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An evaluation of records from 1975 to 1992 at MetroHealth Medical Center in Cleveland found several trends. The hospital is a large inner-city institution serving clinic and private patients and high-risk patients. Information was collected on 63,519 mothers. In the 18-year period, the median maternal age increased from 20 to 23 years. The average gestational age at birth declined from 39.2 weeks to 38.3 weeks, but this was due to a decline in gestational age among clinic patients. Among private patients it increased by a week. The proportion of preterm births increased from 3.3% to 7.8% as did the proportion of low-birth-weight infants (12.7% to 17.3%). Again, the increase in preterm birth was due to an increase among clinic patients; it declined among private patients. The cesarean rate declined from 37% to 25% among private patients but increased from 10% to 17% among clinic patients.

A double-blind study evaluating two dose schedules of oral prostaglandin E2(PGE2) was conducted in 56 normal “unripe” multiparas at term. The effect of PGE2was evaluated by comparing the change in Bishop score of the cervix and patient's response to oxytocin induction of labor after the prostaglandin priming. In the two study groups (one group on a fixed PGE2dosage and the other on a variable drug regimen) an average change of more than three points in the Bishop score was observed. In the control group no significant change in cervical ripeness was observed. Nine of the 32 patients (28) receiving prostaglandin delivered during the priming phase of the study, whereas only 1 control patient (4.2) delivered during priming. Six of 24 control patients (25) failed to deliver, whereas only 3 of 32 study patients (9) failed. In the successfully induced patients, the response to oxytocin, as expressed by the time to active phase, total time of labor, and mean dose of oxytocin required, did not vary significantly when control and study groups were compared. It is concluded that PGE2at either dosage schedule is effective in changing the Bishop score of the cervix and that it is not feasible to titrate the PGE2dose in order to effectively ripen the cervix without a very high incidence of induction of labor. In those cases where priming was completed, without accidental deliver)', the induction phase was successful more than 90 of the time. No adverse effect to mother or baby was observed during this study.

A study of 1,966 women who registered in a certified nurse–midwife (CNM) program for pregnancy and delivery at an academic health center is reported. Eleven percent either were medically disqualified or voluntarily transferred out of the program. Of the 1,852 women who entered labor, 46.5% required MD consultation most often for dysfunctional labor patterns. The primary cesarean section rate was 10.4%. The corrected perinatal mortality rate was 3.80/1,000 births. CNM care is a safe, cost-effective, and sought-after alternative to MD-only care for low-risk women within a tertiary care setting.

The uterine and umbilical blood flow response to uteroplacental insufficiency, produced by microsphere embolization of the uteroplacental circulation, was examined by means of electromagnetic flow transducers in 12 pregnant ewes. No acute changes were observed in either circulation immediately after embolization of the uterine vasculature. Significant morphometric fetal growth retardation, in terms of weight, length, and ponderal index, was not associated with early changes in fetal pH, Po2, or Pco2. However, the incremental increases in both flows that were observed in control animals did not occur either during or after embolization because of an increase in vascular resistance. During and after embolization the incremental increase in uterine blood flow was blunted or decreased in most, but not all, animals. A rapid, progressive, and persistent decrease in umbilical flow occurred in the growth-retarded group. The significance of these findings relative to intrauterine growth is discussed.

The effect of methadone on fetal brain function in terms of the elctroencephalogram (EEG) was studied in eight short-term fetal sheep experiments by single injections of 5 to 20 mg. of methadone into the fetal circulation. Plasma methadone concentrations (determined by radioimmunoassay) greater than 0.065 mg. per cent were associated with an immediate but brief decrease in carotid blood flow, a rapid decrease in frequency and amplitude in the EEG that occasionally became isoelectric but recovered, and immediate and relatively prolonged bradycardia. Similar cardiovascular observations were obtained with plasma methadone concentrations less than 0.065 mg. per cent, but the EEG changes were either minimal or not observed. These results indicate that uptake of methadone by the fetal brain is rapid and that electrical activity and heart rate are affected.

Red blood cell 2,3-diphosphoglycerate (2,3-DPG) levels were studied in 227 normal gravid women in all stages of pregnancy, active labor, and early post partum. An increase to peak levels was observed at 19 to 22 weeks followed by a gradual fall toward normal. During labor and early post partum, 2,3-DPG again rose significantly above levels observed at term. Serial 2,3-DPG values through the third trimester, labor, and postpartum period in 11 hypertensive mothers and 20 normal gravid control subjects and their newborn infants were studied. Maternal 2,3-DPG levels were significantly higher in the hypertensive mothers when compared to control mothers at similar gestational stages. However, no difference in 2,3-DPG levels was observed when newborn infants of hypertensive mothers were compared with those of normal control subjects.

The significance of fetal heart rate-uterine contraction (FHR-UC) monitoring as a means of predicting the condition of the fetus during labor was studied by correlating 460 fetal pH determinations obtained from 216 patients with the analysis of the 20-minute FHR-UC record preceding the fetal scalp blood sample. Both qualitative and quantitative analyses of the FHR-UC record were performed. The results indicate a less than 10 chance of fetal pH ≤7.250 with a normal baseline FHR and no periodic changes or with periodic accelerations, early decelerations, and uncomplicated baseline bradycardia or tachycardia. Variable or delayed decelerations with a total surface area (TSA) of 1–100 for the 20-min period were associated with a fetal pH ≤ 7.250 in 23 and 34 of cases, respectively. Variable or delayed decelerations with a TSA > 100 had a 35 or 47 chance of fetal pH ≤ 7.250. It is concluded that FHR-UC monitoring can be used to screen the innocuous from the ominous periodic change but that fetal scalp blood pH must be obtained to identify accurately the true from the false-positive ominous pattern.

Acute and chronic observations of the fetal electroencephalogram (EEG) in a fetal sheep preparation revealed two distinct patterns of sleep activity consisting of high-voltage slow activity (HVSA) and low-voltage fast activity (LVFA). A decrease in fetal heart rate, cerebral perfusion pressure, and cerebral blood flow was observed consistently during LVFA when compared to HVSA. There was no significant difference in cerebral metabolism during the sleep stages.

The longitudinal hemodynamic response of the uterine circulation to pregnancy and to repetitive embolic insult was assessed in 23 singleton ewe pregnancies by means of electromagnetic flow transducers and radionuclide-labeled microspheres. The data indicate that the longitudinal hemodynamic changes observed in the uterine circulation were directly related to the growth rate of the tissue which it supplied. The hemodynamic impact of embolization appears to be secondary to its impact on tissue growth. Embolization simply blunts the normal incremental increases in uterine perfusion and the cross-sectional area of the uterine vascular bed. It alters actual tissue perfusion only within a portion of the cotyledonary circulation. Finally, the data support the presence of functional arterial anastomoses between the two sides of the uterine circulation in this species.

Cerebral function and metabolism, morphology and histology of the nervous system, and lung maturity in terms of surfactant production were studied at term in five sheep fetuses thyroidectomized at gestational ages ranging from 104 to 111 days. Compared to age-matched controls, body weight (thyroidectomized animals, 2.8 ± 0.11 kilograms; controls, 3.9 ± 0.2 kilograms; P < 0.0005) and brain weight (thyroidectomized animals, 43.51 ± 1.38 grams; controls, 48.49 ± 1.75 grams; P < 0.05) were significantly reduced. In the nervous system, morphology, histology, brain function, and metabolism were not significantly different from those of the controls. Lung weight was less, but not significantly, and surfactant production was not deficient as compared to that of age-matched controls. The failure to find any disturbance of maturation in the brain and lungs of fetuses thyroidectomized at 104 to 111 days may be related to the relative maturity of the sheep fetus at this age.

The fetal metabolic response to repetitive placental damage, produced by microsphere embolization of the uteroplacental circulation, was examined longitudinally in eight singleton fetal lambs and compared with similar data from seven controls. Significant morphometric fetal growth retardation was associated with an abrupt cessation of the normal increases in oxygen, glucose, and lactate uptake observed in the control animals. However, fetal blood levels and umbilical substrate quotients did not change. At the time of sacrifice, fetal oxidative metabolic rate was reduced significantly. The significance of these findings relative to intact fetal survival is discussed.

The relationship between fetal electrocortical activity and multiple fetal parameters was examined in chronically instrumented fetal lambs. Consistent small but significant changes in fetal heart rate, mean arterial pressure, umbilical blood flow, and the cerebral uptake of glucose relative to oxygen were observed as fetal electrocortical activity cyclically shifted between high-voltage slow activity and low-voltage fast activity. Cardiovascular parameters were higher and the cerebral uptake of glucose relative to oxygen was lower during high-voltage slow activity than during low-voltage fast activity. The implication of these observations is discussed.

Seven sheep fetuses surgically thyroidectomized (Tx) during the second trimester at 81 to 87 days' gestation were acutely studied near term. Compared to 10 age-matched, sham-operated controls (C), the body weight was significantly reduced in the Tx group (C, 4.45 ± 0.28 kg; Tx, 2.70 ± 0.17 kg; P < 0.01) as were the weights of the brain (C, 48.57 ± 1.24 gm; Tx, 42.89 ± 1.54 gm; P < 0.01), lungs (C, 85.39 ± 4.75 gm; Tx, 64.81 ± 6.45 gm; P < 0.05), heart (C, 28.53 ± 1.50 gm; Tx, 17.50 ± 0.97 gm; P < 0.01), and adrenal glands (C, 0.54 ± 0.07 gm; Tx, 0.33 ± 0.06 gm; P < 0.05). Heart rate (C, 158 ± 4.33; Tx, 126 ± 3.67; P < 0.01), blood pressure (C, 46.50 ± 1.44 mm Hg; Tx, 32.20 ± 4.01 mm Hg; P < 0.05), and cephalic blood flow (C, 108.75 ± 2.36 ml/100 gm/min; Tx, 74.50 ± 6.69 ml/100 gm/min; P < 0.01) were significantly reduced in the Tx group. Cerebral O2consumption was not significantly different in the two groups. By the methodology used, no morphologic or histologic differences were noted between the brains of Tx fetuses and those of the C group. Caudate nucleus dopamine levels were significantly lower in the Tx group (C, 29.46 ± 3.01 μg/gm tissue; Tx, 15.85 ± 0.52 μg/gm tissue; P < 0.01). Brain stem/auditory-evoked responses as an index of maturation of the auditory pathway along the brain stem were tested in the Tx and C groups, as well as in a group of adult ewes and newborn and 1-week-old lambs. The latency period to the wave IV–V complex, as well as wave I to IV–V interval representative of central conduction, was found to be significantly prolonged in both the Tx and C groups as compared with adults and newborn and 1-week-old lambs. The values in these latter three groups were not significantly different from each other, and the Tx group did not differ significantly from the C group. Amplitude was lower in the fetal group, and the morphologic features of waveforms were less defined, but more so in the Tx group, perhaps indicative of relative immaturity. Further investigation is needed before definite conclusions can be drawn about the significance of these observations.

The effect of maternal alcohol infusion on fetal cerebral function in terms of the electroencephalogram (EEG) and fetal brain metabolism was studied in 10 fetal sheep experiments. A 9.75 per cent alcohol-dextrose solution was infused at the rate of 15 c.c. per kilogram of maternal weight for 1 or 2 hours. Fetal cerebral uptake of oxygen was unaffected. Blood flow was significantly increased as a result of a greater decrease in resistance than decrease in blood pressure. The cerebral uptake of glucose and the glucose-oxygen utilization ratio were significantly increased. The EEG showed a decrease in amplitute and slowing of the dominant rhythm as the blood alcohol concentration increased and became isoelectric on occasion during the postinfusion period associated with a severe fetal acidosis.

The placental transport of alcohol and its effect on maternal and fetal acid-base balance studied in 10 sheep experiments by the maternal infusion of a 9.75 per cent solution of alcohol-dextrose at a rate of 15 c.c. per kilogram for 1 or 2 hours. Serial maternal and fetal blood sampling during and following the alcohol infusion revealed rapid placental diffusion of alcohol, a highly significant correlation between maternal and fetal blood alcohol concentrations, and a similar peak concentration of approximately 0.230 Gm. per 100 ml. in maternal and fetal blood that differed only in time of onset during the 1 and 2 hour infusion periods. Blood alcohol concentrations remained high for several hours during the postinfusion period. A significant maternal hyperlactacidemia and hyperglycemia were noted but did not result in significant alterations in maternal acid-base balance. An initial fetal metabolic acidosis and later mixed acidosis were observed during the alcohol infusion and worsened during the postinfusion period.

The uptake of meperidine by the brain of the fetal lamb was investigated by determining the concentration of meperidine in the fetal brachiocephalic artery and sagittal vein after intravenous and intramuscular administration to the mother. A positive arteriovenous gradient across the fetal brain existed for 10 minutes after intravenous administration, and for 20 to 25 minutes after intramuscular administration, thus indicating the uptake of meperidine by the fetal brain. The peak concentration of unbound meperidine in the fetal brain, as estimated from the plasma concentration of free meperidine at equilibrium, was three to four times greater after intravenous administration than after intramuscular administration. The findings suggest that, during labor, the route of administration of meperidine will determine the time course of meperidine in the fetal brain and, consequently, the time action of effects seen in the neonate. The lag time required for plasma-brain equilibration may explain the lack of correlation between the incidence of neonatal respiratory depression and the levels of meperidine in the cord after intramuscular administration.

Retrospective review of 457 breech deliveries failed to reveal a significant improvement in neonatal mortality and morbidity rates for those delivered by cesarean section vs. vaginal delivery. A slight but insignificant improvement in salvage was found for the 1,000 to 1,500 gram weight category when delivery was by cesarean section. Most of the deaths in the less than 1,500 gram breech presentation were associated with hyaline membrane disease or congenital defects incompatible with life and sepsis rather than directly related to the manner of breech delivery.