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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 persistent fetal circulation. [2] The newborn is therefore born with elevated PVR, which leads to pulmonary hypertension.
Infant respiratory distress syndrome (IRDS), also known as surfactant deficiency disorder (SDD), [2] and previously called hyaline membrane disease (HMD), is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs.
A premature ventricular contraction (PVC) is a common event where the heartbeat is initiated by Purkinje fibers in the ventricles rather than by the sinoatrial node. PVCs may cause no symptoms or may be perceived as a "skipped beat" or felt as palpitations in the chest. PVCs do not usually pose any danger. [1]
Transient tachypnea of the newborn occurs in approximately 1 in 100 preterm infants and 3.6–5.7 per 1000 term infants. It is most common in infants born by caesarian section without a trial of labor after 35 weeks of gestation. Male infants and infants with an umbilical cord prolapse or perinatal asphyxia are at higher risk.
As the umbilical vessels are obliterated and the infant starts breathing at birth, the source of oxygen changes from the placenta to the lungs. This major trigger will facilitate the transformation from fetal to postnatal circulation in many ways. First, the ductus venosus was previously kept open by the blood flow from the umbilical vein.
Histopathology of placenta with increased syncytial knotting of chorionic villi, with two knots pointed out. The following characteristics of placentas have been said to be associated with placental insufficiency, however all of them occur in normal healthy placentas and full term healthy births, so none of them can be used to accurately diagnose placental insufficiency: [citation needed]
Pulmonary interstitial emphysema often resolves gradually and may take 2–3 weeks. [2] For longer durations of PIE the length of time of mechanical ventilation needed may increase and the incidence of bronchopulmonary dysplasia becomes higher. Some infants may develop chronic lobar emphysema, which may require surgical lobectomies. [3]
Patent ductus arteriosus (PDA) is a medical condition in which the ductus arteriosus fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs from the aorta, which has a higher blood pressure, to the pulmonary artery, which has a lower blood pressure.