Unisom safe during pregnancy ??

So, I’ve seen many people on here saying that Unisom is safer than Melatonin, which seems crazy to me because Melatonin is already produced in your body and Unisom contains synthetic chemicals. So, upon further investigation, I found some articles stating that Unisom has been linked to certain birth defects such as Cleft lip and cleft palate, pyloric stenosis, hypoplastic left heart syndrome, spina bifida, and neural tube defects due to the main ingredient Doxylamine. Has anyone else heard of this before??