An extracorporeal system to support a human premature fetus immersed in an amniotic fluid held within a fetal chamber and to maintain the fetus during maturation, the system comprising: a fetal chamber including an upper half having a first rigid frame defining a first lip and a lower half having a second rigid frame defining a second lip where the upper and lower halves have an open position where a human premature fetus can be placed within the fetal chamber and a closed position where a plurality of latches creates a fluid-tight seal between the first and second lips to retain the fetal chamber in a closed, fluid tight configuration, wherein the fetal chamber is configured such that when the human premature fetus is laid in the fetal chamber lengthwise in a horizontal position along a first horizontal direction the fetal chamber has a length along the first horizontal direction and a width along a second horizontal direction perpendicular to the first horizontal direction with the length greater than the width; an amniotic fluid circuit (300, 320) configured to provide amniotic fluid to and from the fetal chamber, the amniotic fluid circuit comprising an inlet port to allow flow of the amniotic fluid into the fetal chamber and an exit port to allow flow of the amniotic fluid from the fetal chamber; and an oxygenation circuit comprising an infusion line and a drain line wherein the drain line is configured to transport blood from the human premature fetus to an oxygenator and the infusion line is configured to transport blood from the oxygenator to the human premature fetus and wherein the oxygenation circuit does not include a pump; characterized in that the fetal chamber has at least one flexible wall, supported by at least one of the rigid frames, that facilitates a variable volume that can expand upon growth of the fetus with the fetal chamber in the closed configuration without opening the fetal chamber. a fetal chamber including an upper half having a first rigid frame defining a first lip and a lower half having a second rigid frame defining a second lip where the upper and lower halves have an open position where a human premature fetus can be placed within the fetal chamber and a closed position where a plurality of latches creates a fluid-tight seal between the first and second lips to retain the fetal chamber in a closed, fluid tight configuration, wherein the fetal chamber is configured such that when the human premature fetus is laid in the fetal chamber lengthwise in a horizontal position along a first horizontal direction the fetal chamber has a length along the first horizontal direction and a width along a second horizontal direction perpendicular to the first horizontal direction with the length greater than the width; an amniotic fluid circuit (300, 320) configured to provide amniotic fluid to and from the fetal chamber, the amniotic fluid circuit comprising an inlet port to allow flow of the amniotic fluid into the fetal chamber and an exit port to allow flow of the amniotic fluid from the fetal chamber; and an oxygenation circuit comprising an infusion line and a drain line wherein the drain line is configured to transport blood from the human premature fetus to an oxygenator and the infusion line is configured to transport blood from the oxygenator to the human premature fetus and wherein the oxygenation circuit does not include a pump; characterized in that the fetal chamber has at least one flexible wall, supported by at least one of the rigid frames, that facilitates a variable volume that can expand upon growth of the fetus with the fetal chamber in the closed configuration without opening the fetal chamber.