Maternal risk factors for adverse outcome in asphyxiated newborns treated with hypothermia: parity and labor duration matter

Perinatal maternal characteristics predict a high risk of neonatal asphyxia: A multi-center retrospective cohort study in China

Objective

This study aimed to identify various perinatal maternal characteristics that contributed to neonatal asphyxia (NA) in term and late-preterm newborns based on the data obtained from a Chinese birth registry cohort and to establish an effective model for predicting a high risk of asphyxia.

Method

We retrospectively reviewed and analyzed the birth database from July 1, 2016, to June 30, 2017, in the main economically developed regions of China. Asphyxia was defined as an Apgar score <7 at 5 min post-delivery with umbilical cord arterial blood pH < 7.2 in the infant born after 34weeks. We compared the perinatal maternal characteristics of the newborns who developed asphyxia (NA group, n = 1,152) and those who did not (no NA group, n = 86,393). Candidate predictors of NA were analyzed using multivariable logistic regression. Subsequently, a prediction model was developed and validated by an independent test group.

Result

Of the maternal characteristics, duration of PROM ≥ 48 h, a gestational week at birth <37, prolonged duration of labor, hypertensive disorder, nuchal cord, and birth weight <2,500 or ≥4,000 g, abnormal fetal heart rate, meconium-stained amniotic fluid, and placenta previa were included in the predicting model, which presented a good performance in external validation (c-statistic of 0.731).

Conclusion

Our model relied heavily on clinical predictors that may be determined before or during birth, and pregnant women at high risk of NA might be recognized earlier in pregnancy and childbirth using this methodology, allowing them to avoid being neglected and delayed. Future studies should be conducted to assess its usefulness.

Physiological CTG categorization in types of hypoxia compared with MRI and neurodevelopmental outcome in infants with HIE

BACKGROUND

Commonly used methods of CTG classification do not reliably predict neonatal hypoxic-ischemic encephalopathy (HIE).

OBJECTIVE

To examine whether a relationship exists between the types of hypoxia as identified on the cardiotocograph using novel physiology-based CTG classification and patterns of injury on neonatal cerebral MRI and later neurodevelopmental outcomes.

STUDY DESIGN

A retrospective study of term-born infants admitted to four neonatal units with HIE as part of a brain injury biomarkers study between January 2014 and December 2015. Intrapartum CTG traces were analyzed by two obstetricians trained in physiological CTG classification, blind to neonatal outcomes. Neonatal cerebral MR images were assessed independently by a neuroradiologist and an expert neonatologist. CTG traces were classified into types of hypoxia and allocated to groups; (1) chronic hypoxia or antepartum injury; (2) gradually evolving or subacute hypoxia; and (3) acute hypoxia.

RESULTS

Of 106 infants recruited to the study, records were available for 58 cases. Of these, CTGs were available for 37. All 37 had abnormal CTGs. Twenty-four infants, all of whom had received therapeutic hypothermia had cerebral MRI. Fourteen of the 24 (58%) infants had abnormal MRI. In group 1 (chronic hypoxia/antenatal injury), total brain injury was most predominant (4/6 infants). Group 2 (gradually evolving/subacute hypoxia) was associated with peripheral brain injury (5/5 infants). Group 3 (acute hypoxia) was associated with basal-ganglia thalamic injury pattern (3/3 infants). Later neurodevelopmental outcomes were available for 35 cases. Infants suspected to have a pre-labor injury on CTG (group 1) had a higher proportion of adverse neurodevelopmental outcomes (4/10, 40%) compared to groups 2 and 3 (4/25, 16%).

CONCLUSION

Using this novel physiology-based CTG classification, we demonstrate an association between types of hypoxia observed on the CTG and MRI patterns of hypoxic brain injury. Infants with CTG trace suggestive of chronic hypoxia or other antenatal injuries were overrepresented in this cohort and were also more likely to have a poor neurodevelopmental outcome.

Perinatal asphyxia from the obstetric standpoint

Perinatal asphyxia remains one of the major causes of morbidity and mortality for term newborns. Though access to health care and birth attendants have decreased the rate, Neonatal encephalopathy (NE) has not been eliminated. Worldwide, women at socioeconomic disadvantage have the highest risk of delivering a neonate with NE. Neonates that will experience perinatal asphyxia cannot be easily identified prospectively and the intrapartum testing available is not specific enough to clearly indicate the best course of action in most cases. Despite this, training programs that aim to decrease morbidity and mortality from all causes appear to be associated with fewer cases of perinatal asphyxia. The current best approach is to support education and communication for all people involved in the care of birthing women. Ideally, new technology will address identification of the fetus likely to be affected or the fetus who is beginning to experience injury in advance of delivery.