The anatomical parts that make up a viviparous mammalian organism in the postembryonic period of development.

The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.

A fetus that is not delivered at the initial PARTURITION of a MULTIPLE PREGNANCY, usually of twins in humans. The retained fetus can progress to term and result in LIVE BIRTH.

Synonyms: Mummified Fetus, Fetus, Mummified, Tissues, Fetal, Retained Fetus, Fetus, Retained, Fetuses, Fetal Tissues, Structures, Fetal, Tissue, Fetal, Structure, Fetal, Fetal Structure, Fetus, Fetal Structures, Fetal Tissue