Evaluating the fetus at risk for cardiopulmonary compromise

The in-utero environment is relatively hypoxic, but fetal physiologic adaptation assures adequate tissue oxygen supply. Fetal reactions to acute or chronic hypoxia are different and are modified by the preceding fetal condition. Acute fetal hypoxia episodes are often not preventable. By contrast, good obstetric care during labor may prevent poor fetal outcome in many cases of acute fetal hypoxia. The pathophysiology of chronic fetal hypoxia caused by placental insufficiency differs from chronic fetal hypoxia seen during the last weeks of diabetic pregnancies. The efficacy of antenatal fetal surveillance methods in preventing perinatal complications is different in these two conditions. Electronic fetal heart rate testing and Doppler flow assessment methods have been successful in detecting chronic fetal hypoxia caused by placental insufficiency. However, these methods have been unable to prevent chronic fetal hypoxia complications in diabetic pregnancies. Therefore, research to find new strategies and early and reliable biomarkers is necessary to assess fetal well-being and to decide when to deliver the fetus.