Fetal growth achievement and elevated maternal serum alpha-fetoprotein

Maternal serum alpha-fetoprotein (AFP) was measured by radioimmunoassay in 7223 unselected patients between 16 and 20 weeks gestation. In 141 patients an elevated AFP level (greater than 2.5 multiples of the median for gestation) was found in the absence of a primary cause. When the birthweights of the 137 liveborn infants were corrected for maternal height and weight, sex and birth rank, 37 (27%) fell below the 10th centile of normal birthweight standards. No excess of premature deliveries was found, but there was a significant association with primiparity. Patients delivered of their second infant showed a significant decrement in mean birthweight when compared with their first-born infants and with a matched control group (normal maternal serum AFP levels). There was a highly significant association between elevated serum AFP and subsequent placental abruption.     

High maternal serum alpha-fetoprotein and low birthweight. A study concerning possible correlation between maternal weight, smoking, and serum alpha-fetoprotein and subsequent birthweight and gestational age

Maternal serum alpha-fetoprotein (AFP) levels between 15 and 19 weeks gestation were studied in relation to birthweight, gestational age, maternal weight, and daily cigarette consumption in 1739 pregnancies. All infants were born after the 28th week of gestation and all were without neural tube defects. Gestational age was estimated by early measurement of the fetal biparietal diameter. High maternal serum AFP, low maternal weight, and the number of cigarettes smoked per day were found to correlate with low birthweight, but not with gestational age. By testing the influence of the individual parameters on the subsequent birthweight, no significant correlation was found between the AFP levels and birthweight. Low birthweight was mainly a result of cigarette smoking and low maternal weight. Screening for AFP in the second trimester, therefore, seems to be of no value in predicting low birthweight when maternal weight is taken into consideration.     

Fetal growth achievement and elevated maternal serum α-fetoprotein

Summary. Maternal serum α-fetoprotein (AFP) was measured by radio-immunoassay in 7223 unselected patients between 16 and 20 weeks gestation. In 141 patients an elevated AFP level (.2.5 multiples of the median for gestation) was found in the absence of a primary cause. When the birthweights of the 137 liveborn infants were corrected for maternal height and weight, sex and birth rank, 37 (27%) fell below the 10th centile of normal birthweight standards. No excess of premature deliveries was found, but there was a significant association with primiparity. Patients delivered of their second infant showed a significant decrement in mean birthweight when compared with their first-born infants and with a matched control group (normal maternal serum AFP levels). There was a highly significant association between elevated serum AFP and subsequent placental abruption.     

Activin A, inhibin A, inhibin B and parturition: changes of maternal and cord serum levels according to the mode of delivery.

OBJECTIVE: To evaluate whether activin A, inhibin A, and inhibin B levels in maternal and umbilical artery serum change according to the mode of delivery. DESIGN: Maternal and cord blood specimens were collected at term after spontaneous labour and vaginal delivery, or elective caesarean section. SETTING: Universities of Pisa, Turin, Naples and Udine. POPULATION: Forty-two healthy pregnant women, at 3940 weeks of gestation, divided into two subgroups: group 1 vaginal delivery (n = 21), were delivered of 10 female and 11 male infants; group 2 elective caesarean section (n = 21), were delivered of 11 female and 10 male infants. MAIN OUTCOME MEASURES: Serum activin A, inhibin A, inhibin B concentrations in maternal and umbilical cord blood. RESULTS: At vaginal delivery, maternal serum inhibin A and inhibin B levels were lower and activin A levels higher than at elective caesarean section. Maternal levels of activin A, inhibin A and inhibin B were constantly higher than in umbilical arterial blood, independent of the mode of delivery. No significant difference was observed in umbilical arterial serum levels of the three proteins between the two modes of delivery. Umbilical arterial serum activin A and inhibin A concentrations did not show a significant difference between male and female infants in either vaginal or caesarean section, but male infants showed inhibin B levels significantly higher than female, independent of the mode of delivery. CONCLUSIONS: In the presence of active labour, the human placenta secretes larger amounts of activin A and lesser amounts of inhibin A and inhibin B into the maternal circulation. Inhibin-related proteins in the fetal circulation do not show differences according to the mode of delivery, suggesting that they have a different method of production or metabolic rate compared with maternal activin and inhibins.     

Activin A, inhibin A, inhibin B and parturition: changes of maternal and cord serum levels according to the mode of delivery

Objective To evaluate whether activin A, inhibin A, and inhibin B levels in maternal and umbilical artery serum change according to the mode of delivery.
Design Maternal and cord blood specimens were collected at term after spontaneous labour and vaginal delivery, or elective caesarean section.
Setting Universities of Pisa, Turin, Naples and Udine.
Population Forty–two healthy pregnant women, at 39–40 weeks of gestation, divided into two subgroups: group 1 vaginal delivery (   n = 21  ), were delivered of 10 female and 11 male infants; group 2 elective caesarean section (   n = 21  ), were delivered of 11 female and 10 male infants.
Main outcome measures Serum activin A, inhibin A, inhibin B concentrations in maternal and umbilical cord blood.
Results At vaginal delivery, maternal serum inhibin A and inhibin B levels were lower and activin A levels higher than at elective caesarean section. Maternal levels of activin A, inhibin A and inhibin B were constantly higher than in umbilical arterial blood, independent of the mode of delivery. No significant difference was observed in umbilical arterial serum levels of the three proteins between the two modes of delivery. Umbilical arterial serum activin A and inhibin A concentrations did not show a significant difference between male and female infants in either vaginal or caesarean section, but male infants showed inhibin B levels significantly higher than female, independent of the mode of delivery.
Conclusions In the presence of active labour, the human placenta secretes larger amounts of activin A and lesser amounts of inhibin A and inhibin B into the maternal circulation. Inhibin–related proteins in the fetal circulation do not show differences according to the mode of delivery, suggesting that they have a different method of production or metabolic rate compared with maternal activin and inhibins.     

Umbilical cord serum levels of thromboxane B2 in term infants of women who participated in a placebo-controlled trial of low-dose aspirin

OBJECTIVE: Our aim was to quantify thromboxane B2 (TXB2) in umbilical cord serum of term infants of nulliparous, low-risk women who were randomly assigned to either placebo or low-dose (60 mg) aspirin (ASA) on a daily basis from 24 weeks' gestation through delivery as part of a randomized clinical trial for prevention of preeclampsia. METHODS: Umbilical cord sera from 230 singleton, term infants whose mothers were involved in our low-dose ASA trial were assayed for TXB2, the stable metabolite of thromboxane A2, without knowledge of treatment or outcome data. The data were related to assigned treatment group, longitudinal pattern of maternal serum TXB2 levels, and other maternal and newborn characteristics. The data also were analyzed according to whether or not maternal serum levels of TXB2 at 29-31, 34-36, and delivery were reduced > or =50% compared to values prior to initiation of the trial. RESULTS: Umbilical cord TXB2 levels (ng/ml, mean +/- SE) were significantly lower at term in the ASA group (36.1 +/- 3.3, n = 111) than in the placebo group (56.6 +/- 5.7, n = 119; P = 0.002). Umbilical cord TXB2 levels were correlated to those in maternal serum at delivery in the ASA group (r = 0.3441; P = 0.0005) but not in the placebo group (r = 0.0626; P = 0.53). Regardless of assigned treatment group, infants whose mothers had a > or =50% longitudinal reduction in serum TXB2 had lower umbilical cord TXB2 levels (39.2 +/- 3.6, n = 114) than infants whose mothers had <50% reductions in TXB2 (54.6 +/- 5.9, n = 116; P = 0.027). Birthweights of these infants correlated inversely (r = 0.1678, P = 0.017) with maternal serum TXB2 at delivery but not to umbilical cord TXB2 levels; the best correlation between birthweight and maternal serum TXB2 was noted in pregnancies assigned to receive placebo (r = -0.2558, P = 0.009). CONCLUSIONS: Umbilical cord serum levels of TXB2 1) are reduced in instances of long-term maternal ingestion of ASA, 2) correlate well with maternal serum levels of TXB2 at delivery when there is evidence for consistent maternal use of ASA, but 3) do not correlate with maternal serum TXB2 levels when there is no evidence for frequent maternal ingestion of cyclooxygenase inhibitors. These data suggest that the capacity for platelet production of TXA2 in fetal and maternal compartments are regulated independently. Finally, there is an inverse relationship between maternal serum TXB2 levels at delivery and birthweight of newborn infants that is most evident among the pregnancies assigned to placebo and also among pregnancies in which there was little evidence to suggest a pattern of cyclooxygenase inhibitor use during pregnancy.     

The association of birthweight with maternal and cord serum and amniotic fluid growth hormone and insulin levels, and with neonatal and maternal factors in pregnant women who delivered at term

AIM: To investigate the influence of maternal and cord serum and amniotic fluid growth hormone (GH) and insulin and other neonatal and maternal factors on birthweight. METHODS: A total of 160 pregnant women at 38-42 weeks' gestation were studied. All infants were categorized as small for gestational age (SGA) (n = 50), large for gestational age (LGA) (n = 50) or average for gestational age (AGA) (n = 60). GH and insulin levels were measured in maternal and cord serum and amniotic fluid at birth. RESULTS: GH levels in maternal and cord serum and amniotic fluid showed no differences among the three weight groups (P > 0.05). The cord insulin level was significantly lower in SGA (P < 0.01). The insulin level in venous cord blood correlated with birth and placental weights and neonatal height, whereas maternal serum and amniotic fluid insulin levels, and maternal and cord serum and amniotic fluid GH levels did not show any correlation with birthweight. The cord GH level at birth was correlated with GH levels after 4 postnatal weeks in the SGA group (P < 0.01). In addition, birthweight showed a correlation with prepartum maternal weight, maternal weight gain, maternal height, neonatal length and placental weight in all three weight groups. CONCLUSIONS: Cord GH, maternal serum and amniotic fluid GH and insulin levels did not correlate with birthweight in all three weight groups. The lack of correlation for GH levels in maternal and cord serum and amniotic fluid suggests that these compartments may be non-communicating separate units.     

Fetal and maternal levels of lipid peroxides in term pregnancies

OBJECTIVE: To examine the relationships between maternal and fetal concentrations of lipid peroxides in term pregnancies before the onset of labor. METHODS: Umbilical cord arterial and venous blood samples were collected from 114 singleton term pregnancies delivered by elective cesarean section. Base excess, oxygen, carbon dioxide and pH were measured in both samples and compared to identify double venous samples. Maternal venous and umbilical cord arterial and venous concentrations of organic hydroperoxides and malondialdehyde were assayed. RESULTS: Maternal plasma malondialdehyde was, on average, double that of cord blood, whereas maternal organic hydroperoxide was only 18% higher. Maternal organic hydroperoxide was correlated with cord arterial and venous levels of organic hydroperoxide but not with pH, carbon dioxide, oxygen or base excess. Maternal malondialdehyde concentration was significantly correlated with both umbilical arterial and venous values of malondialdehyde and with arterial oxygen. Multiple regression shows that 70% of the variation in maternal malondialdehyde can be accounted for by variation in arterial and venous malondialdehyde, and arterial oxygen and base excess. A similar regression analysis with maternal organic hydroperoxide as dependant variable incorporated only umbilical arterial organic hydroperoxide concentration. CONCLUSION: These findings suggest that there is significant trans-placental transport of malondialdehyde from the fetal circulation.     

beta-Endorphin and beta-lipotropin concentrations in umbilical cord blood

Antisera suitable for human beta-endorphin and beta-lipotropin radioimmunoassay were developed, and radioimmunoassays were established to measure these peptides in umbilical cord plasma, with silicic acid extraction and gel chromatography used to separate the beta-endorphin from the beta-lipotropin fraction. These two peptides were determined in umbilical venous plasma from 64 newborn infants. Umbilical vein beta-endorphin and beta-lipotropin concentrations averaged 38.5 +/- 3.2 and 50.4 +/- 4.1 (+/- SE) fmoles/ml in the 54 newborn infants without and 115 +/- 18 and 110 +/- 25 fmoles/ml in the 10 newborn infants with apparent fetal distress. Neither the presence or absence of labor nor the route or mode of delivery was found to affect umbilical vein beta-endorphin or beta-lipotropin concentrations. However, cord plasma levels of both peptides were significantly elevated in conjunction with fetal distress, as evidenced by prolonged bradycardia, late and prolonged variable fetal heart rate decelerations, or fetal acidosis. In 18 of 22 pairs of simultaneously measured umbilical venous and arterial beta-endorphin and beta-lipotropin concentrations in newborn infants without apparent intrapartum distress, the venous beta-endorphin concentrations, which averaged 40.4 +/- 3.5 fmoles/ml, were significantly higher than the arterial beta-endorphin levels, with a mean of 28.5 +/- 4.2 fmoles/ml. No significant umbilical arteriovenous concentration difference could be observed for beta-lipotropin. This suggests that at least a portion of the coad plasma beta-endorphin is derived from the placenta. The ratio of umbilical arterial to venous beta-endorphin concentrations rose as the absolute cord plasma beta-endorphin levels increased. Furthermore, both the molar umbilical venous and arterial beta-lipotropin to beta-endorphin ratios decreased significantly in association with intrapartum fetal distress. These data indicate tat the stress-related increase in umbilical plasma beta-endorphin exceeds that of beta-lipotropin and may be, at least in part, of fetal origin. Umbilical venous beta-endorphin and beta-lipotropin levels of neonates whose mothers did not receive meperidine or other narcotics agents did not differ from those of neonates whose mothers were given meperidine or other narcotics during labor. Our data, in conjunction with those of others, are consistent with the hypothesis that fetal hypoxia causes the release of neurotransmitters such as beta-endorphin, which may modulate the regulation of fetal heart rate patterns.     

The relationship among intrauterine growth, insulinlike growth factor I (IGF-I), IGF-binding protein-3, and bone mineral status in newborn infants

Insulinlike growth factors (IGFs) exert profound effects on somatic growth and cellular proliferation of many tissues and play an essential role in bone metabolism. The aim of this study was to investigate how fetal growth and bone mineralization correlate with IGF-I and IGF-binding protein-3 (IGFBP-3) levels of newborn infants and their mothers. In addition, we aimed to determine the predictive value of anthropometric measurements on variability in bone mineral status. Umbilical cord venous blood samples were obtained at delivery from 100 term newborn infants. Forty of the newborn infants had birthweights appropriate for gestational age (AGA), 30 were small for gestational age (SGA), and 30 were large for gestational age (LGA). Data were acquired using whole-body dual-energy X-ray absorptiometry scanner with a pediatric platform. Umbilical cord serum IGF-I concentrations were higher in LGA newborns ( P < 0.01), but lower in SGA newborns ( P < 0.01) than in AGA newborns. Umbilical cord serum IGFBP-3 concentrations in LGA newborns were significantly greater than in SGA and AGA newborns ( P < 0.01 and P < 0.01, respectively). Whole-body bone mineral density (WB BMD) was higher in LGA babies (0.442 +/- 0.025 g/cm2 [SD]; P < 0.01) but lower in SGA (0.381 +/- 0.027 g/cm 2; P < 0.0001) than in AGA babies (0.426 +/- 0.022 g/cm2). WB BMD and content (WB BMC) were correlated significantly with birthweight, birth height, head circumference, body mass index (BMI) of the infants; ponderal index and triceps skinfold thickness (reflecting fat stores) of the infants; cord serum IGF-I concentration, serum IGF-I concentration of the mothers; and fat mass, proportionate fat mass, weight, and BMI of the mothers. In contrast, WB BMC was also correlated positively with cord serum IGFBP-3 concentration and gestational age, and WB BMD was positively correlated with serum IGFBP-3 levels of the mothers. Umbilical cord serum IGF-I concentration of the infants was correlated significantly with the concentration of the mothers ( R = 0.232; P = 0.020). Umbilical cord serum IGF-I and IGFBP-3 concentrations were correlated significantly with the fat mass, gestational age, birthweight, birth height, head circumference, and BMI of the infants. Umbilical cord IGF-I concentration was also correlated with ponderal index and triceps skinfold thickness of the infants, maternal weight, BMI, and proportionate fat mass of the infants. Stepwise multiple regression analyses showed no significant relation between bone indices (WB BMD, WB BMC) and the infant's or mother's variations including serum IGF-I and IGFBP-3 concentrations. Birthweight and gestational age are related to bone indices. However, the present study does not provide support for the hypothesis that serum IGF-I and IGFBP-3 levels of infants and their mothers may play a major role in the regulation of bone metabolism in the developing skeleton.     

Antioxidant levels in the cord blood of term fetus.

The aim of this study was to compare the differences in the total antioxidant levels in the cord blood after a normal vaginal delivery and after an elective caesarean section. This was a prospective study approved by the Wirral Hospital ethical research committee. The study was carried out in a district general hospital. We investigated 96 healthy pregnant women who had normal antenatal period with singleton pregnancies between 37 and 42 completed weeks of gestation. Sixty-five women had a spontaneous normal vaginal delivery and 31 underwent elective caesarean section. Umbilical cord blood was obtained immediately after delivery. Antioxidants such as glutathione peroxidase (GPX) and superoxide dismutase (SOD) were measured and compared between the normal vaginal delivery and elective ceasarean sections. The mean values for GPx in umbilical cord arterial blood (95; 86-103, n=74) was found to be significantly higher (P=0.0133) than that found in umbilical cord venous blood (84; 80-88, n=95). The arterial SOD values were found to be significantly higher (P=0.0337) in infants who had been delivered by caesarean section (1188; 1065-1311, n=22) than by vaginal delivery (1021;958-1083, n=39). The differences in the levels of GPX between the arterial and venous systems is not well documented but may be due to differences in the level of selenium, hydroperoxides or glutathione. In addition, why infants delivered by ceasarian section have a higher level of arterial SOD than those delivered by vaginal delivery remains unclear, but it may be a reflection of a relatively low level in infants subjected to the stress of labour.     

The correlation of biochemical monitoring versus umbilical flow velocity measurements of the human fetus

The pulsatility index of the fetal umbilical arteries was evaluated in 14 high-risk pregnant patients delivered by cesarean section between 30 and 35 weeks of gestation. Transabdominal cord sampling by ultrasonic guidance was performed on 10 of these patients. Umbilical arterial and venous blood was obtained in all patients from the doubly clamped cord at the time of cesarean section. The blood samples were analyzed for respiratory gases, acid-base balance, and lactate concentrations. A significant relationship was found between the pulsatility index and pH, PCO2, and lactate concentrations measured on umbilical venous blood sampled in utero. The pulsatility index also correlated with the same variables measured on venous and arterial blood sampled at cesarean section. Umbilical venous blood obtained transabdominally had a significantly higher oxygen content than blood obtained at cesarean section. No significant correlation was found between umbilical venous oxygen content obtained at transabdominal cord sampling and the pulsatility index. At a pulsatility index greater than 1.5, lactate concentrations in umbilical venous blood increased sharply. There would appear to be a curvilinear relationship between umbilical blood flow and these indices of fetal oxygenation, such that moderate increases in pulsatility index were not associated with a significant increase in fetal lactate concentrations.     

Plasma adrenomedullin levels in pregnancies with appropriate for gestational age and small for gestational age infants.

AIMS: To evaluate whether maternal and fetal plasma adrenomedullin levels in pregnancies with small for gestational age (SGA) infants are different from those in pregnancies with appropriate for gestational age (AGA) infants. METHODS: Maternal and fetal circulating adrenomedullin levels were compared between 62 pregnancies with AGA (43 delivered vaginally and 19 delivered by elective cesarean section) and 28 pregnancies with SGA (20 delivered vaginally and 8 delivered by elective cesarean section) at birth. Plasma adrenomedullin levels were measured from maternal and cord venous blood samples using a radioimmunoassay. Umbilical artery blood pH was also measured. RESULTS: There were no significant differences for maternal total adrenomedullin levels, mature adrenomedullin levels, and its ratio among the groups. There were also no significant differences for fetal total adrenomedullin levels, mature adrenomedullin levels, and its ratio among the groups. In the AGA group delivered vaginally, fetal mature/total adrenomedullin ratio (mean +/- standard error, 16.6 +/- 0.7%) was significantly higher than the maternal ratio (13.8 +/- 0.6%) (p < 0.05). In the SGA group delivered vaginally, fetal mature/total adrenomedullin ratio (18.5 +/- 1.0%) was also significantly higher than the maternal ratio (14.5 +/- 0.6%) (p < 0.05). There was no significant difference in umbilical artery blood pH among the groups. CONCLUSIONS: These results suggest that maternal and fetal plasma circulating adrenomedullin levels may play a role in maternal and fetal cardiovascular adaptation during delivery in pregnancies with both AGA and SGA infants.     

Trace elements’ concentrations in maternal and umbilical cord plasma at term gestation: a comparison between active labor and elective cesarean delivery

Objective.?Trace elements are minerals required in minute quantities to maintain proper physical functioning. The role of trace elements in the process of parturition is poorly understood. This study was aimed to determine levels of trace elements’ concentration in maternal plasma and umbilical venous and arterial plasma at term during active labor vs elective cesarean delivery (CD).

Study design.?A prospective case–control study was conducted. Forty healthy parturients in active labor at term with their newborns were compared to 40 healthy parturients matched for maternal age, parity, and gestational age, who delivered by elective CD (before commencement of labor). Samples of maternal venous blood and umbilical cord arterial and venous blood were drawn immediately following delivery. Trace elements’ concentrations were measured using the inductively coupled plasma mass spectrometer (ICP-MS).

Results.?Significant higher levels of manganese (Mn) and selenium were found in maternal venous plasma during active labor vs elective CD. Magnesium (Mg) levels were significantly higher in maternal venous blood during elective CD compared to active labor. Umbilical cord artery levels of Mg, Mn, and zinc (Zn) were significantly higher in active term labor vs elective CD. Also, significant higher levels of copper and Zn were found in umbilical cord vein between active labor and elective CD.

Conclusion.?Trace elements’ concentrations differ significantly in fetal blood during active labor vs elective CD. Hence, trace elements may play a crucial role in the process of human parturition.     

Hormonal regulation of neonatal weight: placental leptin and leptin receptors

Objective To examine whether umbilical and maternal leptin levels correlate with birthweight, placental weight, and maternal weight; and to detect membrane-bound leptin receptors in placental tissue as well as soluble leptin receptors in umbilical and maternal blood.
Design Prospective observational study.
Setting University teaching hospital.
Methods Serum levels of leptin and soluble leptin receptors were analysed in 31 randomly selected mother/newborn pairs at delivery. In addition, placental tissue was assayed for leptin receptors using immunocytochemistry and Western blot.
Results The mean [SD] leptin level in umbilical cord venous blood (7.1 ng/mL [4.0]) was significantly lower (   P < 0.001  ) than in maternal blood (22.5 ng/mL [10.8]). Umbilical cord leptin concentrations correlated significantly with birthweight (   P < 0.001  ), placental weight (   P < 0.005  ) but not with maternal leptin. Maternal leptin concentrations correlated only with maternal weight (   P < 0.001  ). In chorionic villous tissue, trophoblasts stained strongly positive for leptin receptor-like immunoreactivity. Two membrane-bound isoforms of the leptin receptor were also detected in placental tissue. In both umbilical and maternal serum, a soluble leptin receptor was found migrating as broad band at M_r 97,000 D.
Conclusion The present data strongly reinforce the idea that circulating leptin levels may provide a growth-promoting signal for fetal development during late pregnancy. While membrane-bound leptin receptors may be involved in autocrine regulation of placental leptin production, the soluble receptor form may serve as a transport vehicle for leptin to fetal tissues.     

Hepatocyte growth factor concentration in maternal and umbilical cord blood samples and expression in fetal liver

OBJECTIVE: To determine whether human placenta secretes hepatocyte growth factor (HGF) and could influence fetal liver development. METHODS: Expression of HGF and c-met mRNA in paired samples of first- and second-trimester fetal liver and placenta was compared using a quantitative ribonuclease protection assay. Serum HGF concentration in 30 samples of paired umbilical and maternal blood from term pregnancies was evaluated using an enzyme-linked immunosorbent assay. RESULTS: HGF and c-met mRNA were expressed at similar levels in liver and placenta, with expression increasing from 9 to 16 weeks' gestation. Median serum HGF values were 1.4 ng/mL (maternal venous), 1.2 ng/mL (cord venous), and 1.3 ng/mL (cord arterial). The maternal venous HGF levels were significantly higher than fetal venous levels (P =.02). CONCLUSIONS: This study does not support the hypothesis that the placenta secretes HGF, because maternal serum levels were higher than fetal and there was no significant difference between umbilical arterial and venous samples. Fetal liver expresses abundant HGF mRNA during the first and second trimester and expression increases in line with receptor (c-met) expression, suggesting that hepatic growth and development are independent of placental HGF.     

Levels of plasminogen activators and their inhibitors in maternal and umbilical cord plasma in severe preeclampsia

OBJECTIVE: The purpose of this study was to evaluate the plasminogen activator system in maternal and umbilical cord plasma in patients with severe preeclampsia compared with control subjects with normotensive pregnancies. STUDY DESIGN: Maternal blood was sampled from 42 patients at a median gestational age of 32 weeks; after delivery, arterial and venous umbilical cord blood was sampled from 37 and 36 of these patients, respectively. Maternal blood from women with uncomplicated pregnancies was sampled at the gestational age of 32 weeks (n = 18, group I), and umbilical cord blood was sampled after premature deliveries of normotensive pregnancies (n = 5, group II). Data were analyzed with the use of Mann-Whitney U tests. RESULTS: Patients had significantly higher tissue plasminogen activator (P <.01) and unchanged urokinase plasminogen activator plasma levels compared with control subjects at 32 weeks of gestation; lower plasminogen activator inhibitor type 2 (P < 0.01) and no different plasminogen activator inhibitor type 1 concentrations were observed compared to control subjects at 32 weeks of gestation. In the arterial and venous umbilical cord plasma of patients, plasminogen activator inhibitor type 1 levels were significantly higher(P <.01) compared with control subjects at 32 weeks of gestation, although urokinase plasminogen activator levels in arterial and venous umbilical cord plasma (P < 0.01) were significantly lower. CONCLUSION: Lower plasminogen activator inhibitor type 2 levels are associated with placental insufficiency, and higher tissue plasminogen activator levels are associated with endothelial dysfunction in patients with severe preeclampsia. The higher plasminogen activator inhibitor type 1 levels and lower urokinase plasminogen activator levels in umbilical cord of these patients are suggestive of decreased fibrinolysis in the fetal circulation.     

Umbilical cord pH, PCO2, and bicarbonate following uncomplicated term vaginal deliveries

Normal values for umbilical arterial and venous pH, PCO2, PO2, and bicarbonate must be known before these parameters can be used for assistance in clinical decisions. We evaluated the cord blood from 146 infants born after uncomplicated labor and vaginal deliveries at 37 to 42 weeks' gestation. All infants had a normal baseline fetal heart rate and normal beat-to-beat variability for at least 10 minutes preceding expulsion. The cord blood of infants born to women with pregnancy complications such as diabetes mellitus, preeclampsia, twins, meconium-stained amniotic fluid, or fetal growth retardation was not included. Mean umbilical arterial values +/- 1 SD for the parameters studied were: pH, 7.28 +/- 0.05; PCO2, 49.2 +/- 8.4 mm Hg; PO2, 18.0 +/- 6.2 mm Hg; bicarbonate, 22.3 +/- 2.5 mEq/L. Umbilical venous values were: pH, 7.35 +/- 0.05; PCO2, 38.2 +/- 5.6 mm Hg; PO2, 29.2 +/- 5.9 mm Hg; bicarbonate, 20.4 +/- 4.1 mEq/L.     

Umbilical cord plasma interleukin-6 concentrations in preterm infants and risk of neonatal morbidity

OBJECTIVE: This study was undertaken to evaluate the association between umbilical cord interleukin-6 (IL-6) levels and neonatal morbidity in infants born at less than 32 weeks' gestation. STUDY DESIGN: Umbilical cord plasma IL-6 levels and neonatal outcomes were assessed in 309 infants born between 24 weeks and 0 days' and 31 weeks and 6 days' gestation. RESULTS: Mean IL-6 levels were higher in spontaneous (n = 193, 355 +/- 1822 pg/mL) compared with indicated preterm births (n = 116, 37 +/- 223 pg/mL, P < .0001). Adjusting for gestational age, a progressive relationship was noted between increasing IL-6 levels and increased risk of neonatal systemic inflammatory response syndrome (SIRS). IL-6 levels beyond the 90th percentile (> or =516.6 pg/mL) were also significantly associated with periventricular leukomalacia (PVL; odds ratio [OR] 15, 95% CI 2-149) and necrotizing enterocolitis (NEC; OR 6, 95% CI 1.1-33). In the multivariate analysis, an IL-6 level 107.7 pg/mL or greater (determined by receiver operating curve analysis) remained a significant independent risk factor for PVL (OR 30.3, 95% CI 4.5-203.6). CONCLUSION: Umbilical cord IL-6 levels are higher in preterm infants born after spontaneous preterm labor or premature rupture of membranes. Elevated IL-6 levels are associated with an increased risk for SIRS, PVL, and NEC in infants born at less than 32 weeks' gestation.     

Platelet counts in maternal and umbilical venous blood at the time of delivery

Platelet count in 38 paired maternal venous and umbilical venous specimens were determined at delivery. Umbilical values were significantly higher than simultaneous maternal values (p = 0.004), and a significant relationship was demonstrated between umbilical values and maternal values (r = 0.54, p = 0.0004). Associations between platelet counts and acid-base variables were found to be insignificant in the mother and the umbilical cord.