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Sperm Morphology (Size and Shape)
Sperm morphology overview
- Sperm morphology refers to the size, shape and appearance of a man’s sperm, which when abnormal can decrease fertility and make it more difficult to fertilize the woman’s egg.
- Sperm can be misshaped based on the size of the head, having an extra head, and having no head or tail. Other sperm defects include bent tail, coiled-tail, stump-tail and not having the tail attached at the correct location.
- For a sperm sample to be considered to have fertility potential, it only needs 4 percent or more of the sperm population to be considered normal, using the “strict” morphology criteria.
- Some couples will need to use IUI, IVF or ICSI to improve their chances of becoming parents based on the sperm morphology results.
What is sperm morphology?
Sperm morphology refers to the determine of the sperm, which includes head size and promontory DNA contented ( revealed by a nuclear color blot ), the midpiece appearance and the structure of the tail. The head shape is authoritative because it can affect the sperm ’ s ability to penetrate the outer airfoil of a woman ’ mho egg to fertilize it .
Sperm morphology is assessed during routine semen analysis that examines the sperm cells under a microscope. The semen psychoanalysis will besides examine the motion ( movement ability ) and concentration of sperm introduce .
Every male, prolific or sterile, has varying percentages of abnormally-shaped sperm. There are many factors that can lead to abnormally determine sperm including increase testicular temperature, exposure to toxic chemicals, infection and genetic traits. The medical term for when a valet has a big number of abnormally shaped sperm is teratozoospermia or teratospermia .
Loma Linda Center for Fertility & IVF uses the Kruger Strict Criteria to evaluate sperm morphology, which is used by most doctors. Below are the Kruger Strict Criteria scores and their explanations :
- Over 14 percent of sperm have normal morphology – high probability of fertility
- 4-14 percent – fertility slightly decreased
- 0-3 percent – fertility extremely impaired.
The World Health Organization besides published their own sperm analysis criteria. As of 2010, they consider the presence of 4 percentage and higher of sperm having normal morphology as the ideal sample distribution writing for fertility .
Types of sperm morphology
A normal sperm will have an egg-shaped head, an intact midpiece and an uncoiled individual tail. Sperm with convention morphology are able to swim well and in a straight lineage. normal sperm will besides contain goodly genetic information quite than having excessively many or besides few chromosomes, which are coarse in abnormally shaped sperm .
Macrocephaly refers to when the sperm has a giant fountainhead. These types of sperm often carry extra chromosomes and have problems fertilizing the woman ’ second testis. Macrocephalic sperm may be caused by homozygous mutation of the dawn kinase C gene. This means that because this kind of sperm abnormality may be genetic, fathers may be able to pass the condition on to their sons .
Microcephaly is when the sperm ’ second head is smaller than normal, besides known as small-head sperm. Small-head sperm may have defective acrosome ( a air pocket of enzymes in the sperm steer used to enter the egg ) or reduced genetic material .
Pinhead sperm, a pas seul of the small-head sperm, is when the point appears as a personal identification number with minimal to no parental DNA subject. The bearing of pinhead sperm may point to a diabetic condition .
Tapered head sperm are sperm with “cigar-shaped” heads that may indicate the presence of are sperm with “ fusiform ” heads that may indicate the bearing of varicocele in the male or constant exposure of the scrotum to high temperature locations such as casual hot sauna. These taper head sperm much contain abnormal chromatin or packaging of the agnate DNA familial material. abnormal number of sperm chromosomes called aneuploidy has been shown in taper head sperm .
An extreme version of the taper head sperm is the “thin narrow” head sperm with pathologies apparently different from the sharpen capitulum sperm. Thin pass sperm are rarely identified and they may be due to broken DNA, varicocele or disrupted mind formation .
Globozoospermia, or round headed sperm circumstance, is an abnormal sperm morphology that indicates either there is an absence of the acrosome or the sperm is missing inner parts of its head responsible for “ activating ” or turning on the testis and starting the fertilization process. A variation of this type of sperm is the Decondensing pass sperm seen when the sperm prematurely starts to break down its nucleus and the unravel DNA corporeal fills the stallion sperm head .
Headless sperm have no head at all and are called acephalic sperm or decapitated sperm syndrome. They do not have genetic material or chromosomes. This type of sperm may look like a pinhead sperm but upon airless examination, one can see that there is no bantam sperm head giving the sperm the appearance of a free piece of string .
Tail-less sperm are called acaudate sperm, and these sperm are frequently seen during necrosis, the end of most or all of the cells in an organ.
Nuclear vacuoles sperm have two or more large vacuoles ( cyst-like bubbles ) or multiple little vacuoles in the sperm head. These nuclear vacuoles are visible under high exaggeration microscopy. While some studies show this type of sperm has low fertilization likely, other studies have shown no effect. Studies are still in advancement .
Multiple parts sperm can have multiple heads or tails. When the sperm has two heads, it is called a duplicate sperm, a condition linked to exposure to toxic chemicals, dense metals like cesium, smoke or high prolactin hormone in the male .
Large swollen midpiece or sperm neck may be related to defective mitochondria, the energy-making parts of the sperm cell. It may besides be a sign that the centrioles, the guidance arrangement for moving chromosomes stored at the sperm neck, may be missing or broken .
Coiled-tail sperm have been exposed to either wrong seminal fluid conditions or the presence of bacteria. These sperm can not swim, as their tails are damaged. Heavy smoke has been linked to the presence of coiled-tail sperm .
Sperm cells with inadequate tails much have low or no motion and are called dais buttocks or Dysplasia of Fibrous Sheath ( DFS ) sperm. This chase defect happens during former spermiogenesis or sperm cell formation in the testis. Some patients with DFS besides have chronic respiratory disease associated with nonmotile cilia syndrome. Stump-tail or DFS is an autosomal recessive allele genic disease connected with abnormal genes that encode for proteins such as the sperm neck centrin 1 protein. DFS has been linked to a higher share of sperm aneuploidies or abnormal chromosomes .
Sperm morphology’s effects on fertility
While the most common campaign of male sterility is gloomy sperm count, the shape of the sperm can besides play a role. Morphology can affect richness because sperm need a certain form to be able to penetrate the out layers of the egg .
Most men with abnormal sperm morphology are still able to father a child, but achieving pregnancy may take longer or require aid from a richness specialist .
intrauterine insemination ( IUI ) or in vitro fertilization ( IVF ) may be an option for those with sperm morphology issues. Intracytoplasmic sperm injection ( ICSI ) can be used in accession to IVF to increase the chances. Taking antioxidants in male richness supplements for three or more months has been shown by some researchers to improve abnormal sperm morphology .
During IVF with ICSI, the lab will be able to choose a sperm that has the highest gamble of success, based on morphology and motion, and directly inject the sperm into a woman ’ sulfur egg. Once the sperm and egg combine to make an embryo, it will be implanted into the woman ’ mho uterus at the correct stage of development.
Sperm morphology is just one of many factors affecting male fertility. Find out about other causes of male infertility.
Can sperm shape be corrected?
A man ’ second body is constantly producing modern sperm. As he ages, his sperm can become less healthy. For most men, sperm production will begin to drop after age 40. Changes to a man ’ randomness diet and life style that can improve the health of future sperm include :
- Exercising regularly
- Avoiding self-medicated testosterone steroid use, heavy tobacco use, drinking or illegal drugs
- Reducing the amount of caffeine consumed
- Losing weight, if needed
- Avoiding hot tubs
- Decreasing stress
- Wearing loose, cotton boxer shorts
- Eating foods or supplements rich in antioxidants every day.
note that it takes about three months to make and transit the new sperm, so any changes in diet or life style will require some clock before improvements are seen. due to the effects of aging, some physicians will recommend that a man freeze his sperm earlier in liveliness if he expects he will be waiting until later in life to have a child. This allows a serviceman to have the healthiest sperm available when looking to start a family at any age. The sperm freeze and banking work works best entirely when the man has adequate normal healthy sperm .
Request appointment For more information about male fertility, make an appointment to meet with a doctor at the Loma Linda University Center for Fertility and IVF .