Because a fetus develops substantially with respect to external form and internal organs during the second half of pregnancy, our current capability to deliver and maintain preterm infants actually is a kind of partial ectogenesis. Supported by all of the equipment in the neonatal intensive care unit (NICU), a premature infant continues its development as a normal fetus of the same gestational age would do inside the mother’s uterus, but with one important exception. Inside the womb, oxygenated, nourished blood comes in, and blood carrying waste goes out, through the placenta and umbilical cord. Once delivered, however, a preemie must breathe through its lungs, cleanse the blood with its liver and kidneys, and get nutrition through its gastrointestinal tract.