Every year 70% of neonatal
deaths take place because simple yet effective interventions do not
reach those who need them the most. Coverage of interventions is low,
progress in scaling up is slow, and inequity is high [1]. This gap is
due to poor coverage within the health system, shortage of health care
providers, and issues related to access to referral services. While
community-based research is receiving attention and investment, rigorous
evaluation and research on facility-based interventions is lagging
behind [2]. Appropriate linkage and coordination are pertinent with
facility-based care for achieving successful gains in community-based
interventions.
Facility based care includes essential care at birth
and care of sick babies in different facilities. Stratification of
various levels according to the ability of the units to handle cases has
been devised. While it is desirable to see babies receiving care at
appropriate facilities, designing such a model and operationalizing it
within the health system is a challenge. It is understood that very
high-risk babies should get the highest level of care but investment
would vary accordingly. It is thus imperative to learn from experiences
of different facilities in diverse settings in the context of facility
based neonatal interventions. The learning will be vital as to how
different models have tackled and improved neonatal outcomes and
challenges confronted by these facilities.
This review is undertaken to assess different factors
that affect neonatal outcomes in facilities providing newborn care. It
also aims to synthesize evidence on parameters that influence the
performance of the facilities.
Methods
All observational and interventional studies that
have documented the establishment of neonatal facilities and their
functioning have been considered. Interventions relating to setting
up/managing/upgrading facility based newborn care include essential care
at birth in facilities, special care for sick newborns, follow up of
neonates admitted with any illness and care of neonates in post natal
wards.
Inclusion criteria: Facility based care in
developing country setting, and evaluation of regionalized system of
perinatal care in both developing and developed countries. Articles on
community based newborn care and on impact of level III care facilities
in developed countries with reference to management/ treatment of
specific illnesses were excluded.
Outcome measures: Primary outcome of this search
was neonatal and perinatal mortality among hospitalized newborns and
when available, at the population level.
Search strategy and study selection
All publications in English between 1966 and August,
2010 in any scientific journal were considered. Electronic searches were
using Pubmed, IndMed, BioMed Central, Cochrane, PopLine and Google.
Besides, websites of national and international organizations working on
neonatal health (National Neonatology Forum, WHO, Save the newborn,
UNICEF) were screened. Grey literature and journal hand searching were
done to explore more information.
Search was done using the following keywords-
neonates/newborns, facility/hospital/ SCNU/secondary level care, and
survival/ reduction in mortality/reduction in morbidity. This was done
by two primary reviewers independently. The search criteria were
mutually agreed upon prior to the actual search. After a preliminary
exercise, all the citations were screened by both the reviewers
independently. The citations selected by both/any of them were
considered for abstract review. These were reviewed independently by
both of them and the final list of the selected abstracts prepared. In
case of disagreement on the selection of any study abstract, it was
settled by mutual discussion and advice sought from a Senior
Investigator of the team. The full articles of the selected abstracts
were reviewed by the reviewers. All the studies relied on data retrieved
from their usual records, births and death certificates.
The key findings were pooled together. A summary
measure could not be calculated owing to heterogeneity in study designs
and quality and different ways in which outcomes were expressed.
Reporting of findings was done as per MOOSE guidelines (Appendix
1).
Based on the review of the shortlisted papers, we
classified the interventions for improving neonatal outcomes into three
groups viz. (i) Regionalization of perinatal care (17
studies); (ii) Strengthening of level I/II facilities (12
studies); and (iii) Studies assessing the impact of health system
factors such as - inborn/outborn status, size and volume of the unit,
referral transport and availability of human resources on neonatal
outcomes (11 studies).
Results
Regionalization
Regionalization implies the development, within a
geographic area, of a coordinated, cooperative system of maternal and
perinatal healthcare in which, by mutual agreements between hospitals
and physicians and based upon population needs, the degree of complexity
of maternal and perinatal care each hospital is capable of providing is
identified so as to accomplish the following objectives: quality of care
to all pregnant women and newborns, maximal utilization of highly
trained perinatal personnel and intensive care facilities, and assurance
of reasonable cost effectiveness.
Different studies have used different nomenclature
and designations for different units [6,7]. By and large, level III were
defined as the units which provided specialized services like
ventilatory support, level II as units that could manage neonates more
than 1500g and provide intermediate care, and level I as the units that
could manage low risk neonates. Level II care includes supportive care,
feeding of low birth weight neonates, management of sepsis, asphyxia and
pathological jaundice and stabilization of neonates before referring to
level III care.
Many authors have reported experience with various
models of regionalized perinatal services [6-9]. Most observers have
found it difficult to relate perinatal outcome to regionalization, since
controlled clinical trials of perinatal care and regionalization are not
acceptable [10]. These have correlated morbidities and mortalities
arising out of high-risk deliveries. As a consequence of
regionalization, more high-risk deliveries and very low birth weight
(VLBW) births were managed at higher level units with advanced
technology [11,12]. Regionalization resulted in increased emphasis on
transfer of at risk mothers to perinatal centres, as reported from 17
NICUs in Canada before delivery of the infant, instead of transferring
infants after they were born [13]. Similar findings were reported from
all level II and III units in New Zealand where around 3% of infants
were high-risk infants [14]. The outcomes were better for inborn babies
with VLBW as compared to outborn babies (OR= 1.7; 1.2-2.5).
In addition to early in utero transfer of high
risk infants, developments were also noted in intensifying transport
mechanisms after birth from lower to higher level units. In Portugal
in-hospital deliveries increased from 74% to 90%. Despite great increase
in intra-uterine transport, Portuguese Neonatal transport system with
its own neonatal team also succeeded in stabilizing the newborn before
transport [7]. It was also suggested that several intermediate care
units should be set up and suitably developed to minimize unnecessary
admissions to the tertiary neonatal centers [15].
In the evolutionary process of regionalization, well
established system for infant transport and availability of trained
staff and user friendly technology have allowed the rapid growth of
community NICU. This sometimes attracted births away from regional NICUs
giving rise to ‘deregionalization’ [6]. The number of deliveries
especially high risk, increased at these facilities. This sometimes
resulted in a substantial disadvantage to VLBW babies as noted in
California. Data from a similar study also indicated that 69% of infants
<2000 g birth weight were born outside a regional NICU reflecting the
extent of deregionalization [16].
A total of 17 studies were selected for the review
under this heading that considered change in neonatal/ perinatal
mortality as the outcome.[3-4, 6-7, 10-12, 16-25] Out of these, 1 was a
cohort/ prospective study, 2 studies have documented the impact before
and after regionalization was established and the rest have analyzed the
secondary data as retrieved from the usual records. Authors have
expressed the change in NMR in many different ways. While some have
compared the risk of dying at a level III or level II with level I unit
in the form of odds ratio, others have given the absolute reduction in
NMR or PMR across various birth weight categories and across different
levels. Comparison of the reduction in NMR/ PMR was not possible because
of differing time frames and difference in the ways NMR or PMR were
expressed.
There was a decline in numbers of LBW/ VLBW babies
being born in level I hospitals with no change in the incidence of LBW
babies. More referrals of high risk cases to higher centres (level III)
through improved transportation have resulted in a decline in NMR in
level I units [3,7,10,17,20-22,24]. Proportion of VLBW babies born in
community hospitals increased by 25.7% in California over 7 years [6].
In Ontorio, neonatal transfer rate increased by 19.7% in 2 years among
babies weighing 500-1499 g while it reduced by 3.1% among babies
weighing 1500-2499 g [22]. More than 45% of VLBW babies were born in
level III units in Washington and Wales [24]. The proportion of VLBW (<
1500 g) and moderately LBW (1500- 2499 g) infants delivered at level III
hospitals was higher in states with formal system of perinatal
regionalization [11,12]. This improved the outcome of babies admitted to
level I units.
A concomitant increase in NMR in higher centers was
observed initially followed by a decline, as regionalization matured.
NMR increased by 1.4% per year initially for 5-7 years followed by a
phase of decline that varied from 0.8% to 1.6% per year in various
studies [4,7,10,11,19,23]. On the whole, there was a net decline in NMR
(0.4 to 0.65% per year) and a decline in PMR by 0.6- 1.0% each year
[10,11].
Reduction in NMR in most of cases was owing to a
decline in mortality among LBW infants, more so for neonates weighing
between 1000- 2500 grams. Mortality among LBW babies reduced by 3-4% per
year while it ranged from 1.45 to 4.2% per year among VLBW babies
[6,7,20]. In yet another study, it was found that 80% reduction in NMR
resulted due to improved survival of LBW babies [8]. However,
inconsistent evidence was also provided by a study executed in Alaska
that concluded that perinatal care regionalization (for infants
1500-2499 g birth weight) is unlikely to substantially lower LBW infant
mortality [25]. Though the study pointed out mother-infant pairs who
received all care at single tertiary care center had a lower mortality
rate than those who received some care at a non-tertiary care center,
this study suffered with myriad methodological limitations- low sample
size, lower deaths reported and also mortality was considered as sole
outcome in the study.
Performance of level II/I units
Secondary (level II) units provide a useful link in
the health system to promote regionalization. Evidence supports that if
these units are developed, they may considerably provide good perinatal
care and contribute to reductions in NMR. In a regionalized system, the
policy is to transfer almost all preterm babies to higher referral units
(level III). This way, investment in sophisticated technology could be
limited to chosen units. On the other hand in places where
regionalization is still not present, upgradation of level II could
impact NMR favorably.
A total of 12 studies documented the impact of
non-tertiary units, five of which are from developed countries [26-38] (Web
Table II). While six of them focused on level II units, two
described about the upgradation from level I to III, two described level
II units, one both level I and II combined and one did not mention any
level. Number of units and time frame differed for every study although
the impact was expressed as reduction in NMR and/ or PMR in every study.
Most of these documented the impact on low birth weight category but the
cut-offs used were not uniform. Significant reduction in NMR was seen in
most of the units [26-27, 29-31,33]. While the rate of decline varied
from 1.2- 2.5% per year in developed nations, the impact was greater in
developing countries where it varied from 6-10% per year [27,
29-31,33,35]. Greatest impact was seen in the early neonatal mortality
rate [27,29]. Experience from Norway; however, suggests that the
neonatal death rate remained static while fetal death rate declined from
14.8 to 6.6% between 1976 and 1989 (P<0.001) [28].
Within a year of upgradation of an ICU in Ghana from
level II to level III, there was a significant reduction in the survival
of normal birth weight with birth asphyxia, no change for non-
asphyxiated normal birth weight and significantly improved survival of
LBW babies [35]. Reduced survival of asphyxiated inborn after NICU
refurbishment may have been due to referral of moribund asphyxiated
babies from the labor ward because labor ward neonatal deaths reduced by
47% after NICU refurbishment. The high mortality among outborn
asphyxiated NBW may have been due to mode of transportation to NICU.
The impact was most apparent for LBW/VLBW babies but
not for ELBW babies. Experience worldwide have shown that level II units
can contribute maximally towards bringing down the mortality rate among
LBW babies, especially those weighing between 1000-1500g [26-27,30,36].
With improved performance in the functioning, the NMR among infants
>1500 g can match that of a level III unit. However, NMR among VLBW
infants have yielded mixed results. While New York demonstrated an
increase in survival among VLBW babies, the same was not seen in India
[36,37]. The main features that affect this outcome are better provision
of care, increased stay of LBW infants, and higher rates of inborn
deliveries [38].
Proportion of VLBW births is a strong predictor of
NMR in these units. Rates of inborn VLBW babies have a strong independent
influence on NMR. Dooley suggested that for every 1% increase in
proportion of hospital’s VLBW births, there is an increase of 2/1000 in
NMR. Perinatal surveillance data for 3 years (1990-93) was analyzed in
Illinios to identify the elements in the infrastructure of a
regionalized network that had independent effects on the variation in
mortality among non tertiary units (level I, II). Maternal socioeconomic
behavior risk alone explained 73% of the variation in the hospital fetal
death rates and 38% of that in hospital neonatal mortality rates. When
controlling for maternal socio-behavioral risk, rates of inborn VLBW
deliveries (P<0.001) and neonatal transport (P=0.01) had
independent effects on the variation in hospital fetal death rate; rates
of inborn VLBW deliveries (P<0.001), neonatal transport (P<0.001)
and proportion of VLBW infants transported out (P=0.029) had
independent effects on the variation in hospital neonatal mortality
rate. Maternal transport, on the other hand, had no effect in the final
models contrary to the belief that favorable perinatal outcomes are
facilitated with delivery of at-risk neonate [38].
Other Factors Affecting Nmr Reduction
Size and volume of the unit and admissions
Patient volume of the neonatal care units seems to
influence the mortality. A total of 6 studies were reviewed that
compared the volume of the unit with the NMR and 3 studies that showed
the influence of inborn/ outborn status on the outcome.
In general, units with more than 2000 deliveries/
year influence NMR favorably. In USA, for instance, infants <2000 g had
twice the mortality rate in facilities with less than 2000 deliveries/y
when compared to those born in facilities >2000 deliveries, while little
difference exists between obstetric volume groups for infants >2000g
[12]. The same study, through log linear regression modeling, showed
that when birth weight and maternal risk were controlled, obstetrical
volume added minimal explanatory power to level of nursery care. The
study was challenged due to small sample size and narrowly defined
networks.
Evidence from California, using data from ten years
1991-2000, showed that lower levels of care and lower volumes were
associated with significantly higher odds ratios of death as compared to
high level of care and high volume of VLBW (>100/ year) adjusted for
risk factors[39]. Risk adjusted mortality for infants who were born in
hospitals with large (average census >/= 1500) community NICU (level II)
was not statistically significant compared to regional NICU (OR= 1.11;
0.87-1.43) [16].
Women living in areas where the most frequently used
delivery unit had less than 2000 annual deliveries had 1.2 (95% CI= 1.1-
1.3) times the risk of experiencing neonatal death compared to women
living in areas where the most frequently used delivery unit had more
than 2000 deliveries per year according to Norwegian Medical Birth
Registry. The relative risk of neonatal death in geographical areas with
more than 3000 annual births was 0.8 (95% CI 0.7-0.9) compared with
areas where none delivered in such large units. The highest risk of
stillbirths was found in municipalities with a high proportion of births
occurred in the smallest units [40]. The NMR was lowest for maternity
units with 2001-3000 annual births, steadily increased with decreasing
size of the maternity unit to around twice that for units with <100
births per year. (OR=2.1; 95% CI 1.6- 2.8) [41]. A population based data
from Germany revealed that neonatal mortality among infants (<1500 g)
admitted to NICUs was 12.2% in small NICUs and 10.2% in large NICUs.
Stratification according to gestational age revealed the greatest impact
on mortality for infants of <29 weeks [42].
Besides, having a birth in same facility (being
inborn) exerts a protective factor conferring better chances for
survival later in life. In a survey in Canada, outborn infants had
significantly high unadjusted incidence of mortality and more serious
illnesses [13]. Similar findings were also observed in Ghana and USA
[35,38]. More importantly, prevalence of LBW/ VLBW among inborn
admissions critically acts as a determining factor.
Referral system and transport
As an aid to regionalization, referral system and
inter-facility transfers can also substantially influence NMR. Only 4
studies were found that could correlate an efficient referral transport
with reduction in NMR.
In UK in 1979-80, nearly 40% of neonates could not be
referred because of overcrowding or lack of equipment or lack of
suitably trained nurses. The survival rate of babies who were
transferred was slightly more than twice than that of a group of babies
of similar birth-weights who were not transferred [43]. There was a
marked drop in outborn mortality among infants weighing more than 1000 g
before and after initiating a neonatal transport system in US. Also,
there was an increased rate of outborn admissions in this referral unit
[19].
The association between duration of inter-facility
transport and perinatal mortality has also been reviewed. A
cross-sectional study from India showed that neonates with a long
duration of transport had 79% higher odds of death than those
transported for a short duration, after adjusting for confounding
factors [44]. A cohort study conducted in Osaka, Japan between 1980-2000
reported a strong evidence that those transported for more than 90 mins
had more than twice the rate of neonatal death (RR 2.26, 95% CI 1.26-
4.04) and some evidence that those transported for between 60 and 89
minutes had 80% higher rate of neonatal deaths (RR 1.81, 95% CI
1.07-3.06), both compared with those transported for between 30 and 59
minutes. A 14% raised RR was observed for those transported for < 30
minutes. This could be due to the fact that because of their condition,
severaly ill neonates could be transported faster than less severely ill
neonates [45].
Human resources
Human resources, especially the staff nurses, form
the backbone of a neonatal unit can affect NMR and as evident from five
studies. Analysis of data about perinatal mortality and indicators at
maternity hospitals showed that pediatric staff ratios were inversely
related to in-house mortality rates. Risk of neonatal mortality has been
shown to be independently related to staffing-levels in NICU, such that
the odds of mortality significantly increased when one nurse cared for
more than 1.7 newborns [46].
Deficiency of nursing staff in intensive care units
poses an additional challenge of infections due to poor adherence to
asepsis. In a neonatal special care unit in USA, infant: nurse ratio and
infant census were the key determinants of nosocomial infections. The
incidence rate of clustered infection was 16 times higher during periods
when infant: nurse ration exceeded 7 [47]. In a Special Care Baby Unit
in Barbados, shortage of staff had fostered deterioration in handwashing
technique leading to outbreaks [48].
The neonatal mortality rate in US has been found to
be lower in regions with 4.3 neonatologists per 10,000 births than in
those regions with 2.7 neonatologists per 10,000 births. Further
increase in the number of neonatologists was not associated with greater
reduction in the risk of deaths. Lack of resident medical staff,
especially at night and over weekends, contributed to increased SCBU
mortality, as reported from Uganda. Perinatal mortality data from West
Midlands suggest that neonatal mortality was less when high-risk babies
were born in maternity homes with improved staffing ratios [49].
Discussion
The review brings into light three broad categories
of interrelated strategies that can influence NMR– regionalization of
neonatal care, strengthening of level I/II facilities, and improvement
in health systems. The current review indicates that as regionalization
evolves and matures, the proportion of high risk deliveries decrease in
less specialized units while there is a concomitant increase in more
specialized centres. The increased proportion of high risk deliveries
occurring in specialized units gets translated into an overall improved
neonatal survival.
All the studies reviewed relied on data retrieved
from their usual records, births and death certificates The advantages
are that in developed nations, filing of births and death records tends
to be complete. Moreover, data are collected in a single office and they
have been collected for many years and allow comparisons of relatively
large population over long periods of time. The disadvantages, however,
are that some parameters like gestational age, time of death etc. may be
inaccurately recorded. Another problem is the possible underreporting of
neonatal deaths [3]. In yet another study, it was revealed that only 73%
of the records could be retrieved [4].
India and other developing countries with relatively
weaker healthcare systems are increasingly investing in strengthening
neonatal units to address high neonatal mortality. The review does show
that these investments can decrease neonatal mortality significantly.
However, to have significant and sustained impact at the population
level, it is much more important to concentrate on the system in which
the units are functioning. Apart from strengthening these units in
isolation, it is critical to establish linkages with the lower and
higher centers to optimally utilize the resources at a level where it is
required the most. The review has shown that strengthening of level I/II
units can have a great impact on the survival of LBW/VLBW babies but not
for ELBW babies. This probably could be addressed in specialized units
in a regionalized set up. Performance of level II units is strongly
influenced by the proportion of VLBW births. By appropriately referring
such pregnancies to higher levels, where the outcomes are likely to be
better, the performance of individual units can also be improved.
While developing countries are investing resources in
improving facility based care, it is imperative to look beyond
establishing the standalone Special Care Newborn Units to having a
system of networked facilities providing different levels of perinatal
care. Such a "regionalized" system will have clear mechanisms to
transfer high-risk pregnancies to appropriate levels. Currently, this is
being accorded priority in many countries but it is important to
consider that in-utero transfers have better outcomes than ex-utero
transfers, as suggested by the review.
The study suffers from certain limitations. Owing to
the heterogeneity of the studies, quantitative assessment of bias could
not be ascertained. It was also difficult to provide an overall estimate
of the gains achieved by investing on facility-based newborn care. Due
to problems with translation, non-English articles were excluded. The
quality of each studies included with was not assessed as per the
guidelines laid down, since very few of them were actually research
studies conducted under controlled conditions. There was a reliance on
secondary data primarily due to the ease of data collection. This also
means that the results can be generalized.
To conclude, the synthesized evidence from this
review points out the critical components of facility based neonatal
interventions. Advancements in neonatal care practices if cocooned with
developing regionalized care, has promising potential in averting
neonatal deaths. Based on the review, it appears that such a
regionalized system will have following important constituents
highlighted in the box. The review components provide a critical insight
for nations that are in process of scaling up facility-based newborn
interventions and adopting strategies to address unfinished agenda of
high neonatal mortality.
Important constituents of a regionalized system
• A network of perinatal care units that provide
different levels of perinatal care
• All high risk births will be transported in-utero
to the higher levels of care
• All units conducting about 2000 deliveries per
year to be strengthened to provide level II newborn care. Key
element is availability of adequate, skilled human resources,
especially nurses.
• A well-functioning transport system connecting
the facilities that provide different levels of care, in-utero
transport, where the risk is predictable, and emergency transport
where such a risk is not predictable.
1. Knippenberg R, Lawn JE, Darmstadt GL, Begkoyian G,
Fogstad H, Walelign N, et al. Systematic scaling up of neonatal
care in countries. Lancet. 2005;365:1087-98.
2. Bahl R, Martines J, Ali N, Bhan MK, Carlo W, Chan
KY, et al. Resaerch priorities to reduce global mortality from
newborn infections by 2015. Pediatr Infect Dis. 2009;28:S43-8.
3. Bowes WA. A review of perinatal mortality in
Colorado, 1971 to 1978, and its relationship to the regionalization of
perinatal services. Am J Obstet Gynecol. 1983; 141: 1045-52.
4. Hein HA, Lathrop SS. The changing pattern of
neonatal mortality in a regionalized system of perinatal care. Am J Dis
Child. 1986;140:989-93.
5. Committee on Perinatal Health.Toward Improving the
Outcome of Pregnancy: Recommendations for the Regional Development of
Maternal and Perinatal Health Services. White Plains, NY: March of Dimes
National Foundation;1976.
6. Gould JB, Marks AR, Chavez G. Expansion of
community based perinatal care in California. J Perinatol.
2002;22:630-40.
7. Neto MT. Perinatal care in Portugal: effects of 15
years of a regionalized system. Acta Pediatrica. 2006;95:1349-52.
8. Mullem CV, Conway AE, Mounts K, Weber D, Browning
CA. Regionalization of care in Winconsin: a changing health care
environment. Wisconsin Medical Journal. 2004;103:35-8.
9. Howell EM,Richardson D, Ginsburg P, Foot B.
Deregionalization of neonatal intensive care in urban areas. Am J Public
Health. 2002;92:119-24.
10. Peddle LJ, Brown H, Buckley J, Dixon W, Kaye JM,
Muise M, et al. Voluntary regionalization and associated trends
in perinatal care: The Nova Scotia Reproductive Care Program. Am J
Obstet Gynecol. 1983;145:170-6.
11. Kirby RS. Perinatal mortality: the role of
hospital at birth. J Perinatol. 1996;16:43-9.
12. Mayfield JA, Rosenblatt RA, Baldwin LM, Chu J,
Logefro JP. The relation of obstetrical volume and nursery level to
perinatal mortality. Am J Public Health. 1990;80:819-23.
13. Chien LY, Whyte R, Aziz K, Thiessen P, Matthew D,
Lee SK, et al. Improved outcome of pre term infants when
delivered in tertiary care centres. Obstet Gynecol. 2001;98:247-52.
14. Cust AE, Darlow BA, Donoghue DA, on behalf of the
Australian and New Zealand Neonatal Network (ANZNN). Outcomes for high
risk New Zealand newborn infants in 1998-1999: a population based,
national study. Arch Dis Child Fetal Neonatal Ed. 2003;88:F15-F22.
15. Manatgos S. International Perinatology/
neonatology- a global perspective. Neonatal perinatal care in Greece. J
Perinatol. 1997;17:156-60.
16. Cifuentes J, Bronstein J, Phibbs CS, Phibbs RH,
Schmitt SK, Carlo WA. Mortality in low birth weight infants according to
level of neonatal care at hospital of birth. Pediatrics.
2002;109:745-51.
17. Bode MM, O’Shea TM, Metzguer KR, Stiles AD.
Perinatal regionalization and neonatal mortality in North Carolina
1968-1994. Am J Obstet Gynecol. 2001;184:1302-7.
18. Goldenberg RL, Humphrey JL, Hale CB, Boyd BW,
Wayne JB. Neonatal deaths in Alabama, 1970-80: an analysis of birth
weight- and race specific neonatal mortality rates. Am J Obstet Gynecol.
1983;145:545-52.
19. Skelton MA, Perkett EA, Major CW, Vaughan RL,
Stahlman MT. Transport of the neonate. Southern Medical Journal.
1979;72:144-8.
20. Walker DB, Vohr BR, Oh W. Economic analysis of
regionalized neonatal care for very low-birth-weight infants in the
state of Rhode Island. Pediatrics. 1985;76:69-74.
21. Rosenblatt RA, Mayfield JA, Hart LG, Baldwin LM.
Outcomes of regionalized perinatal care in Washington state. West J Med.
1988;149:98-102.
22. Campbell MK, Chance GW, Natale R, Dodman N,
Halinda E, Turner L. Is perinatal care in south western Ontorio
regionalized? Can Med Assoc J. 1991;144:305-12.
23. Hein HA, Lofgren MA. The changing pattern of
neonatal mortality in a regionalized system of perinatal care: a current
update. Pediatrics. 1999;104:1064-9.
24. Rosenblatt RA, Dawson AJ, Larson EH. The
regionalization of perinatal care in Wales and Washington state. Am J
Public Health. 1996;86:1011-5.
25. Gessner BD, Muth PT. Perinatal care
regionalization and low birth weight infant mortality rates in Alaska.
Am J Obstet Gynecol. 2001;185:623-8.
26. Thompson RE, Souma ML, Cassdy G, Sumners J.
Impact of intensive newborn acre on neonatal mortality in a community
hospital. South Med J. 1976;69:688-90.
27. Jivani SKM. Evolution of neonatal intensive care
in a district general hospital. Arch Dis Child. 1986;61:148-52.
28. Berge LN, Rasmussen S, Dahl LB. Evaluation of
fetal and neonatal mortality at the University Hospital of Tromso,
Norway, from 1976 to 1989. Acta Obstet Gynecol Scand. 1991;70:275-82.
29. Hotrakitya S, Tejavej A, Siripoonya P. Early
neonatal mortality and causes of death in Ramathibodi Hospital. J Med
Assoc Thai. 1993 Oct;76 Suppl 2:119-29. 1981- 90
30. Pollack LD. An effective model for reorganization
of perinatal services in a metropolitan area: a descriptive analysis and
historical perspective. J Perinatol. 1996;16:3-8.
31. Were FN, Mukhwana BO, Musoke RN. Neonatal
survival of infants less than 2000 grams born at Kenyata National
hospital. East African Med J. 2002;79:77-9.
32. Sen A, Mahalanabis D, Singh AK, Som TK,
Bandyopadhyay S. Development and effects of a neonatal care unit in
rural India. Lancet. 2005;366:27-8.
33. Sen A, Mahalanabis D, Singh AK, Som TK,
Bandyopadhyay S. Impact of a district level newborn care unit on
neonatal neonatal mortality rate: 2 year follow up. J Perinatol.
2009;29:150-5.
34. Nzinga J, Ntoburi S, Wagal J, Mbindyo P, Mbaabu
L, Migiro S, et al. Implementation experience during an eighteen
month intervention to improve paediatric and newborn care in Kenyan
District. Implementation Science. 2009;4:45.
35. Laryea CCE, Nkyekyer K, Rodrigues OP. The impact
of impoved neonatal intensive care facilities on referral patternand
outcome at a teaching hospital in Ghana. J Perinatol. 2008;28:561-5.
36. Mootabar H, Fox HE. Level 2 hospital delivery of
low birth weight infants 1970-1979. Int J Gynaecol Obstet.
1983;21:27-32.
37. Subramaniam C, Dadina ZK. Intensive care for high
risk infants in Calcutta. Am J Dis Child. 1986;140:885-8.
38. Dooley SL, Freels SA, Turnock BJ. Quality
assessment of perinatal regionalization by multivariate analysis:
Illinois, 1991-1993. Obstet Gynecol. 1997;89:193-8.
39. Phibbs CS, Baker LC, Caughey AB, Danielsen B,
Schmitt SK, Phibbs RH. Level and volume of neonatal intensive care and
mortality in very low birth weight infants. N Engl J Med.
2007;356:2165-75.
40. Moster D, Lie RT, Markestad T. Neonatal mortality
rates in communities with small maternity units compared with those
having larger maternity units. BJOG2001;108: 904-9.
41. Moster D, Lie RT, Markestad T. Relation between
size of delivery unit and neonatal death in low risk deliveries:
population based study. Arch Dis Child Fetal Neonatal Ed.
1999;80:F221-5.
42. Bartels DB, Wypij D, Wenzlaff P, Dammann O, Poets
CF. Hospital volume and neonatal mortality among very low birth weight
infants. Pediatrics. 2006;117:2206-14.
43. Sims DG, Wynn J, Chiswick ML. Outcome for newborn
babies declined adsmission to a regional neonatal intensive care unit.
Arch Dis Child. 1982;57:334-57.
44. Sehgal A, Roy MS, Dubey NK, Jyothi MC. Factors
contributing to outcome in newborns delivered out of hospital and
referred to a teaching institution. Indian Pediatr. 2001;38:1289-94.
45. Mori R, Fujimura M, Shiraishi J, Evans B, Corkett
M, Negishi H,et al. Duration of inter facility transport and
neonatal mortality: systematic review and cohort study. Pediatrics
International. 2007;49:452-8.
46. Callaghan LA, Cartwright DW, O’Rourke P, Davies
MW. Infant to staff ratio and risk of mortality in very low birth weight
infants. Arch Dis Child Fetal Neonatal Ed. 2003;88:F94-7.
47. Ferster G, Pethybridge RJ. A local maternity care
system in South West England under review. International Journal of
Health Services. 1975;5:663-78.
48. Denny F, St John MA, Lewis DB, Daniel B.
Nosocomial Klesiellapneuminiae colonization in a neonatal special care
unit. Ann Trop Pediat. 1986;6:123-6.
49. Mugford M, Szczepura A, Lodwick A, Stilwell J.
Factors affecting the outcome of maternity care II: neonatal outcomes
and resources beyond the hospital of birth. J Epidem Comm Hlth.
1988;42;170-6.