Why would a woman consider freezing her eggs?

Egg freezing offers multiple benefits for women in a variety of situations. La preservation of fertility It is the primary benefit, especially relevant considering that the quality and quantity of eggs progressively decreases with age. This biological reality contrasts with the growing number of women who postpone motherhood for educational, professional or personal reasons.

Statistics show that the average age for the first pregnancy has increased significantly in recent decades. In Mexico, according to data from the National Institute of Statistics and Geography (INEGI), the average age of the first pregnancy has increased from 22 years in the 80s to almost 29 years today. Freezing eggs allows women to preserve younger, healthier gametes for use when they are ready for motherhood.

Another fundamental benefit is the reproductive autonomy. Egg freezing gives women greater control over their family planning, reducing biological pressure and allowing them to make reproductive decisions that are more aligned with their life plans. This technology makes it easy to preservation of fertility faced with circumstances such as not having found the right partner or wanting to settle down professionally before starting a family.

For patients who face medical treatments that may affect their fertility, such as chemotherapy, radiation therapy or ovarian surgery, egg freezing represents a valuable option for medical preservation of fertility. The American Society for Clinical Oncology (ASCO) recommends discussing fertility preservation options with all patients of reproductive age before starting cancer treatments (Trusted Source).

What are the success rates of freezing eggs?

Egg freezing success rates have improved markedly over the past decade thanks to advances in vitrification techniques. According to recent studies, egg survival rates after thawing exceed 90%, while fertilization rates range from 70-80%.

The most determining factor in the success of the procedure is Age of women at the time of freezing. Data shows that women under 35 years of age have better prognoses, with live birth rates due to embryo transfer that can reach 40-50%. This percentage decreases gradually with age, being approximately 30-35% between 35-37 years old, 20-25% between 38-40 years old, and less than 15% in people over 40 years old.

El number of frozen eggs it also significantly influences the chances of success. Studies indicate that to maximize the chances of a live birth, it is recommended to freeze approximately 8-10 eggs in women under 35, 10-12 eggs between 35-37 years old, 12-15 eggs between 38-40 years old, and more than 15 eggs in women over 40 years old. These numbers are indicative and may vary depending on the individual characteristics of each patient.

La laboratory quality and the experience of the embryological team are equally crucial factors. Specialized centers with established cryopreservation programs usually report better results. It is essential to understand that freezing eggs does not guarantee a future pregnancy, but it increases the chances considerably compared to trying to conceive naturally at an older age.

What are the limitations of freezing eggs?

Despite its benefits, egg freezing has certain limitations that must be considered. El economic cost It is one of the main barriers, with prices that in Mexico range from 40,000 to 70,000 pesos per cycle, not including annual storage, which can cost between 5,000 and 15,000 pesos in addition. Most health insurance doesn't cover this procedure when it's done for non-medical reasons, limiting its accessibility.

Another important limitation is that the process doesn't offer absolute guarantees. Even under optimal conditions, not all eggs survive thawing, are successfully fertilized, or develop viable embryos. This reality can create false expectations in women who postpone motherhood by fully trusting this technology as “fertility insurance”.

Las ethical and legal considerations they also represent limitations. In some countries, there are restrictions on the maximum storage time or on who can access these procedures. In addition, dilemmas may arise about the disposal of eggs in the event of a woman's death if there are no clear advance directives.

The procedure involves medical risks associated with hormonal stimulation and egg extraction, such as ovarian hyperstimulation syndrome, bleeding or infection. Although rare, these complications should be considered in the risk-benefit assessment.

Finally, there is a informational limitation important. Many women are unaware that freezing eggs preserves oocyte quality but does not stop uterine aging or prevent obstetric complications associated with advanced maternal age such as preeclampsia, gestational diabetes or premature birth.

How does it compare to other fertility preservation options?

Egg freezing is one of several options available for fertility preservation, each with distinctive characteristics. Compared to the freezing of embryos, egg cryopreservation offers greater reproductive autonomy, since it does not require sperm at the time of preservation. This is particularly relevant for women without a partner or who prefer not to create embryos for ethical or religious reasons.

La freezing of ovarian tissue represents another alternative, especially for prepubertal patients or women who need to start cancer treatments urgently without time to complete an ovarian stimulation cycle. However, this technique is considered to be more experimental than egg freezing, with lower success rates and limited availability in highly specialized centers.

For men, the sperm freezing is a simpler and cheaper option than freezing eggs, requiring only a semen sample without the need for medication or invasive procedures. Post-thaw sperm survival rates exceed 50% in most cases.

Los gonadal protective drugs during chemotherapy they represent another strategy for cancer patients, although their effectiveness varies depending on the type of cancer and the chemotherapy regimen. These medications can be used in addition to egg freezing but not as substitutes.

For specific situations such as fertility treatment for transgender people, freezing eggs before starting cross-hormonal therapy or gender-affirming surgery preserves the possibility of having biological children in the future.

What are the psychological and emotional considerations?

The egg freezing process has important psychological and emotional implications that deserve specific attention. The decision to preserve fertility can generate a complex mix of Relief and anxiety. On the one hand, many women experience peace of mind by mitigating “biological clock” pressure; on the other, the procedure can intensify concerns about their reproductive future.

During treatment, hormonal fluctuations resulting from ovarian stimulation may cause mood changes, irritability, or emotional lability. These effects, together with the stress inherent in the medical process, can significantly impact patients' emotional well-being.

La Uncertainty about the results represents another stressor. Despite freezing eggs, there is no absolute guarantee of achieving a future pregnancy, which can lead to unrealistic expectations or persistent fears. Mental health professionals who specialize in reproductive medicine can provide valuable support during this stage.

For women who freeze eggs due to cancer diagnosis, the experience can be particularly intense, having to simultaneously process the diagnosis of cancer and decisions about their future fertility in an extremely short period of time. In these cases, specialized psychological support is essential.

The social and relational implications are also relevant. Some women face questions from their environment about their decision to delay motherhood, while others may experience difficulties communicating this process to potential future partners. Support groups among patients with similar experiences can provide valuable space for sharing concerns and coping strategies.

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Who are the best candidates for egg freezing?

Ideal candidates for egg freezing are mainly young women who anticipate a delay in their maternity project. Las women under 35 obtain the best results, since oocyte quality is optimal in this age range. Several studies show that the rate of live births per thawed egg is approximately three times higher when eggs are frozen before age 35 compared to those preserved after 40.

Patients diagnosed with Cancer those who will face gonadotoxic treatments such as chemotherapy or pelvic radiation therapy are priority candidates for the preservation of fertility. In these cases, there is the possibility of carrying out adapted ovarian stimulation protocols that allow the initiation of cancer treatment with minimal delay.

Women with a family history of early menopause or diagnosed with decreased ovarian reserve they can also benefit significantly from freezing eggs early. In these cases, preservation allows gametes to be safeguarded before an accelerated deterioration of ovarian function.

Women who plan to undergo ovarian surgeries for pathologies such as endometriomas or benign tumors they are equally good candidates, since these procedures can reduce ovarian reserve. Freezing prior to surgery optimizes future reproductive possibilities.

Finally, women who want to preserve their fertility for professional, educational or personal reasons that involve delaying motherhood are suitable candidates, especially if they are in the optimal age range. Personalized advice is essential to evaluate each particular case and determine the most convenient time to perform the procedure.

What are the medical requirements prior to the procedure?

Before starting an egg freezing cycle, a comprehensive medical evaluation is required to optimize results and minimize risks. This assessment begins with a detailed medical history including relevant medical, surgical, gynecological and family history.

The evaluation of the ovarian reserve is essential and is performed using specific hormonal tests such as anti-Müllerian hormone (AMH), FSH and estradiol on day 2-3 of the menstrual cycle. In addition, a transvaginal ultrasound is performed to count antral follicles, another reliable indicator of ovarian reserve.

Los laboratory tests preoperative measures include complete blood count, coagulation tests, blood group and Rh factor. Serology is also recommended for infectious diseases such as HIV, hepatitis B and C, and syphilis, following protocols similar to those used in egg donation.

La anesthetic assessment is mandatory to determine the patient's suitability for sedation during oocyte extraction. Factors such as body mass index, chronic diseases and drug allergies are evaluated.

In specific cases such as cancer patients, it may be required authorization of the treating oncologist to confirm that ovarian stimulation is not contraindicated depending on the type of tumor. For patients with endocrine pathologies such as polycystic ovary syndrome or thyroid disorders, it is recommended to optimize their control prior to the start of stimulation to improve results and reduce complications.

Finally, it is essential to psychological evaluation to confirm that the patient fully understands the implications of the procedure, has realistic expectations and has adequate emotional tools to face the process.

What medical conditions might make this procedure contraindicated?

There are a number of medical conditions that may represent absolute or relative contraindications for egg freezing. Between the Absolute contraindications Hormone-dependent tumors such as estrogen receptor-positive breast cancer are found without oncological authorization, since ovarian stimulation could potentially stimulate tumor growth.

Other absolute contraindications include conditions that prevent sedation or transvaginal access to the ovaries, such as severe anatomical malformations. Confirmed premature ovarian failure is also an absolute contraindication, since the response to stimulation would be practically zero.

Between the relative contraindications Morbid obesity (BMI>40) is found, which complicates both the anesthetic procedure and the ultrasound visualization of the ovaries during extraction. Untreated thrombophilia also represents an increased risk due to the elevation of estrogen during stimulation, which increases thrombotic risk.

Las autoimmune diseases uncontrolled, especially those with systemic involvement such as systemic lupus erythematosus, may represent a relative contraindication depending on the activity of the disease. A joint evaluation with rheumatology is recommended to determine the optimal time for the procedure.

La severe endometriosis with ovarian involvement, it may technically hinder oocyte extraction and reduce the response to stimulation. However, paradoxically, these patients could especially benefit from preserving fertility before the disease progresses or requires surgery.

Other situations such as male fertility problems In couples they do not contraindicated the freezing of eggs, but they could make it more advisable to freeze embryos by IVF with ICSI if the parental project is joint.

At what age is it most advisable to do this procedure?

The optimal age for egg freezing is between 25 and 35 years, a period in which a good ovarian reserve is combined with excellent oocyte quality. Scientific studies show that results are significantly better when eggs are frozen before age 35, with success rates that can double or triple those obtained with eggs preserved after 38 years.

Freezing too early, before the age of 25, is generally not recommended unless there are specific medical indications such as imminent cancer treatments or diseases that will prematurely affect fertility. This is due to potential future regret and the fact that many women will be able to conceive naturally without the need to resort to this technology.

On the other hand, although freezing after age 38 has more limited results, it may still be a valid option. However, patients should receive realistic advice about the reduced chances of success. In these cases, it is generally recommended to perform multiple stimulation cycles to accumulate a greater number of eggs that compensate for the lower success rate per individual egg.

Scientific evidence shows that to achieve a 75% chance of at least one live birth, approximately 8-10 mature eggs are needed in women under 35, while this number increases to 15-20 eggs in women aged 38-40. After age 42, even with 25-30 eggs preserved, the odds are no more than 50%.

Personalized counseling is essential that considers not only chronological age but also individual ovarian reserve, family history of early menopause, and socioeconomic factors such as cost of fertility treatments and the possibility of carrying out multiple cycles if necessary.

Can cancer patients safely freeze eggs?

Fertility preservation by freezing eggs is generally safe for cancer patients, although it requires a specialized and multidisciplinary approach. For many patients diagnosed with cancer of reproductive age, the preservation of fertility is an essential priority along with the treatment of their disease.

Los adapted protocols for cancer patients, they include accelerated ovarian stimulation schemes known as “random start”, which allow stimulation to start at any time of the menstrual cycle, reducing waiting times to only 2-3 weeks. This adaptation minimizes delays in the initiation of cancer treatment, a critical factor in many types of cancer.

For hormone-sensitive tumors such as some breast cancers, protocols are implemented with aromatase inhibitors (such as letrozole) that allow ovarian stimulation while maintaining lower estradiol levels. Several studies have demonstrated no negative impact on cancer survival or recurrence with these modified protocols (Trusted Source).

Coordination between the oncology and assisted reproduction team is essential. It is recommended to do a ovarian reserve test before starting cancer treatments to establish a baseline reproductive prognosis. In cases of hematological cancers such as leukemia, where there may be a theoretical risk of contamination of eggs with malignant cells, some centers implement special washing and analysis protocols.

It is important to stress that cancer prognosis remains the absolute priority, and fertility preservation should only be considered when it does not compromise the treatment of the underlying disease. For pediatric or prepubertal patients, there are other alternatives such as cryopreservation of ovarian tissue, although this technique is considered more experimental.

Is this procedure suitable for women with low ovarian reserve?

Egg freezing in women with low ovarian reserve presents specific challenges but may be a valid option in certain cases. Patients with this condition, characterized by reduced levels of anti-Müllerian hormone (AMH<1.1 ng/ml) and low antral follicle count (<5-7 follicles), generally obtain fewer eggs per stimulation cycle.

For these patients, it is essential to establish realistic expectations. The response to stimulation will be limited even with high doses of gonadotropins, and multiple cycles may be required to accumulate an adequate number of eggs that offer a reasonable chance of future success. Some centers recommend accumulating at least 8-12 eggs for women under 35 with a low reserve, and proportionately more for older ages.

Los stimulation protocols regimens with GnRH antagonists and high doses of gonadotropins are usually included for these patients, often supplemented with adjuvants such as growth hormone or androgens to optimize the follicular response. Evidence on the efficacy of these adjuvants is limited but promising in selected cases.

El double stimulus The DuoStim protocol is an emerging strategy for these patients, consisting of performing two consecutive stimulations in the same menstrual cycle (follicular and luteal phase). This approach doubles the number of eggs obtained in a shorter period, which is particularly beneficial when time is limited or the reserve is significantly compromised.

Egg freezing in cases of low ovarian reserve should be considered an early preventive measure rather than a late solution. Medical advice will generally recommend proceeding as soon as possible, as oocyte quality and quantity will continue to decline over time. For some patients with extremely low reserve, the egg donation may represent a more realistic alternative that should be discussed as part of comprehensive counseling.

An individualized approach that considers the age, the degree of commitment of the reserve, the patient's expectations and their financial resources for possible multiple cycles is crucial. Specialized psychological support is especially important in these cases, where the chances of success may be more limited.

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How much does it cost to freeze eggs in Mexico?

The cost of egg freezing in Mexico varies considerably depending on the clinic, the city and the services included. The base price of the procedure ranges from 50,000 to 90,000 Mexican pesos per stimulation cycle, including medications, follicular monitoring, egg extraction and vitrification.

Los medicines for ovarian stimulation they represent a significant part of the total cost, approximately 30-40% of the budget. The required dose depends on individual factors such as age, body mass index and ovarian reserve, and can vary between 25,000 and 40,000 pesos. In some cases, these medications can be purchased at a discount through special patient support programs.

To the initial cost must be added the annual storage of eggs, which varies between 5,000 and 15,000 pesos per year. Clinics often offer multi-year storage plans with prepayment discounts. It is important to consider this recurring expense in the financial planning of the procedure.

When the patient decides to use the stored eggs, she must consider additional costs such as defrosting, fertilization using ICSI And embryo transfer, which together can add up to between 40,000 and 70,000 additional pesos. Some clinics offer comprehensive packages with significant discounts that include the entire process from stimulation to future transfer.

Compared to countries such as the United States, where the same procedure can cost between 10,000 and 20,000 dollars (approximately 200,000-400,000 Mexican pesos), Mexico offers a more accessible alternative while maintaining international quality standards. However, it's still an expensive treatment not covered by most health insurance when it's done for non-medical reasons.

What does the price of a full cycle include?

A complete egg freezing cycle includes several components that are important to know in order to properly understand the total budget. Most clinics structure their packages including the following essential elements:

La initial evaluation includes specialized medical consultations, basic hormonal tests and ultrasound to determine the ovarian reserve. This diagnostic phase can cost between 5,000 and 8,000 pesos, although some clinics include it at no additional cost as part of their business strategy or discount it from the total price if the patient proceeds with the treatment.

El stimulation protocol includes the personalized design of the medication scheme and follicular monitoring ultrasound (usually 4-5 during the cycle). This medical follow-up represents approximately 10,000-15,000 pesos of the total budget.

La egg extraction under sedation, performed in the operating room with the presence of an anesthesiologist, involves an approximate cost of 15,000-25,000 pesos, including the use of specialized facilities and equipment. Vitrification and storage for the first year usually add another 10,000-15,000 pesos.

It is important to check if the package includes all the Medications necessary or only a limited quantity, as this can lead to significant additional costs. Some clinics offer “all-inclusive” packages while others budget medications separately based on each patient's individual needs.

Many clinics perform female fertility tests complementary ones such as karyotyping, serologies or complete hormonal profiles that may or may not be included in the base price. It is advisable to request a detailed breakdown of all the concepts included and to verify possible additional expenses not initially contemplated.

Are there financing or insurance options that cover this procedure?

Funding options for egg freezing in Mexico have increased in recent years, although they are still limited compared to other medical procedures. Some fertility clinics offer payment plans own that allow the total cost to be distributed in monthly installments, generally without interest or with reduced interest for periods of 6 to 12 months.

A number of financial institutions have developed specific loans for fertility treatments, with more favorable conditions than conventional personal loans. These options usually offer extended terms of up to 36 or 48 months, although they involve the payment of interest that increases the final cost of the procedure.

With regard to insurance coverage, the situation is more restrictive. Most of the policies of private health insurance Mexico does not cover egg freezing when it is done for social or family planning reasons. However, when there is a clear medical indication such as preservation prior to cancer treatments, some insurers may partially cover the procedure, generally requiring special authorizations and detailed medical documentation.

Some multinational companies have started to include the fertility preservation as part of its employee benefits packages, following trends initiated in the United States and Europe. These coverages can be full or partial and are generally limited to a single stimulation cycle.

There are also support programs specific to cancer patients through foundations and non-profit organizations that can provide financial assistance or significant discounts. These programs evaluate each case individually based on medical and socioeconomic criteria.

It is advisable to explore multiple financial options and negotiate directly with clinics, as many offer unadvertised discounts or personalized plans to make treatment more accessible.

What factors can change the final cost of the procedure?

Multiple factors can significantly modify the final budget of an egg freezing process. La age and ovarian reserve of the patient have a direct impact on the amount of medication required; older women or women with diminished ovarian reserve generally need higher doses of gonadotropins, which can increase the pharmacological cost by up to 50%.

La experience and prestige of the clinic and its specialists represents another determining factor. Schools with higher published success rates or international certifications tend to charge higher rates, although this extra cost can be justified by better final results and more advanced technology.

La geographical location it also has a significant influence. Clinics in Mexico City, Monterrey or Guadalajara generally have higher prices than those located in less populated cities, with differences that can reach 20-30% for equivalent services.

El protocol type selected also affects the budget. Personalized protocols with special adjuvants such as growth hormone or complementary immune treatments can increase costs by up to 15,000-25,000 additional pesos.

Los complementary services such as genetic testing of eggs (for example, PGT-A), which can cost between 30,000 and 50,000 pesos; long-term storage with advance payment; or guarantees of minimum results, represent options that substantially modify the final budget.

Finally, some clinics offer staggered packages where the second or third cycle, if necessary to accumulate more eggs, is offered with significant discounts that can reach up to 30-40% of the initial price. This modality is particularly relevant for patients with low ovarian reserve or over 37 years of age.

How much does it cost to keep eggs frozen in the long term?

Long-term storage of vitrified eggs involves recurring costs that must be carefully considered in the financial planning of the procedure. The annual rates of maintenance in liquid nitrogen tanks In Mexico they typically range between 5,000 and 15,000 pesos, depending on the clinic and the geographical region.

Most centers offer multi-year plans with significant early payment discounts. A 3-year plan can cost approximately 30,000-35,000 pesos (representing savings of 10-15% compared to the annual payment), while 5-year plans can range between 45,000-60,000 pesos (with discounts of up to 20-25%). Some clinics also have 10-year plans with even greater savings.

It's important to check what services are included in the storage fees. Basic maintenance includes preservation in specialized tanks with safety systems, monitoring of temperatures and nitrogen levels, and specialized personnel in charge. However, some centers include additional services such as insurance against contingencies which cover possible technical failures or natural disasters.

Storage costs may vary depending on the Stored volume. Some clinics set tiered rates depending on the number of eggs preserved, although this practice is less common than when storing embryos or semen.

A crucial aspect to consider are the price adjustment policies in the long term. It is advisable to review the contractual clauses regarding possible increases in maintenance fees, since some clinics establish annual increases linked to inflation or their own commercial policies.

Finally, it is essential to clarify the abandonment policies and what happens if the payment of maintenance fees is interrupted. Contracts must specify grace periods, notifications and procedures for the disposal of eggs in the event of non-payment or impossibility of contacting the patient.

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What are the risks of the ovarian stimulation procedure?

Controlled ovarian stimulation involves certain risks that, although rare, should be known before starting treatment. El ovarian hyperstimulation syndrome (OHS) represents the most significant complication, characterized by excessive ovarian growth and fluid leakage into the abdominal cavity. The incidence of severe OHS has fallen considerably in recent years and is currently below 1% thanks to safer protocols.

Risk factors for developing OHS include young age, low body weight, polycystic ovary syndrome, and excessive response in previous cycles. Symptoms can range from mild abdominal discomfort to serious cases with complications such as thromboembolism, kidney failure, or respiratory distress requiring hospitalization.

Other complications include risk of bleeding or infection after follicular puncture, with an approximate frequency of 0.2-0.5%. Most of these events are mild and self-limiting, although in rare cases they may require surgery or intravenous antibiotic therapy.

There is concern about the possible association between ovarian stimulation and cancer risk, particularly ovarian or breast. However, long-term studies with follow-up of up to 30 years have not demonstrated a significant increase in cancer risk in women undergoing these treatments. The European Society for Human Reproduction and Embryology (ESHRE) confirms that there is no scientific evidence to support this association (Trusted Source).

El risk of pregnancy During the stimulation cycle, it exists if you have unprotected sexual intercourse. This risk is relevant because stimulation induces the development of multiple follicles, which could result in multiple high-order pregnancies. For this reason, sexual abstinence or barrier methods of contraception are recommended during treatment.

Finally, some studies suggest a small increase in the risk of ovarian torsion during stimulation due to increased ovarian size, although this complication is extremely rare (< 0.1%). Symptoms include acute abdominal pain that requires urgent medical evaluation.

Does freezing eggs affect future natural fertility?

Freezing eggs does not adversely affect a woman's future natural fertility. This procedure preserves some of the available eggs, but it does not alter normal ovarian function or accelerate the decline of remaining ovarian reserve.

During a typical stimulation cycle, multiple follicles develop that would naturally have atresided (degenerated) in regular menstrual cycles. Anti-Müllerian hormone (AMH), the main marker of ovarian reserve, shows a transient decline during the first few weeks after treatment, but generally recovers to baseline values within 2-3 months. Longitudinal studies have shown that women undergoing multiple stimulation cycles do not show an accelerated decline in their ovarian reserve compared to control groups.

Fears about “premature depletion” of eggs have no scientific basis. Each woman is born with approximately 1-2 million primary follicles, of which only 400-500 will naturally ovulate throughout their reproductive life. The extraction of 10-15 eggs for cryopreservation represents a minimal fraction of the total and does not significantly modify the available reserve.

La ovarian endocrine function nor is it affected in the long term. Menstrual patterns usually normalize 1-2 cycles after the procedure. In rare cases, transient menstrual irregularities may occur, usually self-limited and without relevant clinical consequences.

It is important to note that freezing eggs does not protect against pathologies that may subsequently affect fertility, such as endometriosis, pelvic inflammatory disease or ovarian surgery. Nor does it prevent the natural decrease in uterine receptivity associated with aging, a relevant factor in women who plan to use their eggs at an older age.

Patients who have frozen eggs keep all reproductive options open, being able to attempt natural pregnancies or, if necessary, to use eggs preserved through embryo transfer prior fertilization.

Are there risks for children born from frozen eggs?

Scientific evidence accumulated over two decades shows no increase in risks for children born from vitrified eggs compared to those conceived through conventional or natural IVF. Several long-term follow-up studies have systematically evaluated different aspects of child development without finding significant differences.

The rate of congenital anomalies in children conceived with vitrified eggs, it remains at approximately 2-3%, similar to the general population. Larger studies, including national registries from Nordic countries monitoring more than 5,000 births after oocyte cryopreservation, have not identified specific patterns of malformations or statistically significant increases in their prevalence.

El neurocognitive development has been evaluated using standardized tests up to school age, showing results comparable to control groups. Parameters such as IQ, motor skills, language development and socialization remain within normal ranges.

The profiles of growth and physical development including birth weight, height and head circumference are comparable to those of the general population, adjusted for relevant maternal factors. Medium-term follow-up (up to adolescence) has not revealed any changes in pubertal development or anthropometric parameters.

Preliminary epigenetic studies have not detected significant alterations in DNA methylation patterns or gene expression in children conceived using this technology. However, this is an active research area where information continues to expand.

It is important to contextualize that egg vitrification is a relatively recent technique in its widespread clinical application (from approximately 2005-2008), so very long-term follow-up data (>30 years) are not yet available. However, the absence of alarm signals in the current monitoring is reassuring.

What guarantees do clinics offer about egg viability?

The guarantees offered by fertility clinics regarding the viability of frozen eggs vary considerably, and this is a fundamental aspect that must be evaluated before selecting a center. It's important to carefully analyze the specific terms of these guarantees to understand exactly what they cover and under what conditions.

Some clinics provide guarantees of survival post-thawing, committing that a minimum percentage of eggs (generally 70-80%) will survive the devitrification process. If this threshold is not reached, they can offer compensations such as additional stimulation cycles with reduced costs or partial reimbursement of fees.

Others establish fertilization guarantees, ensuring that a minimum number of thawed eggs will be successfully fertilized using ICSI. These agreements are usually more restrictive and apply only to patients who meet specific criteria such as age under 35-37 and normal seminal parameters in the partner or donor.

Las guarantees of embryonic development are less common, but they exist in some premium centers, ensuring that at least one good quality embryo is obtained, suitable for transfer or for pre-implantation genetic analysis. These guarantees generally require having frozen a minimum number of eggs (usually 10-12) under optimal conditions.

It's exceptional to find clinics that offer guarantees of pregnancy or live birth with frozen eggs, due to the multiple factors that influence these results beyond oocyte quality, such as endometrial receptivity or obstetric complications.

It is essential to review the exclusion clauses of these guarantees, which may include limitations due to older age, extreme body mass index, certain pathologies or suboptimal sperm quality. It should also be checked if there are temporary restrictions, as some guarantees only apply for a limited period of storage (usually 5-10 years).

Transparency in specific statistics of the vitrification program of the center is perhaps the most valuable indicator, including oocyte survival rates, fertilization and live births stratified by age group. These statistics allow for more objective evaluations than commercial guarantees.

What long-term complications could there be?

Egg freezing is considered a safe procedure with minimal long-term complications. However, there are some considerations that should be considered when evaluating potential late side effects.

Long-term follow-up epidemiological studies have not demonstrated a increased cancer risk associated with ovarian stimulation. Larger investigations, with follow-up for up to 25 years in thousands of women undergoing fertility treatments, have not found a higher incidence of hormone-dependent cancers such as breast or endometrial cancers. The American Society for Reproductive Medicine (ASRM) concludes that there is no evidence to justify concern about this aspect (Trusted Source).

Regarding the effects on menopause, freezing eggs has not been observed to alter the age of onset of natural menopause or its clinical characteristics. Comparative studies between women undergoing ovarian stimulation and control groups show no significant differences in long-term ovarian reserve or in hormonal markers associated with ovarian function.

It is important to consider the long-term psychological implications, which may include feelings of pressure to use stored eggs, especially when the preservation was carried out with significant economic investment. Some women report “false security” that can lead them to postpone reproductive decisions by relying excessively on preserved eggs.

Aspects Ethical-legal such as the disposal of eggs in the event of the owner's death or separation disputes when eggs were frozen in joint parenting projects can cause significant complications. It is advisable to establish clear advance directives on these situations.

For patients who use their eggs at an advanced age, it is necessary to consider that, although preserved eggs maintain the quality corresponding to the freezing age, the uterine and systemic aging it doesn't stop. This may be associated with a higher risk of obstetric complications such as preeclampsia, gestational diabetes or premature birth when pregnancy occurs after 40-45 years.

References

1. Practice Committee of the American Society for Reproductive Medicine. (2023). Mature oocyte cryopreservation: A guideline. Fertility and Sterility, 119 (1), 22-30. https://doi.org/10.1016/j.fertnstert.2022.09.021 Trusted Source.
2. World Health Organization. (2022). WHO laboratory manual for the examination and processing of human semen. WHO Press, 6th edition, 145-160. https://www.who.int/publications/i/item/9789240030787 Trusted Source.
3. Lambertini, M., Del Mastro, L., Pescio, M.C., Andersen, C.Y., Azim, H.A., & Peccatori, F.A. (2023). Cancer and fertility preservation: International recommendations from an expert meeting. Journal of Clinical Oncology, 41 (5), 705-718. https://doi.org/10.1200/JCO.22.01549 Trusted Source.

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