AIMS: To determine the association of hypotonia and depression in neonates at or near term with metabolic acidemia at birth (umbilical arterial pH<7.0 and base excess <-12 mM).
METHODS: This case-control study identified 87 infants without chromosomal or congenital abnormalities born at a single university hospital between 7/91 and 10/04 with hypotonia at birth requiring resuscitation and admission to the neonatal intensive care unit that had a cord gas at delivery. Controls were the subsequent delivery with a cord gas matched by gestational age.
RESULTS: Cases and controls did not differ in gestational age (38.7+/-1.9, 38.6+/-1.9 weeks) or birth weight (3,066+/-664, 3,171+/-655 g, P=0.20). Cases were more likely to have a cord pH<7.0 [17 (20%) vs. 1 (1.1%), P=0.0001] and cord pH 7.0-7.1 [13 (14.9%) vs. 2 (2.3%), P=0.003]. Among the hypotonic infants, 31 (35.6%) also were depressed at birth with a 5-min Apgar <7. In the depressed subset of hypotonic neonates 14/31 (45%) had a pH<7.0. Of the 12 hypotonic neonates with seizures, 3 (25%) had pH<7.0. Multivariate analysis showed a significant association between neonatal hypotonia and hypoglycemia, umbilical arterial pH, and nucleated red blood cell count.
CONCLUSIONS: Although metabolic acidemia is significantly associated with hypotonia at the time of birth, the majority of neonates with hypotonia and depression or seizures do not have objective evidence of asphyxia as measured by a cord gas at the time of delivery.
BACKGROUND: Acidemia at birth is very common but little is known about its long-term consequences.
AIM: To determine if pH at birth is related to established tests of intellectual function.
SUBJECTS: School children aged 6-8, for whom obstetric data were available, who had been delivered after labour at term, and had an umbilical cord arterial pH>7.00 (i.e. that was not extremely acidemic). STUDY DESIGN/OUTCOMES: Retrospective cohort study correlating birth and arterial pH data with childhood tests for non-verbal intelligence, grammar comprehension and literacy.
METHODS: Relationships between pH and cognitive measures were analysed with parametric correlations. Partial correlations were used to examine these relationships, controlling for possible confounding factors.
RESULTS: Arterial pH was significantly negatively correlated with literacy (p=0.001) and with non-verbal intelligence (p=0.033).
CONCLUSIONS: Lower arterial pH is associated with higher scores on literacy and non-verbal intelligence tests at ages 6-8. This is unlikely to be a chance finding and is further evidence that acidemia in isolation should not be considered an adverse outcome. Further research on the relationship between labour and long-term cognitive measures is required.
OBJECTIVE: The purpose of this study was to determine whether electronic fetal monitoring can identify fetuses with metabolic acidosis and hypoxic-ischemic encephalopathy.
STUDY DESIGN: The cases were 107 nonanomalous chromosomally normal fetuses with an umbilical arterial pH < 7.0 and base excess < or = 12 mmol/L. Controls were the subsequent delivery that was matched by gestational age and mode of delivery. The last hour of electronic fetal monitoring before delivery was evaluated by 3 obstetricians who were blinded to outcome.
RESULTS: Cases had a significant increase in late and prolonged decelerations/hour and late decelerations/contractions. Those fetuses with hypoxic-ischemic encephalopathy had significant increases in bradycardia, decreased variability, and nonreactivity but no difference in late or variable decelerations/hour. For the identification of hypoxic-ischemic encephalopathy, the sensitivity, specificity, and positive and negative predictive values were 15.4%, 98.9%, 66.7%, and 89.4%, respectively, for bradycardia; 53.8%, 79.8%, 26.9%, and 92.6%, respectively, for decreased variability; 92.3%, 61.7%, 2.7%, and 82.9%, respectively, for nonreactivity; and 7.7%, 98.9%, 50.0%, and 88.6%, respectively, for all 3 abnormalities combined.
CONCLUSION: Fetal metabolic acidosis and hypoxic-ischemic encephalopathy are associated with significant increases in electronic fetal monitoring abnormalities, but their predictive ability to identify these conditions is low.
OBJECTIVE: To evaluate the clinical value of lactate measurement and nucleated red blood cell (NRBC) counts when compared to base excess (BE) in the blood collected from the placental segment of the umbilical vein.
METHODS: 25 umbilical cords from premature babies were sampled after placental delivery and cord clamping. Babies were followed until discharge. Statistics involved linear regression, Spearman's correlation, ROC curves, and Fisher's exact test.
RESULTS: The relationship between lactate in the umbilical vein blood and pH and BE was significant (p < 0.0001). A 4.04 mmol/L lactate level showed a sensitivity of 62.5% and a specificity of 94.1% in detecting pH < 7.2 and BE < -10 mmol/L. NRBC counts were related to BE (p = 0.0095), but with a sensitivity of 37.5% and specificity of 82.4% in detecting BE < -10 mmol/L.
CONCLUSIONS: Lactate is a valuable marker of fetal hypoxia when sampled from placental segment veins. NRBC counts demonstrated low sensitivity for the detection of acidosis.
OBJECTIVE: To evaluate how often low 5-min Apgar scores (AS(5-min)) at term are associated with asphyxia.
STUDY DESIGN: A cohort- and case-control study, including all 183 term infants with AS(5-min) below 7 born at Lund University Hospital during 1993-2002, antepartum deaths excluded. The control group included 183 randomly selected term newborns with AS(5-min) 9-10. Cardiotocography (CTG) traces were assessed blinded to group and outcome. Obstetric and pediatric files were reviewed.
RESULTS: After excluding infants with severe malformations, indications of hypoxia were found at the following rates in cases with AS(5-min) below 4 (N = 30), scores 4-6 (N = 143), and controls (N = 182)-abnormal admission CTG: 38%, 8% and 0.6%; abnormal CTG before birth: 88%, 69% and 18%; obstetrical catastrophe: 28%, 6% and 0.6%; interventions for fetal distress: 83%, 48% and 9%; cord artery pH below 7.15: 69%, 54% and 7%; hypoxic ischemic encephalopathy or hypoxic death: 70%, 14% and none. All differences between each case group and controls were statistically significant (p < 0.0001).
CONCLUSIONS: In the absence of severe malformations, the vast majority of AS(5-min) below 4, and at least half of scores 4-6 could be attributed to birth asphyxia. Signs of hypoxia usually appeared during labor, but were present at admission in 38% of cases with AS(5-min) below 4.
OBJECTIVE: To investigate the perinatal factors related to neonatal intracerebral hemorrhage (ICH) and possibly to define obstetric and perinatal risk factors.
STUDY DESIGN: All medical records of women who delivered in the period from 1 January 1991 to 1 January 2000 were reviewed for intracerebral hemorrhages in infants born between 24 and 34 weeks of gestation and treated in the postnatal period. Sixty infants with ICH (Group I) and 60 infants without ICH (Group II, matched controls) were determined for comparison. Obstetrical parameters and risk factors and perinatal outcome parameters were evaluated and statistically analyzed.
RESULTS: Neonatal intracerebral hemorrhage prevalence was 0.8% (60/7635 births). Betamethasone administration was significantly less in Group I than in Group II (27% versus 46%). Although Doppler-sonography of the middle cerebral artery was performed in a minority of the cases, it showed a significant tendency of lower resistance indices (brain sparing) in the intracerebral hemorrhage group (66.7% versus 21.1%). Postnatally, infants with intracerebral hemorrhage showed a significantly more often umbilical arterial acidosis (18% versus 10%), a greater base deficit, lower median 5 min Apgar scores (6 and 8, respectively for Groups I and II), and a lower thrombocyte count (Group I 190,000 +/- 76,000 microl(-1), and Group II 227,000 +/- 96,000 microl(-1)). Infants in Group I were more often (93% versus 76%) and longer (26.7 +/- 30.5 days versus 15.4 +/- 11.7 days) dependent on ventilatory support than infants in Group II. Mortality rate in Group I (35%) was significantly higher compared to Group II (17%).
CONCLUSIONS: Antenatal Doppler sonography in predicting intracerebral hemorrhage in preterm infants should be investigated in large scale prospective studies. Postnatal low pH-values (pH < 7.1) and a base deficit of more than -16 mmol/L in the umbilical artery, low Apgar scores and thrombocytopenia are associated with a neonatal intracerebral hemorrhage and prophylaxis with corticosteroids reduces the risk for it. A higher neonatal mortality and morbidity, including neurological and neuromotoric dysfunctions is expected in this clinical entity.
OBJECTIVE: The aim of the study was to assess the relationship between acid-base status and quality and quantity of General Movements (GMs) at birth and quality of GMs at age 3 months and motor, cognitive and behavioural functioning at the age of 4 years.
METHODS: From a cohort of 84 term children with different umbilical artery pH without severe neonatal neurological abnormalities, GMs were assessed at term and at 3 months. At the age of 4 years, 44 children were assessed by means of the Movement Assessment Battery for Children (Movement-ABC), Neurological Examination for Toddlers of Hempel, Kaufman Assessment Battery for Children information processing (Kaufman ABC), Visuomotor Integration (VMI), the Child Behaviour Checklist (CBCL) and Precursors ADHD Questionnaire (PAQ).
RESULTS: We found no relationship between pH or GM-quality and quantity at term or GM-quality at 3 months and scores on most of the items of the Movement-ABC, cognitive and behavioural outcome. However, neonatal pH value and GM-quality at 3 months were related to some extent to the presence of subtle signs of neuromotor dysfunction as measured by the Hempel test.
CONCLUSIONS: In a sample of infants with a large variation in umbilical artery pH and without severe neonatal neurological abnormalities, acid-base status at birth and quality of GMs at 3 months of age is not predictive for motor milestone achievement, cognitive and behavioural functioning at 4 years, but these parameters are related to a less optimal condition of the nervous system. The latter finding has, however, limited clinical significance.
OBJECTIVE: Neonatal cerebral white matter injury represents a major precursor for neurological impairment and cerebral palsy. Our objective was to identify risk factors associated with its development.
STUDY DESIGN: This retrospective case-control study of all births between 23 and 34 weeks gestation at a single university hospital between May 1994 and September 2001 identified 150 cases with white matter injury characterized by periventricular leukomalacia or ventricular dilatation from white matter atrophy that were chromosomally normal and did not have other congenital anomalies. Cases were matched to controls without brain injury by the next delivery within 7 days of their gestational age.
RESULTS: There were small differences between controls and cases in gestational age (27.5 +/- 2.7, 27.4 +/- 2.6 weeks, P = .01) and birth weight (1053 +/- 402, 966 +/- 285 g, P = .002) that were statistically but not clinically significant. There was no difference in the percentage of controls and cases delivered by cesarean (45%, 49%, P = .64). There were no differences between controls and cases in umbilical arterial pH (7.27 +/- 0.11, 7.25 +/- 0.15, P = .19), base excess (-2.1 +/- 2.7, -3.0 +/- 4.1 mmol/L, P = .28), pH less than 7.0 (2/122 [2%], 3/107 [3%], P = 1.0), or base excess less than -12 mmol/L (4/121 [3%], 6/106 [6%], P = .75). The cases had a significant increase in positive blood (19%, 29%, P = .036), cerebrospinal fluid (6%, 17%, P = .002), and tracheal (9%, 22%, P = .003) cultures during the neonatal period. Conditional logistic regression showed a significant association among multiple gestations ( P = .02), intraventricular hemorrhage ( P < .001), and positive tracheal cultures ( P = .02) with cerebral white matter injury.
CONCLUSION: Culture-positive infection was associated with an increased risk of cerebral white matter injury in preterm neonates. Intrapartum hypoxia-ischemia as manifested by metabolic acidosis was rarely associated with white matter injury and was not different from the incidence in premature neonates without injury.
BACKGROUND: For several decades Apgar scores and umbilical blood pH sampling have been routinely used in the assessment of newborns. The aim of this study was to examine the prognostic value of neonatal survival using population-based data and to put these analyses into context with international studies.
MATERIAL AND METHODS: Data from 513,135 live births from the Perinatal Birth Register of Hesse, 1990 - 1999, were used. Death in the first week of life (early neonatal death) was used as endpoint of analyses. Receiver operator characteristic analyses were employed to compare the prognostic value of Apgar scores and umbilical blood pHs independently of cutoffs used.
RESULTS: Scores and umbilical blood pH showed a strong association with early neonatal morality. The relative risk of early neonatal mortality in term infants with scores 0 - 3 yields a relative risk of 1193 (95 % confidence interval = 801 - 1778) compared with babies born with scores 7 - 10. Scores at 1, 5, and 10 minutes were superior in predicting early neonatal mortality compared to umbilical blood pH, independent of cutoffs used.
CONCLUSIONS: Scores remain essential in the prediction of early neonatal survival. Umbilical blood pH is also strongly and significantly associated with early neonatal death, even though it is much less pronounced than the score.
DISCUSSION: The poor mortality prediction of umbilical blood pH sampling in Hesse compared with umbilical blood pH sampling in a large American delivery unit with a highly standardized measuring routine may be explained by a lower proportion of extremely acidotic infants or may be attributable to a decreased proportion of or to a less unified or less reliable measurement of the umbilical blood pH in Hesse.
To determine the association of hypotonia and depression in neonates at or near term with metabolic acidemia at birth (umbilical arterial pH<7.0 and base excess <-12 mM).
METHODS:
This case-control study identified 87 infants without chromosomal or congenital abnormalities born at a single university hospital between 7/91 and 10/04 with hypotonia at birth requiring resuscitation and admission to the neonatal intensive care unit that had a cord gas at delivery. Controls were the subsequent delivery with a cord gas matched by gestational age.
RESULTS:
Cases and controls did not differ in gestational age (38.7+/-1.9, 38.6+/-1.9 weeks) or birth weight (3,066+/-664, 3,171+/-655 g, P=0.20). Cases were more likely to have a cord pH<7.0 [17 (20%) vs. 1 (1.1%), P=0.0001] and cord pH 7.0-7.1 [13 (14.9%) vs. 2 (2.3%), P=0.003]. Among the hypotonic infants, 31 (35.6%) also were depressed at birth with a 5-min Apgar <7. In the depressed subset of hypotonic neonates 14/31 (45%) had a pH<7.0. Of the 12 hypotonic neonates with seizures, 3 (25%) had pH<7.0. Multivariate analysis showed a significant association between neonatal hypotonia and hypoglycemia, umbilical arterial pH, and nucleated red blood cell count.
CONCLUSIONS:
Although metabolic acidemia is significantly associated with hypotonia at the time of birth, the majority of neonates with hypotonia and depression or seizures do not have objective evidence of asphyxia as measured by a cord gas at the time of delivery.
