Total Anomalous Pulmonary Venous Return (TAPVR): blood from pulmonary veins goes into SVC. Causes mixing of deoxygenated and oxygenated blood. Atrial septal defect leading to shunt of blood from R. atrium to L. atrium.
Atrial Septal Defects: from either excessive resorption of septum primum leading to a large oval foramen or from absence of septum secundum. Leads to L. to R. shunting of blood.
Common atrium: absence of both septum primum and secundum leading to only one atrium.
Ventricular Septal defect: most common and can be fixed. Part of interventricular septum (usually membranous portion) fails to grow. Allows blood from L. ventricle to go into both aorta and pulmonary arteries.
Patent Ductus Arteriosus: ductus arteriosus fails to close and form ligamentum arteriosum. Blood from higher pressured aorta back flows into pulmonary arteries.
Persistent Truncus arteriosus: failure of conotruncal cushions to separate aorta and pulmonary arteries. Single outflow trunk causing mixing of blood leading to cyanosis.
Transposition of Great Arteries: R. ventricle connected to aorta and L. ventricle connected to pulmonary artery. 2 independent circulations. Also have patent ductus arteriosus.
Tracheoesophageal fistula: improper division leading to open communication between trachea and esophagus
Esophageal atresia: esophagus ends in blind pouch. Usually accompanied by tracheoesophageal fistula. Associated with polyhydramnios
Polyhydramnios: fetus is unable to swallow amniotic fluid because of GI tract blockage. Fluid accumulates in amniotic sac.
Pyloric stenosis: muscle layer in pyloric region hypertrophies, causing narrowing of pyloric lumen.
Diaphragmatic Hernia: abdominal contents herniate into pleural cavity because of failure of pleuroperitoneal membrane to fuse. Most found on left side. Abdominal contents compress lung buds causing pulmonary hypoplasia.