Maternal hyperoxygenation in the treatment of intrauterine growth retardation. [Therapy of suspected intrauterine fetal retardation]. [Correlation between the inspired fraction of oxygen, maternal partial oxygen pressure, and fetal partial oxygen pressure during cesarean section of normal pregnancies].
In the current study the efficacy of maternal hyperoxygenation on growth-retarded fetuses was evaluated.
                Thirty-six pregnant women with intrauterine growth retardation were studied. The patients were divided in oxygen-treated (n = 17) and untreated (n = 19) groups. Doppler analysis of the fetal circulation was performed on the arrival to the hospital, after 12 hours, and thereafter on alternate days until delivery. Fetal blood was sampled by cordocentesis for immediate blood gas analysis at entrance to the study and the day of delivery.
                Significant improvement in Doppler flow patterns in treated patients were found when compared with untreated women. The Doppler variations were associated with complementary modifications in fetal blood gas. These differences resulted in a significant modification in perinatal mortality with an incidence of 29% and 68% (p less than 0.01) in treated and untreated groups, respectively.
                Our data suggest a benefit of maternal hyperoxygenation in the treatment of fetal growth retardation. In a randomized prospective study, performed on 45 pregnancies with clinical and sonographic suspicion for intrauterine fetal growth retardation, examinations were done to evaluate the therapeutic effect of bed rest and of additional daily administered glucose infusions or oral galactose applications respectively on the fetal growth, the hemodynamic, respiratory and endocrine insufficiency of the materno-feto-placental unit as well as selected biochemical parameters of the umbilical blood. There is no positive therapeutic effect, either on the impaired endocrine partial function nor on the reduced respiratory function of the feto-placental unit. It is obvious, that despite the improvement of the nutritional supply of the fetus and the revival of the regular fetal growth, the previous lack of fetal growth can not be altered. This can be demonstrated in all three therapeutic groups due to the fact of a resulting high hypotrophy-rate of the newborns. The results prove that the additional supply of the fetus with glucose or galactose does not remarkably improve the therapeutic effectivity as opposed by strict bed rest alone. Despite changes in pulmonary function, maternal oxygenation is maintained during obstetric regional blocks. But in those situations, the administration of supplementary oxygen to parturients is a common practice. Good fetal oxygenation is the main justification; however, this has not been proven. The objective of this randomized, prospective study was to test the hypothesis of whether maternal hyperoxia is correlated with an increase in fetal gasometric parameters in elective cesarean sections.
                Arterial blood gases of 20 parturients undergoing spinal block with different inspired fractions of oxygen were evaluated and correlated with fetal arterial blood gases.
                An increase in maternal inspired fraction of oxygen did not show any correlation with an increase of fetal partial oxygen pressure.
                Induction of maternal hyperoxia by the administration of supplementary oxygen did not increase fetal partial oxygen pressure. Fetal gasometric parameters did not change even when maternal parameters changed, induced by hyperoxia, during cesarean section under spinal block.
There is not enough evidence to evaluate the benefits and risks of maternal oxygen therapy for suspected impaired fetal growth. Further trials of maternal hyperoxygenation seem warranted.