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2023 MAR 25 (NewsRx) -- By a News Reporter-Staff News Editor at Obesity, Fitness & Wellness Week -- Investigators discuss new findings in environment. According to news originating from Barcelona, [...]

Umbilical cord blood from some babies might be contaminated with cells from the mother. In a study of 57 women and their newborn babies, 75% of cord blood samples contained maternal cells. Cord blood is now being used as a source of stem cells for transplantation.

Cord blood taken from pregnant women who have preeclampsia may have fewer stem cells than cord blood taken from healthy pregnant women. Preeclampsia is a serious complication of pregnancy. Cord blood is often used as a source of stem cells for transplantation.

An increased amount of nucleated red blood cells in the cord blood of newborn babies could be a sign of ABO incompatibility, according to a study of 1,661 newborn babies. Nucleated blood cells are immature blood cells. Fortunately, ABO incompatibility is not usually a serious condition in most babies.

Researchers describe a technique they used to successfully detect chromosomal abnormality in a fetus before it was born. This technique relies on the fact that fetal cells can be isolated from the mother's blood. The cells were cultured and analyzed with fluorescence in situ hybridization.

Cardiac troponin T that is present in umbilical cord blood may indicate heart damage in the fetus. Cardiac troponin T is a protein that is normally only present in blood when the heart has been damaged. In a study of 12 babies who had cardiac troponin T in umbilical cord blood, all had been exposed to magnesium sulfate.

Isoflavonoids are apparently transmitted through the placenta. These are the primary beneficial components of soy products. A study of 7 Japanese women during childbirth found high levels of isoflavonoids in the mother's blood, in cord blood and in amniotic fluid.

Umbilical cord blood from second- and third-trimester fetuses contains more CD34+ and CD34+CD38- cells than cord blood from fetuses at the full term of gestation. Researchers compared 31 umbilical cord blood samples for the quantity and characteristics of hematopoietic stem cells, the precursors of all blood cells. Cold preservation and enrichment of blood samples were successful at all stages of gestation, but blood collected earlier in pregnancy was richer in stem cells.

No significant difference was found between arterial and venous plasma concentrations of adrenomedullin in umbilical cord blood of 44 uncomplicated pregnancies with vaginal deliveries. The results indicate that the placenta is not involved in net production or net destruction of adrenomedullin, a vasoactive peptide, under normal conditions.

A noninvasive technique is described that can detect fetal chromosomal abnormalities. Normally, prenatal diagnosis is done via amniocentesis or chorionic villi sampling. However, these techniques can harm the fetus. Researchers used five-color fluorescent in situ hybridization analysis on flow-sorted fetal cells obtained from blood samples of 40 pregnant women. This technique is possible because research has shown that fetal blood cells are present in the mother's blood. Three copies of chromosome 21 were detected in two female fetuses. No abnormalities were detected for chromosomes X, Y, 13, and 18.

Fetal blood has a high level of stem cells during the second trimester and these could be used in gene therapy to correct genetic disorders before the fetus is born. Researchers measured the number of stem cells, which are the precursors of all mature blood cells, in blood samples taken from 48 fetuses between the gestational ages of 17 and 41 weeks. Stem cell levels were higher early in the second trimester compared to term. The levels remained stable until week 28 and then began to drop.

Measures of umbilical cord oxygen levels at birth are only weakly predictive of acidosis in the newborn. Inadequate oxygenation can cause the blood to become dangerously acidic. Researchers measured oxygenation in 18,250 newborns, and found that umbilical vein oxygen saturation averaged 63%, umbilical artery saturation averaged 24%, and fractional oxygen extraction averaged 62%. Babies with the umbilical cord wrapped around the neck, delivered by cesarean section after labor, or delivered postterm had higher oxygen extraction values, indicating greater fetal compromise.

An umbilical artery base deficit of more than 12 millimoles/liter (mmol/L) may be associated with serious newborn complications. The base deficit is a blood test which indicates characteristics of acidity, as might result from inadequate blood supply to the fetus during childbirth. Researchers used this test in the analysis of 174 newborn infants. Ten percent of children with base deficits of 12-16 mmol/L during childbirth had moderate or greater neurologic, respiratory or other complications. As the base deficit became more severe, the rate of complications from asphyxia increased to 40%.

Soluble CD14 receptor protein and elevated levels of lipopolysaccharide binding protein (LBP) in the amniotic fluid and cord blood of patients in labor, with or without infection, may be a general indication of uterine inflammation. These proteins were found in all 33 women at term undergoing cesarean section, 18 of whom were in labor. Elevated levels of LBP were associated with inflammation with or without recovery of microorganisms, and independently associated with the onset of labor. These substances may stimulate inflammation by sensitizing white blood cells.

Oxygen saturation tests using an oximeter appear to be equally valuable as blood analysis tests for evaluating fetuses in distress. Oximetry tests were compared with blood analysis tests in 174 fetuses in apparent distress as indicated by abnormal fetal heart rates. Fetuses with oximetry readings of less than 30% and blood pH of less than 7.20 were equally likely to be born in respiratory distress, have low Apgar scores, or require neonatal intensive care.

Objective: To determine whether the antidote for acetaminophen poisoning, N-acetylcysteine, administered to pregnant women with acetaminophen toxicity, crosses the placenta and can be measured in the newborn circulation following delivery. Design: Over a 15-month period, four pregnant women with acetaminophen toxicity, who delivered their infants while receiving the antidote N-acetylcysteine, were studied. Maternal and cord blood from three viable infants, and cardiac blood sampled during an autopsy on the fourth, were analyzed for the presence of N-acetylcysteine using high-performance liquid chromatography. Maternal and cord blood aminotransferase activities, and autopsy findings on the nonviable infant were used to assess hepatic injury. Results: N-acetylcysteine was detected in the cord blood of three viable infants and in cardiac blood of a fourth, sampled at the time of autopsy. The mean N-acetylcysteine concentration in cord blood was 9.4 [mu]g/mL ([+ or -] 1.3). This is well within the range associated with therapeutic doses of N-acetylcysteine typically administered to adults with acetaminophen poisoning. No adverse sequelae developed in the three viable infants. The fourth infant, delivered at 22 weeks gestational age died 3 h after birth. All mothers recovered and none of the four infants had evidence of acetaminophen-related toxicity. Conclusions: This is the first study documenting placental transfer of N-acetylcysteine in humans and provides impetus for research establishing a direct antidotal effect of N-acetylcysteine in the fetus., INTRODUCTION Acetaminophen is the most common analgesic recommended during pregnancy[1,2] and has an excellent safety profile during this vulnerable period.3 Acetaminophen is also the most commonly reported overdose in pregnancy.[4] [...]

Adenosine appears to play a role in fetal oxygen regulation and protection during periods of low oxygen supply. Blood levels of adenosine were monitored in five fetal sheep as oxygen supply through the umbilical cord was repeatedly blocked and released. Adenosine levels increased from baseline levels of 0.82 micromoles per liter (micromol/L) to a maximum of 1.31 micromol/L after 20 blockage and release cycles. When the 20 cycles were repeated one hour later adenosine levels again increased but not higher than during the previous cycle set. Adenosine levels later returned to baseline levels.

Fetal blood gas measurements may be helpful in distinguishing fetuses with cord prolapse from those with abruptio placentae. Blood gas measurements from the umbilical cord veins and arteries of 19 infants born with cord prolapse were compared with 32 infants born with abruptio placentae. Differential pH and oxygen saturation values were calculated by subtracting arterial values from venous values. Patients with cord prolapse had pH differences of more than 0.15 and oxygen saturation values of more than 24%.

Establishing the normal numbers of circulating red blood cells with nuclei in the newborn may prove useful in determining whether the baby experienced lack of oxygen in labor. Mature red blood cells do not have nuclei. Immature red blood cells may be rushed into circulation in response to stress. Researchers counted the number of nucleated red blood cells per 100 white cells in blood samples taken from the umbilical cords of 1,100 newborns. The values ranged from none to 89 with an average of 9 per 100 white blood cells.

Reduced fetal growth may be caused by insufficiency of the uterus and placenta, as evidenced by abnormal waveforms of spleen artery velocity. Researchers performed color and pulsed Doppler ultrasound scans of 42 small-for-gestational-age (SGA) fetuses and of 316 normally growing fetuses. SGA fetuses with abnormal umbilical artery velocity waveforms had lower splenic artery pulsatility indices than did SGA fetuses with normal waveforms and than did normal fetuses. Ultrasound scans of the middle brain artery pulsatility index and of the inferior vena cava may reveal low oxygen and high carbon dioxide levels.

Dysfunction of the lining of blood vessels may be found in the umbilical cords of infants born to preeclamptic mothers. Preeclampsia is a serious complication of pregnancy marked by high blood pressure and potential seizures. Researchers analyzed blood samples from 17 pregnant women with or without preeclampsia and from their infants. Increased amounts of cellular fibronectin, a marker for dysfunction of the blood vessel lining, were found in preeclamptic mothers and their infants than in nonpregnant women or infants born to healthy mothers. Blood vessel lining dysfunction in preeclampsia may compromise fetal health.

Maternal factors may determine insulin secretion in twin pregnancies, while insulin-like growth factor-1 (IGF-1) production may be genetically determined. Researchers evaluated umbilical cord blood from 110 twin pregnancies and from 178 pairs of nonsibling singleton pregnancies. Insulin levels in the fetus were determined by maternal factors while the fetus's genetic makeup determined the level of IGF-1. Insulin-like growth factor binding protein-1 (IGFBP-1) levels were determined by maternal and genetic factors. Fetuses with high levels of IGFBP-1 had severe growth restriction and placental abnormalities. Insulin facilitates growth and weight gain.

Newborns who have an umbilical cord blood pH level of 7.00 or less may experience multiorgan complications. Low blood pH may indicate the newborn did not receive enough oxygen during labor and delivery. Researchers identified 84 newborns without developmental defects whose cord blood pH measured less than 7.00, and compared their outcomes to those of 84 newborns whose cord blood pH was over 7.24. Newborns with low blood pH levels were more likely to be resuscitated and intubated, and to have respiratory, gastrointestinal, cardiovascular, and neurologic complications than were newborns with pH levels over 7.24.

The number of red blood cells with nuclei in a brain-injured newborn's blood at birth may indicate when oxygen deprivation occurred. Researchers measured the number of nucleated red blood cells in the umbilical cord blood of 153 brain injured newborns and compared results with 83 healthy newborns. Newborns with fetal heart rate patterns indicating distress from the time of hospital admission, which suggests the problem was not labor related, averaged 49 nucleated red blood cells per 100 white blood cells versus 11 to 13 per 100 in newborns who developed distress patterns during labor and 3 in healthy newborns.

Routinely analyzing blood gas levels in the artery of newborns' umbilical cords appears to be warranted. Measurements should at least include relative acid and base levels as measured by blood pH as well as carbon dioxide and carbonate levels. Many factors appear to affect the normal ranges for blood gas measurements. Measurements done routinely may be less likely to be forgotten than those done selectively. The cost of routinely using this test outweighs the legal costs associated with defending potential malpractice suits. These costs could be offset by the more selective use of fetal monitoring.

Normal, vigorous newborns may exhibit a large range of blood acid-base levels. Researchers obtained umbilical cord blood acid-base values and blood gases from 16,000 newborns. Most (94%) were vigorous newborns, defined as those with Apgar scores of seven or higher five minutes after birth. The average blood pH for vigorous newborns was 7.26. Acid-base values that are more than two standard deviations away from this average represent abnormal values. Normal acid-base values range from 2.5 to 97.5th percentiles. Abnormal acid-base values in a newborn can lead to neurologic impairment.

Women with growth-restricted pregnancies may experience significantly increased plasma amino acid concentrations as compared to those of women with healthy pregnancies. Researchers analyzed various amino acid concentrations in the plasma of five nonpregnant women, 21 women with appropriate-for-gestational-age fetuses, and 23 women with growth-restricted pregnancies. Women with normally growing fetuses showed significant reductions in plasma concentrations of most amino acids compared to nonpregnant women. In contrast, women with intrauterine-growth-restricted (IUGR) pregnancies had much higher levels of nine amino acids than women with normal pregnancies. Alpha-amino nitrogen levels were much higher in IUGR pregnancies. A deficiency in the mother's ability to adapt amino acid levels during pregnancy may indicate or lead to IUGR.

The need for fetal scalp blood sampling procedures may be reduced by supplementing standard electronic fetal monitoring with fetal electrocardiograms. Researchers compared fetal outcomes of 100 pregnant women with high risk labors who received electronic fetal monitoring alone to the outcomes of 84 high risk women who received electronic fetal monitoring plus fetal electrocardiogram analysis. Fetuses in the electronic fetal monitoring plus fetal electrocardiogram group received fewer fetal scalp blood samplings, and these samplings were more likely to yield abnormal pH results than in the other group. Slightly more unsuspected instances of lack of oxygen in fetuses occurred in the electronic fetal monitoring group. The use of fetal electrocardiograms did not lower the cesarean delivery rate.

Infants born with an umbilical artery pH of less than 7 may do quite well if they survive the immediate postnatal period. A pH less than 7 indicates the infant is suffering from excessive acid in the blood and is thought to be a sign of future health problems. Researchers gave a developmental test to 25 children who had been born with an umbilical artery pH of less than 7. None of the children had an abnormal score. Three other children whose mothers refused a home visit to administer the test were found to have had normal development during previous visits. However, all 30 children originally identified at serious problems immediately after delivery. Seventy-seven percent had been admitted to the neonatal intensive care unit and 27% had been placed on a ventilator. Two infants died. An umbilical artery pH of less than 7 may not indicate serious developmental problems later in life but it may indicate those infants who may need intensive care following delivery.

Antibodies against insulin in fetal cord blood do not appear to come from the mother. Researchers measured glucose, insulin and insulin autoantibodies in blood samples from 70 pregnant women and cord blood samples from their newborn infants. None of the women had diabetes before pregnancy or gestational diabetes during the pregnancy. Blood levels of insulin autoantibodies were substantially higher in the cord blood samples than in the maternal samples. There was no association between cord blood autoantibodies and maternal autoantibodies. Both cord blood and maternal insulin levels were positively associated with birth weight. Fourteen of the babies were extremely large for their gestational age, a condition called macrosomia.

Lactate levels in umbilical cord blood may indicate a lack of oxygen at birth as accurately as acid-base balance but lactate analysis may be easier. Lactate appears in blood when pH is low, as occurs with oxygen deprivation. Researchers analyzed 4,045 umbilical cord blood samples for the presence of lactate using a new electrochemical method that produces a result in one minute. Lactate levels were highest in fetuses that were delivered by cesarean section because of fetal distress. Lactate levels were much higher among vaginal deliveries than among elective cesarean sections. Neither umbilical blood acid-base measurements nor lactate measurements alone may accurately predict the neurologic outcome of newborns. The advantages of lactate analysis are its ease of use and low cost.

Placental lesions may reduce the respiratory function of the placenta, causing the fetus to experience a chronic lack of oxygen and stunted growth. Researchers studied 431 placentas and fetuses born between 22 and 32 weeks' gestation. Lesions of blood vessels and villous lesions in the placenta and uterus were thought to restrict blood and fluid flow and were associated with poor blood gas values. Preterm placentas without lesions may be less able to withstand the stress of labor than term placentas, as evidenced by the greater incidence of fetal distress among fetuses delivered preterm. Fetuses whose placentas have lesions that compromise placental function may adapt to the lack of oxygen and not show the signs of distress during labor that fetuses with healthier placentas may exhibit.

Labor appears to affect blood levels of preprocessed and completely processed oxytocin. Oxytocin stimulates uterine contractions and is made by the fetus and placenta as well as by the maternal pituitary. Blood samples were collected from the umbilical cord vein and artery immediately after vaginal birth in 26 women and after cesarean delivery prior to labor in 13 women. Overall, the preprocessed form predominated. However, the average concentration of preprocessed oxytocin was 37 picagrams per milliliter in infants delivered before labor versus 17 picagrams per milliliter in those delivered after labor. The concentration of processed oxytocin was 5 to 7 picagrams per milliliter in both groups.

A quantifiable relationship may exist between intrauterine growth retardation (IUGR) and related blood circulation and distribution problems in the womb as measured by fetal blood gases and Doppler ultrasonography. IUGR is the unborn's failure to grow and develop at a normal rate. Further complications include a lack of oxygen in the blood, hypoxemia, and acid imbalance in the blood, acidemia. Researchers measured blood gases obtained from the umbilical cords of 23 pregnant women carrying babies with severe IUGR. Ten women were smokers. In addition, Doppler ultrasonography allowed a view of fetal blood flow circulation patterns. All measurements showed abnormally decreased blood flow in the venous system and across the atrioventricular valves. Blood circulation to and from the brain was also abnormal. The venous blood gas levels in the umbilical cords were correspondingly low. Seven babies died, 19 were delivered by cesarean section, and birth weights ranged from 440 grams to 1,900 g. The distribution mechanism may not be able to compensate for inadequate blood supply to the fetal heart and brain during extreme IUGR.

Administering oxygen for longer than 10 minutes during pushing appears to have an adverse effect on the fetus. Eighty-six women in normal labor with a healthy, term fetus were randomly assigned to receive oxygen via mask during the pushing phase of labor. A blood sample was taken from the umbilical vein after birth and analyzed. As the length of oxygen therapy increased beyond 10 minutes, the pH of the baby's blood declined. Low pH is a symptom of decreased oxygen, although no baby experienced fetal distress. Results may not be applicable to different situations, as, for example, when the baby already lacks oxygen. Several studies have shown that although oxygen is often administered liberally in labor to the mother to improve fetal oxygenation, its use can have this adverse effect. Laboratory studies have shown that umbilical and placental blood vessels constrict in the presence of abnormally high amounts of oxygen, which may be the cause of this phenomenon.

A survey was undertaken among 124 pregnant women living in Riyadh City to investigate the passage of lead from the pregnant mother to the unborn child. The mean maternal blood lead level was 5.49 [+ or -] 2.6 [mu]g/dl and for the umbilical cord was 4.14 [+ or -] 1.81 [mu]g/dl. Lead levels were higher in maternal than in the umbilical cord blood. The results are in agreement with other studies. in this study, an excellent correlation between the maternal and cord blood lead levels (r = .83, p < .0001) confirms the transfer of lead from the mother to the fetus. A weak but significant relationship was found between maternal blood lead concentrations and birth weight of newborns (r = -.271, p < .05), and it is concluded that low levels of lead exposure to pregnant women may be considered hazardous., LEAD has an extensive history as a reproductive toxin, which exerts its effect either directly on the developing fetus, after gestation begins, or indirectly on paternal or maternal physiology before [...]

Fetal endothelin levels exceed those of the mother, but there is no correlation with gestational age. Endothelin is produced by the cells lining blood vessels, and its secretion primarily causes blood vessel constriction. Sixty-four women had blood samples drawn from the umbilical cord by passing a needle through the maternal abdomen. This was done for diagnostic purposes, but all fetuses selected for the study were normal. Prior to the procedure blood was also drawn from the mother. In addition, blood was drawn from the umbilical cord of eight healthy newborns. No correlation was found between either fetal and maternal endothelin levels and gestational age or between endothelin levels between the mother and the fetus. Fetal endothelin levels averaged 2.5 picograms per milliliter versus maternal levels of 1.3 picograms per milliliter versus newborn levels of 15.77 picograms per milliliter. The increase in endothelin level after birth seems reasonable considering the changes in vascular resistance that follow birth.

The effect of air contamination when measuring umbilical cord blood gases can be minimized by drawing blood samples into 1 milliliter (ml) syringes. However, air contamination does not appear to affect the measurements used to evaluate fetal asphyxia. Clinical circumstances were simulated in order to evaluate the effect of time and air contamination on umbilical cord blood samples drawn after birth for blood gas analysis. Umbilical cord blood was collected from 21 healthy, term infants. Blood gases from samples with varying amounts of air in the syringe were compared with gases from air-free syringes. Air contamination had no effect on carbon dioxide levels, pH, or bicarbonate, the parameters used to evaluate fetal asphyxia. Oxygen level was affected by exposure to more than 38% air in a 3 ml syringe, but air contamination had no effect in a 1 ml syringe. The interval between birth and the last sample collected ranged from 26 to 96 minutes and did not affect results.

Plasma and red blood cell cholinesterase activity in blood samples from 259 pregnant women and cord blood from some of their newborn were compared with samples from 25 nonpregnant female volunteers and with laboratory norms (Ellman method). Plasma cholinesterase was significantly lower (p < 0.05) and red blood cell cholinesterase higher (p < 0.05) in pregnant women than in nonpregnant controls in a repeated measures analysis. By the sixth post-partum week, both plasma and red blood cell cholinesterase were similar to nonpregnant control activity. Fetal cord red blood cell cholinesterase activity was also lower than in nonpregnant women, but plasma levels were not significantly different. When compared with standard laboratory normal ranges, most (98-100%) plasma cholinesterase values in pregnant women and newborn were within range, whereas the majority (59-87%, depending on trimester) of red blood cell levels were above range in pregnancy and below range in 53% of newborns. A low red blood cell cholinesterase in pregnant women is more consistent with a possible overexposure to anticholinesterases than a low plasma cholinesterase. Periods of altered sensitivity to specific cholinesterase inhibiting drugs and environmental agents are suggested by these findings. (Key Words: cholinesterases; pregnancy, physiclogy; fetal blood.), INTRODUCTION Abnormal erythrocyte, plasma, and serum acetylcholinesterase (AChE) enzyme activities are used as indicators of overexposure to pesticides, as well as markers for other pathological conditions (1). The interpretation of [...]

Fetal scalp blood sampling technique may affect the results. A system forsimulating fetal blood sampling was constructed so that two sampling techniques could be compared. An air-tight syringe tipped with a blunt needle was filled with fresh umbilical cord blood. The rate of drop formation at the tip was controlled by a small pump. The usual technique - aspiration of individual drops into a tube, transfer into a syringe, and measurement - was compared with collection directly into a small capillary tube or syringe. Differences were found between slow and rapid drop formation rates with the standard technique for pH, oxygen, and carbon dioxide values. No differences were found with the capillary collection technique. The exposure to air in the standard technique can result in erroneous findings, especially when drops of blood form slowly.

Pregnancy appears to increase both production of blood platelets and their responsiveness to stimulation. Platelets mediate clotting, which is known to be enhanced in pregnancy. The fetus has mature looking platelets that respond in adult fashion to stimulation early in gestation. Fetal blood samples were obtained from seven women undergoing elective abortion at 12 to 17 weeks' gestation, from 56 women having prenatal cord blood sampling at 18 to 36 weeks, and from 28 women undergoing elective cesarean from 37 to 42 weeks. Maternal blood came from 117 women from eight to 42 weeks' gestation. Maternal results were compared with those of 30 nonpregnant controls. Both maternal and fetal platelet size decreases with increasing gestational length, signifying increased production of platelets. Responsiveness to stimulation with adenosine diphosphate was enhanced in pregnant women, and fetal platelets both appeared and responded like adults platelet from 12 weeks on.