Due to all the legality issues around CBD in the past, there are unfortunately not very many scientifically validated studies and research materials available on CBD used by pregnant or breastfeeding women.
However, a lot of anecdotal evidence indicates that CBD has certainly helped a lot of women through hyperemesis gravidarum, or severe nausea during pregnancy, with some experiencing almost instantaneous relief. Many also reported to have had it unofficially recommended to them by their doctors, and found that it miraculously worked when pharmaceuticals and traditional cures had been of no help at all.
CBD can also assist with any pain experienced during pregnancy, soothing swollen ankles and easing back ache. After birth it can help to aid in recovery and reduce inflammation in the body, while providing some relief from hormonal mood fluctuations and the stress of taking care of a newborn.
However, as there is no data to show the effects of CBD on breastfeeding babies or when they're still in utero, it is important to consult your own doctor before making the decision to use it as a pregnant or postpartum woman.