Sperm with many tails also have Macrocephaly, meaning that multiple tailed sperm come with the same problems as their big-headed associates: their chromosomal makeup is abnormal and therefore results in failed pregnancies and miscarriages when meeting with the egg.
Abnormal sperm have head or tail defects — such as a large or misshapen head or a crooked or double tail. These defects might affect the ability of the sperm to reach and penetrate an egg. However, having a large percentage of misshapen sperm isn't uncommon.
When the sperm has two heads, it is called a duplicate sperm, a condition linked to exposure to toxic chemicals, heavy 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.
The tail is made of protein fibers that contract on alternative sides, giving a characteristic wavelike movement that drives the sperm through the seminal fluid, which also supplies additional energy. Some sperm have two heads or two tails and if the testes are too warm they may die or spermatogenesis may not occur.
Mutations in Dnah1 gene appear to be the most common identified cause for male infertility related to sperm tail formation [106–108].
Each subunit of tail, including axonemal, peri-axonemal structures, plays essential roles in sperm motility, capacitation, hyperactivation, fertilization.
Double-headed sperm are non-viable. They are unable to fertilize the egg and result in viable embryos. Thus, they are always dismissed in IVF cycles. When a sperm has two heads, the genetic material is also duplicated, which results in triploid embryos.
The answer is no. The structure of the sperm does not affect the baby in terms of causing any defects physically or mentally. The only issue that can cause due to abnormal sperm morphology is that, depending upon the percentage and the density of abnormal sperms, the pregnancy can be delayed or not occur altogether.
Occasionally, two sperm are known to fertilize a single egg; this 'double fertilization' is thought to happen in about 1% of human conceptions. An embryo created this way doesn't usually survive, but a few cases are known to have made it — these children are chimaeras of cells with X and Y chromosomes.
If your sperm is yellowish-green in colour, it means that it contains bacteria that travel from the urinary tract to the prostate gland. You may occasionally have blood in your sperm, which indicates that you have high blood pressure, which makes it impossible for the couple to conceive.
Can an abnormally shaped sperm fertilize an egg? Yes, it can. However, having higher amounts of abnormally shaped sperm has been associated with infertility in some studies. Usually, higher numbers of abnormally shaped sperm are associated with other irregularities of the semen such as low sperm count or motility.
Thick semen: is it better for pregnancy? Thick semen might offer advantages over thin, runny semen, such as holding a higher number of sperm. Thicker semen may also have an easier time staying in the reproductive system long enough to fertilize an egg (Gurung, 2021).
A low sperm count, also called oligozoospermia, is where a man has fewer than 15 million sperm per millilitre of semen. Having a low sperm count can make it more difficult to conceive naturally, although successful pregnancies can still occur.
Healthy semen is a cloudy white color with a jelly consistency similar to a raw egg. Slight changes in semen color, texture, and even smell might be normal and should no pose concern. In some cases, semen color changes could be a sign of an underlying issue.
Although this is quite rare it can happen and it's called superfetation. Two babies are conceived from separate acts in two different cycles. These babies can be from the same father or two different men. When heteropaternal superfecundation occurs, the babies are from different fathers.
Superfecundation is the fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse, which can lead to twin babies from two separate biological fathers. The term superfecundation is derived from fecund, meaning the ability to produce offspring.
Twins conceived from one egg and one sperm are called identical or 'monozygotic' (one-cell) twins. The biological mechanisms that prompt the single fertilised egg to split in two remain a mystery.
Meanwhile, the defective sperm is incapable of forming its pronucleus. With only one half of the chromosomes functional, the plan for building an embryo is incomplete and the process shuts down. These eggs are known as 1pn and have no potential for life. They are immediately discarded.
Sperm DNA can be damaged during sperm production and transport. This damage is known as DNA fragmentation. High levels of sperm DNA fragmentation have been shown to double the likelihood of a miscarriage occurring (Source – Men and Miscarriage Research).
Research indicates that poor sperm quality, particularly sperm with damaged DNA, is linked to miscarriage and recurrent miscarriage. If you've experienced multiple miscarriages, sperm DNA fragmentation testing may help you understand the cause.
About Abnormal sperm morphology
Globozoospermia, where the sperm head appears small and round due to the failure of the acrosome to develop, is an example of a head defect. Midpiece defects include 'bent' neck (where the neck and tail form an angle of greater than 90% to the long axis of the head) (Pic.
But if you discover that your sperm morphology is abnormal, making positive lifestyle changes can be associated with significant improvements to sperm health. A nutrient-rich diet and regular exercise can help improve your sperm morphology, and is something you can take one day at a time.
If more than one sperm fuses—a condition called polyspermy—multipolar or extra mitotic spindles are formed, resulting in faulty segregation of chromosomes during cell division; nondiploid cells are produced, and development usually stops. Two mechanisms can operate to ensure that only one sperm fertilizes the egg.