الفهرس | Only 14 pages are availabe for public view |
Abstract Foetal hypoxia activates a range of biophysical, cardiovascular, endocrine and metabolic responses. Foetal cardiovascular responses to hypoxia, which include modification of the heart rate, an increase in arterial blood pressure and redistribution of the cardiac output towards vital organs, are probably the most important adaptive reactions responsible for maintaining foetal homeostasis. Hypoxic pregnancy conditions can be classified into 3 subtypes: 1. Pre placental hypoxia, where both the mother and her foetus will be hypoxic (i.e., high-altitude, cyanotic maternal heart disease; etc.). 2. Utero placental hypoxia, where the maternal oxygenation is normal, but the utero-placental circulation is impaired (i.e., preeclampsia, placental insufficiency, etc.). 3. Post placental hypoxia, where only the foetus is hypoxic. A foetus with intrauterine growth restriction (IUGR) is a foetus with an estimated weight less than the 10th percentile for gestational age. With a prevalence of 5 % in the general population. Chronic hypoxia associated with placental insufficiency plays a key role in the aetiology of intrauterine growth restriction, also the foetal heart plays a central role in the adaptive mechanisms for hypoxemia and placental insufficiency. |