Implantation failure is diagnosed when pregnancy is not achieved after at least three cycles of In vitro fertilization (IVF) or after transferring more than ten good-quality embryos. We now have very effective options for every cause of implantation failure: blastocyst-stage transfer (day 5), preimplantation genetic testing, and assisted hatching, among others. Implantation failure: what is it and how does it happen? For an embryo to implant properly, you need a healthy embryo and a receptive endometrium, as well as precise molecular communication. We speak of implantation failure after three IVF cycles without pregnancy or after transferring more than ten embryos with good morphology. Factors that can prevent implantation They are multiple and affect the embryo, the uterus, or the general condition: Embryonic: chromosomal abnormalities, difficulty breaking the zona pellucida, or genetic defects. Uterine: fibroids, synechiae, polyps, infections (hydrosalpinx), scarring, or a thin endometrium (< 7 mm mid-cycle). Systemic: insulin resistance, obesity (BMI > 30), antiphospholipid syndrome, or thrombophilias that alter blood flow. Step-by-step diagnosis To identify the problem, several tests are combined: Blood tests: hormones, metabolic profile, immunological markers, and coagulopathies. Transvaginal ultrasound: uterine malformations, endometrial thickness, and hydrosalpinx detection. Semen analysis and DNA fragmentation: especially if there is a history or male risk factors. PGT-A: preimplantation genetic testing for embryonic aneuploidies. Assisted hatching: study of the zona pellucida in the blastocyst. Reviewing your previous cycles (eggs retrieved, fertilization rate, and embryonic development) is key for an accurate prognosis. Treatment options after repeated failure The strategy will depend on the identified cause: Blastocyst transfer (day 5–6): improves selection of embryos with higher potential. PGT-A: transfer only euploid embryos. Assisted hatching: laser to help the embryo exit the zona pellucida. Hormonal therapies and surgery: for fibroids, polyps, or synechiae. Immunological treatments and anticoagulants: in cases of antiphospholipid syndrome or thrombophilias. Do not self-medicate: always consult a reproductive medicine specialist before starting any drug or treatment. For more details, visit our section on implantation failure or read Implantation Failures: Understanding the Challenge. Frequently Asked Questions 1. Can lifestyle changes improve implantation? Yes. Maintaining a BMI between 18.5 and 24.9, controlling blood glucose, and reducing stress (mindfulness, yoga) favors uterine receptivity and embryo quality. Moderate exercise (30 min/day) and a Mediterranean diet rich in omega-3 balance hormones and reduce inflammation. Quitting smoking and limiting alcohol (< 7 units/week) improves uterine blood flow and decreases oxidative stress. Consult your specialist before making radical changes. 2. How many IVF cycles before diagnosing implantation failure? It is considered failure after three cycles without pregnancy or ten good-quality embryos transferred. However, factors such as age (≥ 38 years), low ovarian reserve, or male factor may prompt earlier evaluation. Your reproductive endocrinologist will guide you on the right timing. 3. How does PGT-A help reduce the risk of miscarriage? PGT-A detects aneuploidies before embryo transfer. Transferring only euploid embryos can reduce miscarriage rates by 50% in women over 35 and increases live births per transfer. Although it raises costs and extends the cycle by about 14 days, it decreases the emotional and financial burden of failed cycles. 4. What immunological treatments are available? In cases of antiphospholipid syndrome or immune alterations, low-dose aspirin (75 mg/day) and heparin (5 000 IU/day) regimens improve uterine perfusion. Some profiles may add IVIG or steroids. An antibody and cytokine panel customizes the therapy; work with a reproductive immunologist to optimize your protocol. Sources Practice Committee of the American Society for Reproductive Medicine. (2018). Evaluation and treatment of recurrent implantation failure: a committee opinion. Fertility and Sterility, 110(5), 704–713. https://doi.org/10.1016/j.fertnstert.2018.08.026 American College of Obstetricians and Gynecologists. (2021). Ovulation induction and assisted reproductive technologies. In ACOG Practice Bulletin No. 208. Obstetrics & Gynecology, 137(1), e49–e64. MedlinePlus. (2023). Embryo transfer. Retrieved from https://medlineplus.gov/embryotransfer.html Ubaldi, F. M., et al. (2017). Culture of human blastocysts with sequential media type: medium and embryo development. Human Reproduction, 32(7), 1424–1432. https://doi.org/10.1093/humrep/dex113 We know how hard this path is. Don’t lose hope: every situation is unique and there are personalized solutions. Consult a reproductive medicine specialist to design the best strategy toward your dream of becoming a parent.