Prevalence of Perinatal Asphyxia in Neonates at a Tertiary Care Hospital: A Descriptive Cross-sectional Study

ABSTRACT Introduction: Perinatal asphyxia is one of the major causes of perinatal and early neonatal mortality in developing countries. The main objective of this study was to observe the prevalence of perinatal asphyxia in babies born at Kathmandu Medical College Teaching Hospital. Methods: This was a descriptive cross-sectional study conducted at Kathmandu Medical College Teaching Hospital over six month period (January to June 2019). All preterm, term and post term babies delivered at Kathmandu Medical College Teaching Hospital were included. Ethical clearance was received from Institutional Review Committee of Kathmandu Medical College (Ref.:2812201808). Convenient sampling method was applied. Data analysis was done in Statistical Package for Social Sciences version 18, point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. Results: A total of 1284 babies delivered over six months period were enrolled in this study and 47 (3.66%) babies were asphyxiated, at 95% Confidence Interval (2.64-4.68%). The mean birth weight of asphyxiated babies was 2759.75±65 grams and gestational age was 37.57±2 weeks. Among asphyxiated babies, 15 (32%) babies were normal, 15 (32%) babies were in Hypoxic Ischemic Encephalopathy stage I, 14 (30%) were in stage II and 3 (6%) were in stage III. Twenty Three (49%) asphyxiated babies had antenatal risk factors and all 47 babies had intrapartum risk factors leading to asphyxia. Conclusions: Prevalence of perinatal asphyxia was lower compared to that of other similar tertiary care hospitals. Perinatal asphyxia remains a major cause of neonatal morbidity and mortality.

Perinatal asphyxia is one of the major causes of perinatal and early neonatal mortality in developing countries contributing one quarter of the world's three million neonatal deaths and almost half of 2.6 million third trimester stillbirths. 1,2 Every year approximately 4 million babies are born asphyxiated resulting 1 million deaths and 1 million serious neurological consequences ranging from cerebral palsy and mental retardation to epilepsy. 2 The major complication of perinatal asphyxia is Hypoxic Ischemic Encephalopathy (HIE). HIE is a syndrome of disturbed neurological function manifested by difficulty in initiating and maintaining respiration, abnormal muscle tone and reflexes, subnormal level of consciousness and often seizures. 3 It is classified in different stages by Levene Classification. 4 In severe HIE (HIE stage III), the newborn is comatose, severely hypotonic, prolonged seizure and is unable to sustain Free Full Text Articles are Available at www.jnma.com.np spontaneous respiration. 5 The main objective of this study was to observe the prevalence of perinatal asphyxia in babies born at Kathmandu Medical College Teaching Hospital.

METHODS
A descriptive cross-sectional study was carried out on neonates with perinatal asphyxia at 10 bedded Neonatal Intensive Care Unit (NICU) of Pediatrics Department, Kathmandu Medical College Teaching Hospital (KMCTH), Sinamangal, Kathmandu, Nepal over six months period (Jan 2019 to June 2019). Ethical clearance was received from Institutional Review Committee (IRC) of Kathmandu Medical College (Ref.:2812201808) and written consent was taken from the parents and possible complications of perinatal asphyxia were explained. Data were entered in Excel and analysis was done in SPSS 18, point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data.
Perinatal Mortality Rate (PMR) of this tertiary hospital is 10/1000 births and Neonatal mortality rate (NMR) is 4.5/1000 live births. 6 All preterm, term and post term babies born at KMCTH with perinatal asphyxia due to any antepartum cause (e.g. Pregnancy Induced Hypertension (PIH), pre-eclempsia/eclempsia, Oligohydramnios etc.) or Intrapartum cause (e.g. Meconium stain liquor, prolonged labor, prolonged 2 nd stage of labor, Obstructed labor) were included in this study.
Neonates were diagnosed as perinatal asphyxia when at least three of the following four criteria were fulfilled: 7 1.Umbilical Arterial cord pH <7.2 determined by blood gas analysis within first hour of birth 2.
Apgar score <6 at 5 minute 3. Requirement of >1 minute of positive pressure ventilation 4. Signs of fetal distress (heart rate of less than 100 beats per minute, late decelerations, or an absence of heart rate variability) Detailed obstetric history, birth history, risk factors in the pregnancy, type of delivery and need of resuscitation procedure required at birth were recorded. During resuscitation in labor room/operation theatre, Neonatal Resuscitation Program (NRP) guideline 2015 recommended by American Academy of Pediatrics (AAP) were followed and detailed neurological examination of asphyxiated newborns were performed. 8 The staging of HIE was assessed by Leven's classification. 5 All neonates were managed according to hospital protocol.

RESULTS
A total of 1284 babies over six month's period were enrolled in this study. Out of which 47 babies were asphyxiated with a prevalence of perinatal asphyxia at KMCTH is 3.66%, at 95% Confidence Interval (2.64%-4.68%). Among 47 asphyxiated babies, 35 (75%) were term babies with male predominance 33 (70%). The mean birth weight of asphyxiated babies was 2759.57±65gms and mean gestational age was 37.57±2 weeks. Similarly, mean Apgar score at 1 min was 3.28±0.7 and at 5 min was 5.15±0.8. Mean maternal age of asphyxiated babies was 25.5±3.2yrs and mean maternal BMI was 20.04±2.4 kg/m 2 . Mean fetal heart sound (FHS) during admission at hospital was 132.60±18.1/min whereas during the delivery of baby, FHS has dropped to 88.87± 6.3/min depicted (Table 1).   Table 3).
Outcome of total 47 asphyxiated babies were observed as follows: 45 (95.7%) babies were discharged and 2 (4.3%) babies with HIE stage III were expired. After following 45 asphyxiated babies till one month of postnatal age, 44 (93.6%) babies were neurologically normal and one baby (2.1%) survived with HIE stage III has developed spastic cerebral palsy (Table 4).

CONCLUSIONS
Perinatal asphyxia still remains major cause of neonatal mortality and morbidities particularly in developing countries. This study highlighted, even with low prevalence of perinatal asphyxia, intrapartum risk factors eg. thick meconium stain liquor, prolonged labor and requirements of neonatal resuscitation procedure eg. Intubation and Bag and mask with chest compression were the common risk factors associated with HIE. Since, this is a single institutional study with convenient sampling, outcome cannot be generalized.

ACKOWLEDGEMENTS
My sincere hearty thanks and acknowledgment to all the Obstetrics and Pediatric faculties, post graduate residents and nurses for their tireless effort on better intrapartum fetal monitoring and immediate interventions in Labor room, Operation theatre and NICU to make this study successful.
Conflict of Interest: None.