Abnormal Head Morphology
Fertility marker
Abnormal Head
Abnormal Head Morphology
The share of sperm with head defects. Reported as a breakdown of the abnormal forms, not as a share of all sperm.
PED Notes
Deliberately carries no reference range, because it is descriptive rather than pass or fail. Under strict Kruger criteria only about 4% of sperm are normal even in fertile men, so a figure like 96% here is arithmetic, not alarm: almost every abnormal sperm has some head irregularity. Judge morphology from [Sperm Morphology](/markers/fertility/sperm-morphology) and the [Teratozoospermia Index](/markers/fertility/teratozoospermia-index) instead. Head defects are the sub-type most linked to fertilisation failure, since the head carries the DNA and the acrosome, so a high head-defect share alongside high DNA fragmentation is a more meaningful pairing than either alone.
This number is not a verdict. It describes which defect dominates among sperm already counted as abnormal, so it will look high in almost everyone. Use Sperm Morphology for the actual assessment.
Why the head matters most: it carries the DNA and the acrosome, the structures required to penetrate and fertilise the egg. Head defects therefore correlate more strongly with fertilisation failure than tail or mid-piece defects do.
Worth pairing with Sperm DNA Fragmentation: high head-defect share with high fragmentation suggests spermatogenesis is under real strain rather than producing cosmetically imperfect but functional sperm.
Timeline: a full spermatogenic cycle is about 74 days, so nothing you change shows up for roughly 3 months.
History Chart
Reading History
Frequently Asked Questions
Reference Ranges
Standard Range
Not available