Non-invasive measurements of hemodynamic transition at birth

The transition to extra uterine life at birth is one of the greatest
physiologic challenges that most humans encounter. It begins with lung aeration
and the onset of air-breathing. Liquid that fills the airways must be cleared
immediately after birth to allow entry of air, recruitment of a functional
residual capacity (FRC) and onset of pulmonary gas exchange. These processes
initiate respiratory and cardiovascular responses in the newborn including a
large increase in pulmonary blood flow, closure of vascular shunts, the onset
of sustained regular breathing, and increased blood oxygenation.

Recent research has been focusing on the factors that regulate lung aeration
and the establishment of FRC at birth. Hemodynamic changes that need to take
place after birth are also essential for adequate gas exchange and oxygenation
of the vital organs. These are regulated by a complex, interactive group of
factors, which interplay is incompletely understood. Much of our knowledge at
birth is based on animal studies. Data on human fetuses and newborns are sparse
because of the invasive techniques that would be necessary to obtain them.

Traditionally the only objective parameter measured for evaluation of the
hemodynamic condition of the infant at birth is heart rate. Oxygen delivery to
the peripheral tissue is defined by the peripheral blood flow and arterial
oxygen content. More information is needed to evaluate the hemodynamic
condition at birth because peripheral blood flow is dependent on cardiac output
and peripheral vascular resistance. There is very little human data available
on hemodynamic changes during transition directly after birth. A better
understanding is essential when attempting to understand problems associated
with circulation in the immediate newborn period and develop strategies to
support transition.

To explore the hemodynamic changes during transition at birth by gathering
non-invasive physiological data in healthy term infants.

Prospective observational study performed in the Leiden University Medical
Center (LUMC)

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