Association between umbilical artery cord pH, five-minute Apgar scores and neonatal outcome

Correlation of cardiotocography with combined APGAR scores and diagnostic performance of umbilical cord parameters in predicting low combined APGAR scores - A prospective Cohort study

Objectives

Combined Apgar score includes utilization of interventions such as Continuous positive airway pressure, Oxygen, Mask and Bag ventilation, I ntubation and ventilation, Ne onatal chest compression, Drugs, and newborn assessment. It has been proposed as a substitute for conventional Apgar score which is the gold standard for evaluating newborns right after birth but is impacted by medical interventions and preterm. Combined Apgar scores were examined to check for correlation with CTG tracing and umbilical cord blood parameters which gives an objective assessment of fetal hypoxia, in response to the demand for a more accurate tool for evaluating the neonate and to be used for medico-legal purposes. The study's objectives were to (1) determine the association of combined Apgar scores with suspicious and pathological CTG (2) the association of umbilical cord parameters with low combined Apgar scores and the diagnostic performance of these parameters in predicting low combined Apgar scores.

Study design

A prospective observational cohort study was conducted in a tertiary care center in East India. 2350 consecutive laboring mothers who had completed 34 weeks of gestation underwent cardiotocography according to institutional protocol and those with suspicious and pathological CTG who delivered within 1 h of abnormal CTG were recruited. Arterial blood was analyzed and the newborn was evaluated immediately after delivery with a combined Apgar scoring system.

Results

Of the 2350 women, 50.7 % and 49.3 %, respectively, exhibited suspicious and abnormal CTG tracings. CTG was reported to have low diagnostic accuracy and specificity, with a sensitivity of 66.7 % and 88.9 %, respectively, in detecting combined Apgar at 1 and 5 min. The combined Apgar score at five minutes showed a strong association with acidosis. There was a statistically significant correlation between low combined Apgar and excess lactate and base at one and five minutes. With 100 % sensitivity and 95 % specificity, high lactate levels > 4.1 mM/L were found to predict newborn encephalopathy.

Conclusion

Umbilical cord blood parameters were found to be correlated with low combined Apgar scores. Combined Apgar scores may be a more useful tool for neonatal assessment and long-term morbidity of newborns. Additional research is required to determine whether it can take the role of conventional Apgar scores in clinical practice.

Association of maternal, fetal and labor variables with a low Apgar score in the fifth minute in term pregnancy: a case-control study

PURPOSE

To search for maternal, labor-related and fetal variables associated with low Apgar in the fifth minute in term pregnancy.

METHODS

A retrospective case-control study with term births was conducted in a public teaching hospital from 2013 to 2020. Cases were term births with Apgar score less than 7 in the fifth minute, and controls, the next one or two births following a case, with Apgar of 7 or more. Non-cephalic presentations, multiples and malformations were excluded. We accessed 100 cases and 190 controls. We considered significant values of p < 0.05.

RESULTS

Were accessed 27 variables which could be risk factors, from which 12 were associated with the outcome. We found a protective effect of prelabor cesarean for the outcome, odds ratio (OR) 0.38, p = 0.013. Consequently, we conducted two sets of analyses: in the whole group and in the group of laboring women. The values of OR were in general greater in the group of laboring women, compared with the whole group. We conducted multivariate analysis within the group of women in labor. The variables which fitted best in the model were nulliparity, male sex of the fetus, less than six prenatal visits and abnormal cardiotocography; all remained significant. An association of rupture of membranes more than 360 min with the outcome, even after controlling fpr duration of labor, was found; adjusted OR 2.45, p = 0.023.

CONCLUSION

Twelve variables were associated with the outcome. Prelabor cesarean had a protective effect. The time of ruptured membranes was associated with low Apgar.

Association of CTG Diagnosis of Intrapartum Fetal Distress and Immediate Postpartum Acidemia in Foetal Umbilical Artery

Background

Intrapartum fetal hypoxia which is one of the leading causes of neonatal morbidity and mortality is a preventable cause. Over the past years, many methods have been employed to diagnose fetal distress, a sign of fetal hypoxia, among these, cardiotocography (CTG) is the most widely used method. Diagnosis of fetal distress based on CTG can have high inter and intraobserver variation leading to either delayed or inessential intervention henceforth increasing maternal morbidity and mortality. Fetal cord arterial blood pH is an objective method to diagnose intrapartum fetal hypoxia, hence by observing the incidence of acidemia in cord blood pH among those newborns born through cesarean section (CS) in view of non-reassuring CTG can help make a judicious decision.

Methods

In this single institutional observational study, patients admitted for safe confinement were subjected to CTG in the latent and active phases of labor. Non-Reassuring traces were further classified based on NICE guideline CG190. The cord blood of these neonates born through CS in view of non-reassuring CTG was drawn and sent for ABG analysis.

Results

Among the 87 neonates delivered through CS in view of fetal distress, 19.5% had acidosis. Among those with pathological traces, 16(28.6%) had acidosis and one (100%) which was categorized as the need for urgent intervention showed acidosis. This result showed a statistically significant association (p value-0.003). No statistically significant association was obtained when variation in baseline characters of CTG when taken independently.

Conclusions

In our study, neonatal acidemia which is the objective evidence of fetal distress was seen in 19.5% of our study population who underwent cesarean in view of non-reassuring CTG. Among these, acidemia was significantly associated with pathological CTG trace compared to suspicious trace. We also observed that abnormal FHR features when taken independently showed no significant association with acidosis. Acidosis among newborns certainly increased the requirement for active resuscitation and additional hospital stay. Hence, we conclude that by recognizing specific fetal heart rate patterns associated with acidosis in a fetus, a more judicious decision can be made, thereby preventing both delayed as well as inessential intervention.

Impact of implementation of a breech clinic in a tertiary hospital

BACKGROUND

The incidence of breech presentation in single pregnancies at term is between three to 5 %. In order to support eligible women in their choice of mode of delivery, a dedicated breech clinic with a care pathway was developed in December 2015 in a tertiary referral centre in Brussels. The primary objective of this study was to evaluate the vaginal birth rate before and after the introduction of a dedicated breech clinic. The secondary objective was to compare the early neonatal outcomes before and after the breech clinic was introduced.

METHODS

This was a single centre retrospective and prospective study. The inclusion criteria were term (from 37 weeks), singleton fetus and breech presentation at delivery. The exclusion criteria were suspected intrauterine growth restriction, severe fetal malformations and intrauterine fetal demise. We used a composite outcome as an indicator of neonatal morbidity and mortality.

RESULTS

After the introduction of the breech clinic, we observed a significant increase in planned vaginal delivery from 7.4% (12/162) to 53.0% (61/115) (OR: 13.5; 95% CI: 6.7-27.0). The effective vaginal breech delivery rate (planned and unexpected) significantly increased from 4.3% (7/162) pre-implementation of breech clinic to 43.5% (50/115) post-implementation (OR: 17.0; 95% CI: 7.3-39.6). Neonatal outcomes were not statistically different between the before and after periods.

CONCLUSION

The introduction of a dedicated breech clinic has led to an increase in vaginal deliveries for breech babies without adversely affecting neonatal outcomes.

Assessment of Risk Factors and Prognosis in Asphyxiated Infants

BACKGROUND

Asphyxia is considered an important cause of morbidity and mortality in neonates. This condition can affect many vital organs including the central nervous system and may eventually lead to death or developmental disorders.

OBJECTIVES

Considering the high prevalence of asphyxia and its adverse consequences, the present study was conducted to evaluate the risk factors for birth asphyxia and assess their correlation with prognosis in asphyxiated infants.

PATIENTS AND METHODS

This two-year follow-up cohort study was conducted on 260 infants (110 asphyxiated infants and 150 healthy neonates) at Mashhad Ghaem Hospital during 2007 - 2014. Data collection tools consisted of a researcher-designed questionnaire including maternal and neonatal information and clinical/laboratory test results. The subjects were followed-up, using Denver II test for 6, 12, 18, and 24 months (after discharge). For data analysis, t-test was performed, using SPSS version 16.5. P value ≤ 0.05 was considered statistically significant.

RESULTS

Of 260 neonates, 199 (76.5%) and 61 (23.5%) cases presented with normal neonatal outcomes and with abnormal neonatal outcomes (developmental delay), respectively. Variables such as the severity of asphyxia (P = 0.000), five-minute Apgar score (P = 0.015), need for ventilation (P = 0.000), and severity of acidosis at birth (P = 0.001) were the major prognostic factors in infants with asphyxia. Additionally, prognosis was significantly poorer in boys and infants with dystocia history (P = 0.000).

CONCLUSIONS

Prevalence of risk factors for developmental delay including the severity of asphyxia need for mechanical ventilation, and severity of acidosis at birth, dystocia, and Apgar score were lower in surviving infants; therefore, controlling these risk factors may reduce asphyxia-associated complications.

Permissive hypercapnia--role in protective lung ventilatory strategies

"Permissive hypercapnia" is an inherent element of accepted protective lung ventilation. However, there are no clinical data evaluating the efficacy of hypercapnia per se, independent of ventilator strategy. In the absence of such data, it is necessary to determine whether the potential exists for an active role for hypercapnia, distinct from the demonstrated benefits of reduced lung stretch. In this review, we consider four key issues. First, we consider the evidence that protective lung ventilatory strategies improve survival and we explore current paradigms regarding the mechanisms underlying these effects. Second, we examine whether hypercapnic acidosis may have effects that are additive to the effects of protective ventilation. Third, we consider whether direct elevation of CO(2), in the absence of protective ventilation, is beneficial or deleterious. Fourth, we address the current evidence regarding the buffering of hypercapnic acidosis in ARDS. These perspectives reveal that the potential exists for hypercapnia to exert beneficial effects in the clinical context. Direct administration of CO(2) is protective in multiple models of acute lung and systemic injury. Nevertheless, several specific concerns remain regarding the safety of hypercapnia. At present, protective ventilatory strategies that involve hypercapnia are clinically acceptable, provided the clinician is primarily targeting reduced tidal stretch. There are insufficient clinical data to suggest that hypercapnia per se should be independently induced, nor do outcome data exist to support the practice of buffering hypercapnic acidosis. Rapidly advancing basic scientific investigations should better delineate the advantages, disadvantages, and optimal use of hypercapnia in ARDS.

[Definition of asphyxia neonatorum and incidence of neurologic and systemic complications in the full-term newborn]

PATIENTS AND METHODS

In a prospective multicentric study, 152 of 10,065 live term births had birth asphyxia, defined by the association of three indicators (fetal distress, depression at birth and metabolic acidosis).

RESULTS

The incidence of birth asphyxia was 1.5% of live term births when birth asphyxia was defined by the presence of at least two indicators, and 1% of live term births when birth asphyxia was defined by the association of metabolic acidosis and another indicator. Neurological complications were observed in 66 cases (43%). The incidence of post-asphyxial encephalopathy (PAE) was 5.9/1000 of live term births (mild PAE: 3/1000; moderate PAE: 2.7/1000; severe PAE: 0.2/1000). Systemic complications were observed in 87 patients (57%). Renal injury and coagulopathy were associated with moderate or severe PAE. Respiratory complications (39%), infections (17%) and gastro-intestinal intolerance (15%) often complicated the course. Severe complications were never seen in the absence of significant metabolic acidosis at 30 minutes of life.

CONCLUSION

Our study has many implications concerning the diagnosis of birth asphyxia and its complications. A terminology based on clinical observation and arterial pH evaluation is proposed in order to clarify the situation.

Blood pH in the umbilical artery at birth: an analysis of data from patients delivered in Hesse between 1986 and 1989

OBJECTIVE

Measuring blood pH in the umbilical artery at birth is an important means of maintaining obstetrical quality. Consideration of the interrelations between low umbilical blood pH and perinatal risk factors may enable obstetricians to provide better care of the mother and child during pregnancy and delivery. We therefore studied the incidence of measuring blood pH at birth, the distribution and normal range of umbilical blood pH at birth, and the correlation between umbilical blood pH and pre-, sub-, and postnatal risk factors in patients delivered in Hesse between 1986 and 1989.

SUBJECTS

Over this period 2053 women were delivered between 30 and 32 weeks and 128,654 between 39 and 41 weeks of gestation. Each of these two groups was further subdivided according to the mode of delivery (spontaneous vaginal delivery; operative vaginal delivery; Cesarean section). Of the patients delivered between 39 and 41 weeks of gestation, 24,315 had exhibited no risk factors during pregnancy or delivery.

RESULTS

The overall incidence of measuring umbilical blood pH at birth was about 70%, whereas pH measurements were taken in only 60% of preterm babies delivered vaginally. The percentage of preterm neonates with an umbilical blood pH < 7.10 was considerably higher than that of term fetuses (5.0% vs. 1.3%). Of the neonates born of women displaying no risk factors during pregnancy and delivery, 22.4% had an umbilical blood pH < or = 7.25. In patients delivered at term hardly any correlation was found between prenatal risk factors and umbilical blood pH. This contrasted to the situation in patients delivered between 30 and 32 weeks of gestation. In most subgroups a close correlation could be demonstrated between umbilical blood pH and both sub- and postnatal risk factors. No correlation was detected between umbilical blood pH and perinatal mortality.

CONCLUSION

In view of the aim of maintaining and improving obstetrical quality in Hesse, the incidence of measuring umbilical blood pH at birth should be increased, especially in preterm fetuses. Since 22.4% of all babies from patients exhibiting no risk factors during pregnancy and delivery had an umbilical blood pH < or = 7.25, we have to reflect once again on the range of 'normal' umbilical blood pH at birth. Consideration of the various interrelations between umbilical blood pH and pre-, sub-, and postnatal risk factors demonstrated in this study may enable obstetricians to reduce the incidence of severely compromised fetuses at birth.

The validity of the Apgar scores in the assessment of asphyxia at birth

A prospective study was performed in 613 consecutively live born infants to investigate the validity of 1- and 5-min Apgar scores as an index for asphyxial assessment at birth. The independent and combined relationship between Apgar scores, metabolic acidemia, pulse oximeter (SaPO2) measurements and neonatal outcome were determined. In the term infants 1-min Apgar score was more influenced by the mode of delivery and by gestational age than by asphyxia. Instead, 5-min Apgar score had a high concordance with metabolic acidemia. Infants with low Apgar scores, metabolic acidemia and arterial desaturation have the highest incidence of neonatal intensive care unit admission and poor neonatal outcome. The study suggests that the 5-min Apgar score is useful for immediate clinical assessment and care of the neonate.