A report that the Trump administration plans to define gender based on the appearance of infants runs counter to developmental biology and individual privacy.
Life might be more orderly and easy to understand if biology worked just like this:
People come in one of two sexes, male or female. This is determined by chromosomes, and XX means female, and XY means male. Males have penises and testicles—which are all similar in appearance and curvature and size—that secrete testosterone in similar proportions. This testosterone is metabolized and functions similarly in all men and causes them to have similar amounts of musculature and deep voices and certain amounts of facial and back hair, and to act in particular ways due to this hormone. It causes their brains to develop and make them behave in ways that are “manly.”
These men are attracted to women, specifically women who look normal, which is a result of the fact that they definitionally have exactly and only two XX chromosomes that cause them to develop clitori and uteri and breasts and ovaries that produce estrogen and other hormones that cause cycles of growth and shedding of the uterine lining, and who predictably bear children when sperm meets egg. All of these features develop and function the same way in all women who are normal—whose amounts of hormones make their bodies look and feel more or less the same, and whose brains develop and function in a way that is female, and which consigns them to certain roles in social hierarchies.