Singapore Med J 2012; 53(12) : 826 O riginal A rticle INTRODUCTION Necrotising enterocolitis (NEC) is a serious condition in preterm infants, which is associated with high mortality and morbidity. The incidence of NEC varies from country to country and between neonatal intensive care units (NICUs). (1-5) The Malaysian National Neonatal Registry (MNNR) was set-up in 2004 to study the outcome of critically ill and very low birth weight (VLBW; weight < 1,501 g) infants. NICUs in Malaysia were invited to participate in this registry, with the primary aim to improve the standard of neonatal intensive care in Malaysia. Based on the data collected for 2004, (6) 2005 (7) and 2006 (8) from the MNNR, the incidence of NEC among VLBW infants was reported to be 9%, 10% and 8%, respectively, with fatality rates for these years being very high at 26%, 34% and 34%, respectively. The present study was undertaken in an effort to reduce the incidence of NEC among VLBW infants in NICUs in Malaysia, with the objective to identify potentially preventable risk factors associated with the condition in Malaysian NICUs. METHODS This was a retrospective study based on the data of all VLBW infants born in 2007 and admitted to the NICUs of hospitals participating in the MNNR in 2007. Participating NICUs submitted data on these infants to the MNNR upon their discharge or death. A standardised format was used for data collection. Each infant was considered a unique case and not duplicated in the registry, irrespective of the number of admissions to different participating NICUs. Infants of birth weight < 501 g were excluded from the MNNR. A diagnosis of NEC was made based on the presence of clinical, radiological and/or histopathological evidence that fulflled the stage II or III of Bell’s criteria. (9) Infants were defned as small for gestational age (birth weight < 10th percentile for respective gestational age), appropriate for gestational age (birth weight between 10th–90th percentile for respective gestational age), and large for gestational age (birth weight > 90th percentile for gestational age). (10) Intrapartum antibiotics were considered to have been given if they were administered to the mothers of these infants within 24 hours prior to delivery. A diagnosis of respiratory distress syndrome (RDS) was made in the presence of a partial pressure of arterial oxygen (PaO2) < 50 mmHg when breathing room air, central cyanosis in room air or a requirement for supplemental Risk factors associated with necrotising enterocolitis in very low birth weight infants in Malaysian neonatal intensive care units Nem-Yun Boo 1 , MRCP, FRCPCH, Irene Guat Sim Cheah 2 , MRCP, FRCPCH; Malaysian National Neonatal Registry 1 Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Selangor, 2 Department of Paediatrics, Hospital Kuala Lumpur, Kuala Lumpur, Malaysia Correspondence: Prof Nem-Yun Boo, Senior Professor, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, 43000 Kajang, Selangor, Malaysia. nemyun_boo@yahoo.com INTRODUCTION This study aimed to identify the risk factors associated with necrotising enterocolitis (NEC) in very low birth weight (VLBW; weight < 1,501 g) infants in Malaysian neonatal intensive care units (NICUs). METHODS This was a retrospective study based on data collected in a standardised format for all VLBW infants born in 2007 (n = 3,601) and admitted to 31 NICUs in Malaysian public hospitals. A diagnosis of NEC was made based on clinical, radiological and/or histopathological evidence of stage II or III, according to Bell’s criteria. Logistic regression analysis was performed to determine the significant risk factors associated with NEC. RESULTS 222 (6.2%) infants developed NEC (stage II, n = 197; stage III, n = 25). 69 (31.3%) infants died (stage II, n = 58; stage III, n = 11). The significant risk factors associated with NEC were: maternal age (adjusted odds ratio [OR] 1.024, 95% confidence interval [CI] 1.003–1.046; p = 0.027), intrapartum antibiotics (OR 0.639, 95% CI 0.421–0.971; p = 0.036), birth weight (OR 0.999, 95% CI 0.998–0.999; p < 0.001), surfactant therapy (OR 1.590, 95% CI 1.170– 2.161; p = 0.003), congenital pneumonia (OR 2.00, 95% CI 1.405–2.848; p < 0.001) and indomethacin therapy for the closure of patent ductus arteriosus (PDA) (OR 1.821, 95% CI 1.349–2.431; p = 0.001). CONCLUSION Increasing maternal age, decreasing birth weight, surfactant therapy, congenital pneumonia and indomethacin therapy for the closure of PDA were associated with an increased risk of NEC in Malaysian VLBW infants. Infants that received intrapartum antibiotics were associated with a reduced risk of developing NEC. Keywords: necrotising enterocolitis, risk factors Singapore Med J 2012; 53(12): 826–831