"The women understand it" is grammatically correct. I assume that it is not a good translation here because it refers to a specific group of women and not to women in general.
Not only that, katrinkadee, but the Czech sentence contains no demonstrative (such as to, ty, etc.) That is a pretty good indication that 'the' should not be arbitrarily inserted into the English.
In translating, you sometimes need to insert a "the" into the English, even when there is no demonstrative in the Czech, in order to be idiomatic; but you should not do so routinely.
Just to be clear, is "it" here a demonstrative or a pronoun ? I mean, it can be both right ? So you can put "ho" like in "ženy ho chápou", or "to", right ?
But I probably get what you mean.
Ženy ho/jej chápou. relates to some particular object in masculine or neuter (ten dopis, ten článek, to sdělení, to psaní) .
Ženy to chápou. relates to some "it". Some concept or abstract or concrete object, the thing we were discussing... It can be a clause "Ženy chápou to, že...".
Many thanks. So, if I understand it right, "to" used in this sort of sentence is conceptually at a greater distance from the actual object than "ho/jej", just as we use "to" to refer to a generalized object in other sentences, for example, "Je to tady hezké".