We are big time users & my husband's step mom has done a lot of research into this-because our hormones are so different from usual while pregnant when topically applied we are more prone to reactions such as rashes & burning. There's no evidence linked to miscarriage or defects just our own skin irritation.
Some oils are unsafe for pregnancy. My mother had gotten me a headache relief oil roller and it turns out one of the oils in it isn't safe for pregnancy. Just look up an oil before you use it
I read that cinnamon based oils aren't safe in first trimester. In fact, a lot aren't. I'm an avid user of oils. I want to be able to use thieves. I ordered the Gentle Baby book, so I hope it helps.
I use essential oils all the time? Why do you think their not safe?
I use the peppermint one and I think it's fine. It was my fiances mom that gave it too me and she's a nurse so I would think she would know if it's not safe.