A study on prevalence and pattern of clinically recognisable congenital malformations in babies born in a rural medical college hospital in West Bengal, India

Introduction: Congenital anomalies are a major cause of neonatal mortality and morbidity both in developed and developing countries. It accounts for 8-15% of perinatal deaths and 13-16% of neonatal deaths in India. Aims and Objective : This study was done to determine the proportion and changing pattern of congenital anomalies in live newborns and to study the associated maternal and perinatal risk factors. Materials and Method: This is a hospital based cross-sectional descriptive study and was conducted in Bankura Sammalini Medical College and Hospital, West Bengal India during the period July 2016 to December 2017. Results: During his period 31989 babies were born, of which 598 had congenital malformations, making the prevalence 1.86%. Distribution of malformation was predominant among males than in females (66.7 vs. 32.6%; p < 0.05). Discussion : The predominant system involved was musculo-skeletal system followed by cardiovascular and genitourinary system. Congenital anomalies were more likely associated with low birth weight, prematurity, multiparity, consanguinity and caesarean delivery. Various maternal risk factors were studied as well as the role of early preventive interventionalstrategies. Conclusion: Public awareness is to be created and early prenatal diagnosis and management of common anomalies is highly recommended.


Introduction
Congenital anomalies or birth defects are among the leading causes of infant mortality and morbidity around the world. The impact of congenital anomalies is particularly severe in middle-and low-income countries where health care resources are limited. The prevalence of congenital anomalies varies in different parts of the world, which could reflect different aetiological factors in different geographical regions.
It accounts for 8-15% perinatal deaths and 13-16% neonatal death in India. It is not only a leading cause of fetal loss but also contributes significantly to preterm birth, childhood and adult morbidity. According to World Health organisation (WHO) fact sheet of October 2012, congenital anomalies can be defined as structural or functional anomalies which are present at the time of By International convention frequency of congenital malformation is reported as prevalence rather than incidence, as congenital malformations are not newly arising disease in the usual sense; but rather disorders affecting a given population at a given moment of time (the time of birth). Prevalence of major malformation has been variously reported as 3-4% to 6-8% [4,5]. Congenital abnormalities play a major role in a morbidity and mortality of neonates and children [6].
Due to high cost of treatment and rehabilitation of these anomalies, early identification of causative and risk factors and early prevention is necessary where possible. In the tropical countries malnutrition and infection are main causes of infant morbidity and mortality while in temperate zones cancer, accidents and congenital abnormalities are the key causes of infant morbidity and mortality. Prevalence studies of congenital malformation are useful to establish baseline rates, to document changes over time and to identify clues to etiologic. They are also important for health service planning and evaluating antenatal screening in population with high risk. Such studies are important as those help to raise the awareness of surgical intervention and to emphasize the loss of babies with congenital malformation [7]. The present study was conducted with an intention to determine the prevalence of congenital malformation

Aims and Objectives
In developing countries like India the leading cause of neonatal mortality is sepsis and low birth weight with its complications; in the coming years owing to improved perinatal and neonatal care, mortality due to sepsis and low birth weight will be reduced significantly and congenital malformation may become a leading cause of neonatal mortality. The current study was carried with the objective to determine the overall prevalence and pattern ofclinically recognisable congenital malformation in live birth and the associated maternal and perinatal risk factors.

Material and Methods
Place and design of Study: This cross-sectional descriptive study was carried out in the Sick newborn Care Unit. (SNCU) of a rural Medical College Hospital in Bankura, West Bengal during the period of July 2016 to December 2017.
Inclusion and Exclusion criteria: All intramural babies born with congenital anomalies during this period were included in the study. All still born were excluded from this study.

Materials and Methods:
An interviewer administered questionnaire was used to collect information on sociodemographics and risk factors associated with congenital malformations. Face-to-face interviews with parents / caretakers of young infants were carried out. Physical examinations were performed on all newborns with clinically recognisable congenital malformation. Echocardiography, X-ray, cranial as well as abdominal ultrasonography was performed when indicated.
For each case, a detailed antenatal and maternal history including the age of the mothers, parity or the history of consanguinity were obtained by reviewing the maternal and labour ward records and by interviewing the parents.
A marriage has been considered consanguineous, when that is found to have occurred between a male and a female who are blood-related, e.g., between brother and sister, between 1 st cousins etc., Birth weights >2.5 kg were considered to be normal; whereas, birth weights <2.5 kg and <1.5 kg were termed as low birth weight (LBW) and very low birth weight (VLBW) respectively. Babies born at <37 completed weeks (i.e., <259 days), calculated from the 1 st day of last menstrual period, were considered as premature.
Data analysis: Data analysis was done using SPSS 13. Rates and proportions were calculated with 95% confidence intervals. The proportions were compared using standard T-test. Level of significance was set at P<0.05. Ethical approval of the study and consent to publish the clinical data derived from the study have been obtained from the Ethics Committee of BS Medical College, Bankura, West Bengal, India.

Results
During the study period, 32325 new borns were born in our institution out of which 31989 (97.7%) were live births and 765(2.3%) were stillborn. The number of babies with congenital malformations diagnosed at birth was 598 had congenital malformations, making the prevalence 1.86%. Among all the newborns, 182 babies were born of twin Pediatric Review: International Journal of Pediatric Research Available online at: www.pediatricreview.in 559|P a g e delivery, 13 of triplet delivery 8 out of 195 babies that were products of multiple gestations, had one or more congenital anomalies. Distribution of malformation was predominant among males than in females (66.7 vs. 32.6%; p < 0.05). The congenital anomalies affected significantly higher proportion of male babies 399 (2.11%) than their female counterparts195 (1.48%).   Mother less than 20 years has 1.95% babies with congenital anomalies whereas mothers between 20 and 30 years have maximum number of babies with congenital anomalies (87.2%). There was a history of oligohydramnios in 33 (5.5%) cases and polyhydramnios in 19(3.1%) cases. There was 13.2% mother with babies with congenital anomaly who had history of previous abortions; 19% where diabetic mothers Prematurity and LBW was found to have a higher risk of congenital anomalies. The occurrence was about 2 times more in case of preterm delivery as compared with the term ones, making it statistically significant. Mode of delivery was also associated with congenital anomaly and it was more in case of caesarean deliveries.
Pediatric Review: International Journal of Pediatric Research Available online at: www.pediatricreview.in 561|P a g e

Discussion
The pattern and prevalence of congenital anomalies may vary over time or with geographical location, reflecting a complex interaction of known and unknown genetic and environmental factors including sociocultural, racial and ethnic variables [8] with improved control of infections and nutritional deficiency diseases, congenital malformations have become important causes of perinatal mortality in developing countries like India [9].
In the present study, the prevalence of congenital malformations in the newborns were 1.86%, which is comparable with the earlier studies from India, which reported incidence of 2.72% and 1.9% [10]. There are other reports from different parts of the world representing different frequency of congenital malformations. [11,12]. Although we got nearly the same result as reported in other studies, [13]. The number of documented birth defects in infant is increasing antenatally and during neonatal period due to advanced diagnostic technology, especially USG and echocardiography. The prevalence of congenital anomaly would have been more than the present rate, if we could have included the abortions and stillbirths.
With regard to pattern of congenital anomalies in the study, the most common system involved was musculoskeletal system (38.2%), followed by cardiovascular system (10.86%), genitourinary (10.5%), gastro-intestinal tract (GIT) (5.81%), CNS (6.37%), skin (7.85%) etc., This was comparable with studies conducted by others (16,17) Some studies however recorded higher incidence of CNS malformations followed by GIT and musculoskeletal system, [14] whereas Suguna Bai et al [15] reported GI malformations as the most common one. More male babies with congenital anomalies than females were noted in the present study. Male preponderance was like the other studies [9,10].
Association of low birth weight with increased risk of congenital malformation was noted in this study which is in line with previous studies [18,19,20]. The prevalence of congenital malformations was higher in preterm babies as compared to full term neonates [21].
Earlier data showed a definite increase in prevalence of congenital malformation in babies born to consanguineous marriage [21]. 35 cases had a history of consanguinity in our study. This study has statistically shown that mothers, above 30 years of age are at a higher risk of producing malformed babies. Sagunabai et al [22,23] reported that mothers' age more than 35 years have a greater risk of giving birth to malformed babies whereas Datta et al [14] documented statistically insignificant association of increased maternal age and congenital malformation.
Congenital talipes equinovarus (CTEV) was the commonest musculoskeletal abnormalities observed in our study. Among the genitourinary tract anomalies, undescended testis hypospadias, and polycystic kidney were the most prevalent lesions. In the central nervous system, the most common anomaly found was Hydrocephalus followed by Microcephaly, meningomyelocele and meningocele.
The present study helps us to know the pattern of congenital malformations prevalent in this part of rural West Bengal. Observations made in this study also help us to know the possible correlation of various factors as to the cause of congenital anomalies.
Most of the observations are comparable with the similar studies undertaken in other parts of the country.
However some of the observations differ which is expected given the nature of various studies like hospital versuscommunity based, differences ingeographical and environmental factors, differences in time period for follow up, criteriafor classification used etc.
Despite the high risk of recurrence of congenital malformations, there are no well-accepted preventive measures in developing countries like India. It indicates that strong preventive measures for congenital anomalies in this region are needed. Increasing awareness about maternal care during pregnancy, educational programs on congenital malformations and the consequences of consanguineous marriages need to be highlighted to decrease the incidence of congenital anomalies and their co morbidities Limitations-As it is a tertiary care hospital, prevalence calculated may be higher than the general population in this hospital-based study. Hence, the data cannot be projected to the general population, for which population-based studies are necessary. Secondly, we could not include the abortions and stillborns, because often the abnormalities are not obvious or visible externally. In those cases, a pathological autopsy is warranted and in most of the cases, parental consent is not available for pathological autopsy.