The Ninth Circuit has rejected an equal protection challenge to derivative citizenship statute found at 8 USC 1432(a)(3).
“Section 1432(a)(3)’s second clause discriminates on the basis of gender. It grants citizenship upon ‘the naturalization of the mother if the child was born out of wedlock and the paternity of the child has not been established by legitimation,’ but it does not grant citizenship in the converse scenario: upon the naturalization of the father if the child was born out of wedlock and the child’s maternity has not been established by legitimation.” “Petitioner, however, does not challenge the clearly disparate treatment identified above. Nor could she, because both her paternity and her maternity were established during her youth. Instead, she argues that the statute unconstitutionally discriminates ‘because it does not contain any equivalent provision stating that a child automatically becomes a citizen upon the naturalization of the father if the child was born out of wedlock and the mother has relinquished parental rights’ or has abandoned the child.”
The full text of Roy v. Barr can be found here:
https://cdn.ca9.uscourts.gov/datastore/opinions/2020/06/04/15-72942.pdf