Reproductive Immunology: Answers When Embryos Keep Failing
When embryos keep failing and no one can tell you why, the cause is often immune. For some women the problem isn't the egg or the embryo — it's the immune system rejecting a pregnancy before it can establish, or the chronic inflammation of endometriosis working against it. Aurea Fertility tests for what a standard work-up misses, and treats it.
Recurrent miscarriage
Failed IVF cycles
Implantation failure
Endometriosis
Infertilidad de causa desconocida
One of the few reproductive immunologists in the country.
Aurea's program is directed by Dr. Zaher Merhi — a reproductive endocrinologist with over 20 years in the field, three American board certifications, and a research record of more than 110 peer-reviewed publications. He is one of the small number of physicians in the United States practicing reproductive immunology, and has been named among the "Top 2% of Scientists in the World."
Continuing a distinguished legacy. After the Braverman Reproductive Immunology & Endometriosis Surgical Center closed in 2024, the practice was selected to carry its reproductive-immunology legacy forward — a program since featured in Radar Magazine and national medical outlets.
What is reproductive immunology?
Reproductive immunology is the study of how the immune system interacts with pregnancy — and how, in some women, an overactive or misdirected immune response prevents an embryo from implanting or causes it to be lost. It's the field that explains many cases of recurrent miscarriage, repeated IVF failure, endometriosis-related infertility, and "unexplained" infertility.
A pregnancy is an immunological paradox: half of the embryo's genetic material comes from the father, making it partly foreign to the mother's body. Normally the immune system adapts to tolerate and protect it. When that tolerance fails, the body can treat a healthy embryo as a threat — and the loss looks unexplained because standard testing never checks for it.
Aurea Fertility's Reproductive Immunology & Endometriosis program is built for exactly the patients other clinics run out of answers for — women who've been told their embryos were "good" and their tests were "normal," and still have no baby and no explanation.
What the program can help with
Immune and inflammatory factors show up across several of the hardest fertility problems. These are the situations where this evaluation most often changes the outcome.
Situation | How the immune system may be involved |
|---|---|
Autoimmune history | Hashimoto's, lupus, rheumatoid arthritis and others raise immune-related pregnancy risk
|
Infertilidad de causa desconocida | A "normal" work-up that never examined the immune layer |
Endometriosis with infertility | Chronic inflammation of endometriosis overlaps heavily with immune dysfunction |
Failed IVF cycles | Repeated transfer failures with no anatomical or embryo explanation |
Fracaso recurrente de la implantación | Good-quality embryos that don't implant — often an immune or receptivity problem |
Recurrent miscarriage | Immune intolerance, elevated NK cells, clotting disorders, or inflammation causing repeated early loss |
How the immune system can block a pregnancy
Three ideas explain most of reproductive immunology — and why an immune problem can stop a perfectly healthy embryo.
1
Maternal tolerance
The mother's body must accept an embryo that is half "foreign," since 50% comes from the sperm. When there's too much genetic similarity between partners, that tolerance can fail to switch on.
2
Placental protection
The placenta shields the embryo from immune attack and secretes molecules that let it develop safely. If that protective signaling is disrupted, the pregnancy is exposed.
3
Immune overactivity
Elevated natural killer cells, cytokine imbalances, clotting tendencies, and autoimmune activity can turn the immune system against an embryo. All of these are testable — and treatable.
Why "good embryo, normal tests" isn't the end
Standard IVF grades embryos and checks hormones and anatomy. It does not measure how your immune system will respond to a pregnancy. So a woman can transfer beautiful embryos, over and over, and lose each one — with every routine test coming back clean.
Reproductive immunology looks at the layer underneath: the immune environment the embryo actually has to survive in.
Endometriosis and the immune connection
Endometriosis — tissue similar to the uterine lining growing outside the uterus — is deeply entwined with immune dysfunction, and the American Society for Reproductive Medicine estimates up to half of women with infertility have it. Its chronic inflammation overlaps heavily with the immune problems reproductive immunology treats, which is why Aurea addresses the two together rather than as separate conditions.
Why it's so often missed
Endometriosis is confirmed definitively only by surgery, so it routinely hides behind an "unexplained infertility" label while quietly lowering egg quality, raising pelvic inflammation, and interfering with implantation. Many women have no pain at all — trouble conceiving is the only sign.
For women under 40 with good reserve, Aurea treats endometriosis directly — minimally invasive laparoscopic excision of lesions and cysts, endometriosis-specific IVF protocols, and anti-inflammatory support — alongside the immune work-up.
Comprehensive immune testing
Finding an immune cause takes more than a standard fertility panel. Aurea uses comprehensive reproductive-immunology testing that assesses the immune, genetic, clotting, and hormonal factors affecting whether a pregnancy can establish and continue.
A full immune and genetic profile
WHAT THE PANEL ASSESSES
Parental histocompatibility (genetic match between partners)
Maternal immunogenetics
Immune cell populations, including natural killer cells
Cytokine balance (inflammatory signaling)
Thrombophilia (clotting tendencies)
Endocrine and thyroid function
~5 wks
Most results return within about five weeks, timed to align with your natural cycle or an upcoming IVF cycle.
How Aurea treats immune-related infertility
Intralipid infusions
A roughly 45-minute infusion of a synthetic fat emulsion that helps calm elevated natural killer cell activity, reducing the chance of the immune system rejecting the embryo. Typically given before embryo transfer and continued periodically into early pregnancy when testing indicates it.
Helps with: recurrent pregnancy loss, implantation failure, elevated NK cells.
Uterine PRP
Platelet-rich plasma, drawn from your own blood and concentrated in growth factors, is introduced into the uterine lining. It can improve lining thickness and receptivity — helping an embryo implant and hold.
Helps with: thin lining, poor receptivity, repeated implantation failure.
IVIG therapy
Intravenous immunoglobulin to modulate a broadly overactive immune response, used in selected cases guided by testing.
Blood thinners
For clotting tendencies (thrombophilia) that impair blood flow to a developing pregnancy.
G-CSF (NEUPOGEN)
A growth factor that can support the uterine lining and implantation environment.
Anti-inflammatory & hormonal
Prednisone, metformin, omega-3, and CoQ10 among others, matched to the specific imbalance found in testing.