Choosing an egg donor in the USA can open a hopeful path to parenthood for individuals and couples who cannot use their own eggs or who face medical, genetic, age-related, or fertility challenges. The process combines advanced reproductive medicine, detailed donor screening, legal protections, and personalized IVF planning. For many intended parents, the most important questions are practical ones: how to find a screened donor, what egg donor IVF costs in the United States, how success rates are measured, and which options may best match their timeline, budget, and family-building goals.

Understanding Egg Donation in the United States

Egg donation is a form of assisted reproduction in which eggs from a donor are fertilized with sperm in an IVF laboratory. The resulting embryos may be transferred to the uterus of an intended mother or gestational carrier, or frozen for later use. In the USA, egg donation is widely practiced and supported by a network of fertility clinics, egg donor agencies, cryobanks, reproductive attorneys, genetic counselors, mental health professionals, and IVF laboratories.

Intended parents may consider donor eggs for many reasons. Some people have diminished ovarian reserve, premature ovarian insufficiency, poor egg quality, repeated IVF failure, or age-related infertility. Others carry genetic conditions they do not wish to pass on. Same-sex male couples and single men generally need both an egg donor and a gestational carrier. Cancer survivors or individuals with surgically removed ovaries may also pursue donor egg IVF. The common thread is that donor eggs can provide access to healthy oocytes and often improve the probability of embryo development compared with using eggs affected by low quantity or reduced quality.

The USA is considered one of the most established destinations for donor egg IVF because donor availability is broad, anonymity or identity-release options may be available depending on the program, compensation is regulated by program policies, and screening standards are highly structured. However, the process can feel overwhelming at first. Learning the difference between fresh and frozen donor eggs, agency and clinic donor pools, anonymous and known donors, and single-cycle versus shared-donor arrangements can help intended parents make confident decisions.

Who May Need an Egg Donor?

Donor eggs are not a “last resort” in a negative sense; rather, they are an evidence-based option when the chance of success with one’s own eggs is low or when donor eggs better support the family’s medical and personal goals. A reproductive endocrinologist may recommend discussing egg donation after reviewing ovarian reserve testing, age, previous IVF outcomes, miscarriage history, embryo quality, and genetic risk.

  • Advanced reproductive age: Egg quality declines significantly with age, especially after the late 30s and early 40s.
  • Diminished ovarian reserve: Low AMH, high FSH, or low antral follicle count may suggest fewer eggs are likely to be retrieved.
  • Premature ovarian insufficiency: Some individuals stop ovulating or have very low ovarian function earlier than expected.
  • Repeated IVF failure: Multiple cycles with poor egg maturity, poor fertilization, poor embryo development, or no euploid embryos may lead to donor egg consideration.
  • Genetic disease risk: Donor eggs may help avoid transmission of certain inherited conditions.
  • Ovarian surgery or medical treatment: Chemotherapy, radiation, endometriosis surgery, or oophorectomy may affect egg supply.
  • LGBTQ+ family building: Same-sex male couples and single men may use donor eggs with a gestational carrier.

Every case is individual. Some intended parents move to donor eggs quickly to save time and emotional energy, while others attempt additional IVF cycles with their own eggs first. The right decision depends on medical prognosis, finances, emotional readiness, partner preferences, cultural values, and the guidance of qualified fertility specialists.

Types of Egg Donors in the USA

In the United States, intended parents can choose among several donor arrangements. Each option has advantages, limitations, cost implications, and timeline differences. Understanding these categories early can prevent confusion when comparing clinics and agencies.

Donor Type How It Works Best For Key Considerations
Fresh egg donor The donor undergoes ovarian stimulation and egg retrieval specifically for the intended parents. Parents wanting more eggs, more embryos, or potential siblings from one donor cycle. Higher cost, longer coordination, risk of donor cycle cancellation or variable egg yield.
Frozen donor eggs Previously retrieved and vitrified eggs are purchased from a clinic or egg bank. Parents who want a faster, more predictable timeline and lower upfront coordination burden. Usually fewer eggs per lot; sibling planning may require purchasing additional eggs.
Known donor A friend, relative, or personally identified person donates eggs. Families who value a pre-existing relationship or genetic connection. Requires careful counseling, legal agreements, and boundaries for future roles.
Anonymous or de-identified donor The donor’s identifying information is not shared, though profiles usually include extensive non-identifying details. Parents seeking privacy and a defined donation arrangement. Future genetic testing and changing norms around donor conception may affect anonymity.
Identity-release donor The donor agrees that identifying information may be available to the donor-conceived child at adulthood or under agreed terms. Parents who want future openness while maintaining privacy during childhood. Policies differ widely; details should be documented clearly.

How to Find Screened Egg Donors in the USA

The search for an egg donor often begins with a fertility clinic, donor agency, or frozen egg bank. Some clinics maintain in-house donor programs, while independent agencies recruit and coordinate donors across multiple clinics. Egg banks provide frozen donor eggs that have already been retrieved, screened, and stored. Each route can be appropriate, but intended parents should verify the quality of screening, transparency of costs, legal structure, refund policies, and laboratory outcomes.

A typical donor profile may include age, height, weight, ethnicity, education, occupation, interests, personality notes, family medical history, reproductive history, photos, blood type, genetic carrier screening results, and sometimes audio or video interviews. Some intended parents focus heavily on physical resemblance; others prioritize medical history, education, personality, ancestry, or proven fertility. There is no universally “correct” way to choose, but it helps to separate essential criteria from preferences.

Reputable programs do not rely only on appearance-based matching. They assess whether a donor is medically suitable, psychologically prepared, genetically screened, and able to comply with medication and retrieval requirements. Many programs prefer donors between about 21 and 34 years old, although exact limits vary. Younger donors generally have stronger ovarian response and better egg quality, but screening and history matter more than age alone.

When comparing donor sources, ask how donors are recruited, whether medical records are verified, what genetic carrier panel is used, whether psychological evaluation is performed, whether the donor has completed previous cycles, and whether outcome information is available. If choosing frozen eggs, ask about survival rate after thaw, fertilization rate, blastocyst development, guarantee programs, and what happens if no viable embryos result. If choosing a fresh donor, ask about estimated egg yield, medication costs, travel expenses, cycle cancellation policies, and whether you will receive all retrieved mature eggs or share the cohort with another recipient.

What Does Egg Donor Screening Include?

Egg donor screening in the USA is designed to protect recipients, donors, and future children. Screening standards may draw from FDA requirements, professional guidance from organizations such as the American Society for Reproductive Medicine, state laws, and clinic-specific protocols. While details vary, a thorough screening process usually includes medical, reproductive, infectious disease, genetic, and psychological components.

Screening Area Common Elements Why It Matters
Medical history Personal health, surgeries, medications, menstrual history, BMI, lifestyle factors, family disease history. Identifies medical risks and inherited patterns that may affect suitability.
Reproductive testing AMH, antral follicle count, hormone testing, ultrasound, prior retrieval outcomes if applicable. Helps estimate ovarian response and egg yield.
Infectious disease testing FDA-required testing may include HIV, hepatitis B and C, syphilis, gonorrhea, chlamydia, and other tests depending on timing and tissue rules. Reduces risk of transmitting infectious disease through reproductive tissue.
Genetic carrier screening Carrier panels for recessive and X-linked conditions; matching with sperm provider results when appropriate. Helps reduce risk of serious inherited disorders when both genetic contributors carry variants in the same gene.
Psychological evaluation Clinical interview, mental health history, motivation to donate, understanding of donation implications. Ensures the donor is emotionally prepared and able to provide informed consent.
Legal consent Contracts addressing parental rights, compensation, confidentiality, future contact, and embryo disposition where relevant. Clarifies that intended parents, not the donor, will have parental rights and responsibilities.

Genetic screening deserves special attention. A donor can be healthy and still carry a recessive gene variant; in fact, carrier status is common in the general population. The goal is not to find a donor with zero carrier findings, which may be unrealistic, but to identify whether the donor and sperm provider carry variants that create a significant reproductive risk together. A genetic counselor can interpret results and explain whether a particular donor is compatible with the sperm source.

Fresh Donor Eggs vs. Frozen Donor Eggs

One of the most important choices is whether to use fresh or frozen donor eggs. Fresh donor egg IVF involves synchronizing the donor’s stimulation cycle with the recipient’s uterine preparation or freezing embryos after fertilization. Frozen donor eggs are already available, so the process can move faster. Advances in vitrification have made frozen donor eggs a strong option, but they are not identical to fresh cycles in logistics or planning.

Fresh donor egg cycles may provide a larger number of eggs, especially if the donor responds well. This can be helpful for parents who want more than one child and hope to create multiple embryos from the same donor. However, fresh cycles require donor availability, medication monitoring, retrieval scheduling, and sometimes travel. There is also uncertainty: a donor may produce fewer eggs than expected, the cycle may be delayed, or a medical issue may require cancellation.

Frozen egg lots are usually sold in smaller cohorts, often around six to eight mature eggs, though this varies. They allow faster matching and reduce the risk that a donor will withdraw before retrieval. Many egg banks offer some form of guarantee, such as a minimum number of eggs surviving thaw or a replacement lot under specific conditions. Still, intended parents should read guarantees carefully. A guarantee of egg survival is not the same as a guarantee of blastocysts, euploid embryos, pregnancy, or live birth.

The best choice depends on your priorities. If speed and simplicity are most important, frozen eggs may be appealing. If maximizing embryo number for future siblings is a priority, a fresh donor cycle may be worth the added cost and coordination. Some programs also offer shared fresh cycles, where eggs from one donor are divided among recipients, reducing costs but also reducing the number of eggs available to each family.

Step-by-Step Egg Donor IVF Process

While each clinic has its own protocol, the donor egg IVF journey usually follows a predictable sequence. Knowing the steps can make the process feel more manageable and can help intended parents prepare emotionally and financially.

  1. Initial fertility consultation: The reproductive endocrinologist reviews medical history, previous fertility treatment, uterine evaluation, sperm testing, and family-building goals.
  2. Decision-making and counseling: Intended parents discuss donor conception, disclosure to future children, emotional readiness, and expectations. Many clinics require a counseling session.
  3. Donor search and match: Parents review donor profiles through a clinic, agency, or egg bank and select a donor or egg lot.
  4. Legal agreements: For fresh or known donation, attorneys generally draft and finalize contracts before medications begin. Frozen egg purchases also include consent documents and purchase agreements.
  5. Medical preparation: The donor undergoes stimulation if fresh eggs are used. The recipient prepares the uterine lining with estrogen and progesterone if planning a transfer.
  6. Egg retrieval or egg thaw: Fresh eggs are retrieved under sedation; frozen eggs are warmed in the IVF lab.
  7. Fertilization: Eggs are inseminated with sperm, commonly using ICSI, especially with frozen eggs or when sperm factors are present.
  8. Embryo culture: Fertilized eggs are monitored as they develop, often to the blastocyst stage around day five, six, or seven.
  9. Optional embryo testing: Preimplantation genetic testing for aneuploidy, known as PGT-A, may be considered to assess chromosome number, though it is not mandatory for every case.
  10. Embryo transfer: A selected embryo is placed into the uterus. Many clinics recommend single embryo transfer to reduce twin and high-risk multiple pregnancy.
  11. Pregnancy test and follow-up: Blood hCG testing occurs about nine to fourteen days after transfer, followed by ultrasound if positive.

Some intended parents complete these steps in a few months, especially with frozen eggs. Fresh donor arrangements may take longer, often several months, because of donor availability, screening, legal work, cycle scheduling, and possible travel. If a gestational carrier is involved, the timeline can be longer because carrier screening, legal contracts, insurance review, and agency matching may add additional months.

Egg Donor IVF Costs in the USA

Costs vary dramatically by location, clinic, donor type, agency fees, medication needs, laboratory services, embryo testing, and whether a gestational carrier is involved. In the United States, donor egg IVF is often a significant investment. A frozen donor egg cycle may be less expensive than a fresh agency donor cycle, but the total cost depends on how many egg lots are needed and whether the first transfer succeeds.

The following ranges are general educational estimates and not a quote. Intended parents should request a written fee schedule that separates clinic fees, donor compensation, agency fees, medications, laboratory services, genetic testing, legal costs, storage, and transfer costs. Insurance coverage for IVF and donor eggs varies by state and policy; some plans cover diagnostic testing but not donor tissue, while others may cover portions of treatment.

Cost Item Typical Range in the USA Notes
Frozen donor egg lot About $12,000–$25,000+ Depends on number of eggs, bank, donor profile, and guarantees.
Fresh donor compensation About $8,000–$20,000+ May be higher for certain donor characteristics or proven donors; policies vary.
Agency fee About $6,000–$15,000+ Applies when using an independent donor agency.
IVF clinic and lab fees About $12,000–$25,000+ May include monitoring, retrieval, fertilization, culture, and transfer, but packages differ.
Donor medications About $3,000–$7,000+ Usually for fresh donor cycles; can vary by protocol.
Recipient medications About $500–$3,000+ Estrogen, progesterone, and related medications for uterine preparation.
PGT-A embryo testing About $3,000–$7,000+ Often priced by base biopsy fee plus per-embryo testing.
Legal fees About $1,000–$5,000+ Higher if known donor, complex negotiations, or gestational carrier arrangements are involved.
Embryo storage About $500–$1,500+ per year Applies if embryos are frozen for future transfer or sibling attempts.

A rough total for a frozen donor egg IVF attempt may fall somewhere around $25,000 to $45,000 or more. A fresh donor egg cycle through an agency may range from about $40,000 to $70,000 or higher. If a gestational carrier is needed, total family-building costs can rise substantially, often exceeding $120,000 to $200,000 depending on agency, carrier compensation, insurance, legal requirements, IVF costs, and pregnancy expenses.

Cost should be evaluated alongside expected value. A less expensive egg lot may not be the best option if it offers fewer eggs, limited guarantees, or poor transparency. A higher-cost fresh cycle may be justified if it yields several embryos for future siblings, but it is not guaranteed. Ask each program to explain what is included, what is excluded, what happens if the donor fails screening, and whether any refund, replacement, or live birth guarantee program is available.

Success Rates: What Intended Parents Should Know

Donor egg IVF often has higher success rates than IVF using eggs from older patients because egg age is one of the strongest predictors of embryo chromosomal normality and implantation potential. Since donors are typically young and medically screened, embryo development and pregnancy rates can be favorable. However, success is never guaranteed. Outcomes depend on egg quality, sperm quality, laboratory performance, embryo development, uterine health, transfer technique, embryo genetics, and overall medical factors.

In the USA, clinic-specific success data may be reported through the Society for Assisted Reproductive Technology and the Centers for Disease Control and Prevention. When reviewing success rates, pay attention to the denominator. Rates may be reported per transfer, per cycle start, per retrieval, or per patient. A clinic with excellent per-transfer results may still have patients who do not reach transfer. For donor egg IVF, it is also useful to ask about blastocyst formation, euploidy rates if PGT-A is used, implantation rates, miscarriage rates, live birth rates, and cumulative success after multiple transfers from the same cohort.

Many clinics recommend single embryo transfer, particularly when using donor eggs and high-quality blastocysts. Transferring two embryos may increase the chance of twins but also increases risks such as preterm birth, low birth weight, gestational diabetes, hypertensive disorders, cesarean delivery, and neonatal intensive care. For many families, the safest path is one healthy baby at a time.

PGT-A is another decision point. Because donor eggs come from younger donors, a higher proportion of embryos may be chromosomally normal compared with embryos from older eggs. Some clinics still recommend PGT-A to help select embryos, reduce miscarriage risk, or support single embryo transfer. Others may consider it optional, especially if embryo numbers are limited. Intended parents should discuss the benefits, limitations, costs, and possible risks of embryo biopsy with their physician.

Legal and Ethical Considerations

Egg donation in the USA involves important legal planning. Laws and practices vary by state, and fertility clinics typically require signed legal agreements before proceeding with a fresh known or agency donor cycle. Even when using frozen donor eggs, consent documents should clarify ownership, use of eggs, embryo disposition, privacy, and responsibilities.

A donor agreement commonly states that the donor relinquishes any parental rights and that the intended parents will be the legal parents of any resulting child. It may also address compensation, medical risks, confidentiality, future contact, unused eggs or embryos, handling of abnormal genetic findings, and what happens if one party withdraws before retrieval. Intended parents and donors should generally have separate legal counsel to avoid conflicts of interest.

Known donation requires special care. A sister, cousin, or friend may be a loving donor, but emotional complexity can arise around boundaries, future disclosure, family roles, and expectations for contact. Psychological counseling is not a formality; it can help everyone discuss difficult questions before treatment begins. For example, what will the child be told? Will the donor attend family events? Will the donor be called an aunt, donor, or another term? What if the donor later has regrets or wants more contact than planned? Clear communication protects relationships.

Ethical conversations around donor conception have evolved. Many experts encourage age-appropriate openness with children conceived through donor eggs. Research and lived experience from donor-conceived people suggest that early, honest, normalized disclosure can support trust and identity development. Parents may choose books, counseling, and community resources to help explain the story in a loving way: “We needed help to have you, and a kind donor gave us eggs so you could grow in our family.”

Choosing the Right Fertility Clinic or Egg Donor Program

The quality of the clinic and laboratory matters. A donor with excellent potential still needs a skilled IVF lab, appropriate sperm preparation, careful embryo culture, and a well-managed transfer. When evaluating clinics, look beyond marketing claims. Ask for data, policies, and transparent communication.

  • Experience: How many donor egg cycles does the clinic perform each year?
  • Laboratory performance: What are the clinic’s thaw survival, fertilization, blastocyst, and live birth rates for donor eggs?
  • Screening standards: Which medical, genetic, infectious disease, and psychological screenings are required?
  • Donor availability: Does the clinic have in-house donors, work with agencies, or partner with egg banks?
  • Transparency: Are all fees listed clearly? Are cancellation and refund policies in writing?
  • Communication: Will you have a dedicated coordinator? How quickly are questions answered?
  • Legal process: Does the clinic require independent attorneys and completed contracts before treatment?
  • Support services: Are counseling, genetic counseling, financial counseling, and third-party reproduction coordinators available?

It is reasonable to consult more than one clinic before deciding. A second opinion may clarify whether donor eggs are truly indicated, whether uterine testing is complete, whether sperm factors have been addressed, and whether a frozen or fresh donor approach is best. The right program should make you feel informed rather than pressured.

Improving Your Chances of Success

Although donor egg IVF can improve the odds for many patients, preparation still matters. Before embryo transfer, the recipient should have a uterine evaluation, which may include saline sonogram, hysteroscopy, ultrasound, or other testing depending on history. Polyps, fibroids affecting the cavity, adhesions, chronic endometritis, or hydrosalpinx can reduce implantation chances and may need treatment before transfer.

Sperm quality is equally important. Even with excellent donor eggs, severe sperm abnormalities can affect fertilization, embryo development, miscarriage risk, and embryo genetics. Semen analysis, sperm DNA fragmentation testing in select cases, lifestyle optimization, urology referral, or use of donor sperm may be discussed depending on the situation.

General health also plays a role. Before pregnancy, intended mothers should review medications, chronic conditions, thyroid function, diabetes control, blood pressure, weight, nutrition, and prenatal vitamins with folic acid. Smoking, heavy alcohol use, and uncontrolled medical conditions can reduce pregnancy safety. For recipients in their mid-40s or older, clinics may require medical clearance because pregnancy risks can increase with age even when the egg source is young.

Emotional preparation is part of success as well. Donor egg treatment can bring grief about not using one’s own eggs, hope about a new path, anxiety about costs, and questions about genetic connection. These feelings can coexist. Counseling, support groups, and conversations with other donor egg parents can help intended parents process the transition and build confidence in their family story.

Questions to Ask Before You Commit

Before signing agreements or paying deposits, prepare a checklist. Good programs welcome detailed questions because informed patients are better prepared for treatment.

Topic Questions to Ask
Donor screening What tests has the donor completed? Are genetic results available? Has a psychologist evaluated the donor?
Egg quantity How many mature eggs are guaranteed? What happens if fewer eggs are retrieved or survive thaw?
Embryo expectations What fertilization and blastocyst rates are typical? Are there embryo or live birth guarantee options?
Costs What is included in the package? What fees are separate? Are medications, legal fees, storage, and embryo testing included?
Legal terms Who owns unused eggs or embryos? What are the donor’s rights and obligations? What future contact is allowed?
Timeline How long from donor selection to embryo transfer? What can delay the process?

Success Options for Different Family-Building Goals

The phrase “success options” can mean different things. For one family, success means the fastest route to one child. For another, it means creating enough embryos for two or three children. For another, it means reducing financial uncertainty through a refund program. Matching your treatment strategy to your goal is essential.

If your goal is one child as quickly as possible, frozen donor eggs may be efficient. The eggs are available, the donor has already completed retrieval, and the clinic can move directly to egg thaw, fertilization, embryo culture, and transfer preparation. If you want more than one child genetically related through the same donor, a fresh donor cycle or multiple frozen egg lots from the same donor may be more appropriate.

If minimizing financial risk is a priority, ask about outcome-based programs. Some clinics and networks offer embryo guarantee, pregnancy guarantee, or live birth refund plans, though eligibility criteria may be strict and costs may be higher upfront. Read the fine print: guarantee programs may specify donor egg source, sperm parameters, embryo transfer rules, BMI limits, uterine requirements, and whether PGT-A is required.

If you have a history of miscarriage or implantation failure, the plan should include a careful review before assuming donor eggs alone will solve the problem. Uterine cavity assessment, endocrine testing, sperm evaluation, embryo genetic testing, and review of transfer protocols may be appropriate. Donor eggs improve egg-related factors, but they do not automatically correct uterine, sperm, immune, endocrine, or obstetric risks.

If you need a gestational carrier, choose a clinic experienced in third-party reproduction and coordinate early with an attorney and carrier agency. Embryos may be created first and transferred later to a screened carrier, or donor and carrier timelines may overlap depending on the arrangement. Legal parentage requirements vary, so professional guidance is essential.

Emotional Realities of Using an Egg Donor

The medical steps of donor egg IVF are often easier to describe than the emotional ones. Intended parents may feel relief that a strong option exists, sadness about losing a genetic connection, worry about bonding, excitement about pregnancy, fear of judgment, or uncertainty about disclosure. These feelings are normal and do not mean you are making the wrong decision.

Many parents who use donor eggs report that bonding grows through pregnancy, birth, caregiving, and daily family life. Genetics is one way families are formed, but it is not the only foundation of parenthood. Love, intention, nurturing, protection, and presence are central to the parent-child relationship. Still, it is healthy to honor any grief instead of suppressing it. A fertility counselor can help intended parents integrate the donor’s role into a positive family narrative.

Disclosure planning can reduce future anxiety. Instead of waiting for a dramatic conversation in adolescence or adulthood, many families introduce the concept early in simple language and expand details as the child matures. This approach makes donor conception part of the child’s story rather than a secret. It also allows parents to answer questions gradually and confidently.

Practical Tips for Your Donor Egg Journey

  • Request itemized pricing: Do not rely on a single package number without understanding exclusions.
  • Confirm screening dates: Infectious disease testing must meet timing requirements, especially in fresh cycles.
  • Think about siblings early: If you may want another child, ask whether more eggs or embryos from the same donor can be reserved.
  • Use qualified attorneys: Reproductive law is specialized; general family law experience may not be enough.
  • Review insurance: Check fertility benefits, medication coverage, maternity coverage, and exclusions for donor tissue or surrogacy.
  • Consider genetic counseling: Especially when donor or sperm provider carrier results need interpretation.
  • Protect your emotional health: Build support before treatment begins, not only after setbacks.
  • Compare realistic timelines: The fastest donor match is not always the best match, but unnecessary delays can add stress and cost.

A Balanced Path Forward

Finding an egg donor in the USA involves more than choosing a profile. It is a coordinated medical, legal, financial, and emotional process. The strongest programs combine careful donor screening, transparent pricing, experienced IVF laboratories, thoughtful counseling, and clear legal protections. Intended parents should feel empowered to ask detailed questions and to take time with decisions that will shape their future family.

Donor egg IVF can offer excellent possibilities, especially for people facing egg quality challenges, genetic concerns, or family-building paths that require donor eggs. At the same time, responsible planning means understanding that success rates are probabilities, not promises. Costs can be substantial, timelines can shift, and emotions may change along the way. The best approach is informed, individualized, and supported by professionals who respect both your medical needs and your values.

Whether you choose frozen donor eggs for speed, a fresh donor cycle for embryo quantity, a known donor for personal connection, or an identity-release donor for future openness, the goal is the same: building a healthy family with clarity and care. With the right clinic, a thoroughly screened donor, realistic cost planning, and compassionate guidance, your fertility journey can move from uncertainty toward a well-prepared and hopeful next step.

This article is for educational purposes only and does not replace personalized medical, legal, genetic, or psychological advice. Intended parents should consult a reproductive endocrinologist, reproductive attorney, genetic counselor, and qualified mental health professional when planning donor egg IVF in the USA.