A typical human pregnancy lasts 40 weeks, but most parents know this number is only a rough estimate. Babies are born on a seemingly unpredictable timeline, with a normal pregnancy ranging from 38 ...

Early symptoms of pregnancy ... during the first trimester due to your human chorionic gonadotropin (hCG) levels. HCG is a hormone produced during pregnancy that's made by cells formed in the ...

Researchers reveal that the guinea pig pre-implantation embryo is very similar to the human embryo, spurring a better understanding of infertility and early human development.