Is perinatal asphyxia predictable?

Abstract

Background: The objective of our study was to evaluate the association between perinatal asphyxia and hypoxicischemic encephalopathy (HIE) with the presence of ante and intrapartum risk factors and/or abnormal fetal heart rate (FHR) findings, in order to improve maternal and neonatal management. Methods: We did a prospective observational cohort study from a network of four hospitals (one Hub center with neonatal intensive care unit and three level I Spoke centers) between 2014 and 2016. Neonates of gestational age ≥ 35 weeks, birthweight ≥1800 g, without lethal malformations were included if diagnosed with perinatal asphyxia, defined as pH ≤7.0 or Base Excess (BE) ≤ − 12 mMol/L in Umbical Artery (UA) or within 1 h, 10 min Apgar < 5, or need for resuscitation > 10 min. FHR monitoring was classified in three categories according to the American College of Obstetricians and Gynecologists (ACOG). Pregnancies were divided into four classes: 1) low risk; 2) antepartum risk; 3) intrapartum risk; 4) and both ante and intrapartum risk. In the first six hours of life asphyxiated neonates were evaluated using the Thomson score (TS): if TS ≥ 5 neonates were transferred to Hub for further assessment; if TS ≥ 7 hypothermia was indicated. Results: Perinatal asphyxia occurred in 21.5‰ cases (321/14,896) and HIE in 1.1‰ (16/14,896). The total study population was composed of 281 asphyxiated neonates: 68/5152 (1.3%) born at Hub and 213/9744 (2.2%) at Spokes (p < 0.001, OR 0.59, 95% CI 0.45-0.79). 32/213 (15%) neonates were transferred from Spokes to Hub. Overall, 12/281 were treated with hypothermia. HIE occurred in 16/281 (5.7%) neonates: four grade I, eight grade II and four grade III. Incidence of HIE was not different between Hub and Spokes. Pregnancies resulting in asphyxiated neonates were classified as class 1) 1.1%, 2) 52.3%, 3) 3.2%, and 4) 43.4%. Sentinel events occurred in 23.5% of the cases and FHR was category II or III in 50.5% of the cases. 40.2% cases of asphyxia and 18.8% cases of HIE were not preceded by sentinel events or abnormal FHR. Conclusions: We identified at least one risk factor associated with all cases of HIE and with most cases of perinatal asphyxia. In absence of risk factors, the probability of developing perinatal asphyxia resulted extremely low. FHR monitoring alone is not a reliable tool for detecting the probability of eventual asphyxia.

The evaluation of the antepartum and intrapartum risk factors in predicting the risk of birth asphyxia

“…Locatelli et al indicated the contribution of nulliparity to the development of perinatal asphyxia by the higher incidence of pregnancy complications associated with it, including defective placentation and impaired fetal growth. Also, they reported that due to the longer duration of labor, nulliparous women are at higher risk of infection and fetal intolerance to labor, surgical interventions, and related perinatal incidents 18 . However, Liljestrom et al stated that obstetric emergencies are more common in the multiparous women than in the nulliparous women among HIE cases, illustrating a major problem in the labor process 35 .…”

“…Also, they reported that due to the longer duration of labor, nulliparous women are at higher risk of infection and fetal intolerance to labor, surgical interventions, and related perinatal incidents. 18 However, Liljestrom et al stated that obstetric emergencies are more common in the multiparous women than in the nulliparous women among HIE cases, illustrating a major problem in the labor process. 35 In our study, as mentioned in previous studies, nulliparity was more prevalent in the birth asphyxia group than in the control group.…”

“…A non‐vigorous infant at birth was defined as a newborn with a 5‐min Apgar score <7 17 . Perinatal asphyxia was defined as at least the presence of one of the following features in a newborn: 10 min Apgar score ≤5, need for resuscitation >10 min, and metabolic acidosis (pH ≤ 7.0 or base excess [BE] ≤ −12 mmol/L in the umbilical artery or within 1 h of life) 18 …”

“…17 Perinatal asphyxia was defined as at least the presence of one of the following features in a newborn: 10 min Apgar score ≤5, need for resuscitation >10 min, and metabolic acidosis (pH ≤ 7.0 or base excess [BE] ≤ À12 mmol/L in the umbilical artery or within 1 h of life). 18 Subjects were divided into two groups as birth asphyxia group and control group. Data regarding maternal demographic features, maternal laboratory values at the time of admission, pregnancy complications, and obstetric and neonatal outcomes were collected.…”

Multiscale Entropy Analysis of Heart Rate Variability in Neonatal Patients with and without Seizures

“…HRV entropy indexes seem to be appropriate to describe neonatal seizures with a specific etiology such as the hypoxic-ischemic encephalopathies or, in general, with asphyxia episodes [ 56 , 57 ]. Moreover, cardio-regulatory system differences from a newborn with seizures from a seizure-free one might also be present during interictal activity rather than only during or close to an ictal event.…”