"His mother, Mary, was going to marry Joseph." Parents normally arranged the marriages of their children. Alternate translation: "The parents of Mary, the mother of Jesus, had promised her in marriage to Joseph" (See: [[rc://en/ta/man/translate/figs-explicit]])
Translate in a way that makes it clear that Jesus was not already born when Mary was engaged to Joseph. Alternate translation: "Mary, who would be the mother of Jesus, was engaged" (See: [[rc://en/ta/man/translate/figs-explicit]])
"before they got married." This may refer to Mary and Joseph sleeping together. Alternate translation: "before they had slept together" (See: [[rc://en/ta/man/translate/figs-euphemism]])
This can be stated in active form. Alternate translation: "they realized that she was pregnant" or "it happened that she was pregnant" (See: [[rc://en/ta/man/translate/figs-activepassive]])