Why Do Embryo Transfers Fail? Common Causes and When Surrogacy May Be the Better Option

Embryo transfers can fail for several reasons, including embryo quality, uterine conditions, hormonal preparation and timing. Successful implantation depends on these factors working together, which means one unsuccessful transfer does not always reveal exactly what went wrong.

Another transfer may make sense after one unsuccessful attempt. But when transfers repeatedly fail, particularly with genetically tested embryos, your fertility specialist may investigate whether carrying the pregnancy has become the primary challenge.

Fill out our contact form to connect with a surrogacy professional and explore whether gestational surrogacy could address the barriers you have experienced. You can learn how the process works and what to consider before deciding on your next step.

Why Do Embryo Transfers Fail?

An embryo transfer can fail when an embryo does not implant in the uterine lining or stops developing shortly after implantation. Successful implantation depends on a healthy embryo, a receptive uterine lining and appropriate hormonal support.

Hormones help prepare the uterine lining for implantation at the right time. If embryo development, uterine receptivity or hormonal preparation is affected, the transfer may not result in pregnancy.

Understanding what may have contributed to a failed transfer can help you and your fertility specialist decide what to evaluate or change before trying again.

Embryo Problems Are Still the Most Common Reason IVF Transfers Fail

Embryo-related factors are a common reason transfers do not result in an ongoing pregnancy. Chromosomal abnormalities or problems with embryo development can prevent implantation or cause development to stop soon afterward.

Even embryos that receive a high grade based on their appearance can have chromosomal abnormalities. Embryo grading evaluates development and appearance, but it cannot determine whether an embryo is chromosomally normal.

When an embryo has a chromosomal abnormality, it may not implant successfully. In other cases, implantation may occur but result in a chemical pregnancy or early miscarriage.

Does PGT-A Eliminate the Risk?

PGT-A screens embryo cells for chromosome abnormalities before transfer, but it cannot guarantee implantation or pregnancy. Embryo genetic testing provides different information than embryo grading, which evaluates an embryo based on its development and appearance.

A euploid result means the tested cells showed the expected number of chromosomes. Even a euploid embryo may not implant, since other embryo, uterine and hormonal factors can affect the outcome.

PGT-A can also identify mosaic embryos, which have a mixture of cells with different chromosome findings. This is why neither a strong embryo grade nor genetic testing can predict with certainty whether an individual transfer will succeed.

Uterine Factor Infertility Can Prevent Healthy Embryos From Implanting

When viable embryos repeatedly fail to implant, your fertility specialist may evaluate whether a uterine condition is contributing to the problem. The uterine lining and cavity both play a role in creating an environment that can support implantation and pregnancy. Conditions that may affect implantation include:

Previous uterine surgery can also lead to adhesions or scarring that affect the uterine cavity. When these abnormalities are present alongside repeated unsuccessful transfers, they may be considered as part of an evaluation for recurrent implantation failure.

Some uterine conditions can be treated before another transfer, while others may be difficult or impossible to fully correct. Understanding the extent of the condition can help your fertility specialist determine whether another transfer is likely to address the problem.

Hormonal Problems Can Make Implantation Less Likely

Hormonal balance and timing help prepare the uterine lining for implantation. Progesterone and estrogen need to support the endometrium so that it is receptive when the embryo is transferred.

If progesterone timing or levels are not appropriate, the embryo and uterine lining may be out of sync. Inadequate estrogen support can also affect how the lining develops before transfer. Your fertility specialist may also evaluate underlying hormonal conditions, including:

• Thyroid Disease: Uncontrolled thyroid conditions can affect fertility, implantation and early pregnancy.
• Polycystic Ovary Syndrome (PCOS): Hormonal and metabolic changes associated with PCOS may affect endometrial receptivity.
• Elevated Prolactin: High prolactin levels can interfere with normal reproductive hormone function.

Endometrial receptivity testing, such as the ERA, is sometimes used to evaluate transfer timing after repeated failures. Evidence supporting its routine use continues to evolve, so your fertility specialist can help determine whether this testing is appropriate for your situation.

Evaluating hormone levels, thyroid function and other endocrine factors can help identify changes that may be appropriate before another transfer.

Can Immune Problems Cause Embryo Transfer Failure?

Certain autoimmune conditions can affect pregnancy, but the role of the immune system in embryo implantation is complex. Not every failed transfer is evidence of an immune-related problem. Conditions your specialist may consider include:

• Antiphospholipid Syndrome (APS): An autoimmune condition associated with abnormal blood clotting and pregnancy complications.
• Lupus: An autoimmune disease that can increase certain pregnancy risks and may require additional medical management.
• Thyroid Autoimmunity: Thyroid antibodies have been studied in relation to fertility and pregnancy outcomes, although their role in implantation failure is not always clear.

Other areas of reproductive immunology remain less established. Natural killer cell testing and some immune-based treatments have limited or conflicting evidence and are not routinely recommended for every patient with failed transfers.

Your fertility specialist can determine whether your medical history supports further immune evaluation and which tests or treatments have evidence for your situation.

Other Medical Conditions That Can Contribute to Failed Embryo Transfers

Your overall health can also influence implantation and pregnancy outcomes. Certain medical conditions and lifestyle factors may be worth evaluating before another transfer. These can include:

• Endometriosis: Inflammation associated with endometriosis may affect fertility and implantation.
• Uncontrolled Diabetes: Uncontrolled blood sugar can affect fertility and increase pregnancy risks.
• Weight-Related Factors: Being significantly above or below a healthy weight may affect hormone levels, fertility and treatment outcomes.
• Smoking and Nicotine Exposure: Tobacco and nicotine use can negatively affect fertility and reproductive health.
• Certain Medications: Some medications may need to be reviewed or adjusted before fertility treatment or pregnancy.

Your fertility specialist can review your health history, medications and lifestyle factors to identify changes that may support your next transfer.

When Do Fertility Specialists Investigate Recurrent Implantation Failure?

There is no universal definition of recurrent implantation failure (RIF). After repeated unsuccessful transfers, your fertility specialist may recommend further evaluation based on your medical history, embryo quality and previous IVF cycles. This evaluation may include:

Your fertility specialist will also review previous IVF cycles to look for patterns involving embryo development, transfer timing and treatment. Some of these evaluations have stronger supporting evidence than specialized tests for immune factors or endometrial receptivity, where evidence continues to evolve.

Should You Keep Trying IVF or Consider Surrogacy?

Deciding whether to try another embryo transfer or consider surrogacy depends on what your fertility team believes is preventing pregnancy. If testing identifies a treatable uterine, hormonal or transfer-related factor, addressing it before another transfer may make sense.

Surrogacy may be worth discussing when you have viable embryos but repeated transfers suggest that implantation or carrying a pregnancy is the primary challenge. A gestational surrogate can carry an embryo created through IVF, allowing you to use your existing embryos without relying on your uterus to sustain the pregnancy.

As you consider your options after IVF fails, look at what your previous cycles have revealed and whether another transfer would meaningfully address the suspected cause of failure.

When Surrogacy Can Improve the Chances of Success After Failed IVF

Gestational surrogacy may improve the chances of success when viable embryos are available but a uterine or medical condition makes implantation or pregnancy difficult. It allows an existing embryo to be transferred to a screened gestational surrogate. Surrogacy may be considered for:

• Severe Uterine Scarring or Asherman Syndrome
• Persistent Thin Uterine Lining
• Congenital Uterine Abnormalities
• Severe Adenomyosis
• Medical Conditions That Make Pregnancy Unsafe

When carrying a pregnancy is the primary barrier, surrogacy can address that underlying challenge rather than repeating embryo transfers under the same circumstances.

What to Look for If You’re Comparing Surrogacy

As you compare surrogacy agencies, look beyond advertised costs and match times. Consider the protections and support included throughout the process.

Comparing these details can help you understand what each program actually provides and choose an agency that fits your priorities.

Explore Whether Surrogacy Fits Your Situation

When viable embryos are available but repeated IVF failures suggest that carrying a pregnancy is the primary barrier, gestational surrogacy may be worth exploring. Learning how surrogacy works can help you determine whether it addresses the challenges you have experienced.

Fill out our contact form to connect with a surrogacy professional who can answer your questions, discuss your situation and help you evaluate whether surrogacy could be an appropriate next step.