Such a registry is farcically useless though.
At best, it would provide some diagnostic data to dox future porn stars / and or / identify sexual predators posting illicit photos of their junk.
At worst, it would be rendered useless by genital mutilation (either early in life, such as circumcision, or for cosmetic reasons later in life, such as all those thing people do with piercings and scarification), and provide sick fucks with a national registry of baby crotch shots.
And for what? To placate some bizarre moral panic?
Here's a very real, very likely consequence of trying to do this shit, with it being the basis for providing health care services, or assigning gender. There's a disorder called Swyer Syndrome. It is caused by the SRY gene being defective in an XY genotype fetus's development.
https://rarediseases.org/rare-diseases/swyer-syndrome/It results in a normal appearing female external genital package, but missing or severely stunted (and non-functional) ovaries, with otherwise normal vaginal and uterine development. People with it develop as female identity type more often than not.
So-- A baby is born, and it has the external female package. Its DNA is sampled, per this bullshit plan. Whoa there, cowboy-- that's a boy! (Except it's totally not.)
How does Orange Idiot intend to resolve this? Do they do a full on sex-change operation to give the baby a reconstructed penis, and some marbles with hormone therapy, and call it a *WIN!*, or do they offer reproductive/gynecological health services for the female baby, so that it can get pregnant via donor eggs, and gets proper hormone replacement for health reasons?
Really, this kind of thing is just pure epic fail before it even leaves the gate. Why even trial balloon it?