Some say to be safe, don’t start any new supplements once you get pregnant but here’s a study that refutes that.

In a review of hundreds of studies, reseachers found 19 randomized trials with strong evidence showing that compared with supplements, probiotics taken after the 36th week of pregnancy and the first month of lactation were associated with a 22% reduction in the risk of eczema in children.

Also they found 6 randomized trials with solid evidence that women who took omega 3 fatty acid supplements during pregnancy and lactation reduced the risk for childhood allergic reactions to eggs, the most common food allergy, by 31%. 

New York Times Health Section March 13, 2018