What is Fertilization Failure?
💡 Fertilisation failure is 0% or near-0% fertilisation of mature oocytes in IVF or ICSI. In conventional IVF, failure reflects sperm-oocyte interaction defect — switching to ICSI resolves most cases. In ICSI, oocyte activation failure from PLCζ-deficient sperm is primary — treated with assisted oocyte activation (AOA).
Fertilisation failure is the complete or near-complete absence of fertilisation of mature oocytes in an IVF or ICSI cycle — defined as 0% or <25% fertilisation across all mature eggs retrieved. It affects approximately 5–10% of IVF cycles and 1–3% of ICSI cycles, leaving no embryos available for transfer.
🇮🇳 India Context: Fertilization Failure is widely assessed and treated across major Indian fertility centres including Chennai, Mumbai, Bangalore, Delhi, and Hyderabad.
What are the key characteristics of Fertilization Failure?
- Defined as complete (0%) or near-complete (<25%) fertilisation failure across all MII (mature) oocytes retrieved
- Incidence: ~5–10% of conventional IVF cycles; ~1–3% of ICSI cycles
- Conventional IVF failure causes: zona binding defect, sperm head decondensation failure, oocyte immaturity
- ICSI fertilisation failure cause: oocyte activation failure — PLCζ (phospholipase C zeta) deficiency in sperm
- PLCζ triggers calcium oscillations in the oocyte — essential for pronuclei formation and early embryo development
- Assisted oocyte activation (AOA) using calcium ionophore bypasses PLCζ deficiency — restores fertilisation in 60–80%
- Oocyte quality factors: all eggs may be immature (GV or MI stage) at retrieval — premature triggering or poor maturation
- Diagnostic: PLCζ testing (specialist andrology labs), sperm DNA fragmentation, repeat semen analysis
How does Fertilization Failure work?
Why does Fertilization Failure matter in fertility?
Fertilisation failure leaves couples with no embryos from an entire retrieval cycle — one of the most distressing IVF outcomes. Identifying the specific cause determines the next cycle strategy. For IVF failure: switching to ICSI eliminates sperm-zona binding as a barrier — most IVF failure couples achieve fertilisation with ICSI. For ICSI failure: PLCζ testing and AOA should be offered. Where oocyte quality is confirmed as the primary issue (poor maturation, advanced age), donor eggs may become necessary. In India, AOA is offered at specialist reproductive embryology laboratories; availability varies by centre.
What are related terms to Fertilization Failure?
ICSI (Intracytoplasmic Sperm Injection)
ICSI is an advanced fertility technique. A single healthy sperm is injected dire…
IVF (In Vitro Fertilisation)
IVF (In Vitro Fertilisation) is an assisted reproductive technology (ART) in whi…
Sperm DNA Fragmentation
Sperm DNA Fragmentation means the DNA inside sperm cells has breaks or damage. S…
FAQs about Fertilization Failure
What causes fertilization failure in IVF?
In conventional IVF: sperm fails to bind or penetrate the zona pellucida, or fails to decondense inside the oocyte. In ICSI: oocyte activation failure from sperm PLCζ (phospholipase C zeta) deficiency — sperm is injected but cannot trigger the calcium oscillations required for pronuclei formation.
What is PLCζ deficiency?
PLCζ (phospholipase C zeta) is a sperm protein that triggers calcium oscillations in the oocyte after ICSI injection — essential for oocyte activation and pronuclei formation. PLCζ deficiency means the sperm lacks sufficient PLCζ to activate the oocyte, causing ICSI fertilisation failure. Treatment: assisted oocyte activation (AOA).
What is assisted oocyte activation (AOA)?
Assisted oocyte activation (AOA) uses calcium ionophore (A23187 or ionomycin) added to culture medium immediately after ICSI. It artificially triggers calcium release in the oocyte — bypassing the requirement for sperm PLCζ. AOA restores fertilisation in 60–80% of previously failed ICSI cycles due to oocyte activation failure.
What should I do after fertilization failure?
After IVF fertilisation failure: switch to ICSI in the next cycle — resolves most IVF failure cases. After ICSI fertilisation failure: request PLCζ testing and discuss AOA (assisted oocyte activation) with your embryologist. If oocyte quality is confirmed as primary issue, donor egg IVF may be considered.
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