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The effect of elevations of arterial carbon dioxide tension on renal blood flow has been evaluated with the use of a semichronic fetal lamb preparation and the radioactive microsphere method. Hypercapnia caused a decrease in renal blood flow and an increase in renal vascular resistance. The renal perfusion pressure remained stable throughout the experiment.

During the six years 1970--1975, 62,266 deliveries occurred at Women's Hospital, Los Angeles Country--University of Southern California Medical Center. Of these patients, 18,106 (29 per cent) were monitored, with an incidence of 18 per cent in 1970 which rose to 35 per cent in 1975. The patients were divided into monitored and unmonitored groups for comparison of cesarean section rates and various aspects of perinatal mortality. The overall cesarean section rate was 9.6 per cent with 2,830 cesareans performed in monitored patients (16 per cent) and 3,124 in those unmonitored, a 7 per cent incidence including repeat cesarean. The cesarean rate remained remarkably stable over the 6-year study period even though the monitoring incidence nearly doubled. From 1970 to 1975, the intrapartum death rate fell progressively in contrast to the incidence of antepartum fetal deaths, which remained unchanged. Overall, 50 per cent survival rate was achieved in the birth weight range of 1,200 grams. A particular group of perinatal patients who apparently benefited from intrapartum monitoring were those liveborns with birth weights of 1,500 grams or less. Over the study period, the neonatal mortality in monitored patients declined, whereas mortality in the neonates which were not monitored during labor remained high.

One hundred women with moderate-to-very-severe prepartum pain participated in a double-blind study of intravenously injected butorphanol and meperidine that compared the analgesic properties, effect on the process of labor, condition of the newborn and the incidence of side effects associated with the two drugs. Cervical dilation, infant birth weight and Apgar scores were not significantly different between the test groups. The mean fetal heart rate for the butorphanol group was significantly faster than that of the meperidine group. Butorphanol provided significantly more analgesia than meperidine at 30 minutes and one hour after administration, based on pain intensity and pain relief scores. Some side effects, including sedation, dizziness, lightheadedness, nausea, vomiting and pain at the injection site, were reported for both drugs.

The kinetics of maternal-fetal interferon and a chemical interferon inducer were studied in Swiss-Webster white mice at 8, 15, and 19 days of gestation. Crude interferon was administered by maternal tail vein injection to one group. There was no transfer of interferon to the fetus despite high maternal levels. A chemical interferon inducer (10-carboxymethyl-9-acridanone) was given intramuscularly to a second group. Both maternal and fetal interferon responses rapidly reached significant levels, although the fetal response was less than that of the mother. Presence of the inducer was demonstrated in both maternal and fetal samples, indicating placental transport of the chemical to the fetus. The implications of these findings for the fetal immune response are discussed.

Atropine was given to the semichronic sheep fetus intravenously. Fetal heart rate, fetal perfusion pressure, and carotid blood flow increased. Cerebral blood flow was measured with the radioactive microsphere technique. Atropine was capable of increasing the cerebral blood flow. Elevation of carbon dioxide also caused an increase in cerebral blood flow, adding to the effect of atropine.

A basic understanding of fetal nutrition and metabolism is essential in the clinical management of the obstetric patient. The fetus depends upon a constant infusion of glucose for energy production and growth. Maternal glucose is the prime source of this nutrient. Alterations in maternal carbohydrate homeostasis will lead to changes in fetal metabolism. In diabetes mellitus, hyperglycemia may produce hyperinsulinemia and macrosomia. The growth-retarded fetus may have a decreased supply of maternal glucose and reduced amounts of hepatic glycogen and adipose tissue. The fetus must depend upon these stores for survival during periods of intrauterine hypoxia. In the newborn period, hypothermia and hypoxia may rapidly deplete energy reserves. With this information, the clinician may more knowledgeably manage dietary demands in the antepartum patient, fetal distress during labor, and the immediate newborn period.

A prospective study of the management of term frank breech presentation is currently ongoing at LAC-USC Medical Center. To date, 57 patients have been randomized to an elective cesarean section group and 70 to a vaginal delivery group. Of the 70 patients selected for vaginal delivery, 35 had one or more inadequate pelvic measurements by x-ray pelvimetry and were scheduled for indicated cesarean section. Of the remaining 35 patients in this group, 30 delivered vaginally without perinatal death. Two of the infants, however sustained brachial plexus injuries. Of the 57 patients scheduled, 55 underwent elective cesarean section. There were no maternal deaths, but 20 (36.4%) patients experienced morbidity and 5(9.1 per cent) patients experienced intraoperative complications. Based on the data accumulated to date, it seems reasonable to allow vaginal delivery in carefully selected cases of term frank breech presentation.

A study was done on the occurrence of neonatal seizures in 14,367 infants delivered by cesarean section in a perinatal region in 4 years. Although seizures occurred in 1% of all of these infants, small infants weighing less than 2500 gm at birth had the highest frequency (greater than 4%). Term infants delivered before labor (repeat cesarean section) had the lowest seizure rate (less than 0.2%), and this was a significantly lower (four times) frequency than that seen in term infants delivered by primary cesarean section. These data suggest that brain function as indexed by neonatal seizures can be adversely affected during labor.

NATIONAL INSTITUTES OF HEALTH Consensus Development Conferences have been established to address in a broad manner recent developments in medical practice and research. The Task Force participants are chosen entirely from outside the NIH and are asked to provide a comprehensive review of the state of the art including recommendations for current clinical practice and future research in a given area of medicine. The National Institute of Child Health and Human Development recently established three such Consensus Development Task Forces on antenatal diagnosis. This report summarizes the findings of the Task Force on Predictors of Intrapartum Fetal Distress. The other two concerned predictors of hereditary disease and congenital defects, and predictors of fetal maturity; these will be reported separately. The format for such conferences calls for a broad and detailed examination of the topic at hand, by a task force composed of physicians, epidemiologists, sociologists, ethicists, economists, lawyers, and public (consumer) representatives. The full text of this report was circulated to interested individuals, institutions, and organizations before being presented in summary form at a public forum on March 6, 1979, at The National Institutes of Health. Those interested in commenting on the draft report had an opportunity to do so at that time, either in writing or verbally, after which the Task Force reviewed the comments made, and incorporated them into the repoN as necessary. The entire

1. 1. The intervillous space and the amniotic fluid pressures were recorded simultaneously and continuously for prolonged periods of time. 2. 2. As long as the uterus is not in active systole, the pressures in the two spaces remain virtually identical. 3. 3. Recording on a sensitive scale the pressure difference between the intervillous space and the amniotic fluid shows that during uterine systole the amniotic fluid pressure increases slightly faster than does the pressure in the intervillous space, the average maximum differential being approximately 2.6 mm. Hg. This pressure differential is partially “erased” by virtue of the fact that the pressure in the intervillous space makes up part of the pressure deficit by the time the apex of the contraction is reached. 4. 4. Movement of the patient brings about alterations in the pressure of approximately equal amounts in both spaces, and without appreciable lag. The amniotic fluid-intervillous space pressure relationship seems to be unaffected by either rupture of the membranes or the administration of oxytocin in physiologic dosage.

Cephalic blood flow and distribution studies were performed on 11 sheep fetuses in utero, 24 hours after the surgical implantation of probes and catheters, during different arterial blood gas tensions of carbon dioxide. Carbonized microspheres (35 ± 5 h diameter) were used to determine the blood flow distribution in the cerebral and extracerebral cephalic structures. The estimated blood flow was determined by correlating this distribution with the measured carotid blood flow. A reciprocal distribution between the cerebral and extracerebral circuits was noted with increasing carbon dioxide tensions up to about 70 mm. Hg. This occurred without any appreciable change in the total cephalic blood flow.

In an attempt to explain excessive fluid retention, the most common feature in the syndrome of subjective and objective changes called premenstrual tension, we investigated changes in the peripheral circulations of women with this complaint. To obtain evidence on the vascular system's ability to maintain a constant circulating fluid volume, we measured capillary filtration coefficient in the forearm. Women who complained of premenstrual distress showed a significant change in capillary filtration coefficient (CFC) during the month; the lowest CFC values were found immediately after the onset of the menses; the highest values occurred just before the beginning of menstruation. In a group of women who claim to be completely free of the complaint, the CFC was uniform throughout the cycle.

1.1. The amniotic fluid pO 2 and pCO 2 have been determined in late pregnancy and in labor, both with normal pregnancies and in a group wherein the fetus was dead in utero. 2.2. It was not possible to correlate fetal arterial gas tensions with the amniotic fluid tensions. 3.3. The average gas tension in the amniotic fluid surrounding the dead fetus was normal. 4.4. The suggestion is made that a portion of gas in the amniotic fluid is contributed by the uterus via a chorioamnion transfen.

This study confirms the fact that women with the eclamptogenic toxemias demonstrate a marked increase in the sodium-retaining activity of the urinary corticoids, but this is a statement true on the average. Individually some nontoxemic pregnant patients also demonstrate increased excretion of this factor, while some individual toxemic women show no such change. Diuresis diminished the amount found, although in all other respects the patient's clinical picture may have remained the same; by our technique of measurement it had disappeared from the urine after the third postpartum day in all cases. Placental extracts did not contain a strong sodium-retaining fraction. Chromatographic quantitations of aldosterone have indicated in this group of normal pregnant women a higher range than reported for the nonpregnant. Attempts to increase this factor by the administration of steroids were unsuccessful. The results with prolonged ACTH in a small group of women were not conclusive, but certainly cannot be called finally negative. Also, the pregnant woman in the last trimester responds to sodium restriction with some increase in the urinary aldosterone. Finally, adding a potassium load has not as yet demonstrably increased the excretion of the sodium-retaining factor. This steroid—the most potent of the sodium retainers yet isolated—has not been demonstrated to be the cause of the edema in the eclamptogenic toxemias and from the studies reported here could be a sequel as much as a cause of the syndrome. It undoubtedly forms a part of the normal mechanism for electrolyte control, and its role as an eliminator of potassium will require additional study of the metabolism of this ion in toxemia.

1. 1. In a study of 47 patients by a modified pulse pressure method, changes in cardiac output were recorded during late pregnancy, in labor, and in the early puerperium. This is the first report on cardiac output in labor. 2. 2. During effective contractions in labor, the cardiac output rises an average of 30.9 per cent over the output in the resting state. 3. 3. The act of bearing down in the absence of a contraction results in most cases in a small but transient drop in cardiac output. Bearing down with a contraction, however, may result in an actual increase in output. 4. 4. Pain and anxiety can produce significant elevations in cardiac output. 5. 5. Placental separation per se was not demonstrated to result in consistent variations in cardiac output. Contraction of the uterus post partum, however, may raise the output level significantly. 6. 6. Cardiac output appears to rise during the first stage of labor, and may rise even further at delivery. In some cases a small additional rise is seen in the first few minutes post partum. The output persists at a moderately elevated level for a variable period thereafter.

Cardiac output estimations done by the pulse pressure method were compared to those done simultaneously by the dye method in pregnancy, labor, and in the early puerperium. The subjects selected were young, healthy and without edema or clinical evidence of heart disease. A total of 30 determinations was carried out on 23 subjects. Agreement within 25 per cent of the dye method was attained in 90 per cent of the blood pressure method tests.

A study was done on the occurrence of neonatal seizures in 14,367 infants delivered by cesarean section in a perinatal region in 4 years. Although seizures occurred in 1% of all of these infants, small infants weighing 4%). Term infants delivered before labor (repeat cesarean section) had the lowest seizure rate (