Francesca Stavrakopoulou was interviewed on BBC Radio 5 live about a variety of things related to the Christmas story: “Hebrew expert: ‘Virgin Birth a Mistranslation'”. One of those things is Matthew 1:23’s use of Isaiah 7:14 to argue that Jesus’ “virgin birth” was foretold by the prophet. She argues that since the Hebrew עלמה means “young woman”, unlike the LXX’s παρθένος, which means “virgin”, that the whole concept is based on a “mistranslation”.
T. Michael Law contest this claim, arguing that παρθένος is used in the LXX of Genesis to describe “young woman”, not necessarily “virgin”, and therefore it is an acceptable translation. You can read his response here: “Was the Virgin Birth a ‘mistranslation’?”
Somehow Mark Goodacre was able to produce a podcast in response already. I haven’t listened to it yet, but his podcast are always good: NT Pod 64: Is the Virgin Birth based on a Mistranslation?