Birth asphyxia is a serious clinical problem worldwide and contributes greatly to neonatal mortality and morbidity. The combination of the decrease in oxygen supply (hypoxia) and blood supply (ischemia) results in a cascade of biochemical changes inside the body, whose events lead to neuronal cell death and brain damage. Continuous asphyxia also leads to multiple organ systems dysfunction [1].

World Health Organization (WHO) defines Birth asphyxia as failure to initiate and sustain breathing in a newborn at birth [2].

Definition of birth asphyxia is given by the ACOG, AAP includes the existence of 3 factors: Metabolic or mixed acidemia (pH<7) which is determined by umbilical cord arterial blood samples; APGAR score of <3 for longer than 5 min; neurological manifestations; and multisystem organ dysfunction [3]. The major causes of neonatal seizures are Hypoxic-ischemic encephalopathy (HIE), which represents about 50% of the causes of neonatal seizures. Metabolic abnormalities, infection, intracranial hemorrhage, developmental anomalies, and other like inborn errors of metabolism are other causes of neonatal seizures [4].

The causes of seizures in preterm neonates are different from those seen in term neonates, where the HIE is the most frequent cause in term neonates, followed by cerebral malformations and metabolic disturbances. In preterm neonates, intraventricular hemorrhage and infections are the most frequent causes [5]. Hypocalcemia is defined as total serum levels less < 7mg/dl, although the exact level at which seizure occurs is debatable.

Criteria for diagnosing biochemical abnormalities:

Hypoglycemia: blood sugar < 40mg/dl

Hypocalcemia: total serum calcium <7mg/dl and ionized serum calcium < 4.4mg/dl

Hypomagnesemia: serum magnesium <1.5mg/dl

Hypermagnesemia: serem magnesium>2.5mg/dl

Hypernatremia: serum sodium >150meq/dl

Hyponatremia: serum sodium <130meq/dl

Metabolic causes of neonatal seizures with a good prognosis are hypoglycemia, hypomagnesemia, hypocalcemia.

p = Estimated prevalence of birth asphyxia 27% (Prevalence in India in the Year 2017) [42]

q = 100-p

L = Margin error at 5% (Standard value of 0.05)

Methodology: A pre-structured proforma is used to record the information from the individual. After getting the consent from the parent’s clinical data collected and inter in the proforma which includes age, sex, religion presenting complaints, type and duration of seizure, demographic details and examination, a maternal history risk factor for perinatal asphyxia age, weight, maternal education, preeclampsia, eclampsia, diabetes in mother, maternal infection, Multiple gestations, finding on admission are noted according to study proforma. All information is recorded in a pre-designed proforma.

Statistical Analysis: Collected data will be tabulated graphically displayed. Percentage, arithmetic mean and standard deviation to be calculated and data statistically analyzed using SPSS version 21 (statistical package for social sciences).

Interferential analysis for quantitative variables to be done using an independent ‘T’ test whereas analysis for qualitative data is done using the chi-square test. Statistical significance is set at ‘p’ <0.05. Data will be analyzed using standard methods. Consent will be taken from the attendants before enrolling the baby in the study.

Table-1: Association of hypocalcemia and birth asphyxia.

In the present study, 24 (7.6%) patient out of 315 was found to be hypocalcemia.

Table-2: Association of calcium level and magnesium level.

In the present study, 315 neonates with birth asphyxia were studied in 1 year. Both intramurally and extramurally delivered babies were included in this study. In a study by Asif Aziz Wani et al, a total of 100 consecutive neonates presenting with seizures from September 2013 to August 2014 were enrolled in the study. Clinical details of each seizure episode reported by the mother and subsequently observed by the resident doctors on duty were recorded.

It was found that around 54% of neonates had a biochemical abnormality alone or in association with other etiologies like hypoxic-ischemic encephalopathy (HIE), intracranial hemorrhage (ICH), meningitis, and sepsis. 31% of neonates had primary metabolic seizures. Hypocalcemia was the commonest biochemical abnormality in primary metabolic seizures and was present in 70% of neonates in this group. Hypoglycemia was the next common abnormality and was present in 41% of neonates within this group. 37 neonates (68.5%) had biochemical abnormalities superimposed on other etiologies of neonatal seizures. Metabolic abnormalities were more commonly associated with intracranial hemorrhage (53.8%) and birth asphyxia (50%). Hypoglycemia (22.7%) followed by hypocalcemia (20.5%) were the commonest biochemical abnormalities in these patients. Hyponatremia was found in 20% (n=3) cases of meningitis and 15.4% (n=2) cases of ICH [6].

Arun Kumar A.R et al conducted a study on biochemical abnormalities in neonatal seizures in a tertiary care rural teaching hospital of south India in which out of 100 neonates with seizures, 69 were outborn (referred to the hospital from outside) and 31 were inborn. Seizures occurred more frequently among term infants (78%).

Associated biochemical abnormalities were seen in 33 (30%) cases with hyponatremia 13 (39.3%) being most common followed by hypoglycemia. These were most often seen with Hypoxic- ischaemic- encephalopathy. He concluded that Biochemical abnormalities are common in neonatal seizures and often go unrecognized. These abnormalities may significantly contribute to seizure activity and hence a biochemical workup is necessary for all cases of neonatal seizures [10].

In the present study prevalence of hypocalcemia in birth asphyxia was 7.6%, a study done by Suganthi V et al [11] prevalence of hypocalcemia in birth asphyxia was 31.5%, another study done by Jain N et al the prevalence of hypocalcemia was 28% [12] and a study done by Nawab T et al [13] had 23.7% cases of hypocalcemia in birth asphyxia. In all these three studies the prevalence of hypocalcemia was higher than the present study. None patients had hypocalcemia with hypomagnesemia was found while a study done by Suganthi V et al [11] had 7.9% cases of hypocalcemia associated with hypomagnesemia and another study done by Saha D et al had 3.33% cases had hypocalcemia with hypomagnesemia [14].

In the present study 20 out of 315 (6.3%) had hyponatremia, 4 out of 315 (1.3%) had hypernatremia while a previous study had 15% cases of hyponatremia and 5.8% of hypernatremia, and another study done by Kumar et al had 11.1% hyponatremia [15,16]. The value of the present study was lower than these two studies.

None of the patients had hyponatremia with hypomagnesemia; there was no association of hyponatremia and hypomagnesemia. In the present study 4 out of 315 (1.3%) patient’s mother had a significant antenatal history of high-risk factor, a study done by Aziz A et al [6] mothers with antenatal risk factor was 13% while a previous study done indicated 4% mothers had a history of high-risk factor which value was higher than the present study [15].

The mean value of serum calcium was 9.36 mg/dl in the present study while a study done by Saha D et al mean serum calcium was 7.37± 0.1mg/dl which value was lower than the present study [14]. The mean value of serum sodium was 139 mEq/L found in the present study, a study was done by Basu P et al (2010) mean serum sodium was 122.1± 6.0 mEq/L which value was lower than the present study [17].