IVF Add-Ons: What the Evidence Says About ERA, ICSI, and More

Every year, thousands of fertility patients are offered IVF add-ons — extra procedures with plausible theories and significant price tags. Some spend $1,500 on a test that may delay their transfer. Others pay for technology that is safer than traditional methods but no more effective. The fertility field is genuinely innovative, and that pace of progress has a side effect: some procedures enter clinical practice before the evidence has confirmed they work.

Understanding which add-ons are supported by current research — and which are not — can help you have a more informed conversation with your clinic and protect your time, money, and emotional reserves during treatment.

In this article, we cover four of the most commonly offered IVF add-ons: the ERA test, routine ICSI, assisted hatching, and time-lapse embryo imaging. For each, we summarize what the evidence shows, what major reproductive societies recommend, and when — if ever — it may be worth discussing with your doctor.

What "add-on" actually means — and why the term matters

In fertility medicine, an IVF add-on is any elective procedure offered alongside standard treatment — one that carries a separate fee and comes with the suggestion that it may improve your chances of success. Some add-ons are laboratory procedures; others are diagnostic tests or fertilization techniques applied beyond their proven indications.

Reproductive specialists speaking on the SART Fertility Experts podcast made a pointed observation: the word "add-on" is itself a signal. If an intervention had robust, peer-reviewed evidence behind it, it would simply be called standard care. The term exists precisely because that evidence has not yet materialized — or has materialized and come up negative.

That distinction matters. Fertility patients are often in a state of urgency, and the emotional weight of wanting to do everything possible makes it hard to push back on a procedure that sounds medically plausible. But "plausible" and "proven" are not the same thing — and as more large, high-quality trials have been completed, the picture has become clearer for four of the most widely offered add-ons.

ERA: a compelling theory that hasn't held up in clinical trials

The Endometrial Receptivity Assay (ERA) is a diagnostic test that involves taking a small biopsy of the uterine lining during a mock transfer cycle. It analyzes gene expression patterns to identify a patient's personal "window of implantation" — the narrow period when the uterus is most receptive to an embryo attaching. If timing is off, the theory goes, even a healthy embryo may fail to implant. Adjust the timing, and success rates should improve.

Clinical trials have not confirmed this logic translates into better outcomes. A 2026 meta-analysis reviewing 44 studies found no difference in live birth rates between patients who used ERA-guided transfers (52.9%) and those who followed standard timing protocols (53.7%). A large randomized controlled trial published in the Journal of the American Medical Association found something more concerning: patients with "pre-receptive" ERA results who delayed their transfer as the test recommended actually had lower clinical pregnancy rates than the control group that used standard protocols.

Research also suggests the ERA's apparent benefit diminishes or disappears entirely when chromosomally normal (euploid) embryos are transferred — meaning the genetic quality of the embryo matters far more to implantation than subtle timing adjustments.

The American Society for Reproductive Medicine (ASRM) recommends against routine ERA use outside of research settings. The European Society of Human Reproduction and Embryology (ESHRE) concluded there is insufficient data to recommend any commercially available endometrial receptivity test. The Human Fertilisation and Embryology Authority (HFEA) assigns it a Red traffic light rating — meaning high-quality evidence shows no proven benefit and possible harm in some scenarios. The test typically costs $800–$1,500 and requires an additional uterine biopsy and a full mock transfer cycle before treatment begins.

The ERA may be worth discussing with your physician if you have experienced recurrent implantation failure — defined as multiple failed transfers with chromosomally normal embryos. Even in that group, the evidence remains mixed, and any decision should weigh the added cost, extra procedural steps, and the time it adds to an already demanding process.

Routine ICSI: essential for some, unnecessary for most

Intracytoplasmic sperm injection (ICSI) was developed to solve one of the hardest problems in reproductive medicine: fertilization failure caused by severe male factor infertility. Instead of placing sperm and egg together in a dish, ICSI injects a single sperm directly into each egg. For patients with low sperm count, poor motility, or abnormal morphology, it has been transformative.

The problem arises when ICSI is used as a default for everyone. Approximately three-quarters of all IVF cycles globally now use ICSI — including many cycles with no male factor infertility. Population studies consistently find that routine ICSI for patients with normal semen parameters does not improve clinical pregnancy or live birth rates compared to conventional IVF. For these patients, standard fertilization often produces comparable or higher fertilization rates per egg, and it avoids the mechanical risk the injection itself introduces. Some studies have also associated routine ICSI without a clear indication with a slightly elevated risk of birth defects.

ASRM recommends ICSI only when there is a specific clinical reason:

• Severe male factor infertility (low count, poor motility, abnormal morphology)
• Prior fertilization failure with conventional IVF
• Fertilization of previously vitrified (frozen) eggs
• Cycles that include preimplantation genetic testing (PGT)

When one of these criteria applies, ICSI is not an add-on — it is the appropriate standard of care. For intended parents pursuing surrogacy with donor eggs or using frozen embryos, ICSI is clinically justified and typically part of the standard protocol. The concern about routine ICSI applies specifically to patients with no male factor indication who are offered it as a default rather than a reasoned recommendation.

Assisted hatching: what the data actually shows

Assisted hatching involves using laser, mechanical, or chemical methods to thin or make a small opening in the zona pellucida — the outer shell surrounding the embryo — before it is transferred. The aim is to help the embryo break free and implant more easily, particularly in older patients or those with a history of failed transfers.

Multiple large studies have not confirmed this helps in practice. A meta-analysis of 36 randomized controlled trials found no significant improvement in live birth rates from laser-assisted hatching in fresh IVF cycles. A high-quality trial of 203 patients with good prognoses found virtually identical live birth rates in both groups (47% with hatching, 46% without). More concerning, data from the SART national registry found lower live birth rates in patients who underwent assisted hatching — including in subgroups that had been expected to benefit, such as women with diminished ovarian reserve. A separate large retrospective analysis of over 151,000 first frozen embryo transfer cycles found a similar pattern, with a more pronounced decrease in women over 42.

ASRM, ESHRE, and NICE (the UK's National Institute for Health and Care Excellence) all recommend against routine use. The HFEA assigns assisted hatching a Grey rating — meaning there is no high-quality evidence to support it. The procedure typically costs $500–$1,500 and requires microsurgery on the embryo, introducing a small but real risk of damage and, in some studies, a possible increase in the rate of identical twinning.

One context where breaching the zona pellucida is appropriate: cycles that include preimplantation genetic testing (PGT-A), where the embryo shell must be opened to obtain cells for analysis. This is not an elective add-on — it is a necessary procedural step.

Time-lapse embryo imaging: impressive technology, unproven benefit

Time-lapse incubators contain built-in cameras that photograph developing embryos continuously — thousands of images per embryo — creating a detailed record of how each one grows from fertilization to the blastocyst stage. The goal is to help embryologists identify the best embryo for transfer by analyzing developmental timing patterns (a process called morphokinetic profiling). The technology also eliminates the need to briefly remove embryos from the incubator for traditional microscopic checks, minimizing small fluctuations in temperature and gas concentrations.

In September 2024, The Lancet published the TILT trial — the largest randomized controlled trial of its kind, involving over 1,500 participants across multiple sites. It found no significant difference in live birth rates between time-lapse-guided selection, standard undisturbed culture, and conventional microscopic assessment (33.7%, 36.6%, and 33.0%, respectively). The result held whether embryos were analyzed manually by embryologists or through automated AI algorithms.

The HFEA assigns time-lapse imaging a Black rating — the category reserved for add-ons where moderate to high-quality evidence shows no effect on the primary outcome of having a baby. The technology is safe; it carries no known risks for the patient or resulting child. But for patients being charged extra for it, the current evidence does not support the additional cost.

Researchers note that AI-powered morphokinetic analysis may eventually identify developmental patterns that better predict implantation success. As of 2025, that clinical benefit has not been demonstrated in high-quality trials. Time-lapse technology does offer genuine advantages for laboratory workflow and embryo culture conditions — but those benefits accrue to the clinic. Passing that cost to patients as a treatment add-on is difficult to justify on current evidence.

IVF add-ons at a glance

Four questions to ask your clinic before agreeing to any add-on

Reproductive specialists on the SART Fertility Experts podcast recommend asking these specific questions before accepting any add-on procedure. A clinic that engages with them honestly is one worth trusting with your care.

1. Does this add-on actually improve my chances of having a baby — and how strong is the evidence? Ask specifically about live birth rates, not just implantation or clinical pregnancy rates, and ask whether the evidence applies to someone with your specific profile: your age, your diagnosis, your embryo quality.

2. What are the specific risks — including added cost, delayed treatment time, or potential harm to the embryo? Some add-ons require additional procedures (such as a uterine biopsy for ERA) or embryo manipulation (assisted hatching) that carry small but real risks.

3. How much will this cost, and what are my alternatives? Get a clear number, and ask whether the evidence supports this cost given your situation. Sometimes the most evidence-based option is simply to proceed with a standard transfer.

4. What does your clinic's own data show for this procedure? Aggregate trial data reflects outcomes across many clinics. Your clinic may have internal outcomes data that differs — ask for it.

These questions are not confrontational. They are the standard of informed consent that any responsible clinic should welcome.

What this means when a surrogate is carrying your embryo

For intended parents pursuing surrogacy, the IVF add-on conversation has an additional layer. The embryo transfer happens at a clinic that may be in another country, and it is your surrogate — not you — who undergoes the transfer procedure. Decisions about add-ons affect her body, her time, and the overall treatment timeline.

A few practical points for surrogacy patients:

• ERA testing would require a mock transfer cycle for your surrogate — an additional uterine biopsy and a full hormone protocol before the actual transfer begins. Given current evidence, this is difficult to justify without a specific clinical reason, such as prior implantation failures in the same surrogate.
• ICSI is clinically appropriate and standard in surrogacy cycles using donor eggs or previously frozen embryos — this is not an elective add-on situation. If ICSI is included in a protocol involving these biological materials, that is evidence-based care, not upselling.
• Assisted hatching is required when preimplantation genetic testing (PGT-A) is part of your protocol, as the zona pellucida must be opened to collect cells for biopsy. Outside of this requirement, it lacks strong evidence as a standalone procedure.
• Time-lapse imaging is safe for the embryo if your clinic uses it, but current evidence does not support paying a separate fee for it as a live birth rate improver.

Whatever your protocol includes, you have the right to ask for a clear explanation of the clinical rationale for each element. If you're trying to understand the full picture — including costs and timelines — our surrogacy cost calculator and timeline estimator are good places to start. And if you've gone through IVF and are wondering whether surrogacy may be the next step, our guide on when to consider surrogacy after IVF covers that transition in detail.

How Delivering Dreams supports you through this process

At Delivering Dreams, we coordinate with partner clinics that follow evidence-based protocols, and we encourage every intended parent to ask questions about each step of their medical plan. Our team is available to help you understand what your protocol includes and why — and to connect you with the information you need to feel confident in your decisions. If you have questions about IVF in a surrogacy context, we're here to talk.