Profile of Neonatal Jaundice in Low Birth Weight Infants- Comparison between AGA and SGA Subgroups

Karvendhan, R (2013) Profile of Neonatal Jaundice in Low Birth Weight Infants- Comparison between AGA and SGA Subgroups. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION: A newborn infant weighing less than 2500g at birth is termed as low birth weight (LBW) neonate. Low birth weight in newborn infant occurs due to intrauterine growth restriction (IUGR)/small for gestational age (SGA) or prematurity. Although quantification and data on global distribution of LBW remain limited, World Health Organization estimates that nearly 20 million LBW infants are born every year, affecting approximately 16 percent of all newborns in developing countries. Around 8% of live births are born LBW and 12% of live births are preterm in the USA. UNICEF estimates put the incidence of LBW neonates in India at 30% while the proportion of IUGR has been found to be 54%. As per the National Neonatal Perinatal Database (NNPD) of the National Neonatology Forum (NNF) the incidence of LBW in tertiary care centres was 31.3% and 9.65% were SGA infants5.It is estimated that nearly 8 million LBW infants are born each ear in India. This shows that the major low birth weight problem in India stems from intrauterine growth restriction and not prematurity, in contrast to the western world. LBW is the most significant factor contributing to neonatal mortality and morbidity. These neonates are at higher risk of asphyxia, sepsis, hypothermia, and feeding problems and neonatal jaundice. Common illnesses tend to be more severe and last longer in this group. Neonatal jaundice is the yellow discolouration of the sclera and skin of newborn infants caused by unconjugated hyperbilirubinaemia. About 50% of term and 80% of preterm infants develop jaundice in the first week of life. Several risk factors have been identified for the occurrence of exaggerated or severe unconjugated hyperbilirubinaemia. Low birth weight and preterm birth are major risk factors for exaggerated jaundice warranting intervention. Clinically significant levels that warrant treatment occur in nearly 50% to 80% of preterm neonates. Preterm infants are at risk of developing bilirubin encephalopathy at lower total serum bilirubin levels than term neonates. The practice parameter published by the American Academy of Pediatrics (AAP) is followed for the management of neonatal hyperbilirubinemia (NNH) in newborn infants 35 weeks or more. The AAP guidelines were framed from data available from babies weighing 2500g or more at birth. Low birth weight (LBW) babies constitute nearly one third of live births in our country as mentioned earlier. Small for Gestational Age (SGA) infants make up to two thirds of these LBW babies in India unlike the industrialized countries where most of the LBW infants or preterm but not growth restricted. Although both the terms IUGR and small for gestational age (SGA) are used interchangeably, there is a minor difference in the terminology. Small for gestational age is a statistical definition, and is used for neonates whose birth weight is lower than 10th percentile for the particular gestational age. IUGR is a clinical definition and includes neonates with clinical evidence of malnutrition and recognized growth restriction during antenatal growth monitoring. Data on neonatal jaundice in LBW infants is scarce. There is particularly no data available about the profile of neonatal jaundice in SGA infants. Whether the „accelerated maturity‟ of liver enzymes and its effect on bilirubin metabolism and ultimately its toxicity means these babies can handle bilirubin similar to their age matched appropriate weight infants is not well established. There is no consensus yet on management of neonatal hyperbilirubinemia whether it should be gestational age based as maturity of liver enzyme UDP glucuronyl transferase handling bilirubin conjugation is gestational age dependent or weight based as is the more widely prevalent current practice. AIMS AND OBJECTIVES: 1. To study the incidence, risk factors, duration, interventions and bili- rubin toxicity of neonatal jaundice in low birth weight infants. 2. To compare the profile of jaundice in LBW infants between the AGA and SGA subgroups. MATERIALS AND METHODS: Study type: Prospective descriptive study. This study was conducted between September 2012 and January 2013 at the Department of Neonatology, Institute of Obstetrics and Gynecology and Government Hospital for Women and Children, Egmore, Chennai. All consecutively born infants with birth weight <2500g were eligible for inclusion in the study. The babies were recruited after informed consent from the parents. The gestational age was calculated from LMP/ First tri- mester USG and corroborated by New Ballard Scoring. Assignment to Ap- propriate for Gestational Age (AGA) or Small for Gestational Age (SGA) was done based on AIIMS intrauterine growth chart. The infants were classified as AGA if the weight for GA was between the 10th to 90th centile and SGA if the weight was less than the 10th centile for the GA.AIIMS chart was used as it was constructed with data from Indian infants and that is the chart used by NNF for data collection for National Neonatal Perinatal Data Base (NNPD). The relevant perinatal and neonatal data were recorded prospectively in a predesigned case reporting form. Maternal anthropometry, pregnancy asso- ciated illnesses, perinatal data and postnatal morbidities along with total bili- rubin values were recorded. Capillary blood sample was collected from recruited babies at 24 hours (24- 36), 48 hours (48-60), and 72 hours (72-84) and on day 5 of life in hepari- nized micro-capillaries. Bilirubin estimation: The bilirubin estimation was done by sphectrometric bilirubin analyzer (Bil- Micro Meter,Kohsoku Denki Co Ltd, Tokyo,Japan). The micro-capillary tube containing the blood sample was blocked on one end and centrifuged at 12,000 rpm for 5 minutes in a micro centrifuge to separate out the serum. The processed microcapillary was fixed on to the holder of spectrometric bi- lirubin analyzer ensuring the serum column covered the entire length of the slit through which the light passes. A microprocessor converts the light intensity received by the photo detector into the total bilirubin value which is digitally displayed. This method for estimation of bilirubin is simple, requires no reagents and needs only 50-70 µL of blood. The analyzer was calibrated as recommended by the manufacturer. CONCLUSIONS: 1. There is negative correlation between total serum bilirubin and gesta- tional age from 24 hours to up to 5 days of birth. 2. There is no correlation between birth weight and total serum bilirubin from 24 hrs up to 5 days of life. Lesser the gestational age higher was the peak serum bilirubin observed. 3. The mean bilirubin and the rate of change in bilirubin were similar in both AGA and SGA subgroups for any given gestational age. 4. The intrauterine growth status does not seem to influence the bilirubin level or the rate of rise during the first 5 days of life. 5. Bilirubin level of intervention should be gestational age based rather than weight based in LBW infants. 6. Risk factors associated with significant hyperbilirubinemia in normal birth weight infants like gestational age, perinatal asphyxia, neonatal sepsis were associated with significant jaundice in LBW infants too.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Profile ; Neonatal Jaundice ; Low Birth Weight Infants ; Comparison ; AGA and SGA Subgroups.
Subjects: MEDICAL > Neonatology
Depositing User: Kambaraman B
Date Deposited: 15 Jun 2018 01:48
Last Modified: 15 Jun 2018 01:48

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