The poster above is being down voted because they are not using the proper terms. What they are talking about is called sex, with gender explicitly being the socially constructed notion usually based on biological sex.

Further, they are using a bad definition of biological sex anyway, as 'people who can impregnate' and 'people who can give birth' is limiting (many cis men can't impregnate for various reasons, and no cis woman can give birth after a certain age, or before a certain age).

The rest of your own comment is low-effort claims with no connection to the topic at hand.

However he is exactly wrong. Check the dictionary “ either of the two sexes (male and female), especially when considered with reference to social and cultural differences rather than biological ones”. Gender is the term used when talking about the social construction.