Umbilical Arterial Samples Research Articles

Umbilical artery creatine kinase brain-band isozyme as a predictor of neonatal periventricular-intraventricular hemorrhage

In low-birth-weight neonates, an elevation in the percentage of creatine kinase brain-band isozyme in the umbilical artery was significantly correlated with future development of neonatal grade III and grade IV periventricular-intraventricular hemorrhage, when compared with levels in those neonates who did not show periventricular-intraventricular hemorrhage or who developed grade I and grade II periventricular-intraventricular hemorrhage (p = 0.025). In these neonates the relative levels in maternal venous, umbilical arterial, and umbilical venous samples indicated that the source of the isozyme was fetal.

Umbilical cord acid base changes associated with perinatal cardiac failure

Two infants delivered by emergency cesarean section because of fetal distress are described, and the umbilical blood acid-base findings are discussed. One fetus was stillborn, the other died in the immediate neonatal period, and both showed signs of cardiac dilation and failure on postmortem examination. Umbilical cord blood gas determination at the time of delivery showed almost normal values of pH, Pco2. and Po2 in the umbilical vein but acidotic pH with high Pco2 and low Po2 values in the umbilical artery samples. These findings are probably the result of a prolonged umbilical blood circulation time because of fetal cardiac failure. This sluggish perfusion allows the equilibration of fetal blood with maternal intervillous blood, and the findings in the fetal umbilical vein approximate maternal uterine venous values. Umbilical cord acid-base determinations in perinatal surveillance are commonly recommended without specific details. Umbilical artery samples must be obtained to properly assess the metabolic status of the fetus at the time of birth.

The Pharmacokinetics and Maternal and Neonatal Effects of Epidural Lidocaine in Preeclampsia

Ramanathan, J.; Bottorff, M.; Jeter, J. N.; Khalil, M.; Sibai, B. M. Author Information

Fetal sympatho‐adrenal mediated metabolic responses to parturition

Plasma cortisol and noradrenaline were measured in 15 mothers and babies following vaginal delivery and in 17 following elective caesarean section and related to blood concentration of glucose and glycerol. Significant elevations in umbilical artery cortisol and noradrenaline concentration were found in the vaginal delivery group. Blood glucose and glycerol concentrations were significantly higher in the vaginal delivery group for maternal venous, umbilical artery and vein samples. However, when allowances were made for placental transfer of these substances, little evidence was found to support sympatho-adrenal mediated mobilization of glycerol and glucose in the fetus. The possible explanation for the apparent dissociation between marked sympatho-adrenal activity and metabolic responsiveness during parturition in the fetus is discussed.

Fetal sympatho‐adrenal mediated metabolic responses to parturition

Summary. Plasma cortisol and noradrenaline were measured in 15 mothers and babies following vaginal delivery and in 17 following elective caesarean section and related to blood concentration of glucose and glycerol. Significant elevations in umbilical artery cortisol and noradrenaline concentration were found in the vaginal delivery group. Blood glucose and glycerol concentrations were significantly higher in the vaginal delivery group for maternal venous, umbilical artery and vein samples. However, when allowances were made for placental transfer of these substances, little evidence was found to support sympatho‐adrenal mediated mobilization of glycerol and glucose in the fetus. The possible explanation for the apparent dissociation between marked sympatho‐adrenal activity and metabolic responsiveness during parturition in the fetus is discussed.

Low-Dose Enflurane as Adjunct to High-Dose Fentanyl in Patients Undergoing Coronary Artery Surgery

The pharmacokinetics and maternal and neonatal effects of epidural lidocaine were compared in ten preeclamptic and five normotensive women undergoing cesarean section at 36-40 weeks of gestation. Lumbar epidural anesthesia was achieved using 15-20 ml of 2% lidocaine without epinephrine. Serial venous samples for lidocaine levels were drawn from all the mothers during the procedure and up to 6 hr after the initial injection. Umbilical venous and arterial samples were drawn at delivery for measurement of neonatal acid-base status and lidocaine levels. There were no significant differences between normotensive and preeclamptic patients in the total dose of lidocaine, peak maternal plasma concentration, volume of distribution, maternal elimination half-life and umbilical vein/maternal vein ratios. The calculated area under the concentration time curve in pre- eclamptic patients (18.5 ± 4.7 μg•hr•ml-1) was significantly greater than in normotensive mothers (14.1 ± 1.3 μg•hr•ml-1) (P < 0.02). Total maternal body clearance in preeclamptic patients (24.5 ± 7.1 L/hr) was significantly lower than in normotensives (31.1 ± 4.4 L/hr) (P < 0.05). Neonatal outcome as evaluated by Apgar scores, umbilical arterial and venous blood gas tensions, umbilical vein/maternal vein ratios, and early neonatal neurobehavior scores at 4 hr and 24 hr after birth were similar in the two groups. The results indicate that the total maternal body clearance of lidocaine is prolonged in preeclampsia, and repeated administration of lidocaine can result in higher blood levels than in normotensive parturients.

Low-Dose Enflurane as Adjunct to High-Dose Fentanyl in Patients Undergoing Coronary Artery Surgery

The pharmacokinetics and maternal and neonatal effects of epidural lidocaine were compared in ten preeclamptic and five normotensive women undergoing cesarean section at 36-40 weeks of gestation. Lumbar epidural anesthesia was achieved using 15-20 ml of 2% lidocaine without epinephrine. Serial venous samples for lidocaine levels were drawn from all the mothers during the procedure and up to 6 hr after the initial injection. Umbilical venous and arterial samples were drawn at delivery for measurement of neonatal acid-base status and lidocaine levels. There were no significant differences between normotensive and preeclamptic patients in the total dose of lidocaine, peak maternal plasma concentration, volume of distribution, maternal elimination half-life and umbilical vein/maternal vein ratios. The calculated area under the concentration time curve in pre- eclamptic patients (18.5 ± 4.7 μg•hr•ml-1) was significantly greater than in normotensive mothers (14.1 ± 1.3 μg•hr•ml-1) (P < 0.02). Total maternal body clearance in preeclamptic patients (24.5 ± 7.1 L/hr) was significantly lower than in normotensives (31.1 ± 4.4 L/hr) (P < 0.05). Neonatal outcome as evaluated by Apgar scores, umbilical arterial and venous blood gas tensions, umbilical vein/maternal vein ratios, and early neonatal neurobehavior scores at 4 hr and 24 hr after birth were similar in the two groups. The results indicate that the total maternal body clearance of lidocaine is prolonged in preeclampsia, and repeated administration of lidocaine can result in higher blood levels than in normotensive parturients.

Negative Feedback Regulation of Gonadotropin Secretion by Androgens in Fetal Rhesus Macaques1

Previously we described sex differences in circulating gonadotropin concentrations (greater in females) in fetal rhesus macaques, and demonstrated that these sex differences relate, at least in part, to the negative feedback actions of testicular secretions. A fully functional gonadal-hypothalamic-pituitary feedback relationship is present as early as Day 100 of gestation in fetal males because castration at this time results in a dramatic increase (greater than 10-fold) in fetal luteinizing hormone (LH) concentrations. Although short-term (6-h) treatment of fetuses with testosterone (T) 3 wk after gonadectomy (GX) does not lower LH levels in males, it is completely effective in females. These data suggest that either T is not the primary testicular factor responsible for feedback suppression of LH in fetal males, or the hypothalamic-pituitary axis becomes insensitive to T after GX. To determine if immediate treatment with T after GX is effective in maintaining LH levels, we gonadectomized five fetal rhesus males on Days 98-104 of gestation and immediately implanted crystalline-T-containing intraabdominal Silastic capsules. An additional five fetuses were treated with the nonaromatizable androgen dihydrotestosterone (DHT). Umbilical arterial samples for hormone analysis were obtained prior to GX and again approximately 3 wk later. Serum from control males (n = 11) castrated in utero on Day 100 of gestation contained significantly greater concentrations of LH and follicle-stimulating hormone (FSH) 3 wk after the operation than before GX. Five sham-operated male fetuses did not have elevated levels of either LH or FSH in their serum on Day 120 of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)

1529 FACTORS INFLUENCING TRANSCUTANEOUS CARBON DIOXIDE MEASUREMENT (tccO2) IN NEONATES

The relationship between tcCO2 and PaCO2 was studied in 20 neonates and the factors effecting this relationship determined.Infants ranging from 28 to 36 weeks gestation were studied during the first week after birth using an irridium/irridium oxide electrode (Hellige Kapnomonitor) which was maintained at a temperature of 42°C. Four to eight readings were obtained on each neonate and compared to simultaneous umbilical arterial samples. There is a linear relationship between PaCO2 and tcCO2 for the entire population (tcCO2=1.30 PaCO2+16.65, r=0.80). Variation among individuals accounts for 42% of the variance about the regression line.Stepwise multiple regression revealed that increases in base deficit and mean arterial blood pressure were associated with increases in tcCO2. Arterial pH did not significantly effect the tcCO2 measurement.We conclude that, 1) for a population of premature infants, there is a linear relationship between tcCO2 and PaCO2 using the Hellige Kapnomonitor, 2) there is considerable individual variation among infants making precise prediction of PaCO2 from tcCO2 difficult, and 3) base deficit and mean arterial blood pressure have a significant effect on tcCO2 measurements.

Epidural Bupivacaine, Chloroprocaine, or Lidocaine for Cesarean Section???Maternal and Neonatal Effects

The effects of epidural anesthesia on maternal blood pressure, newborn Apgar scores, neonatal acid-base status, and the early neonatal neurobehavioral scale (ENNS) were studied in 54 pregnant women undergoing cesarean section. Maternal and neonatal blood levels of the local anesthetics were also determined. Group 1 (n = 16) received 0.75% bupivacaine, group 2 (n = 18) received 3% chloroprocaine, group 3 (n = 11) received 2% lidocaine, and group 4 (n = 9) received 2% lidocaine with 1:200,000 epinephrine. The incidence of maternal hypotension did not differ significantly among the four groups. Fetal outcome as determined by Apgar scores, acid-base status, and neurobehavioral testing was equally good in all four groups. At delivery, the fetal/maternal concentration ratio of bupivacaine was 0.27, that of lidocaine without epinephrine 0.48, and that of lidocaine with epinephrine 0.58. Chloroprocaine was detected in 12 maternal samples, in seven umbilical venous samples, and in six umbilical arterial samples. It is concluded that epidural anesthesia as administered in this study had no adverse effect on the newborn Apgar scores, cord acid-base status, or the ENNS.

Epidural Bupivacaine, Chloroprocaine, or Lidocaine for Cesarean Section-Maternal and Neonatal Effects

The effects of epidural anesthesia on maternal blood pressure, newborn Apgar scores, neonatal acid-base status, and the early neonatal neurobehavioral scale (ENNS) were studied in 54 pregnant women undergoing cesarean section. Maternal and neonatal blood levels of the local anesthetics were also determined. Group 1 (n = 16) received 0.75% bupivacaine, group 2 (n = 18) received 3% chloroprocaine, group 3 (n = 11) received 2% lidocaine, and group 4 (n = 9) received 2% lidocaine with 1:200,000 epinephrine. The incidence of maternal hypotension did not differ significantly among the four groups. Fetal outcome as determined by Apgar scores, acid-base status, and neurobehavioral testing was equally good in all four groups. At delivery, the fetal/maternal concentration ratio of bupivacaine was 0.27, that of lidocaine without epinephrine 0.48, and that of lidocaine with epinephrine 0.58. Chloroprocaine was detected in 12 maternal samples, in seven umbilical venous samples, and in six umbilical arterial samples. It is concluded that epidural anesthesia as administered in this study had no adverse effect on the newborn Apgar scores, cord acid-base status, or the ENNS.

Oxygen Transfer from Mother to Fetus During Cesarean Section Under Epidural Anesthesia

The correlation between maternal PaO2 levels and umbilical vein (UV) and umbilical artery (UA)PO2 levels was studied in 40 healthy patients undergoing elective cesarean sections under lumbar epidural anesthesia. Patients were divided into four equal groups. Each group inhaled oxygen at a FIO2 of 0.21, 0.47, 0.74 (in nitrogen), or 1.0. Maternal arterial samples and fetal UV and UA samples were collected at the time of delivery. Maternal PaO2 levels increased from 96 +/- 4 (1 SE) torr during exposure to to a FIO2 of 0.21 to 232 +/- 6, 312 +/- 16, and 423 +/- 6 torr while breathing FIO2 of 0.47, 0.74 and 1.0, respectively. UV PO2 levels increased from 28 +/- 1 to 36 +/- 1.5, 41 +/- 1.3 and 47 +/- 1.2 torr in the hyperoxic groups. UA PO2 levels increased from 15 +/- 0.7 to 19 +/- 0.8, 21 +/- 0.3, and 25 +/- 1.8 torr, respectively. Oxygen saturation and blood O2 contents increased in maternal and fetal blood. Maternal arterial, UV, and UA base excess values in the hyperoxic groups were significantly higher than in the normoxic groups. There was no difference in 1- or 5-minute Apgar scores between the normoxic and hyperoxic groups. It is concluded that maternal hyperoxia improves fetal oxygen stores and acid-base status during cesarean section under epidural anesthesia.

Fetal oxygen affinity and its parameters in a random obstetric population.

Fetal oxygenation studies have provided the obstetrician with some basic information regarding oxygen supply to the fetus. Although standard values for normal fetuses at term have been made, little has been done to evaluate any changes occurring with fetal and neonatal abnormality. Twenty-two sets of analyses were performed to measure oxygen affinity (P50) 2,3-diphosphoglycerate concentration and full blood gas analysis on umbilical arterial and venous samples. The samples were taken from a random obstetric population. All babies were at term or post term by antenatal data and paediatric assessment at delivery. A further study was performed on a group of normal and growth retarded term infants, assessing the same parameters as the random population. Following analysis, 2 cases of cardio-pulmonary abnormality, resulting in neonatal death, were found to have the highest oxygen affinity, the remaining oxygenation parameters of PO2, PCO2, pH and 2,3-diphosphoglycerate concentration were found to be similar to the rest of the group. The results of this study agree with previous investigative findings for the normal babies. The finding of low P50 (or high oxygen affinity) in these 2 cases is an unusual finding and may reflect an adaptive function towards extra-uterine life. No alteration of fetal oxygen affinity was found in a small group of growth retarded babies despite the lowering of the 2,3-diphosphoglycerate concentration. The latter finding probably reflects the lowered intrauterine fetal blood pH found with growth retarded babies. Further research is required to elucidate the comples process of fetal oxygenation that occurs in the presence of fetal abnormality.

Dissociation of Plasma and Cerebrospinal Fluid Beta-Endorphin-like Immunoactivity Levels during Pregnancy and Parturition

The association between central (cerebrospinal fluid [CSF]) and peripheral (plasma) levels of beta-endorphin-like immunoactivity (beta-ELI) in nonpregnant women (n = 8) and pregnant women (a) at 16 to 20 weeks of gestation (n = 6), (b) at term (n = 21), and (c) in labor (n = 15) was investigated. Umbilical arterial (n = 11) and venous (n = 11) samples were also obtained. In agreement with previous investigations, it was found that plasma levels of beta-ELI increased during labor (mean +/- SEM: nonpregnant women, 63.5 +/- 18.2; pregnant women at term, 64.0 +/- 12.2; women in labor, 110.8 +/- 30.3 pg/ml), and that levels of umbilical arterial plasma of beta-ELI exceeded those in umbilical venous plasma (132.5 +/- 34.0 versus 68.2 +/- 22.2). However, CSF levels of beta ELI did not change over the course of pregnancy or during labor (nonpregnant women, 36.5 +/- 15.8; pregnant women at 16 to 20 weeks of gestation, 60.1 +/- 10.3; pregnant women at term, 57.5 +/- 8.4; women in labor 48.5 +/- 8.3 pg/ml). This evidence that plasma and CSF levels of beta-ELI are dissociated during labor calls into question inferences regarding behavioral changes during parturition based on plasma beta-ELI measurements.

Oxygen Transfer from Mother to Fetus during Cesarean Section under Epidural Anesthesia

The correlation between maternal Pao2 levels and umbilical vein (UV) and umbilical artery (UA) Po2 levels was studied in 40 healthy patients undergoing elective cesarean sections under lumbar epidural anesthesia. Patients were divided into four equal groups. Each group inhaled oxygen at a Fio2 of 0.21, 0.47, 0.74 (in nitrogen), or 1.0. Maternal arterial samples and fetal UV and UA samples were collected at the time of delivery. Maternal Pao2 levels increased from 96 ± 4 (1 SE) torr during exposure to a Fio2 of 0.21 to 232 ± 6, 312 ± 16, and 423 ± 6 torr while breathing Fio2 of 0.47, 0.74 and 1.0, respectively. UV PO2 levels increased from 28 ± 1 to 36 ± 1.5, 41 ± 1.3 and 47 ± 1.2 torr in the hyperoxic groups. UA Po2 levels increased from 15 ± 0.7 to 19 ± 0.8, 21 ± 0.3, and 25 ± 1.8 torr, respectively. Oxygen saturation and blood O2 contents increased in maternal and fetal blood. Maternal arterial, UV, and UA base excess values in the hyperoxic groups were significantly higher than in the normoxic groups. There was no difference in 1− or 5-minute Apgar scores between the normoxic and hyperoxic groups. It is concluded that maternal hyperoxia improves fetal oxygen stores and acid-base status during cesarean section under epidural anesthesia.

PANCURONIUM IN CAESAREAN SECTION AND ITS PLACENTAL TRANSFER

Pancuronium bromide was used in 49 patients undergoing repeat elective Caesarean section. In 26 patients who received only pancuronium 0.1 mg kg-1, pancuronium was detected in all umbilical venous or arterial samples (0.12 micrograms ml-1). In 23 other patiets who received suxamethonium 1.0 mg kg-1 followed by pancuronium 0.05 mg kg-1, pancuronium was detected in fetal blood 2 min after injection; the concentration of pancuronium in umbilical venous or arterial samples in 14 subjects was 0.08 micrograms ml-1, and less than 0.05 micrograms ml-1 in nine subjects. There was no evidence that such concentrations of pancuronium were detrimental to the fetus. The use of suxamethonium before pancuronium resulted in reduction of pancuronium dosage, induction-delivery time, and fetal concentrations of pancuronium, and was associated with better condition of the neonate.

Simultaneous determination of seven unconjugated steroids in maternal venous and umbilical arterial and venous serum in elective and emergency cesarean section at term

In order to assess specific gluco- and mineralocorticoid functions in both mother and fetoplacental unit in relation to the presence or absence of labor, serum levels of unconjugated aldosterone (A), corticosterone (B), deoxycorticosterone (DOC), progesterone (P), 17-hydroxyprogesterone (17-OHP), cortisol (F), and cortisone (E) were determined simultaneously. These levels were determined by specific radioimmunoassays in two groups of 24 paired maternal venous and umbilical arterial and venous samples obtained at term delivery by either elective (Group I, N = 8) or emergency (Group II, N = 8) cesarean section. In Group II, after spontaneous labor, mean maternal serum levels of all steroids investigated exceeded those found in Group I (not in labor). These increases were most pronounced (p < 0.005) in F (74%) and DOC (106%) levels demonstrating stimulation of both the glucocorticoid (cortisol)-and the mineralocorticoid (aldosterone)-producing pathways of the maternal adrenals by spontaneous labor. Arteriovenous differences in umbilical steroid levels revealed in both groups the placental origin of P, 17-OHP, and E (p < 0.05 to 0.005), with greater (more negative) mean AV differences after labor (Group II). The negative AV differences of DOC, B, A, and F found in Group I, however, decreased after labor and became even positive in the cases of B and F, reflecting the close relationship between spontaneous labor and the fetal adrenal's active production not only of the glucocorticoids B and F, but also, to a lesser extent, of the mineralocorticoids DOC and aldosterone.

Maternal and fetal plasma prostaglandin levels at vaginal delivery and cesarean section

Prostaglandin F has been measured in plasma from the maternal peripheral vein (MPV), umbilical artery (UA), and umbilical vein (UV) of women at elective cesarean section but not in labor, and in patients during spontaneous or oxytocin induced vaginal delivery. In all groups of patients, the PGF concentration in the UA and UV plasma was significantly greater than in the corresponding MPV sample. However, there was no consistent difference in the plasma concentration of PGF between pairs of UA and UV samples. The plasma concentration of PGF in the UA and UV was significantly elevated at vaginal delivery compared to cesarean section. These data indicate that there is an increase in the concentration of PGF within the fetal compartment during active labor, but no single source of the prostaglandin could be defined.

Fetal plasma steroids in relation to parturition. II. The effect of gestational age upon umbilical plasma corticosteroids following hysterotomy and Caesarean section.

SummaryTotal plasma corticosteroid levels were measured by competitive protein binding assay in matched umbilical arterial and venous samples obtained immediately following delivery of 78 infants by Caesarean section. At 38 to 40 weeks gestation, the mean umbilical arterial levels (±S.E.) were 94.9 ± 10.0 ng./ml. following elective Caesarean section and 142.2 ± 23.7 ng./ml. following emergency Caesarean section in labour. The corresponding mean venous levels were 132.3 ± 10.0 ng./ml. and 172.9± 19.1 ng./ml. Within the emergency Caesarean section group, corticosteroid levels were related to the stage of labour. In fetuses obtained by hysterotomy, the mean heart blood level of plasma corticosteroids was 16.3±3.6 ng./ml. at 12 to 16 weeks gestational age. Within the elective Caesarean group, corticosteroid levels increased with gestational age, reaching a peak at 35 to 37 weeks gestation.

Fetal plasma steroids in relation to parturition. I. The effect of gestational age upon umbilical plasma corticosteroid levels following vaginal delivery.

SummaryTotal plasma corticosteroid levels were measured by a competitive protein‐binding technique in matched umbilical arterial and venous samples obtained from 234 infants immediately following vaginal delivery. Both arterial and venous levels were related to the gestational age of the infant at delivery, rising to a peak at 37 to 38 weeks gestational age and thereafter declining. Corticosteroid levels were generally less in infants delivered following oxytocin‐induced (or augmented) labour than in those delivered following spontaneous labour. The mean umbilical arterial levels (±S.E.) of plasma corticosteroids at 38 to 40 weeks were 213.2 ± 16.3 ng./ml. for the spontaneous labour group and 171.9 ± 12.3 ng./ml. for the oxytocin‐induced and augmented group. The corresponding mean venous levels were 242.9 ± 14.8 ng./ml. and 227.4 ± 13.2 ng./ml. The mean plasma corticosteroid level in four fetuses spontaneously miscarried at 17 to 20 weeks was 65.0 ± 21.6 ng./ml. The results suggest that the human fetal adrenal may have an active role in fetal maturation and the initiation of labour.