* Nutrients are provided by the mother through the placenta, which acts as a bridge between the mother's bloodstream and the fetus's bloodstream. These nutrients include carbohydrates, proteins, fats, vitamins, and minerals, all of which are essential for fetal growth and development.

* Oxygen is also transported from the mother's blood to the fetus through the placenta. This oxygen is crucial for the fetus's cells to function and grow.

It's important to note that while these are the two primary substances, the fetus also needs other factors for healthy development, such as a healthy environment in the womb and protection from infections.