It was absolutely not medical orthodoxy at the time, at all.

Classical (ancient western) medical tradition of course traced all women's health problems back to the uterus--physical or what we would call mental; wherever in the body they might occur. There were, however, differing views on exactly how the uterus could cause all these problems. Soranus (author of a major gynecological text, including advice on early child-rearing) and Galen (super important medical authority in general) thought that the uterus, from its location in the lower torso, affected other internal organ through vapors/humors and imbalances of temperature. But there was a competing school of thought, too.

Aretaeus of Cappadocia, who was exceptionally interested in what we'd call mental illness, was one of the most influential authors pushing the idea of the "wandering womb." That is, that the uterus roved throughout a woman's body, wreaking havoc wherever it went.

Early modern physicians, moving beyond scholastic thought experiments to conduct practical research, inherited both traditions! William Harvey, credited with discovering as important and fundamental a phenomenon as the circulation of the blood, wrote in 1651:

When the uterus either rises up or falls down, or is in any way put out of place or is seized with spasm

while Thomas Willis, an Oxford professor with a particular interest in the nervous system (and the uterus' influence on mental health in women) scoffed:

The former opinion, although it plead antiquity, seems the less probable, for that the body of the womb is of so small a bulk...and is so strictly tyed [sic] by the neighbouring parts round about, that it cannot of it self be moved, or ascend from its place

But by the mid-18C, anatomical research had sealed the point. The uterus was cemented in its place inside the body.