Faculty Bibliography

Umbilical blood was analyzed for pH, pO2, pCO2, HCO3-, base excess, and plasma lactate to evaluate possible errors of fetal scalp blood analysis. Two studies to determine the effect of delayed collection and exposure to air on fetal blood acid-base measurement analyzed anaerobically collected umbilical blood in syringe and capillary samples. In the first study, 37 samples were analyzed and then placed in small droplets on a glass slide and exposed for 30 seconds and 60 seconds respectively. These samples were then collected and reanalyzed. No significant change was noted through 1 minute of exposure in any of the acid-base parameters measured. In the second study, 34 samples were again analyzed and then exposed in droplets for a full 5 minutes. Differences in measurement of pO2, base excess, and plasma lactate remained insignifiicant even up to 5 minutes. The results of this study demonstrate that the occasional slow scalp blood collection or admixture with air do not present a significant obstacle to proper use of fetal acid-base analysis

One hundred forty-six patients were monitored for up to 2 hours after third-trimester amniocentesis. The patterns of uterine and fetal activity, as well as fetal heart rate, were analyzed using the criteria for nonstress and contraction stress testing. There was a clear relationship between these observations and perinatal outcome. Postamniocentesis monitoring was associated with an Apgar score of 6 or less in only 10% of cases with reactive patterns, compared with in 75% of cases with nonreactive patterns and reduced variability and in all cases with late-component deceleration. All cases of immediate fetal jeopardy were detected and there was no fetal loss. Postamniocentesis monitoring appears to offer significant prognostic information for perinatal outcome in high-risk pregnancy

Twelve patients underwent induction of labor at term, seven by prostaglandin F2 alpha (PGF) and five by oxytocin infusion. Serum samples were drawn before induction and at two hour intervals after infusion was started, throughout labor. The samples were analyzed for estriol (E3) and its principal conjugates, estriol-3-sulfate (E3-3S), estriol-16-glucosiduronate (E3-16G), estriol-3-glucosiduronate (E3-3G), and estriol-3-sulfate-16-glucosiduronate (E3-SG). No significant changes occurred before eight hours of infusion. Two pre-eclamptic patients showed a 100% increase in serum E3 while receiving PGF. The increases correlated best with rising levels of E3-SG. None of the five pre-eclamptic patients given oxytocin showed this striking changes. These observations raise the possibility that PGF may alter the metabolism of estriol in pre-eclamptic patients, during labor

A trial of intravenous dexamethasone for prevention of neonatal respiratory distress syndrome was carried out prospectively. There were 112 treated and 188 control patients, matched for gestational age, birth weight, rupture of membranes, and antepartum diagnosis. No short-term deleterious effects on mother or infant were demonstrable. There was an increased incidence of cesarean section and puerperal infection in the treated patients. This was not related to the steroid therapy. There was no increased incidence of infection in the treated neonates. At 28 to 33 weeks' gestation, the treated newborn infants had one half the perinatal mortality and one fourth the incidence of severe respiratory distress syndrome seen in the controlls. Under 28 weeks, and from 34 to 36 weeks, no difference between treated and control groups was observed. Intravenous dexamethasone is effective in reducing perinatal mortality from respiratory distress syndrome in premature infants delivered between 28 to 33 weeks' gestation