|Year : 2018 | Volume
| Issue : 1 | Page : 63-67
The prevalence and pattern of central nervous system anomalies in a neonatal unit in a tertiary hospital in Jos, north-central Nigeria
Bose O Toma1, Danaan J Shilong2, David D Shwe1, Gyang M Bot2, Udochukwu M Diala1, Akinyemi O Ofakunrin1, Anyebe Prince1, Peter O Binitie2
1 Department of Paediatrics, Jos University Teaching Hospital, Jos, Nigeria
2 Department of Surgery, Jos University Teaching Hospital, Jos, Nigeria
|Date of Web Publication||29-May-2018|
Dr. Bose O Toma
Department of Paediatrics, Faculty of Medical Sciences, University of Jos/Jos University Teaching Hospital, PMB 2076, Jos, Plateau State
Source of Support: None, Conflict of Interest: None
Background: Congenital anomalies are an important cause of neonatal deaths, chronic illness, and disability and are most common in low- and middle-income countries. Central nervous system (CNS) congenital anomalies are one of the most common abnormalities. Information on the burden and types of CNS anomalies will facilitate health system planning and an efficient allocation of scarce resources. We determined the prevalence and pattern of CNS congenital anomalies in a neonatal unit in Jos, north-central Nigeria.
Materials and Methods: A retrospective descriptive study of all neonates admitted with CNS congenital anomalies into the neonatal unit of Jos University Teaching Hospital (JUTH) from October 2013 to September 2016 was conducted.
Results: One hundred and fifty-five (14.8%) of the 1046 babies admitted during the period had congenital anomalies. Twenty-seven babies (14 males and 13 females) had CNS anomalies giving a prevalence rate of 2.6%. CNS anomalies constituted 17.4% of the 155 babies admitted with congenital anomalies. All 27 (100%) of the babies were born outside the teaching hospital, with 13 (48.2%) of them delivered at home. Neural tube defects (NTDs) were the most common CNS malformations (26; 96.3% of the CNS anomalies). Talipes equinovarus was the most common associated anomaly (6; 22.2% of the babies).
Conclusion: The prevalence of CNS anomalies among admitted neonates in the JUTH is high. NTDs were the most common CNS anomalies, with myelomeningocele being the single most common disorder.
Keywords: Birth defects, central nervous system anomalies, congenital anomalies, jos, malformation, neonatal unit, neural tube defects, Nigeria
|How to cite this article:|
Toma BO, Shilong DJ, Shwe DD, Bot GM, Diala UM, Ofakunrin AO, Prince A, Binitie PO. The prevalence and pattern of central nervous system anomalies in a neonatal unit in a tertiary hospital in Jos, north-central Nigeria. J Med Trop 2018;20:63-7
|How to cite this URL:|
Toma BO, Shilong DJ, Shwe DD, Bot GM, Diala UM, Ofakunrin AO, Prince A, Binitie PO. The prevalence and pattern of central nervous system anomalies in a neonatal unit in a tertiary hospital in Jos, north-central Nigeria. J Med Trop [serial online] 2018 [cited 2018 Dec 15];20:63-7. Available from: http://www.jmedtropics.org/text.asp?2018/20/1/63/233417
| Introduction|| |
Birth defects or congenital anomalies are an important cause of infant and childhood deaths, chronic illness, and disabilities. Globally, an estimated 303,000 newborns die within 4 weeks of birth every year from congenital anomalies. About 94% of severe congenital anomalies occur in low- and middle-income countries. In Nigeria, in 2015, there were an estimated 14,395 deaths due to congenital anomalies. Central nervous system (CNS) congenital anomalies are one of the most common abnormalities. Apart from its contribution to neonatal mortality, congenital anomalies can contribute to long-term disability, which may have significant impact on individuals, families, healthcare systems, the economy, and societies.
Although approximately 50% of all congenital anomalies currently cannot be linked to a specific cause, there are some known risk factors, which include genetic, sociodemographic, and environmental factors, infections, and folic acid deficiency, to mention a few. The prevalence and pattern of congenital anomalies vary from place to place and time to time., Different authors have reported various prevalence figures for CNS anomalies, ranging from 1.3% in Pakistan to 8.8% in Tanzania. Ambe et al. found the prevalence of CNS anomalies in a neonatal unit in Maiduguri, northern Nigeria to be 3.4%, while a previous study on congenital anomalies in our center about 16 years ago observed a prevalence of 1.6%. Information on the burden and types of CNS anomalies will facilitate health system planning and the efficient allocation of scarce resources. It is also necessary that the situation be reviewed periodically to determine any trends, so that appropriate strategies can be implemented. The aim of this study, therefore, was to determine the prevalence and pattern of CNS congenital anomalies in a neonatal unit in a teaching hospital in Jos, north-central Nigeria.
| Materials and methods|| |
This was a retrospective study conducted in the neonatal unit of Jos University Teaching Hospital (JUTH), a tertiary-level public hospital in Jos, north-central Nigeria from October 1, 2013 to September 30, 2016. The hospital has a bed capacity for 520, with 30 beds in the neonatal unit.
All neonates admitted with CNS congenital anomalies into the unit during the study period were identified from the admission registers and were included in the study. Their case notes were retrieved, and information about the diagnoses, the types of anomalies, and sociodemographic data were extracted. The CNS birth defects were classified in line with the ICD 10 version 2016 classification. The data were entered into a Microsoft Office Excel sheet and analyzed using the Statistical Package for the Social Sciences version 17.0 software [SPSS Inc., Chicago, IL, United States of America (USA)]. Approval to conduct the study was obtained from the Human Research and Ethics Committee of JUTH.
| Results|| |
One hundred and fifty-five (14.8%) of the 1046 babies admitted in the neonatal unit during the period had congenital anomalies. Twenty-seven babies had CNS anomalies, giving a prevalence rate of 2.6%. Babies with CNS anomalies constituted 17.4% of the pediatric population (155 babies) that was admitted with congenital anomalies. There were 14 males and 13 females, with a male-to-female ratio of approximately 1:1. All 27 (100%) of the babies were born outside the teaching hospital, with 13 (48.2%) of them delivered at home. [Table 1] shows the types of CNS malformations and their ICD 10 version 2016 classification. Neural tube defects (NTDs) were the most common CNS malformations affecting 26 (96.3%) of the babies with CNS anomalies. Moreover, over 69.2% (18) of the NTDs were because of spina bifida. Other NTDs included encephalocele (7, 28%) and anencephaly (1, 3.7%). In 8 (44.4%) of the babies with spina bifida, the protruding sac was ruptured on presentation. Eight babies had the following other associated anomalies: 6 (22.2%) babies had talipes equinovarus and 2 (7.4%) babies had rectovaginal fistulae.
|Table 1: Pattern and classification of CNS congenital anomalies in the neonatal unit, JUTH, Jos|
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[Table 2] shows the trend in admission of babies with CNS and congenital anomalies in the neonatal unit over the period under review. Seventeen (63%) of the mothers resided in different parts of Plateau State, while 10 (37%) came from the neighboring states of Bauchi (4), Nassarawa (3), Kaduna (2), and Taraba (1).
|Table 2: Trend of admissions for babies with CNS anomalies and total congenital anomalies in the neonatal unit, JUTH|
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| Discussion|| |
The prevalence of CNS anomalies of 2.6% of the total admissions in our study was nearly double that observed in the previous study (1.6%) at the same hospital, which was obtained from the same neonatal unit almost two decades ago, and the 1.3% reported from a neonatal unit in Abbottabad, Pakistan. It is, however, lower than the 3.4% reported from Maiduguri in northeastern Nigeria. In contrast, a prevalence of 8.8% was reported from Tanzania. This difference may be due to the inclusion of infants up to 60 days of life in the Tanzanian study as opposed to the other studies that were restricted to neonates.
Comparable to our study, birth defects and CNS anomalies appear to be a global problem, although their incidence varies in developed and nondeveloped countries. A number of the studies quoted birth prevalence with varied numerators and denominators. For example, in the State of New York, USA, a survey of birth registry about two decades ago reported the prevalence of congenital anomalies for all races to be 4.1% of the total births, thereby contributing to about 20% of infant deaths in the USA. Moreover, CNS anomalies accounted for about 17.7% of the congenital anomalies. This is comparable to the 17.4% CNS anomalies observed in this study. However, the situation in the USA appears to have changed, because some studies have shown a decline in the prevalence of some CNS anomalies in the USA by up to 31% in some cases. Another study from three public referral hospitals in Honduras reported a 6-year (2010–2015) birth prevalence of CNS malformations at 13.9–31.1/10,000 live births. Similarly, a study from 29 provinces in China about two decades ago found the prevalence of CNS congenital malformations to be 37.22 per 10,000 births. Meanwhile, a study from a hospital in Saudi Arabia reported the incidence of congenital malformations to be 17.0/1000 live births, with CNS anomalies accounting for 48.8% of the total defects, which was almost triple that observed in this study. It is, therefore, important that every country and region determine the burden in their local environment and maintain a registry so that appropriate locally adapted control strategies can be developed. Additionally, there is a need for global control strategies.
The CNS malformations accounted for 17.4% of the total congenital anomalies seen in the unit within the study period, which was comparable to the 20% prevalence reported from Kharian, Pakistan. This figure is lower than the 26% prevalence observed in the previous study conducted at our center and the range of 24–31% obtained from other studies.,, Some authors, however, have reported a lower prevalence of 11% from eastern India. These different figures are in support of the fact that the epidemiology of congenital anomalies varies among different regions and even in the same region over time, underscoring the necessity for surveillance, which should guide control strategies.
NTDs was the most common CNS malformation, contributing up to 96% in this study. Among the NTDs, myelomeningocele was the most common abnormality. A similar observation was noted by Binitie in a previous study of children with CNS malformation treated in the neurosurgical unit of the same hospital some two decades ago. Other studies from Nigeria also reported similar findings.,,,,, The pattern has not changed much over the years. A recent meta-analysis in 2016 on the global birth prevalence of spina bifida showed that spina bifida is significantly more common in regions of the world where there was no government legislation regulating the full coverage of folic acid fortification in the food supply (i.e., Asia and Europe). Mandatory folic acid fortification has been shown to result in a lower prevalence of spina bifida. Data from Africa were, however, scarce. In view of the results from this study and these other studies from Nigeria and the neighboring region, the situation may not be different in the whole of Africa. NTDs are potentially preventable., Government legislation on food fortification may be the way forward for the primary prevention of this disorder in our environment, which is likely to reach all women in spite of whether or when they attend antenatal care, especially in view of the early timing of the defect. The challenge that may be faced in Nigeria may be with regard to deciding which staple food(s) to fortify in view of multiple ethnicities and their various foods, especially in rural areas. Flour fortification like in other countries may be a good starting point, but this needs to be later expanded to local staple foods. Alternatively, other food products such as sugar or salt, which are already being fortified and are more universally consumed, may be considered. This however is not without its challenges such as cost and the risk of increased consumption. Folic acid supplementation may be made available to adolescent girls via the school health program, which may be another avenue for the prevention of NTDs in our setting.Another finding of this study was that all of the babies admitted with CNS anomalies in the unit were born outside the teaching hospital, in keeping with the findings of other studies in Nigeria., This implies that the control strategies have to be expanded beyond the teaching hospitals. Furthermore, almost half of the babies were delivered at home, which may have contributed to the rupture of the protruding sac in almost half of the babies with spina bifida. A study of congenital abnormalities from Abidjan similarly reported that 44% of such babies had home deliveries. Home delivery predisposes these babies to infections, rupture, and other risks, which may increase morbidity and mortality. Parents, therefore, need to be educated on the importance of hospital delivery.
Our study is limited by the fact that it is hospital based and, therefore, the findings may not be generalizable. However, it provides data that will be useful in management policy formulation. Furthermore, it will provide data for health system planning to provide adequate services to manage such babies.
| Conclusion|| |
The prevalence of CNS anomalies among the admitted neonates in the JUTH is high. NTDs were the most common CNS anomalies, with myelomeningocele being the most common disorder.
The provision of adequate neurosurgical services and a well-equipped neonatal unit is advocated, while the prevention of NTDs is encouraged in the long run. In addition, parents should be educated on the importance of hospital delivery to decrease morbidity and mortality from CNS anomalies in particular, and other neonatal conditions in general.
We acknowledge the help rendered by Dr. Irozuru and the record staff for assisting with the collection of data.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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