There is a particular kind of quiet that settles in the days before an embryo transfer.
For some people, this is the first attempt — hopeful, nervous, unsure what to expect. For others, it is the third, or the fifth, and the embryo waiting in the lab is the last one left.
There may not be another retrieval planned. There may not be another embryo at all.
Drew has 25 years of clinical experience treating fertility and pregnancy-related conditions, and has spent 18 years training acupuncturists and other healthcare practitioners across Ontario in Traditional Chinese Medicine techniques — including Naturopathic Doctors & Medical Doctors.
Every fertility journey is different, so use this as a starting point for conversation, not a guide to what you should do — your RE is the one who can tell you which of these, if any, make sense for your unique situation.
When having only one embryo remaining is the reality, every decision leading up to transfer day starts to feel enormous. Should the protein intake be higher? Should stress be managed differently? Should there be more monitoring, more testing, more something? It’s an impossible amount of pressure to carry, and it’s made heavier by the fact that most people don’t know what’s actually available to them until after a transfer has already failed — at which point a doctor mentions, almost in passing, that there were other options that could have been considered.
This article exists so that conversation happens before the transfer instead of after.
This Is Not a List of What You Should Do
Before going any further, it’s worth being direct about what this article is and isn’t.
It’s not a recommendation that everyone pursue every intervention listed below. Most patients will not need most of these. Some of these interventions have solid supporting evidence for specific patient profiles; others are still being studied, are used more selectively, or remain genuinely controversial within reproductive medicine. A few are inexpensive and low-risk; others carry real cost, time, or physical burden.
What this article is, is a map of the conversation. If a reproductive endocrinologist (RE) says “this isn’t necessary for your case,” that is useful, reassuring information — but it’s only reassuring if the question was asked in the first place. The goal here is simple: walk into the transfer knowing what exists, so that any advice received — for or against — is actually informed consent rather than an information gap nobody thought to fill.
Immune-Modulating Protocols
For patients with a history of failed implantation or recurrent pregnancy loss, some clinics investigate whether the immune system may be playing a role — either by being overly reactive at the implantation site or by contributing to inflammation that interferes with the embryo attaching successfully.
Corticosteroids (Prednisone or similar). Low-dose steroids are sometimes prescribed around the time of transfer with the goal of dampening inflammatory or immune activity in the uterine lining. This is typically considered for patients with a suspected immune component to implantation failure, though not all REs agree on when — or whether — it’s warranted.
The “CPP” Protocol (Claritin, Pepcid, Prednisone). Sometimes called the Colorado protocol, this combines an antihistamine, an H2 blocker, and a steroid, based on the theory that mast cell or allergic-type activity in the uterus may interfere with implantation in some patients. It is most often discussed with patients who have a personal history of allergies, asthma, eczema, or other atopic conditions, or who have had unexplained recurrent implantation failure. It’s worth knowing this protocol has not been validated in large peer-reviewed trials, and some clinics use it selectively rather than universally — which is exactly the kind of thing worth asking an RE about directly.
IVIG (Intravenous Immunoglobulin) and Intralipid Infusions. These are used in a smaller subset of patients, typically those with suspected elevated natural killer (NK) cell activity or other immune markers identified through specialized testing. They are more invasive and costly than oral protocols, and are generally reserved for patients with a specific immunological workup pointing toward this kind of intervention — not something typically offered as a first step.
G-CSF (Granulocyte Colony-Stimulating Factor). Originally used in cancer treatment to boost white blood cell production, G-CSF is used off-label in fertility care in two main ways: as an intrauterine infusion to support a thin endometrial lining, or as an injection in some recurrent implantation failure protocols. It’s typically discussed with patients who have had difficulty building adequate lining thickness.
Anticoagulants (Blood Thinners)
Low-dose (Baby) Aspirin. Often the most commonly used add-on, low-dose aspirin is thought to support blood flow to the uterine lining. It’s frequently discussed with patients regardless of a specific diagnosis, though it’s more strongly considered for those with a history of clotting concerns or recurrent implantation failure.
Fragmin, Clexane, or other Low-Molecular-Weight Heparins. These injectable blood thinners are typically reserved for patients with a diagnosed or suspected clotting disorder (such as a thrombophilia), a personal or family history of blood clots, or a history of pregnancy loss where clotting is suspected to have played a role. This is a more significant intervention — daily injections, ongoing monitoring — so it tends to be reserved for patients where there’s a specific clinical reason to consider it, rather than used broadly.
Embryo “Glue” (Hyaluronan-Enriched Transfer Medium)
This refers to a transfer medium enriched with hyaluronan, a substance that occurs naturally in the uterus and is thought to help the embryo adhere to the uterine lining during transfer. It’s a simple, low-risk addition to the transfer procedure itself and is used fairly broadly across many clinics, including for patients without a specific implantation issue, though its greatest interest tends to be with patients who have had prior failed transfers.
Assisted Hatching
Before an embryo can implant, it needs to break out of its outer shell (the zona pellucida). Assisted hatching involves creating a small opening in that shell in the lab, prior to transfer, to make that process easier. It’s typically considered for embryos with a thicker-than-average shell, for patients who are older, or for embryos that have been frozen and thawed, where the shell can sometimes harden slightly.
Endometrial Receptivity Testing (ERA)
The ERA (Endometrial Receptivity Array) is a biopsy done in a prior, non-transfer cycle to assess whether the uterine lining is receptive at the standard timing used for transfer, or whether the window of implantation is shifted earlier or later for that particular patient. It’s most often considered after one or more unexplained failed transfers with embryos that were otherwise considered good quality, as a way of asking whether timing — rather than the embryo or the lining itself — was the issue.
Endometrial Scratch
This involves a minor procedure, done in the cycle prior to transfer, in which the uterine lining is lightly scratched or biopsied. The theory is that the resulting healing response may make the lining more receptive in the following cycle. It’s most commonly discussed with patients who have had recurrent implantation failure, and it remains one of the more debated interventions in this list — some clinics use it regularly, others rarely.
PRP (Platelet-Rich Plasma)
PRP involves processing a small sample of the patient’s own blood to concentrate platelets and growth factors, which are then infused into the uterus. It’s most often discussed with patients who have a persistently thin endometrial lining that hasn’t responded well to standard hormonal support, or with recurrent implantation failure where lining quality is a concern.
Vitamin D and Nutrient Optimization
Vitamin D deficiency has been associated with lower implantation and pregnancy rates in some research, and many clinics now check levels as a matter of routine and recommend supplementation if levels are low. This is a low-cost, low-risk step that’s worth asking about even if it hasn’t come up.
A Note on How to Use This List
Reading through a list like this can feel overwhelming in either direction. It might feel like “I need to ask for all of this,” or it might feel discouraging — like there’s a whole world of options that were never mentioned. Neither reaction is the point.
The point is simpler: this is a starting list of questions, not a checklist of treatments. A good conversation with an RE might sound like: “I read about immune protocols, blood thinners, and embryo glue — is there anything in my history that would make any of these worth considering for this transfer?” The answer might be no across the board, and that’s a completely valid, evidence-based answer. But it should be an answer that was actually discussed, not one that was assumed.
For patients who feel like this transfer carries more weight than the ones before it — because it’s the only embryo left, because of how many transfers came before it, or simply because of how much this journey has already asked of them — that conversation is worth having out loud.
Supporting Your Transfer with Acupuncture
Beyond the interventions discussed above, some patients also choose to incorporate acupuncture in the weeks surrounding their transfer. Acupuncture is generally low-risk and can be used alongside virtually any of the protocols described in this article, which is part of why it’s often one of the more accessible additions for patients to consider.
For a closer look at how acupuncture is typically approached before and after an embryo transfer, see my article on Pre and Post Transfer Acupuncture.