 The fetus and embryo develop within the uterus, an organ that sits within the pelvis of the mother.The process the mother experiences whilst carrying the fetus or embryo is referred to as pregnancy.The placenta connects the developing fetus to the uterine wall to allow nutrient uptake, thermo-regulation, waste elimination, and gas exchange via the mother's blood supply; to fight against internal infection; and to produce hormones which support pregnancy.