<unk>  is a condition caused by a failure in the systemic<unk>  and pulmonary<unk>  to convert from the antenatal<unk>  pattern to the "normal" pattern. Infants experience a high mean arterial pulmonary artery pressure and a high afterload at the right ventricle. This means that the heart is working against higher pressures, which makes it more difficult for the heart to pump blood. In a fetus, there is high pulmonary vascular resistance (PVR) and low pulmonary blood flow as the fetus does not use the lungs for oxygen transfer, but instead relies on the placenta for oxygen. When the baby is born, the lungs are needed for oxygen transfer and need high blood flow which is encouraged by low PVR. The failure of the circulatory system of the newborn to adapt to these changes by lowering PVR leads to<unk> . The newborn is therefore born with elevated PVR, which leads to pulmonary hypertension. Because of this, the condition is also widely known as<unk>  pulmonary hypertension of the newborn (PPHN). This condition can be either acute or chronic, and is associated with significant morbidity and mortality.
Persistent fetal circulation
Alveolar capillary dysplasia
Neonatal sepsis
Foetal cerebral redistribution
Umbilical cord compression
Shaken baby syndrome
Fetal distress
Placental insufficiency