Women naturally have a slightly wider pelvis than men, so that there is enough room for the baby's head at birth. As a Swiss study has shown, the pelvis is obviously particularly broad when the woman reaches her most fertile age. As the scientists at the University of Zurich are currently reporting in the journal "Proceedings of the National Academy of Sciences", the width of the female pelvic belt increases significantly from the beginning of puberty, but then becomes narrower again from about 40 years. This "reprogramming" is therefore presumably directly related to changes in the female hormonal balance.
widening begins with onset of puberty
If a woman is built relatively wide in the middle of the body, this is often referred to as a "childish pelvis".Not for no reason, because the female pelvis expands during the childbearing time to prepare the body for an imminent birth. A wide pelvis facilitates the exit of the child, while a very narrow pelvic outlet can cause birth complications. Researchers around Marcia Ponce de León from the University of Zurich are now reporting in the "Proceedings" how these changes in female anatomy are going on. According to this, the widening begins at the beginning of puberty until the female lap belt reaches its maximum width at the most fertile time. In the further course of life, the basin would then become narrower.
"From the age of about ten years the development of women is changing dramatically, while the male development continues its earlier course," the experts write in their article."Around the age of 40 to 45 years the female development changes again, in a direction which corresponds to the male development largely," the scientists further.
Age differences between sexes
The researchers had examined a total of 275 healthy persons using computed tomography( CT) for their project in order to understand the development of the pelvis over time. It was found that between the sexes, although there were slight differences in this area from the outset, they were only really clear at the beginning of puberty. This is because, in the case of women aged between 15 and 25 years,the position of the seat leg pubic region can be changed, thereby broadening the pelvic outlet as well as the distances between the hip pans."All in all, these changes in development lead to a broad, fertile birth canal," the team continued. These changes would peak at the age of 25 to 30, with the researchers wondering whether the woman was born or not.
Interaction of genes and hormones
This particular structure of the female basin is presumably due to a complex interplay of hormones, such asEstrogen and certain genes, and would remain until menopause."The female organism can clearly broaden the pelvis and is not simply exposed to a genetically determined development program," Ponce de León is quoted in a communication from the University of Zurich. At the same time, hormones are also strongly influenced by diet and environmental factors."Birth difficulties are therefore not an evolutionary problem. Rather, it appears to be a question of the balance between the hormones and external factors that affect the size of the birth canal and the prenatal development of the child. "
But why is the width of the pelvis reduced after the woman's childbearing age? According to the researchers, this is presumably related to the upright course. For a narrower basin has a stabilizing effect on the pelvic floor and helps to absorb the high pressure that is produced by walking in the abdomen."During a woman's life, the dilemma is first defused in one direction, as the canal widens during the most fertile period, and then into the other by tightening the dimensions after the menopause," the scientists sum up in their article.(nr)