Matthew 1:18

Τοῦ δὲ Ἰησοῦ Χριστοῦ ἡ γέννησις οὕτως ἦν· μνηστευθείσης γὰρ τῆς μητρὸς αὐτοῦ Μαρίας τῷ Ἰωσήφ· πρὶν ἢ συνελθεῖν αὐτοὺς εὑρέθη ἐν γαστρὶ ἔχουσα ἐκ πνεύματος ἁγίου.

Now the birth of Iesus Christ was as follows: when his mother Maria was betrothed to Ioseph, before they had cohabited, she was found to be with child by the Holy Spirit.