Continuous maternal hyperoxygenation in the treatment of early fetal growth retardation

Continuous maternal hyperoxygenation treatment (2.5 l/min by means of a nasopharyngeal cannula) was given in four patients presenting with intrauterine growth-retarded (IUGR) fetuses and decelerative fetal heart rate (FHR) patterns at 27-28 weeks of gestation. The effect of maternal hyperoxia was studied longitudinally. Neither the incidence of generalized fetal movements (FGM%) nor the pulsatility index of the internal carotid artery increased under hyperoxia. In fact, both variables decreased progressively. FHR variation was abnormal prior to the start of hyperoxygenation and showed a slight but transient increase. On average, maternal hyperoxygenation 'resulted' in a prolongation of the duration of pregnancy of 9 days. The neonatal mortality was similar in the study group as compared to a control group of IUGR infants. However, hypoglycemia, thrombocytopenia and disseminated intravascular coagulation at birth were found more frequently in the study group. Conversely, blood gas abnormalities were less frequent in the fetuses of mothers that were treated with oxygen. We conclude that positive effects of oxygen therapy in IUGR fetuses remain uncertain and that detrimental effects due to prolongation of intrauterine malnutrition have not as yet been sufficiently excluded.