Is guaifenesin safe during pregnancy?

Abstract

It's not clear; little evidence supports or refutes the safety of guaifenesin, a common expectorant, in pregnancy. A small number of observational and case-control studies suggest a weak association between guaifenesin use and inguinal hernias and neural tube defects in newborns. However, substantial methodological flaws, the absence of statistical significance, and low rates of prevalence cast a shadow of a doubt over the data (strength of recommendation [SOR]: B, based on observational and case- control studies).