Faculty Bibliography

Four pregnancies in three patients with spinal cord injury are presented. The major complications encountered include anemia, pyelonephritis, decubiti, premature labor, precipitate labor, and autonomic hyperreflexia. Autonomic hyperreflexia, a severe mass autonomic reflex response to labor, is associated with tachycardia, hypertension, headache, diaphoresis, and severe anxiety. It is probably due to increased norepinephrine release, as very high urinary metanephrines were measured in the latter two cases presented. Maternal and fetal physiology in labor are altered. Despite severe maternal and fetal stress responses, no fetal depression was observed

A patient with group C polycystic kidney disease had abnormally high concentrations of total serum estriol (E3) but low-normal urinary levels of E3 throughout the period of study (20 weeks of gestation until delivery by cesarean section at 33 weeks, 5 days). At delivery and at regular intervals until 6 hours thereafter serum specimens were analyzed for unconjugated E3 and its four major conjugates. Comparisons were made with levels in three normal volunteer subjects studied in the same way. In the 6 hours, total E3 declined 37% in the subject with polycystic kidney disease whereas in normal subjects the decline ranged from 84% to 99%. Unconjugated E3 was depleted from the serum in all subjects in about 2 hours. The major difference between the patient with polycystic kidney disease and the normal subjects was in the profile of E3 conjugates. In polycystic kidney disease, E3-3-glucosiduronate (E3-3G) and E3-3-sulfate-16-glucosiduronate (E3-SG) respectively made up 83% and 1.8% of the total serum estriol, whereas in the normal subjects the average values were 13% for E3-3G and 49% for E3-SG. There were no consistent dramatic changes in the percentage contribution of any conjugate to the total E3 level in either the patient with polycystic kidney disease or the normal subjects in the predelivery or postdelivery periods. The E3 profile in polycystic kidney disease is explainable in terms of impaired renal function coupled with normal enterohepatic metabolism of E3

Continuous transcutaneous measurement of pO2 (tcpO2) has been adapted to fetal and neonatal use, utilizing a noninvasive miniaturized modified Clark pO2 electrode attached to the skin by adhesive. The unprepared ear of the adult female Flemish Giant rabbit was used for attachment of the electrode, and blood for arterial pO2 (apO2) was taken from the auricular artery. The rabbits were gently restrained and unanesthetized. The tcpO2 and pO2 were compared at environmental temperatures of 20-23, 50, and 60 degrees C, in separate experiments. The data demonstrated that tcpO2 is not the same as pO2. It is most clearly related to local blood flow. tcpO2 only indirectly reflects apO2, when peripheral flow is comparable to central flow. Proper use of tcpO2 in the fetus and neonate requires cognizance of blood flow conditions for correct interpretation. tcpO2 is not indicative of apO2 when reduced peripheral circulation is present, in the rabbit ear

A case of vasa previa in twin pregnancy associated with a sinusoidal heart rate was observed. A review of the world literature revealed eight previously reported cases of vasa previa in twins. No first twin survived, and 62.5% of second twins eventually died from partial or complete exsanguination. This is the first reported case of sinusoidal fetal heart rate in association with vasa previa. Continuous fetal monitoring suggested the diagnosis of funic presentation and of fetal bleeding. A high index of suspicion, use of amnioscopy, ability to detect fetal blood in the vaginal pool, continuous fetal heart rate monitoring and ultrasonography may help in reducing the high perinatal mortality associated with vasa previa

Three hundred thirty-six consecutive cesarean deliveries performed under epidural anesthesia were reviewed. Twenty per cent of mothers suffered at least a 20% fall in blood pressure following administration of epidural anesthesia. An additional 24% required ephedrine, a vasopressor with predominantly beta activity, when other corrective measures failed. Thus, 44% of these patients suffered significant hypotension. Forty-one percent of all elective repeat cesarean sections were treated wih ephedrine because of maternal hypotension. Fifty-one patients delivered by scheduled repeat cesarean section were divided into ephedrine-treated and untreated groups. There were no differences in Apgar scores among infants of both groups. Fetal acidosis was proportional to the severity of hypotension and the ephedrine dose. The metabolic abnormalities were most pronounced when severe hypotension, requiring over 15 mg of ephedrine, was present. Following restoration of blood pressure with conventional measures and ephedrine therapy, lactic acidosis persisted until delivery, whereas PO2 and PCO2 reverted toward normal values. The hypoperfusion of the intervillous space was the most likely cause of the observed significant umbilical venous and arterial lactic acidosis. Maternal hypotension remains a significant problem complicating conduction anesthesia

Fetal umbilical artery blood was analyzed for pH and lactate at intervals over a 3-hour period. No significant change occurred in pH over the first 30 minutes, despite a progressive rise in plasma lactate. The pH changes paralleled the lactate in an inverse relationship, but remained within the error of the method for the first hour. Lactate analysis should be considered for clinical use, for confirmation of pH observations. Also pH assays may be used in any hospital with a blood-gas capability, since a 30-minute delay within the assay does not materially alter the results. A laboratory in the delivery room area is not essential to proper use of fetal blood pH analysis