according to the world health organization ( who ) document of 1972 , the term congenital malformations should be confined to structural defects at birth . however , as per the more recent who fact - sheet of october 2012 , congenital anomalies can be defined as structural or functional anomalies , including metabolic disorders , which are present at the time of birth . congenital anomalies are an important cause of neonatal mortality both in developed and developing countries . it accounts for 8 - 15% of perinatal deaths and 13 - 16% of neonatal deaths in india . it is not only a leading cause of fetal loss , but also contributes significantly to preterm birth , childhood and adult morbidity along with considerable repercussion on the mothers and their families . this study was undertaken to determine the proportion and pattern of congenital anomalies in live newborns and to study the associated maternal and perinatal risk factors . this cross - sectional descriptive study was carried out in the neonatal care unit of a tertiary care hospital in kolkata during the period of august 2011 to july 2012 . diagnosis of congenital anomalies was based on clinical evaluation of newborn babies by the pediatrician and other appropriate investigations such as radiography , ultrasonography , echocardiography and chromosomal analysis etc . , system wise distribution of the anomalies was performed . 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 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 day of last menstrual period , were considered as premature . proportion was calculated and the association was tested with chi - square test and fishers exact test . during the study period , 12896 newborns were born in our institution ; of which 286 had congenital malformations , making the prevalence 2.22% . among all the newborns , 56 babies were born of twin delivery , three of triplet delivery and five of these 59 babies , that were products of multiple gestations , had one or more congenital anomalies . the congenital anomalies affected significantly higher proportion of male babies ( 2.9% ) than their female counterparts ( 1.5% ) . the predominant system involved was musculo - skeletal system ( 33.2% ) followed by gastro - intestinal ( gi ) system ( 15% ) and central nervous system ( cns ) ( 11.2% ) [ table 1 ] . talipes ( 17.1% ) was the most common anomaly seen in the musculoskeletal group and likewise cleft lip ( 6.6% ) and cleft palate ( 3.5% ) in gi system and meningomyeleceole ( 6.3% ) in cns . system wise distribution of congenital anomalies ( n=286 ) regarding the parity of the mothers , 9,185 were primiparas and rest 3,425 were multiparas . cases of congenital anomaly were found in 3.3% of multiparas , whereas in primiparas , the proportion was only 1.8% . it has been seen that more than half of the mothers were aged between 20 and 30 years ( 55.7% ) with only 10% of the mothers were over the age of 30 years . 5 mothers had a history of consanguinity and two of them showed some congenital anomaly ( 40% ) in their babies , whereas in non - consanguineous couples , the prevalence was only 2.2% . this percentage was about 18 times less than in consanguineous couples and was highly significant . the occurrence was about 4.5 times more in case of preterm delivery as compared with the term ones , making it statistically significant . mode of delivery was also significantly associated with congenital anomaly and it was more in case of cesarean deliveries [ table 2 ] . 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 socio - cultural , racial and ethnic variables . with improved control of infections and nutritional deficiency diseases , congenital malformations have become important causes of perinatal mortality in developing countries like india . in the present study , the prevalence of congenital malformations in the newborns were 2.22% , which is comparable with the earlier studies from india , which reported incidence of 2.72% and 1.9% . there are other reports from different parts of the world representing different frequency of congenital malformations . although we got nearly the same result as reported in other studies ,   the prevalence of congenital anomaly would have been more than the present rate , if we could have included the abortions and stillbirths . tertiary care hospital usually do not have definite catchment area and complicated cases are more commonly encountered . hence , prevalence calculated in this type of hospital - based study can not be projected to the total population . community based study should be ideal for true estimation of incidence of congenital anomalies in a population . with regard to pattern of congenital anomalies in the study , the most common system involved was musculoskeletal system ( 33.2% ) , followed by gastro - intestinal tract ( git ) ( 15% ) , cns ( 11.2% ) , genitourinary ( 10.5% ) , cardiovascular system ( 9.1% ) , skin ( 8.7% ) etc . some studies however recorded higher incidence of cns malformations followed by git and musculoskeletal system ,   whereas suguna bai et al . reported gi malformations as the most common one . it may be because of the fact that the females were afflicted with more lethal congenital malformations and could not survive to be born with signs of life . the incidence of congenital anomalies was significantly higher in preterm babies as compared with the full term babies , which is in conformity with the previous studies reported from this country . mode of delivery also showed a significant association with congenital anomalies in this study with cesarean section being more commonly associated than normal delivery . reported a higher incidence of malformation in the babies born to mothers aged over 35 years , whereas dutta et al . the relationship between maternal age and babies born with congenital malformations , in our study , revealed that a majority of malformed babies were born of mothers aged 20 - 29 years ; though , it was statistically insignificant . our result is consistent with this finding , which indicates a positive correlation between the birth order and the incidence of congenital anomalies . consanguineous marriages are reported to play a major role in the occurrence of congenital malformations . in the present study also , prevalence of malformed babies was more when born out of consanguineous marriages as seen in studies from kuwait , arab   and also india . despite the high risk of recurrence of congenital malformations , 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 comorbidities . as it is a tertiary care hospital or referral centre , prevalence calculated may be higher than the general population in this hospital - based study . hence , the data can not 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 . as it is a tertiary care hospital or referral centre , prevalence calculated may be higher than the general population in this hospital - based study . hence , the data can not 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 . this study has highlighted the prevalence and types of congenital anomalies seen in our locality . regular antenatal visits and prenatal diagnosis are recommended for prevention , early intervention and even planned termination , when needed .
background : congenital anomalies are a major cause of stillbirths and neonatal mortality . 
 the pattern and prevalence of congenital anomalies may vary over time or with geographical location.aims and objectives : the aim of this study is to determine the proportion and types of congenital anomalies in live newborns and to study maternal and perinatal risk factors.materials and methods : this cross - sectional descriptive study was carried out in the neonatal care unit of r. g. kar medical college and hospital during the period of september 2011 to august 2012 . 
 all the live born babies born in this hospital during this period were included . 
 the newborns were examined for the presence of congenital anomalies and mothers were interviewed for socio - demographic variables.results:during the study period , 12,896 babies were born , of which 286 had congenital malformations , making the prevalence 2.22% . 
 most of the women ( 55.7% ) belonged to the age group between 21 and 30 years . 
 congenital anomalies were seen more commonly ( 3.3% ) in the multiparas in comparison with primiparas ( 1.8% ) . 
 the predominant system involved was musculo - skeletal system ( 33.2% ) followed by gastro - intestinal ( gi ) system ( 15% ) . 
 talipes ( 17.1% ) was the most common one in musculoskeletal group and likewise cleft lip and cleft palate in gi system . 
 congenital anomalies were more likely to be associated with low birth weight , prematurity , multiparity , consanguinity and cesarean delivery.conclusion:public awareness about preventable risk factors is to be created and early prenatal diagnosis and management of common anomalies is strongly recommended .