It is estimated that every year more than 15 million babies are born too early. The lungs of these premature infants are often immature and easily damaged. Premature births happen for a variety of reasons—some known and some unknown. Those that are known include infections and conditions such as diabetes and high blood pressure.
Scientists are researching what causes premature births, in an attempt to develop solutions to prevent them. Scientists are also working on the development of an artificial placenta. At the University of Michigan, five premature lambs were placed in artificial placentas and kept alive for weeks. During this time, each lamb’s blood was circulated through its artificial placenta.

Discuss how the development of an artificial placenta is an important step in the study of premature births.

Question 1: State how an artificial placenta would be of benefit to the lungs of premature infants.

Question 2: Explain why the lambs’ blood must be filtered as it circulates through the artificial placenta.

Question 3: State one reason why premature lambs were likely used as model organisms in this study rather than mice.

The development of artificial placentas can be a solution that would allow the survival of premature babies, favoring the complete development of the organs -such as the lungs- that would allow their viability.

Explanation:

The main problem facing a premature newborn - before 30 weeks of gestation - is his inability to breathe, due to an immature respiratory system.

During pregnancy, the mother provides nutrients and oxygen to the fetus through the placenta and the umbilical cord, which in turn receives carbon dioxide and waste products that eliminates the future baby. At birth, the baby should be able to breathe and nourish itself.

Some circumstances can cause premature birth, with the consequences of a fragile baby who may not be able to breathe due to the immaturity of his lungs.

In the case of a newborn whose lungs are not suitable for breathing, an artificial placenta provides conditions similar to the maternal uterus that allow the complete development of the respiratory system, that is, the formation of the bronchial tubes, bronchioles, pulmonary alveoli, as well as the production of surfactant, a substance that prevents alveolar collapse during breathing.

Knowing that a premature baby cannot return to the mother's womb, it is proposed to extend the period of development by introducing the newborn in a device that simulates the conditions of the uterus and the placenta.

In the artificial placenta, also called biobag, the umbilical cord of the lambs is connected to a gas exchange machine - similar to that of extracorporeal circulation - capable of providing blood, nutrients and oxygen, in addition to eliminating waste products and dioxide carbon

The liquid contained in the biobag has a composition similar to that of the amniotic fluid and provides nutrients to the lamb. External monitors connected to the lamb provide all the necessary information about the vital signs of the developing animal.

Lambs have been chosen as a model to perform studies of artificial placenta because their fetal development is very similar to that of humans although their maximum gestation time is shorter.

In lambs, full gestation lasts up to 22 weeks, and lung development occurs between weeks 15 and 17, while in the human fetus it occurs between weeks 21 and 26. However, the stages of development are quite similar.

Since so far only the use of artificial placentas has been achieved for a maximum of 30 days, the relative rapidity with which lung development occurs in lamb fetuses allows its study, and the results of tests in lambs can be extrapolated to the fetus Human in the future.

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