Water and complex organic molecules are necessary ingredients in the emergence of life. They are detected in various astrophysical environments (e.g., low- and high-mass star-forming regions, prestellar cores, outflows, comets). In particular, they are found to be highly abundant in the warm inner regions of protostars, where the icy grain mantles desorb. These molecules can consequently be incorporated into asteroids and comets and possibly delivered to planetary embryos through impacts. I will present recent observational results obtained on water deuteration and complex organics in star-forming regions. I will discuss the possible formation mechanisms of these species and their similarities and differences with comets.