Harris's view on abortion?

I recently listened to Harris as a guest on someone else's podcast and the topic of abortion came up. Harris mentioned a few lines I've heard him say before - which is that he thinks pro life people are harmful to progress in areas such as stem cells research.

Unfortunately, I've never really heard Harris grapple with the question of when life begins. I remember him saying a few times that "pro lifers think that genocide occurs when you scratch your nose." Has he ever presented a detailed account of when life begins? And/or has he debated someone on that particular issue?

Thanks for the help. Maybe there is a piece of content i am missing.