Acid-base status at birth, spontaneous motor behaviour at term and 3 months and neurodevelopmental outcome at age 4 years in full-term infants

Umbilical cord blood acid-base analysis at birth and long-term neurodevelopmental outcomes in children: a systematic review and meta-analysis

BACKGROUND

Umbilical cord blood acid-base sampling is routinely performed at many hospitals. Recent studies have questioned this practice and the association of acidosis with cerebral palsy.

OBJECTIVE

To investigate the associations between the results of umbilical cord blood acid-base analysis at birth and long-term neurodevelopmental outcomes and mortality in children.

SEARCH STRATEGY

We searched six databases using the search strategy: umbilical cord AND outcomes.

SELECTION CRITERIA

Randomised controlled trials, cohorts and case-control studies from high-income countries that investigated the association between umbilical cord blood analysis and neurodevelopmental outcomes and mortality from 1 year after birth in children born at term.

DATA COLLECTION AND ANALYSIS

We critically assessed the included studies, extracted data and conducted meta-analyses comparing adverse outcomes between children with and without acidosis, and the mean proportions of adverse outcomes. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.

MAIN RESULTS

We have very low confidence in the following findings: acidosis was associated with higher cognitive development scores compared with non-acidosis (mean difference 5.18, 95% CI 0.84-9.52; n = two studies). Children with acidosis also showed a tendency towards higher risk of death (relative risk [RR] 5.72, 95% CI 0.90-36.27; n = four studies) and CP (RR 3.40, 95% CI 0.86-13.39; n = four studies), although this was not statistically significant. The proportion of children with CP was 2.39/1000 across the studies, assessed as high certainty evidence.

CONCLUSION

Due to low certainty of evidence, the associations between umbilical cord blood gas analysis at delivery and long-term neurodevelopmental outcomes in children remains unclear.

Umbilical cord pH, blood gases, and lactate at birth: normal values, interpretation, and clinical utility

Normal birth is a eustress reaction, a beneficial hedonic stress with extremely high catecholamines that protects us from intrauterine hypoxia and assists in the rapid shift to extrauterine life. Occasionally the cellular O₂ requirement becomes critical and an O₂ deficit in blood (hypoxemia) may evolve to a tissue deficit (hypoxia) and finally a risk of organ damage (asphyxia). An increase in H⁺ concentration is reflected in a decrease in pH, which together with increased base deficit is a proxy for the level of fetal O₂ deficit. Base deficit (or its negative value, base excess) was introduced to reflect the metabolic component of a low pH and to distinguish from the respiratory cause of a low pH, which is a high CO₂ concentration. Base deficit is a theoretical estimate and not a measured parameter, calculated by the blood gas analyzer from values of pH, the partial pressure of CO₂, and hemoglobin. Different brands of analyzers use different calculation equations, and base deficit values can thus differ by multiples. This could influence the diagnosis of metabolic acidosis, which is commonly defined as a pH <7.00 combined with a base deficit ≥12.0 mmol/L in umbilical cord arterial blood. Base deficit can be calculated as base deficit in blood (or actual base deficit) or base deficit in extracellular fluid (or standard base deficit). The extracellular fluid compartment represents the blood volume diluted with the interstitial fluid. Base deficit in extracellular fluid is advocated for fetal blood because a high partial pressure of CO₂ (hypercapnia) is common in newborns without concomitant hypoxia, and hypercapnia has a strong influence on the pH value, then termed respiratory acidosis. An increase in partial pressure of CO₂ causes less increase in base deficit in extracellular fluid than in base deficit in blood, thus base deficit in extracellular fluid better represents the metabolic component of acidosis. The different types of base deficit for defining metabolic acidosis in cord blood have unfortunately not been noticed by many obstetrical experts and organizations. In addition to an increase in H⁺ concentration, the lactate production is accelerated during hypoxia and anaerobic metabolism. There is no global consensus on definitions of normal cord blood gases and lactate, and different cutoff values for abnormality are used. At a pH <7.20, 7% to 9% of newborns are deemed academic; at <7.10, 1% to 3%; and at <7.00, 0.26% to 1.3%. From numerous studies of different eras and sizes, it can firmly be concluded that in the cord artery, the statistically defined lower pH limit (mean -2 standard deviations) is 7.10. Given that the pH for optimal enzyme activity differs between different cell types and organs, it seems difficult to establish a general biologically critical pH limit. The blood gases and lactate in cord blood change with the progression of pregnancy toward a mixed metabolic and respiratory acidemia because of increased metabolism and CO₂ production in the growing fetus. Gestational age-adjusted normal reference values have accordingly been published for pH and lactate, and they associate with Apgar score slightly better than stationary cutoffs, but they are not widely used in clinical practice. On the basis of good-quality data, it is reasonable to set a cord artery lactate cutoff (mean +2 standard deviations) at 10 mmol/L at 39 to 40 weeks' gestation. For base deficit, it is not possible to establish statistically defined reference values because base deficit is calculated with different equations, and there is no consensus on which to use. Arterial cord blood represents the fetus better than venous blood, and samples from both vessels are needed to validate the arterial origin. A venoarterial pH gradient of <0.02 is commonly used to differentiate arterial from venous samples. Reference values for pH in cord venous blood have been determined, but venous blood comes from the placenta after clearance of a surplus of arterial CO₂, and base deficit in venous blood then overestimates the metabolic component of fetal acidosis. The ambition to increase neonatal hemoglobin and iron depots by delaying cord clamping after birth results in falsely acidic blood gas and lactate values if the blood sampling is also delayed. Within seconds after birth, sour metabolites accumulated in peripheral tissues and organs will flood into the central circulation and further to the cord arteries when the newborn starts to breathe, move, and cry. This influence of "hidden acidosis" can be avoided by needle puncture of unclamped cord vessels and blood collection immediately after birth. Because of a continuing anaerobic glycolysis in the collected blood, it should be analyzed within 5 minutes to not result in a falsely high lactate value. If the syringe is placed in ice slurry, the time limit is 20 minutes. For pH, it is reasonable to wait no longer than 15 minutes if not in ice. Routine analyses of cord blood gases enable perinatal audits to gain the wisdom of hindsight, to maintain quality assurance at a maternity unit over years by following the rate of neonatal acidosis, to compare results between hospitals on regional or national bases, and to obtain an objective outcome measure in clinical research. Given that the intrapartum cardiotocogram is an uncertain proxy for fetal hypoxia, and there is no strong correlation between pathologic cardiotocograms and fetal acidosis, a cord artery pH may help rather than hurt a staff person subjected to a malpractice suit based on undesirable cardiotocogram patterns. Contrary to common beliefs and assumptions, up to 90% of cases of cerebral palsy do not originate from intrapartum events. Future research will elucidate whether cell injury markers with point-of-care analysis will become valuable in improving the dating of perinatal injuries and differentiating hypoxic from nonhypoxic injuries.

[S3 guidelines on "full-term vaginal birth" from an anesthesiological perspective : Worthwhile knowledge for anesthesiologists]

The publication of the new S3 guidelines on "full-term vaginal birth" and the guidelines on cesarean section, also published in 2020, provide further steps towards the promotion of evidence-based medicine in obstetrics, even if the exact configuration of neonatal monitoring during birth, in particular, is still the subject of current discussions. The multiprofessionality in the medical supervision of a birth is also fundamentally well-represented in the compilation of the S3 guidelines by the participating actors and specialist societies. Important from an anesthesiological perspective is the fact that neuraxial procedures still represent the gold standard in obstetric analgesia. With remifentanil PCA an alternative option is available that enables a reliable analgesia to be accomplished, e.g. when there are contraindications to performing neuraxial methods, if this is appropriate under the prevailing circumstances (1:1 support and appropriate monitoring). During an uncomplicated birth the strict fasting rules are relaxed. Overall, the guidelines underline the importance of self-determination and self-control for the expectant mother and give the highest priority to the safety and well-being of mother and child; however, this presupposes that the expectant mother is sufficiently informed about the value of neuraxial analgesia. For this it appears to be of importance to initiate information proposals, which go beyond the usual information sessions for parents that are often organized exclusively by midwives.

Neurodevelopmental outcome at 24 months of healthy infants at birth with an umbilical artery blood pH ≤ 7 and/or hyperlactacidemia ≥ 7 mmol/L

OBJECTIVE

The incidence of acidosis in term and healthy newborns and the consequences for their neurodevelopment are poorly understood. The aim of our study was to assess neurodevelopmental outcomes at 24 months of age via a parental questionnaire (ASQ, Ages and Stages Questionnaires) for a sample of infants born at term with an umbilical arterial blood pH ≤ 7 or/and hyperlactacidemia ≥ 7 mmol/L. In addition, we compared these groups' neurodevelopmental outcomes with a control group.

METHODS

During the 29 months of the study, we retrospectively included all children who had an umbilical artery (UA) cord blood pH ≤ 7 and/or lactates ≥ 7 mmol/L with good clinical adaptation. We also included a control group of term newborns with normal gases at birth. Ages and Stages questionnaires were sent to parents at 24 months of age.

RESULTS

Among the 9016 births during the study, 7.1% of babies had a UA pH ≤ 7 and/or lactates ≥ 7 mmol/L. The ASQ was considered non-optimal for 32.2% and 36.3% of respondents in the acidosis and control group, respectively, without any significant difference (P = 0.382). After matching for gestational age and sex, there was also no significant difference in the rate of non-optimal ASQ. The percentage of abnormal communication was significantly higher in the control group (19.7% vs 11.4%, P = 0.015).

CONCLUSIONS

Isolated biochemical umbilical cord blood abnormalities in term or near-term newborns with good adaptation do not appear to have a long-term impact on development. These results are rather reassuring, and the absence of specific follow-up for these children seems reasonable.

[Factors related to severe neonatal acidosis in planned cesarean section. A case-control study]

OBJECTIVES

To identify factors related to the occurrence of severe neonatal acidosis in case of planned caesarean section.

METHODS

Case-control study conducted between 1997 and 2016 among women with planned caesarean delivery at term. Cases were women whose neonates had neonatal arterial pH<7,0. For each case, two planned caesarean sections with neonatal pH≥7,0 were selected as controls. Women whose fetus had a congenital malformation and those whose anesthesia was not spinal anesthesia were excluded.

RESULTS

Among the 5014 planned cesarean sections of the study period, 38 severe neonatal acidosis were observed (incidence of 0,76% CI95 [0,54-1,04]). Compared to 72 controls, the 36 caesareans with severe neonatal acidosis were associated with more frequent maternal obesity (BMI≥30kg/m²), higher ephedrine doses, longer time from skin incision to infant delivery, and more extraction difficulties. After logistic regression, only maternal obesity remained associated with a significant increase in the risk of severe neonatal acidosis, ORa=3,73, 95%CI (1,11-12,56).

CONCLUSIONS

In case of planned cesarean section, the main risk factor for severe neonatal acidosis is the existence of maternal obesity.

Umbilical artery pH and base excess at birth are poor predictors of neurodevelopmental morbidity in early childhood

AIM

We sought to evaluate the associations between umbilical artery pH and base excess and neurodevelopmental outcome at four years of age.

METHODS

This study comprised 84 588 singleton children born alive at term in 2005-2011 in the hospital district of Helsinki and Uusimaa in Finland. Data from the maternity hospital information system were linked to the data from the Medical Birth Register and the Hospital Discharge Register. Neurodevelopmental morbidity included cerebral palsy, epilepsy, intellectual or sensorineural impairment.

RESULTS

After adjustment for maternal and perinatal factors, a combination of pH <7.00 and base excess <-16.00 was associated with infant death (adjusted odds ratio 19.97; 95% confidence interval 5.38-74.17). Values of pH 7.00-7.10 were associated with cerebral palsy (adjusted odds ratio 2.40; 95% confidence interval 1.05-5.47). A combination of low five-minute Apgar score and umbilical artery base excess <-16.00 showed the highest positive predictive value (9.1%) for neurodevelopmental impairments. When umbilical artery pH <7.00 was included, a positive predictive value of 25.0% was observed for infant mortality.

CONCLUSION

Low umbilical artery pH and base excess at birth were the poor predictors of long-term neurodevelopmental morbidity in an unselected population. However, these parameters might be useful in assessing the risk of infant mortality.

Dose-dependent relationship between acidosis at birth and likelihood of death or cerebral palsy

BACKGROUND

The acid-base status of infants around birth can provide information about their past, current and future condition. Although umbilical cord blood pH <7.0 or base deficit ≥12 mmol/L is associated with increased risk of adverse outcome, there is uncertainty about the prognostic value of degree of acidosis as previous studies have used different variables, thresholds, outcomes and populations.

METHODS

Retrospective review of routinely collected clinical data in all live-born inborn infants of 35 weeks gestation or more delivered between January 2005 and December 2013 at the Simpson Centre for Reproductive Health, Edinburgh, UK. Infants were included if their lowest recorded pH was <7 and/or highest base deficit ≥12 mmol/L on either umbilical cord blood and/or neonatal blood gas within 1 hour of birth. Neurodevelopmental outcome of the infants with encephalopathy was collected from the targeted follow-up database.

RESULTS

56 574 infants were eligible. 506 infants (0.9%) met inclusion criteria. Poor condition at birth and all adverse outcomes increased with worsening acidosis. Combined outcome of death or cerebral palsy was 3%, 10% and 40% at lowest pH of 6.9-6.99, 6.8-6.89 and <6.8, respectively, and 8%, 14% and 59% at a base deficit of 12-15.9, 16-19.9 and 20 mmol/L or more, respectively.

CONCLUSIONS

There is a dose-dependent relationship between the degree of acidosis within an hour of delivery, and the likelihood of adverse neonatal and later neurodevelopmental outcome in infants born at 35 weeks gestation or more.

Lower Apgar scores and Caesarean sections are related to attention-deficit/hyperactivity disorder

AIM

We examined the associations between prenatal, birth-related and newborn risk factors and attention-deficit/hyperactivity disorder (ADHD).

METHODS

In this population-based study, 10 409 subjects diagnosed with ADHD by 31 December 2011 and 39 124 controls, born between 1 January 1991 and 31 December 2005, were identified from Finnish nationwide registers. Perinatal data were obtained from the Birth Register. Conditional logistic regression was used to examine the associations after controlling for confounders.

RESULTS

Lower Apgar scores were associated with a higher risk of ADHD, with odds ratios of 1.12 (95% confidence intervals 1.06-1.19) for one-minute Apgar scores of 7-8, 1.17 (95% CI 1.02-1.35) for scores of 5-6 and 1.41 (95% CI 1.18-1.68) for scores of 0-4, compared to Apgar scores of 9-10. Elective Caesarean sections were associated with an increased risk of ADHD with an adjusted odds ratio of 1.15 (95% CI 1.05-1.26). Other identified risk factors were breech presentation, induced labour and admission to a neonatal intensive care unit. Low umbilical artery pH did not increase the risk of ADHD.

CONCLUSION

Elective Caesareans and perinatal adversities leading to lower Apgar scores increased the risk of ADHD. Future research to identify the mechanisms behind these findings is warranted.

Neurological condition assessed with the Hempel examination and cognition and behaviour at 4years

AIM

To investigate associations between neurological condition, assessed with the Hempel examination, in terms of minor neurological dysfunction (MND) and neurological optimality, and cognition and behaviour at 4years.

STUDY DESIGN

Cross-sectional analyses within a prospective, assessor-blinded follow-up study.

SUBJECTS

Four-year-old singletons born to subfertile parents (n=235; 120 boys).

OUTCOME MEASURES

Outcome parameters were complex minor neurological dysfunction (complex MND) and the neurological optimality score (NOS). Cognitive outcome was evaluated with the Kaufman Assessment Battery for Children, resulting in a total intelligence quotient (IQ). Behavioural outcome was evaluated with the Child Behavior Checklist, resulting in a total problem T-score.

RESULTS

Fifty-seven (24.3%) children had complex MND. None of the children showed fine motor dysfunction, suggesting a ceiling effect of the Hempel assessment. Complex MND was not correlated with IQ or total problem T-score. Nevertheless, a higher NOS was correlated with a higher IQ and a lower total problem T-score (adjusted mean estimate [95% confidence interval]: cognition: 0.445 [0.026; 0.865], p=0.038; behaviour: -0.458 [-0.830; -0.087], p=0.016).

INTERPRETATION

At age 4, complex MND assessed with the Hempel assessment was not associated with cognition and behaviour, presumably due to a ceiling effect in the Hempel domain of fine motor function. A more optimal neurological condition was associated with higher IQ and better behaviour.

Motor development in 3-month-old healthy term-born infants is associated with cognitive and behavioural outcomes at early school age

AIM

To determine whether motor development at 3 months of age is associated with cognitive, motor, and behavioural outcomes in healthy children at early school age.

METHOD

In this cohort study, we included 74 term-born, healthy children (44 males, 30 females; median gestational age 40.1 wks, range 38.0-42.6 wks). From video recordings (median 12.9 wks, range 9.3-18.6 wks), we assessed the quality of fidgety movements, and calculated a motor optimality score. At school age (median 5 y 11 mo, range 5 y 8 mo-7 y 6 mo), we performed detailed cognitive, motor, and behavioural assessments. We examined whether aspects of motor development were associated with functional outcomes.

RESULTS

An age-adequate motor repertoire, in particular the presence of antigravity, midline leg, and manipulation movements, was related to poorer cognition, whereas variable finger postures was related to better cognition. Children with a monotonous concurrent motor repertoire had better ball skills but experienced more behavioural problems. The presence of antigravity movements tended to be associated with abnormal recognition (odds ratio [OR] 4.4, 95% confidence interval [CI], 0.9-21; R(2) =0.17; p=0.070), where the absence of variable finger postures was associated with borderline and abnormal visual-spatial perception (OR 20, 95% CI, 1.7-238; R(2) =0.39; p=0.018).

INTERPRETATION

Detailed aspects of motor development at 3 months of age are associated with cognition and behaviour, but not with motor outcome, in healthy children at early school age. Our findings suggest that early motor development may be the basis for later cognitive and behavioural performance. Since the associations were only moderate, possible environmental influences should be acknowledged.

[Severe neonatal acidosis: comparison and analysis of obstetrical practices in two French perinatal centers]

OBJECTIVES

To identify and compare risk factors for severe neonatal acidosis, defined by an umbilical artery pH inferior to 7.00, and clinical practices in two different perinatal centers.

PATIENTS AND METHODS

In a retrospective study, from 2003 to 2008, in two university perinatal centers (Poitiers and Saint-Antoine in Paris) on all term pregnancies complicated by severe neonatal acidosis (umbilical artery pH<7.00), we elected to compare the following risk factors: maternal characteristics, medical and obstetrical histories, progress of pregnancy, labour and delivery as well as the neonatal status.

RESULTS

Among 23,508 births, 177 term newborns had severe neonatal acidosis. The rate was similar for both perinatal centers of Poitiers and Saint-Antoine (0.92% and 0.77% respectively). Factors associated with severe neonatal acidosis were similar in both centers: maternal age, thick meconium, prior cesarean section. There were differences in obstetrical practices between the two centers: there were more caesarean sections and assisted vaginal deliveries in Paris and more inductions of labour in Poitiers.

CONCLUSION

Severe neonatal acidosis is associated with the geographical origin, the progress of labour and the mode of delivery. It seems that severe neonatal acidosis is unrelated to cesarean delivery.

Relationship between severe acidemia, verbal abilities, and behavior in a Spanish cohort of 5-year-old children born at term

AIM

To determine whether a relationship exists between the markers of severe acidemia (SA) and the developmental, verbal, and behavioral characteristics of children with SA born at term 5 years previously, without apparent neurological impairment.

METHODS

A cohort of 76 children-38 with SA (pH < 7, base deficit ≥12 mmol/L) and 38 non-SA (pH ≥ 7.20)-were evaluated using the Battelle Developmental Inventory, McCarthy's Verbal Scale, the Token Test for Children, and the Conners 3rd Edition-Parent. The relationships between markers of SA and verbal and behavioral scores were analyzed with parametric correlations. Multiple regression analysis was used to determine the possible effect of these markers on verbal abilities, verbal memory, and attention.

RESULTS

Although none of the scores were in the "impaired" range, the SA group scored lower in verbal index (p = .000) and verbal memory (p = .004) on the McCarthy's Scales and in verbal comprehension (p = .001) on the Token Test for Children-2, and higher on the inattention (p = .003) and hyperactivity-impulsivity domains of the Conners Scales (p = .009) compared with the control group. There were no differences between the groups in the motor, personal-social, or cognitive domains on the Battelle Developmental Inventory. The SA markers were found to be predictors, accounting for 61.6% of verbal variability.

CONCLUSIONS

SA markers reflect mild long-term consequences regarding verbal abilities and inattentiveness among children born at term without apparent neurological impairment on discharge but do not suggest severe impairment to the 5-year development of children. The authors recommend that these children should be monitored to determine whether they need or might benefit from an early intervention program.

Developmental outcome at 6.5 years after acidosis in term newborns: a population-based study

OBJECTIVES

Infants who develop encephalopathy after perinatal asphyxia have an increased risk of death and adverse neurologic outcome. Conflicting results exist concerning outcome in healthy infants with metabolic acidosis at birth. The aim of the current study was to evaluate whether metabolic acidosis at birth in term infants who appear healthy is associated with long-term developmental abnormalities.

METHODS

From a population-based cohort (14,687 deliveries), 78 infants were prospectively identified as having metabolic acidosis (umbilical artery pH < 7.05 and base deficit in the extracellular fluid >12.0 mmol/L). Two matched controls per case were selected. The child health and school health care records were scrutinized for developmental abnormalities.

RESULTS

Outcome measures at 6.5 years of age for 227 of 234 children (97%) were obtained. No differences were found concerning neurologic or behavioral problems in need of referral action or neurodevelopmental diagnosis in comparison of control children with acidotic children who had appeared healthy at birth, ie, had not required special neonatal care or had no signs of encephalopathy.

CONCLUSIONS

Infants born with cord metabolic acidosis and who appear well do not have an increased risk for neurologic or behavioral problems in need of referral actions or special teaching approaches at the age of 6.5 years.

Pre- and perinatal predictors of startle eye blink reaction and prepulse inhibition in healthy neonates

The present study examined the startle eye blink reflex and prepulse inhibition (PPI) in 65 healthy term-born neonates. Although the startle eye blink is already present at birth, some relevant neuronal structures are not fully mature. We therefore investigated the relationship between prenatal maturation and perinatal stress experience on startle eye blink and PPI. Eye blinks were evoked by unilaterally presented acoustic broadband white noise (50 ms, 95 dB, prepulse 75 dB). Startle response magnitude and percent PPI were calculated for ipsilateral and contralateral side of stimulation. Neonates exhibited stronger startle responses ipsilaterally than contralaterally, and a significant PPI. Neonates with more prenatal growth and less perinatal stress had greater startle magnitudes. Neonates with more stress had more PPI contralaterally. Results suggest that startle eye blinks may be useful as indicators of prenatal maturation and perinatal stress.

Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis

OBJECTIVE

To evaluate the association between umbilical cord pH at birth and long term outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline (1966-August 2008), Embase (1980-August 2008), the Cochrane Library (2008 issue 8), and Medion, without language restrictions; reference lists of selected articles; and contact with authors.

STUDY SELECTION

Studies in which cord pH at birth was compared with any neonatal or long term outcome. Cohort and case-control designs were included.

RESULTS

51 articles totalling 481 753 infants met the selection criteria. Studies varied in design, quality, outcome definition, and results. Meta-analysis carried out within predefined groups showed that low arterial cord pH was significantly associated with neonatal mortality (odds ratio 16.9, 95% confidence interval 9.7 to 29.5, I(2)=0%), hypoxic ischaemic encephalopathy (13.8, 6.6 to 28.9, I(2)=0%), intraventricular haemorrhage or periventricular leucomalacia (2.9, 2.1 to 4.1, I(2)=0%), and cerebral palsy (2.3, 1.3 to 4.2, I(2)=0%).

CONCLUSIONS

Low arterial cord pH showed strong, consistent, and temporal associations with clinically important neonatal outcomes that are biologically plausible. These data can be used to inform clinical management and justify the use of arterial cord pH as an important outcome measure alongside neonatal morbidity and mortality in obstetric trials.

General movements in infants born from mothers with early-onset hypertensive disorders of pregnancy in relation to one year's neurodevelopmental outcome

BACKGROUND

Assessment of general movements (GMs) at three months is considered useful for prediction of adverse neurological outcome in high risk infants.

AIMS

To study the prevalence of abnormal GMs in infants born from women with early-onset hypertensive disorders of pregnancy and the association of GMs with neurodevelopmental outcome at one year.

STUDY DESIGN

Prospective study, part of a randomised controlled trial of pre-birth management strategies.

SUBJECTS

Infants born from women with early-onset hypertensive disorders of pregnancy.

OUTCOME MEASURES

GMs observation and neurological examination at term and three months corrected age; at one year neurological examination and Bayley Scales of Infant Development.

RESULTS

From 216 women included, 175 of 178 surviving infants (mean gestational age 31.6 weeks [SD 2.3], mean birth weight 1346 grams [SD 458]), were examined at three months. At term age normal, mildly abnormal and definitely abnormal GMs were observed in 54%, 36% and 10% respectively; and at three months in 47%, 40% and 13%. Mildly or definitely abnormal GMs at three months were not associated with abnormal neurological examination at one year, however, they were associated with delayed psychomotor development at one year (p = 0.01).

CONCLUSIONS

In this prospective study, including small for gestational age, preterm infants about half of them did not have normal GMs at term and three months. There was no association of GMs at term nor three months with neurological outcome at one year, but there was a significant association of GMs at three months with one year psychomotor development.

The association between cord pH at birth and intellectual function in childhood

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.