Why Does IVF Fail? The 8 Most Common Reasons
IVF fails when an embryo does not implant, when implantation occurs but pregnancy does not continue, or when no viable embryo is produced. Understanding the specific reason is the most important step toward succeeding in the next cycle.
Per ESHRE EIM 2023: the live birth rate per IVF cycle is 40-50% for women under 35. Even under optimal conditions more cycles fail than succeed on the first attempt. Failure is common but rarely unexplained once properly investigated.
Reason 1: Embryo Chromosomal Abnormality -- The Most Common Cause
Per ASRM 2023, approximately 50-80% of failed implantations result from aneuploidy (incorrect chromosome number). An aneuploid embryo either fails to implant, causes a chemical pregnancy, or miscarries in the first trimester.
Aneuploidy rates by maternal age:
| Age | Aneuploid Embryos (%) |
|---|---|
| 30-34 | 30-40% |
| 35-37 | 45-55% |
| 38-40 | 60-70% |
| 41-42 | 70-80% |
| 43 and over | 80-95% |
Solution: PGT-A (Preimplantation Genetic Testing for Aneuploidy) identifies chromosomally normal embryos before transfer. ASRM 2023 strongest indications: women aged 38+, recurrent implantation failure, recurrent pregnancy loss.
Reason 2: Endometrial Receptivity Problems
Even a chromosomally normal embryo cannot implant if the uterine lining is not receptive. Three main issues:
Thin or poorly prepared endometrium: Lining below 7mm or lacking the trilaminar pattern. Causes: poor estrogen response, Asherman's syndrome, prior uterine surgery.
Displaced window of implantation: In 20-30% of women with recurrent implantation failure the window opens at an unexpected time. The ERA (Endometrial Receptivity Analysis) test identifies this by biopsy and gene expression profiling. Personalised embryo transfer timed to the individual window has shown improved outcomes in recurrent implantation failure per ESHRE 2023.
Chronic endometritis: Subclinical bacterial infection of the endometrium found in 15-30% of recurrent implantation failure cases. Diagnosed by CD138 immunohistochemistry. Treated with a targeted 2-3 week antibiotic course.
Reason 3: Sperm DNA Fragmentation
A normal semen analysis does not rule out DNA damage. DNA Fragmentation Index (DFI) above 25% impairs fertilisation quality, blastocyst development, and implantation.
Per ASRM 2022: DFI testing is recommended after IVF failure with good embryo quality, particularly if the male partner is over 40 or smokes.
Solutions: 3-month antioxidant protocol; varicocele repair if present; testicular sperm (TESE + ICSI) has 3-4x lower DFI than ejaculated sperm.
Reason 4: Uterine Structural Problems
Abnormalities not visible on standard ultrasound account for a significant proportion of recurrent implantation failure:
| Problem | Impact | Treatment |
|---|---|---|
| Submucous fibroids | Reduce implantation 50-70% | Hysteroscopic myomectomy |
| Endometrial polyps | Found in 15-20% of recurrent implantation failure | Hysteroscopic polypectomy |
| Uterine septum | Increases miscarriage significantly | Hysteroscopic resection |
| Asherman's syndrome | Prevents adequate endometrial development | Hysteroscopic adhesiolysis |
Per ACOG 2021: women with 2+ failed IVF transfers should undergo hysteroscopic cavity evaluation.
Reason 5: Hydrosalpinx
A fluid-filled blocked tube reduces IVF implantation rates by approximately 50% (confirmed by meta-analysis). Embryotoxic fluid refluxes into the uterine cavity at the time of transfer.
Per ASRM 2022 and ESHRE 2023: salpingectomy or proximal tubal occlusion is strongly recommended before IVF when hydrosalpinx is present.
Reason 6: Poor Laboratory Quality
Embryo quality is influenced by incubator stability, air quality (volatile organic compounds are toxic to embryos), culture media, and embryologist experience. If blastocyst development rates are consistently below 40%, a second-opinion consultation at a specialist centre is warranted.
Reason 7: Antiphospholipid Syndrome (APS)
APS causes placental microthrombi and is found in 5-10% of recurrent implantation failure. Diagnosed by lupus anticoagulant, anticardiolipin, and anti-beta-2-glycoprotein antibodies (tested twice, at least 12 weeks apart). Treatment: low-dose aspirin plus LMWH heparin from positive pregnancy test.
Reason 8: Modifiable Lifestyle Factors
| Factor | Impact on IVF |
|---|---|
| Smoking | Reduces success approximately 50%; stop both partners (ESHRE 2023) |
| Obesity (BMI over 35) | Poorer outcomes; even 5-10% weight loss before next cycle helps |
| Vitamin D deficiency | Strongly associated with lower implantation; correct to over 30 ng/mL |
| Uncontrolled thyroid | TSH above 2.5 mIU/L increases miscarriage; treat before next cycle |
Investigation After Failed IVF
After 2 failed cycles with good-quality embryos (Recurrent Implantation Failure definition):
| Test | What It Finds |
|---|---|
| Hysteroscopy or SIS | Polyps, fibroids, adhesions, septum |
| Sperm DNA fragmentation (DFI) | Paternal DNA damage |
| ERA endometrial test | Displaced implantation window |
| Chronic endometritis biopsy | Subclinical uterine infection |
| APS antibody panel x2 | Thrombotic cause |
| Vitamin D + TSH | Common correctable deficiencies |
| PGT-A on remaining embryos | Chromosomal status |
Reference: ASRM -- Recurrent Implantation Failure, 2023. ESHRE Working Group on Recurrent Implantation Failure, 2023. ACOG Practice Bulletin No. 200 -- Early Pregnancy Loss, 2021.
Frequently Asked Questions
Why did my IVF fail with a good embryo?▾
The most common cause is chromosomal abnormality in the embryo -- standard grading cannot detect this. Even a 4AA blastocyst has a 30-50% chance of being aneuploid depending on your age. Other causes: displaced implantation window (ERA test), subclinical endometritis, elevated sperm DNA fragmentation, uterine abnormalities, or antiphospholipid syndrome. After 2 failed good-quality embryo transfers, a structured investigation covering all these areas is recommended by ESHRE and ASRM 2023.
What is recurrent implantation failure (RIF)?▾
Recurrent implantation failure is defined as failure to achieve a clinical pregnancy after 2 or more transfers of good-quality embryos in a woman under 40. It affects approximately 10% of IVF patients. Investigation should include: hysteroscopic uterine cavity evaluation, sperm DNA fragmentation testing, ERA endometrial biopsy, chronic endometritis biopsy, antiphospholipid antibody panel, and PGT-A on remaining embryos.
Does a chemical pregnancy after IVF mean it is working?▾
A chemical pregnancy (positive hCG that does not develop into a clinical pregnancy on ultrasound) confirms implantation occurred -- a positive sign. It typically indicates a chromosomally abnormal embryo that implanted briefly before arresting. After a chemical pregnancy, PGT-A testing of remaining embryos is strongly recommended to identify chromosomally normal embryos for subsequent transfers.
How many failed IVF cycles before investigation?▾
ASRM and ESHRE 2023 define Recurrent Implantation Failure as 2 or more failed transfers with good-quality embryos -- this triggers full investigation. Do not continue cycles without investigating why previous ones failed. After thorough investigation and treatment of any identified cause, cumulative success rates remain meaningful across further cycles.