DOPPLER STUDY OF THE FETAL CIRCULATION DURING LONG-TERM MATERNAL HYPEROXYGENATION FOR SEVERE EARLY ONSET INTRAUTERINE GROWTH-RETARDATION

In 21 severely growth-retarded, hypoxemic fetuses at 22-30 weeks' gestation, the effect of long-term maternal hyperoxygenation on serial Doppler measurements of the fetal descending thoracic aorta mean velocity (V(m)), common carotid artery pulsatility index (PI) and umbilical artery PI was investigated. The treatment was continued on average for 4 weeks and delivery, at 26-34 weeks, was decided for fetal or maternal indications. In the subgroup of 12 fetuses that survived, the mean aortic V(m) increased within 72 h of maternal hyperoxygenation. This increase continued for 1-8 weeks, after which there was a decrease to pretreatment values. In the subgroup of neonatal deaths (n = 5), there was a non-significant increase in mean aortic V(m). In the subgroup of intrauterine deaths (n = 4), there was a non-significant trend for continuing deterioration in mean aortic V(m) throughout the period of maternal hyperoxygenation. The mean carotid PI did not change significantly in any of the subgroups during maternal hyperoxygenation. However, in the subgroup that survived there was a tendency for improvement and in the subgroup of intrauterine deaths a tendency for deterioration. The mean umbilical artery PI did not change significantly in any of the groups or subgroups during maternal hyperoxygenation. Therefore, measurement of aortic V(m) is a useful indicator of fetal response to maternal hyperoxygenation and its increase constitutes a favorable prognostic factor.