Neonatal Hematocrit Research Articles

Erythropoietin increases reticulocyte counts and maintains hematocrit in neonates requiring surgery

Background Limited erythropoietin (Epo) production diminishes neonates' ability to regenerate blood removed by phlebotomy. Neonates requiring surgery are at risk to receive multiple transfusions. We sought to determine if recombinant Epo administration to neonates requiring surgery would stimulate erythropoiesis. Methods Infants were randomized in double-masked fashion to receive Epo (200 units kg −1 d −1) or placebo for 14 days. Complete blood count, absolute reticulocyte count (ARC), phlebotomy losses, and transfusions were measured during the study period. Infants were transfused using a strict transfusion protocol. Results In the Epo group (n = 10, 2034 ± 308 g, 8 ± 2 days old; mean ± SEM), ARC increased significantly, whereas in the placebo group (n = 10, 2400 ± 184 g, 7 ± 2 days old), ARC remained low. Hematocrits in the Epo group trended upward from 34.4 1.7% to 37.3 1.9% (although not statistically significant) despite phlebotomy losses of 53 ± 12 mL/kg. Hematocrits in the placebo group were 35.9 1.8% and 33.2 1.6% on days 1 and 15, respectively, with phlebotomy losses of 27 ± 5 mL/kg. There were no differences in absolute neutrophil counts or platelet counts between groups at the end of the study. No adverse effects were noted. Conclusions Infants randomized to Epo increased reticulocyte counts and hematocrits without adverse effects. Erythropoietin administration may provide an adjunct to present care in decreasing or eliminating erythrocyte transfusions in surgical neonates.

336: Does peak systolic velocity (PSV) at middle cerebral artery (MCA) predict neonatal hematocrit in fetal growth restriction (FRG)?

336: Does peak systolic velocity (PSV) at middle cerebral artery (MCA) predict neonatal hematocrit in fetal growth restriction (FRG)?

The effect of early and late umbilical cord clamping on neonatal hematocrit

To compare the effect of early and late cord clamping (LCC) on neonatal hematocrit at 2 and 18 h of life. In this double-blind randomized trial, 64 healthy full-term vaginally born neonates were randomly allocated to either early (30 s) or late (3 min) umbilical cord clamping. During the interval between delivery and cord clamping, the attendant held the neonate supine at the level of the introitus. Neonatal venous hematocrit was measured at 2 and 18 h of life. Neonatal hematocrit at 2 h of life (61+/-4.9 vs 61.6+/-4.5%) and 18 h of life (56.9+/-4.1 vs 56.2+/-3.9%) was not significantly different between the two groups. This was also true for neonatal polycythemia (20 vs 23.5%). In the LCC group, placental residual blood volume (PRBV) was 39.5% lower and estimated neonatal blood volume (ENBV) was 7.1% higher than that in the early cord clamping (ECC) group (P<0.001). Late cord clamping does not lead to a significant difference in the hematocrit level of the neonate or neonatal polycythemia, but is associated with a significant increase in ENBV and a significant decrease in PRBV. Further trials should examine the effect of delaying cord clamping for a longer period of time or changing the position that the neonate is held in to determine whether these variations result in more clinically significant results.

Epidemiology of congenital malaria in Nigeria: a multi‐centre study

To determine the burden of congenital malaria in newborns in Nigeria. In a prospective multi-centre study, 1875 consecutive mother-baby pairs were enrolled over a continuous 12-month period. Blood smears were prepared from mothers, neonates, placental aspirates and cord blood within 4 h of delivery. Outcome variables were patent parasitaemia in the mother, placenta, cord and neonate in addition to maternal and neonatal haematocrit. Patent parasitaemia was detected in 95 neonates (5.1%). The occurrence varied between study centres, but was found year round in all sites. The mean parasite density among infected neonates was low (48 asexual forms per microl, range 8-200/microl). Maternal and placental parasitaemia were the most important risk factors for patent neonatal parasitaemia (P < 0.0001). Spontaneous clearance of parasitaemia occurred in 62.1% of neonates before day 2. 33.7% were symptomatic within 3 days of birth. Congenital malaria is often asymptomatic, clears spontaneously and may not warrant treatment. However, newborns with unexplained fever and refusal to feed in malaria endemic areas should be tested for malaria.

Effect of Timing of Cord Clamping on Neonatal Venous Hematocrit Values and Clinical Outcome at Term: A Randomized, Controlled Trial

BACKGROUND. The umbilical cord is usually clamped immediately after birth. There is no sound evidence to support this approach, which might deprive the newborn of some benefits such as an increase in iron storage. OBJECTIVES. We sought to determine the effect of timing of cord clamping on neonatal venous hematocrit and clinical outcome in term newborns and maternal postpartum hemorrhage. METHODS. This was a randomized, controlled trial performed in 2 obstetrical units in Argentina on neonates born at term without complications to mothers with uneventful pregnancies. After written parental consents were obtained, newborns were randomly assigned to cord clamping within the first 15 seconds (group 1), at 1 minute (group 2), or at 3 minutes (group 3) after birth. The infants9 venous hematocrit value was measured 6 hours after birth. RESULTS. Two hundred seventy-six newborns were recruited. Mean venous hematocrit values at 6 hours of life were 53.5% (group 1), 57.0% (group 2), and 59.4% (group 3). Statistical analyses were performed, and results were equivalent among groups because the hematocrit increase in neonates with late clamping was within the prespecified physiologic range. The prevalence of hematocrit at 65% was similar in groups 1 and 2 (4.4% and 5.9%, respectively) but significantly higher in group 3 (14.1%) versus group 1 (4.4%). There were no significant differences in other neonatal outcomes and in maternal postpartum hemorrhage. CONCLUSIONS. Delayed cord clamping at birth increases neonatal mean venous hematocrit within a physiologic range. Neither significant differences nor harmful effects were observed among groups. Furthermore, this intervention seems to reduce the rate of neonatal anemia. This practice has been shown to be safe and should be implemented to increase neonatal iron storage at birth.

Effect of Timing of Cord Clamping on Neonatal Venous Hematocrit Values and Clinical Outcome at Term: A Randomized, Controlled Trial: In Reply

Effect of Timing of Cord Clamping on Neonatal Venous Hematocrit Values and Clinical Outcome at Term: A Randomized, Controlled Trial: In Reply

Rh alloimmunization: Doppler or amniotic fluid analysis in the prediction of fetal anemia?

Compare the results of amniocentesis and those of middle cerebral artery peak systolic velocity to detect anemic fetuses in Rh alloimmunized pregnancies. Descriptive observational study involving 99 consecutive Rh-negative pregnancies: 74 alloimmunized patients submitted to amniotic fluid spectrophotometry (group 1) and 25 alloimmunized cases managed with Doppler ultrasonography (group 2). Variables analyzed were the following: need for neonatal transfusion and neonatal hematocrit. Neonatal hematocrit was significantly lower and the need for neonatal transfusion was significantly higher in cases managed with spectrophotometry compared to those managed with Doppler. Infants managed with Doppler velocimetry had higher hematocrit and less need for neonatal transfusion, suggesting that this non-invasive method of monitoring fetal anemia may best preserve the neonate.

Pregnancy outcome for Rh-alloimmunized women

Objective: To compare perinatal results of Rh-alloimmunized pregnancies managed with spectrophotometric amniotic fluid analysis or fetal middle cerebral artery Doppler ultrasonographic velocimetry. Method: A descriptive observational study involving 291 consecutive Rh-negative pregnancies. Group 1 consisted of 74 isoimmunized women managed with amniotic fluid spectrophotometry; group 2 of 25 isoimmunized women managed with Doppler ultrasonography; and group 3 of 192 nonimmunized Rh-negative women. The variables analyzed were need for intrauterine or neonatal transfusion, mode and time of delivery, birth weight, neonatal hematocrit, and perinatal mortality. Results: Need for intrauterine transfusion, birth weight, prematurity, rate of cesarean section, and perinatal mortality were similar in groups 1 and 2. Neonatal hematocrit was significantly lower and the need for neonatal transfusion was significantly higher when spectrophotometry rather than Doppler ultrasonographic velocimetry was used. Conclusion: Fetuses managed with Doppler ultrasonographic velocimetry had a higher hematocrit at birth and a lesser need for neonatal transfusion, suggesting that this noninvasive method of monitoring fetal anemia is a better choice.

12 Effect of Timing of Cord Clamping on Postnatal Hematocrit Values and Clinical Outcome in Term Infants. A Randomized, Controlled Trial

Background: Delayed cord clamping at birth increases iron stores in newborns, which correlates with their iron stores at 6, 9 and 12 months of age. This effect may reduce iron deficiency in infancy. However, there are very few randomized studies about the effects of delaying cord clamping on hematological parameters in the newborn and neonatal outcome Objectives: To determine the effect of umbilical cord clamping timing on venous hematocrit (Hct) and clinical outcomes in term neonates within the first month of life.Subjects: Term neonates (>37 weeks of gestation) born to mothers with normal pregnancies and uncomplicated vaginal or caesarean births.Methods: After written informed consent infants were randomized to have the cord clamped either within the first 15 seconds (group 1), or at one minute (group 2), or at three minutes (group 3). An independent observer measured the cord clamping time using a chronometer. When certain unexpected situations occurred (no spontaneous breathing at birth, meconium stained amniotic fluid and nuchal cord) the cord was clamped immediately. The Hct was obtained from the antecubital veins. The analyses were performed in an intention to treat basis. Main outcome measure: venous Hct measured at six hours after birth. Secondary outcome measures: venous hct and bilirubin levels between 24 and 48 h after birth and neonatal outcome.Results: 273 newborns were recruited (group 1= 90, group 2= 91 and group 3 = 92). The median time of cord clamping was 14“ (Q25:7-Q75:15) in group 1; 60” (Q25:60-Q75:61) in group 2 and 180“ (Q25:180-Q75:181) in group 3. Venous Hct (mean) at 6 hours were: 53.5 (SD= 6.9) in group 1; 57.0 (SD= 5.8) in group 2 and 59.4 (SD = 6.1) in group 3. The differences between means were not statistically significant. The rate of infants with Hct >65% was similar between group 1 and group 2 (4.4% and 5.9%, respectively) but was significantly higher in group 3 (14.1%) vs. group 1 (RR=3.1, CI 95%: 1.14-9.02, p= 0.04). All polycythemic infants were asymptomatic and none needed partial exchange transfusion. There were not significant differences between the groups in any of the secondary outcome measures.Conclusions: The cord clamped at least one minute after birth increases Hct levels within a physiological range. Moreover, no harmful effects were observed, thus the practice seems to be safe. Delayed cord clamping should be recommended in term newborns in order to reduce the iron deficiency during infancy.

Marked Twin-Twin Transfusion in the Absence of Nonimmune Hydrops

The precise pathophysiology of development of nonimmune hydrops in either the recipient or donor twin associated with twin-twin transfusion syndrome is not entirely clear. At times the recipient twin may develop nonimmune hydrops, but at other times the donor twin, and infrequently both, may develop this ominous complication. We present an unusual cases of this syndrome in which discordant twins, despite neonatal hematocrit levels of 86 and 21% were both nonhydropic and discuss the possible underlying pathophysiology of this occurrence.

Clinical Application of the Kleihauer-Betke Test

A prospective study was performed to investigate the benefit of serial quantitation of fetomaternal hemorrhage with the Kleihauer-Betke test for the prediction of neonatal/maternal outcome in pregnancies at risk for such bleeding. Of 65 patients, 14 (22%) had a positive Kleihauer test. Six of these women (43%) had evidence of placental abruption. Neonatal anemia (hematocrit < 48%) was present in only 2 of the 14 patients with a positive Kleihauer test (14%). Morbidity in the newborn correlated with gestational age at delivery, not with neonatal hematocrit. Maternal morbidity was not associated with a positive test. We conclude that Kleihauer-Betke testing is of limited value in patients at risk for fetomaternal hemorrhage.

Blood viscosity and optimal hematocrit in preterm and full-term neonates in 50- to 500-micrometer tubes.

Blood viscosity is an important determinant of blood flow resistance. Because a substantial part of flow resistance arises in small arteries and arterioles with diameters of 100 microns and less, rheologic properties of blood from preterm infants (24 to 36 wk of gestation), full-term neonates, and adults were measured in glass tubes with diameters of 50, 100, and 500 microns for a wide range of adjusted feed hematocrits (0.15-0.70). At each of the feed hematocrits, blood viscosity decreased when going from a 500-microns tube to a 50-microns tube. The viscosity reduction increased with increasing hematocrit. Moreover, the viscosity reduction was more pronounced in the neonates than in the adults. At a hematocrit of 0.70, the viscosity reduction averaged 56% in preterm infants, 50% in full-term neonates, and 39% in adults (p less than 0.005). However, the viscosity reductions at a hematocrit of 0.30 were only 35, 29, and 19%, respectively (p less than 0.05). In all four groups, blood viscosity increased exponentially with increasing hematocrit. The steepness of the hematocrit-viscosity curves decreased with decreasing tube diameter and with decreasing maturity of the infants. Erythrocyte transport efficiency (hematocrit/blood viscosity) was calculated to estimate the optimal hematocrit (i.e. hematocrit with maximum erythrocyte transport). In 500-microns tubes, the optimal hematocrit was about 0.40 in all of the groups. In 100-microns tubes, the optimal hematocrit was 0.44 +/- 0.05 in the adults and 0.52 +/- 0.04 in the neonates (p less than 0.05). In 50-microns tubes, the optimal hematocrit was 0.51 +/- 0.04 in adults and 0.60 +/- 0.05 in the neonates.(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal hematocrit and maternal glycemic control in insulin-dependent diabetes

We hypothesized that in infants of diabetic women neonatal hematocrit would correlate with third-trimester maternal glycemic control. Neonatal hematocrit correlated with the maternal total glycosylated hemoglobin level at delivery (r = 0.36; p less than 0.05) but not at 36 weeks of gestation in 32 mother-infant pairs. Improved maternal glycemic control during late gestation may decrease the incidence of neonatal polycythemia.

Amniotic fluid bilirubin and fetal hemolytic disease

Six different methods for assessing amniotic fluid bilirubin were compared in 111 samples from 37 patients. When the Liley methods were compared, the chloroform extraction and 5% correction methods resulted in 20% and 4% reductions, respectively, in the mean change in optical density at 450 nm when compared with the uncorrected mean (0.086 ± 0.06 [p \\lt 0.05] and 0.104 ± 0.07 [p, not significant] vs 0.108 ± 0.08). This reduction was observed in spite of significant visual blood contamination being rarely noted. The predictions based on amniotic fluid analysis were compared with the first fetal or neonatal hematocrit. The chloroform-extracted change in optical density at 450 nm accurately predicted fetal status in all patients, whereas lesser degrees of accuracy were observed with other methods. Hydrops fetalis did not occur during the observation period, and fetuses needing transfusion (n = 5) or early delivery (n = 10) were indicated correctly. The chloroform extraction change in optic;:al density at 450 nm accurately predicts fetal status, and its use should continue.

The Effects of Insulin Antibodies during Diabetic Pregnancy on Newborn Infants

Levels of insulin antibody, free insulin, and total insulin in the blood of diabetic mothers and their newborn infants were measured, and the relations of these findings to perinatal complications were studied. The subjects were 35 patients: 8 treated with bovine/porcine insulin, 15 with porcine, and 12 with human insulin. Insulin antibody levels (insulin binding capacity; IBC) in patients injected with bovine/porcine insulin were higher. There was no difference in the insulin antibody levels between the groups treated with porcine and human insulin preparations. Infant insulin antibody levels were close to the mother's levels. Free insulin levels did not correlate with total insulin nor antibody levels, but correlated with plasma glucose levels in the infants. The birth weight did not correlate with insulin antibody levels. The frequency of neonatal hypoglycemia and cord hematocrit levels were increased when the mother's insulin antibody levels were over 20%. We conclude the following: 1) Insulin antibodies are transferred through the placenta; 2) The risk of neonatal hypoglycemia is high if the mother's insulin antibody levels are high; 3) Bovine insulin preparations should not be used.

Neonatal Hyperviscosity Association With Lower Achievement and IQ Scores at School Age

A longitudinal study was conducted to determine whether the early neurologic and motor impairment observed in children with neonatal polycythemia and hyperviscosity persisted into school age. Forty-nine children who had neonatal polycythemia and hyperviscosity were evaluated at a mean age of 7 years. Of these, 21 (group 1) received a partial plasma exchange transfusion, whereas 28 (group 2) received symptomatic care. Forty control children (group 3) with a normal neonatal hematocrit were also evaluated. Testing consisted of a battery of measures to evaluate IQ, achievement, neuromotor function, and gross and fine motor skills. Maternal education and IQ were also assessed to avoid potential confounding by differences in the home environment. The neonatal course of the children with polycythemia and hyperviscosity was characterized by an increased number of problems, including hypoglycemia and cyanosis. At 7 years of age, the 49 children who had hyperviscosity (groups 1 and 2) had significantly lower "spelling" and arithmetic achievement test results and gross motor skill scores. Scores for reading, visual motor integration, and neurologic signs did not differ significantly from group 3. Maternal IQ scores were similar for both groups. Left-hand preference was seen in 14% of group 1 and 2 children and 7% of group 3 children (not significant). The scores for IQ, achievement, neuromotor function, and visual motor integration were compared for the hyperviscosity group (groups 1 and 2) and the control group (group 3) by multivariate analysis of variance with sex and hyperviscous group as independent variables and maternal education and maternal IQ as covariates (P = .040).(ABSTRACT TRUNCATED AT 250 WORDS)