Taking CBD during pregnancy is a pretty strict no given its relationship to THC. While research is limited on the effects of CBD on fetal development, marijuana (which contains both THC and CBD) falls into the same category as cigarettes and alcohol when it comes to prenatal nutrition, both of which should be avoided.
Marijuana is reported to affect fetal brain development1 during pregnancy and after (i.e. if you’re using it while breastfeeding), in addition to increasing the risk of birth complications. While more of the conclusive research done on the use of marijuana during pregnancy or while breastfeeding mainly centers around THC, it’s suggested that CBD may have similar effects. For that reason, CBD is something you should probably give up while pregnant and breastfeeding.