Anogenital distance, or AGD, is the distance between the anus and the genitals.
In animal research, hormones called androgens strongly affect this distance before birth. That led researchers to ask whether AGD in adult men might give clues about early reproductive development, sperm quality, or fertility.
It is an interesting idea, but the human studies do not all agree. AGD should not be treated as a simple fertility score or as a reason to panic.
Human studies of anogenital distance are observational and do not all agree. Some find links with sperm count or sperm shape, while others find no clear link with semen quality or fertility. AGD is not an established clinical fertility test.
What AGD May Reflect
Male reproductive development is partly controlled by androgen hormones before birth.
In animal studies, lower androgen activity during an important stage of development can shorten AGD. Researchers have studied whether the same measurement may offer clues about male development in humans.
Some Studies Link Shorter AGD With Lower Sperm Counts
A Danish study of 1,106 young men found that a shorter distance from the anus to the base of the scrotum was linked with lower sperm counts and poorer sperm shape.
Some fertility-clinic studies have also found links between AGD and semen results.
Other Studies Do Not Find the Same Relationship
The results are not consistent.
One study of 656 young men found links with some reproductive hormones but not with semen quality. A 2022 study also found no clear link between AGD and fertility status or the time it took a couple to become pregnant.
That mixed evidence is a major reason AGD is not a standard fertility test.
Why AGD Is Not a Home Fertility Test
The measurement can change depending on how it is taken, and body size may affect it. There is also no agreed cutoff that tells an individual man he is fertile or infertile.
Even a semen analysis cannot perfectly predict fertility. AGD is much less established than semen testing, hormone testing, a testicular exam, and a proper fertility history.
What About Hormone-Disrupting Chemicals?
Chemicals that can interfere with hormone signals are an active area of reproductive research.
Animal studies show that some exposures during fetal development can change male reproductive development, including AGD. Human studies are harder to interpret because people are exposed to many things over many years.
An adult AGD measurement cannot tell us that one chemical or product caused a man's fertility problem decades earlier.
What Matters More if You Are Concerned About Fertility
If fertility is the concern, start with better-established information. That includes semen analysis, hormone tests when needed, testicular health, medications, heat exposure, smoking, alcohol, body weight, sleep, and medical conditions.
AGD may eventually become one useful piece of the picture. It is not ready to replace those tools.
The Bottom Line
Anogenital distance is an interesting research marker. Some studies link a shorter AGD with poorer semen measures, while others do not.
For now, it should be viewed as a research clue, not a diagnosis and not a prediction of whether one man can father a child.
For related reading, explore testosterone replacement therapy, what testosterone does in men, and our Hormones section.
