Some substances in medicines, household items and the environment are known to affect prenatal child development. In a study published in Toxicological Sciences, researchers tested the effects of five drugs (including caffeine and the blood thinner warfarin) on the growth of zebrafish embryos. They found that all five had the same effect, impairing the migration of bone-forming cells which resulted in the onset of facial malformation. Zebrafish embryos grow quickly, are transparent and develop outside of the parent’s body, making them ideal for studying early development. A zebrafish-based system could be used to easily screen for potentially harmful substances, reducing animal testing on mammals and supporting parents-to-be when making choices for themselves and their baby.