Neonatal mortality in a tertiary hospital in Sout

　　　　　　 作者：C.N. Onyearugha1，H. A. Ugboma

【摘要】 Objective: With improved and sustained efforts in the prevention and management of pneumonia， diarrhea and vaccine preventable diseases， neonatal mortality is increasingly becoming a major contributor to childhood mortality particularly in developing countries. Evaluation of neonatal mortality pattern is an essential step in the effort to curb its incidence. We therefore， set out to determine the neonatal mortality pattern and its associated factors in a tertiary hospital in southern Nigeria. Methods: This is a retrospective study of neonatal mortality in a tertiary hospital from August 2004 to July 2007(a 3 year period). Data obtained include total live births， neonatal deaths， relevant information on pregnancy， labour and delivery， neonatal morbidity and duration of life. Results: There were a total of 3，051 live births and 44 neonatal deaths with a neonatal mortality rate of 14.4/1000 live births. Early neonatal mortality constituted 81.8%of over all neonatal mortality with the major causes being prematurity 40% severe birth asphyxia 29.5%and neonatal sepsis 18.3%. Low birth weight babies (&<2500 grams) constituted 55.5% of total neonatal mortality. Conclusion: Early neonatal mortality constitutes an overwhelming proportion of neonatal mortality in Southern Nigeria. This can be significantly curtailed by reducing the incidence and death from prematurity， severe birth asphyxia and neonatal sepsis.

【关键词】 Neonatal Mortality; Associated factors; Southern Nigeria

　Introduction

　　The Millennium Development Goal.(MDG)4 commits international community to reducing mortality in children aged under 5 Years by twothirds between 1990 and 2015[1]. By the year 2000， the proportion of child deaths that occurred in the neonatal period worldwide was 38%[2-5] most of which unfortunately occurred in low and middle income countries .Of the estimated nearly 4 million neonatal death that occurred globally in the year 2000，only about 1% occurred in developed countries where neonatal mortality rate is less than 4 per thousand live births， while 99% took place in the developing countries with average global neonatal mortality rate more than 33 per thousand live birth[6，7].

　　To achieve MDG.4 a substantial reduction in neonatal mortality especially in the developing nations must be made[8].

　　An easily over looked but real challenge in policy analysis is the slow progress recorded in reducing global neonatal mortality over the years. Child survival programs in developing countries have tended to focus on pneumonia， diarrhea malaria， malnutrition and vaccine preventable diseases which are important causes of death after the first month of life[9].

　　As post neonatal mortality rates fall， prenatal and neonatal mortalities are increasingly becoming important public health issues in developing countries.

　　To achieve any significant reduction in neonatal mortality， its pattern of occurrence must be evaluated thereby determining areas where preventive strategies must be focused to curb its presently unacceptable high level.

　　This study was therefore undertaken to determine the pattern of neonatal mortality in a tertiary health institution in Southern Nigeria， as no such study has been done here previously. The results obtained will serve as a baseline data for future analyses and as indispensable tool in the formulation of preventive measures to curb the rate of neonatal mortality in our community.

　　Material and Methods

　　This was a retrospective study conducted in a tertiary health institution in Southern Nigeria. It serves as a secondary and tertiary health care establishment as well as centre for referral of patients from primary and secondary health care institutions， private hospitals and maternities . It offers obstetric and neonatal services amongst other health care services.

　　Routine data on deliveries and neonatal admissions from Ist August 2004 to 31st July 2007 were reviewed. Where data was incomplete relevant case notes were retrieved from records department and data extracted from there. Data documented include total live births， gestational age， sex， birth weight， neonatal morbidity， and age at death of the enrolled new born. Neonatal mortality was defined as death occurring in the first 28 days of life while neonatal mortality rate was defined as number of deaths of newborns occurring in the first 28 days of life per thousand live births.

　　Newborns who fulfilled the above definition constituted the subjects. Newborns delivered outside the hospital were excluded from the study.

　　Data was presented in tabular form and results analyzed as percentages of population.

　　Results

　　Table 1 shows a summary of results. There were 3，051 live births and 44 neonatal deaths over the 3 year study period. The sex ratio of male: female of live births is 1.30:1.0 and for neonatal deaths it was 1.0:1.0. The sex ratio for neonatal births differs significantly from that of neonatal deaths (P&<005). The neonatal mortality rate from this study is 14.4/1000 live births. Early neonatal deaths (within first 7 days of life) occurred in 36(81.8%) of the newborns and is significantly more than 8(18.2%) late neonatal deaths (in 7-28 days of life)，P&<0.05.Table 1 Summary of results

　　Other data are shown in the table.

　　The effect of gestational age on neonatal mortality is shown in Table 2. The overall neonatal mortality for all categories of gestational age from 22 weeks and above was 14.4/1000. The overall early neonatal mortality (death occurring during the first 7 days of life) was 11.8/1000. Early neonatal deaths also constituted 81.8% of total neonatal mortality. The percentage contribution of preterms (less than 37 completed weeks) to neonatal mortality was 40.9% while full term newborns contributed 50.0%.Table 2 Effect of gestational age on neonatal mortalityGestational age

　　Table 3 shows the effects of birth weight on neonatal mortality. All the four live births in birth weight category &<1000 and the 2 macrosomic (&>4000g) had early neonatal deaths respectively. Neonatal mortality in different birth weight brackets decreased with increasing birth weights up to normal sized newborns. Babies with birth weight less than normal (2500gm) constituted 55.5% of total neonatal deaths whereas normal full sized babies constituted 41.5% of neonatal deaths.

　　The majority of neonatal deaths 26(59.1%) were associated with primiparity and is significantly more than neonatal deaths associated with other categories of parity 1-2:8(18.3%); 3-4 and more than 4 5(11.3%) each respectively. P=0.04 More of the deliveries 23(52.3%) were by spontaneous vertex though not significantly more than casarian section births 21(47.7%). P=0.45Table 3 Effect of birth weight on neonatal mortality

　　Table 4 indicates the associated causes of neonatal deaths. Most of neonatal deaths were due to prematurity 40.9%， severe birth asphyxia 29.5% and neonatal sepsis 18.3%. There is also a significant difference in the associated causes of mortality. P=0.045Table 4 Associated Causes of Neonatal Deaths:

　　Discussion

　　The Neonatal mortality rate in this study is 14.4/1000 live births.

　　This is slightly less than the neonatal mortality rate of 16.4/1000 reported in Benin City in Mid western Nigeria in 1984 but falls within the hospital based range for developing countries. This does not portray fully the enormous wastage of neonatal lives which occurs in the communities resulting from unskilled supervision of pregnancies and deliveries. For instance， the average reported neonatal mortality rate in Nigeria is 53 per thousand live births occurring in the North Eastern region and 39/1000 live births in the South West[10]. It however helps to assess the impact of provision and utilization of appropriate healthcare facilities in pregnancy， labour and delivery on neonatal outcome.

　　The result of this study also indicates that overwhelming proportion (81.8%) of the neonatal deaths occurred in early neonatal period. The three main causes of these neonatal deaths were prematurity (40.9%)， severe birth asphyxia (29.5%) and neonatal sepsis (18.3%).

　　C.N. Onyearugha MBBS et al. Neonatal mortality in a tertiary hospital in Southern Nigeria

　　The 81.8% early neonatal deaths reported in this study is greater than 75% of neonatal deaths that occur in first week of life globally[2]. Prematurity， perinatal asphyxia and neonatal sepsis have been reported previously by other authors as causes of early neonatal deaths in Edo State in Mid west Nigeria and Ogun state in Western Nigeria. Early neonatal mortality directly or indirectly reflects the quality of prenatal and obstetric services offered to pregnant women[11].

　　Early neonatal deaths have increased from 23% to over 28% of deaths in children worldwide in the last 3 decades[3]. To attain the MDG4， drastic reduction in neonatal mortality must be achieved and to do this， bringing down early neonatal mortality becomes mandatory.

　　Result obtained in our study also reveals that neonatal mortality decreased with increasing birth weight up to normal sized newborns (2500grams -4000grams). Decreasing mortality with increasing birth weight has been the trend the world over[3，12].

　　Low birth weight results from prematurity or intrauterine growth retardation or both. low birth weight babies have poor adaptation to extra –uterine life and often have difficulty with initiation of breathing and are susceptible to developing lethal metabolic complications such as hypoglycaemia， hypothermia and severe infections， the incidence and severity of which are worse with decreasing birthweight[13，14].

　　Death in the low birth weight category constituted 54.5% of all neonatal deaths in this study and is less than 77.4% reported in Benin in 1984 and 60-80% reported worldwide[15]. This may be explained by the lower incidence of low birth weight (LBW)delivery of 5.17% revealed by our study than 7.3% obtained previously in Benin City . It is known that occurrence of high proportion of LBW delivery in a community is closely related to increased neonatal morbidity and mortality.

　　The relatively low birth weight incidence observed in our study may be partly explained by the increased economic growth obvious in the growing commercial and industrial city of our centre and the improved antenatal services and attendance by mothers.

　　The results of the study also reveal that significant majority of neonatal deaths were associated with primiparous pregnancies as compared with other parity categories. This however contrasts with a previous report that primiparity was associated with low neonatal mortality.

　　The explanation for this， is not readily clear .It may be related to the fact that late booking and irregular visit for antenatal supervision are often observed amongst primiparous women here where as it is also primiparous pregnancy that is more often associated with complications such as pregnancy induced hypertension， pre .eclampsia and eclampsia often resulting in neonatal morbidity and mortality.

　　Conclusion

　　It should be known that intrapartum risk factors are associated with greater increase in neonatal death than pregnancy related factors[16]. Hence more skilled supervision of labor is demanded of all those in the business of labor management with ready delivery by caesarian section whenever indicated .This will help in reducing deaths particularly from birth asphyxia. Also quick resuscitation with clearing of the airway by gentle suctioning and adequate ventilation is more important than additional oxygen.

　　Extra attention to warmth ，feeding and prevention or early treatment of infection will help in lowering mortality due to prematurity[13，19]， In all these sophisticated technology is not required.

　

参考文献

　　1 Hainess A， Cassels A. Can the Milenium development goals be obtained? BMJ，2004，329: 39497.

　　2 Zupan J， Aahman E. Perinatal mortality for the year 2000 estimates developed by WHO， Geneva: World Health Organization， 2005.

　　3 Black RE， Morris SS， Bryce J. Where and why are 10 million newborn babies dying every year? Lancet，2003，361:222634.

　　4 World Health Organization (WHO) partnership for maternal， newborn and child health， partnership for safe motherhood and new born health. Geneva: World Health Organization，2005.

　　5 World Health Organization. Child and adolescent health and development: progress report 20022003. Geneva: World Health Organization，2004.

　　6 Lawn JE， Cousens S， Bhutta ZA， et al. Why are 4 million newborn babies dying each year? Lancet，2004，364:399401.

　　7 Stinker A. Intergrating essential newborn care in other health system. Presentation given at the World Bank， Washingnton DC， Sept. 16， 2002.

　　8 The World Bank Group， data and statistics: country groups http://www.world bank.org/data/countryclass/classgroups.htm#High_income(accessed Jan 12， 2005)

　　9 Chalumeau M， Lanave B， BouvierColle MH. Risk factors for perinatal mortality in West Africa: a population based study of 20326 pregnancies. Acta Paediatr，2000，89:11521.

　　10 National Population Commission (NPC) (Nigeria) and ORC Macro. Nigeria Demographic and Health Survey 2003. Calverton Maryland 2004: National Population Commission (NPC) and ORC Macro 10812.

　　11 Owa JA， Aldabbous I， Owoeye AA. Weight specific morbidity and mortality rates among LBW infants in developing countries. Nigerian Journal of Paediatrics，2004，31:1924.

　　12 Duke T， Wille M. The effect of introduction of minimal standards of neonatal care on in hospital mortality. PNG Med J，2000，43:127  134.

　　13 Kramer MS. The epidemiology of adverse pregnancy outcomes: an overview.J Nutr，2003，133(5 suppl 2): 159256s.

　　14 CondeAgudelo A， DiazRossello JL， Belizan JM. Kangaroo mother care to reduce morbidity and mortality in low birthweight infants (Cochrane Review)in: The cochrane library， issue 4， 2003. Oxford: update software.

　　15 Bang A， Reddy MH， Deshmukh MD. Child mortality in Mahararshtra， Economic Poilitical Weekly， 2002，37:494765.

　　16 Kusiako T， Romanans C， Vander PL. Perinatal mortality attributable to complications of childbirth in Matlab. Bangladesh Bull World Health Organ，2000，78:62127.