390 - Trends in Neonatal Mortality Rates and Changing Pattern of aetiology of Neonatal Deaths over 3 Decades from a Tertiary Care Perinatal Centre in Singapore

Publication Number: 390.6708

Odattil Geetha, SINGHEALTH, Singapore, N/A, Singapore; Sabharwal Sachi, National University of Singapore, NA, N/A, Singapore; Kok Hian Tan, SingHealth, Singapore, N/A, Singapore; MEI CHIEN CHUA, KK Women’s and Children’s Hospital, Singapore, N/A, Singapore; VICTOR SAMUEL RAJADURAI, KK Womens and Children's Hospital, Bishan, N/A, Singapore

Background: Neonatal Mortality Rate (NMR) is considered to be one of the key indicators of a community's health status.

Objective: The objectives of this study are to evaluate the trends of neonatal mortality rates over three decades and to analyze the etiologic factors contributing to neonatal deaths.

Design/Methods: The study period 1993 – 2022 was classified into 3 epochs: 1993-2002 (EP1), 2003-2012 (EP2) and 2013-2022 (EP3).
Prospective audits were conducted following the death to establish the causes of death and identify the learning points from the cases. Modified Wigglesworth classification was used, and the causes were categorised as prematurity and related complications (PRC), congenital malformations (CM), perinatal asphyxia (PA) and others. During EP2 & 3, the neonates in the borderlines of viability were aggressively resuscitated unless they have major malformation. Number of deaths in the first 28 days of life per 1000 livebirths were calculated for Neonatal mortality rate (NMR).
Statistical analysis: chi square tests and logistic linear regression.

Results: Among 39,4789 live births studied the mean live births were 15,470, 12,368, and 11,641 with the mean live births for extremely low birth weight babies < 1 kg was 70.6 ,75.4 and 79.5 for EP1, EP2 and EP3 respectively. The mean NMRs were very low throughout the 3 epochs without any significant change with rates of 2.16, 2.26 and 1.96 per thousand live births respectively. Deaths due to CM showed a significant and serial declining trend from 43.8% to 39.8% to 33.5% over the 3 respective epochs (p < 0.01). Chromosomal aneuploidy reduced from 18% in EP1 to 10% in EP3. The most common cause of CM-related death was congenital non-immune hydrops fetalis in the 3 epochs and it remained unchanged at 20 - 22%.
PRC-related deaths showed no significant trend with time, while deaths from non-resuscitated borderlines of viability reduced from 25% to 10% and 9% over the epochs (p < 0.05). Sepsis in PRC group showed a nonsignificant increase from 16% to 28% and 22% during the 3 decades. The deaths due to PA and hypoxic ischemic encephalopathy decreased significantly from 12% in EP1 to 6.5 – 7.8% over the other two epochs (p < 0.05).

Conclusion(s): The NMRs remained very low throughout the three decades. However, a changing pattern of the causation of neonatal deaths was observed during the latter two epochs: Deaths due to PA, CM and chromosomal aneuploidy showed significant decline, while deaths from non-resuscitated borderlines of viability markedly reduced without affecting the mortality due to prematurity.

Causes of Neonatal Deaths
Classifications of neonatal deaths as per Modified Wigglesworth.

Prematurity and related complications
Prematurity and related causes of death over 3 epochs.

Congenital malformations and spectrum of cases
Deaths due to congenital malformations over 3 epochs