Microrna with placenta-permeability and uses thereof

A method for administering small RNAs to a fetus, characterized in that the method comprises the following step:

• (a) administering small ribonucleic acids (small RNAs) to a mother's body so that the small RNAs can enter the fetus from the mother's body through placenta to play their role in the fetus, wherein the small RNAs include micro-ribonucleic acids (miRNAs), small interference ribonucleic acids (siRNAs) or a combination thereof.

A kit used for the administration of small RNAs, characterized in that the kit comprises:

• (a) a container and a medicament in the container, wherein the medicament comprises the small RNAs as active substances, and when the medicament is administered to a mother's body directly, the small RNAs enter fetus through placenta to play their role in the fetus;
• and
• (b) an instruction for use.

A method for preventing and treating a fetal disease, or regulating normal growth and development of a fetus comprising steps of :

• administering effective amounts of medicament comprising small RNAs as active substances to a mother's body so that the small RNAs can enter the fetus from the mother's body through placenta to play their role in the fetus, wherein the small RNAs include miRNAs, siRNAs or a combination thereof.