycle as no significant doses of medication are used during the first part of the cycle. The embryos obtained from thawed eggs have a better pregnancy and implantation rate after implantation, even though they are of poorer quality compared to fresh embryos.
(Fertil Steril 2016;106:615-22. 2016)
Are there differences in neonatal complications?
There were no significant differences in pregnancy and newborn health outcomes between fresh and frozen eggs.
How many eggs should be frozen to achieve a reasonable chance of live birth?
Egg cell efficiency decreases with age and there is insufficient evidence to achieve a reasonable chance of live birth.
Some studies have estimated that 14 mature oocytes would need to be cryopreserved in women aged 30-34 years, 15 mature oocytes in women aged 35-37 years, and 26 mature oocytes in women aged 38-40 years to achieve a chance of live birth at 70%.
Some studies have estimated that women 35 years of age have a live birth rate of 1.31 TP3T. They have calculated that women under 35 years of age need 38.8 oocytes to achieve a live birth and women over 35 years of age need 77 oocytes.
Frozen Autologous Eggs vs Donated Eggs
Donor eggs are usually younger and naturally have a higher pregnancy rate than frozen eggs. There should be no difference in the pregnancy rate if the ovaries are of similar age and function.
However, refrigeration technology is changing rapidly, and the refrigeration technology of 10 years ago should be slightly lower than the current refrigeration technology, and the pregnancy rate should be lower as well.
Conclusion.
As women age and marry later, egg freezing is becoming an increasingly important treatment that women must consider. It is recommended that this treatment be carried out as soon as possible, and if a married woman chooses to get pregnant at a later age, she may prefer to freeze her eggs after egg retrieval and fertilization, or if she is unmarried, or if the man is unable to provide her with sperm at the time of retrieval, she may choose to freeze her eggs. It is recommended to have at least 2 egg retrievals and accumulate more than 25-30 eggs.