Catholics believe that Christ was conceived in Mary by the power of the Holy Spirit, and not through a human father. (See Luke 1: 26-38). Though there are other religions that feature stories of miraculous conceptions and births, that fact alone is not evidence that the virgin birth was just a narrative detail that was lifted from some other place. Take the Gospels, for example. If you are looking for historical facts about Jesus’ life, that’s clearly where you will go, given that they were based on the oral tradition that came from eyewitness testimony. It’s worth noting that both Matthew and Luke make a clear reference to Mary’s virginity.
If you look at what the Church believes about Jesus, the virgin birth fit there, too. If (as Catholics believe) Jesus is both fully God and fully human, then it makes sense that he would not have a human father, but would be conceived by the power of the Holy Spirit.