Congenital heart disease is an important cause of infant mortality and disability. The frequency, spectrum and contributory risk factors for significant cardiovascular malformations among live-births was retrospectively evaluated at the Aga Khan University Hospital. Of a total of 8331 live births between July, 1987 and December, 1992 34 babies were diagnosed to have congenital heart disease in the neonatal period giving a prevalence of 4 per 1000 live births. Ventricular septal defects was the most common (n = 10, 29%) abnormality. Eight cases had associated chromosomal abnormality, the most common being Trisomy 21. Maternal abortions, still-births, consanguinity and diabetes mellitus were not found to be significant risk factors for congenital heart disease in this survey

Bhutta, Z A

Haleem, A A

Hassan, I

English

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eCommons@AKUDepartment of Paediatrics and Child Health Division of Woman and Child HealthMarch 1997Profile and risk factors for congenital heart diseaseI HassanAga Khan University, imran.hassan@aku.eduA A. HaleemAga Khan UniversityZ A. BhuttaAga Khan University, zulfiqar.bhutta@aku.eduFollow this and additional works at: https://ecommons.aku.edu/pakistan_fhs_mc_women_childhealth_paediatrPart of the Pediatrics CommonsRecommended CitationHassan, I., Haleem, A. A., Bhutta, Z. A. (1997). Profile and risk factors for congenital heart disease. Journal of Pakistan MedicalAssociation, 47(3), 78-81.Available at: https://ecommons.aku.edu/pakistan_fhs_mc_women_childhealth_paediatr/588Profile and Risk Factors for Congenital Heart DiseasePages with reference to book, From 78 To 81 Imran Hassan, Abdul Ahad Haleem, Zulfiqar Ahmed Bhutta ( Department of Paediatrics, The Aga Khan UniversityHospital, Karachi. ) Abstract Congenital heart disease is an important cause of infant mortality and disability. The frequency,spectrum and contributory risk factors for significant cardiovascular malformations among live-birthswas retrospectively evaluated at the Aga Khan University Hospital. Of a total of 8331 live birthsbetween July, 1987 and December, 1992 34babieswere diagnosed to have congenital heart diseasein theneonatalperiod giving a prevalence of 4 per 1000 live births. Ventricular septal defects was the mostcommon (n=10, 29%) abnormality. Eight cases had associated chromosomal abnormality, the mostcommon being Trisomy 21. Maternal abortions, still-births, consanguinity and diabetes mellitus werenot found to be significant risk factors for congenital heart disease in this survey (JPMA 47: 78,1997).Introduction Congenital heart disease (CHD) includes major structural malfonnations of the heart and/or majorvessels present at, or persisting abnormally after birth1. The prevalence of congenital heart disease(CHD) atbirthhasbeen relatively variable at 4.05 to 10.4 cases per 1000 live births in different surveysusing avariety of case discovery methods2-4, In a meta analysis using only cases “confinned” byautopsy, surgery, cardiac catheterization or echocardiography, the birth prevalence was nearly constantat approximately 4 per 1000 live births5.Despite the importance of CHD as a cause of infant mortality and disability, the exact etiology of theseanomalies remans mostly unknown6. Approximately 80-90% of these cases have a genetic-environmental interaction7, Classic Mendelian single gene defects account for about 3-5% andchromosomal defects for 5-8% cases of CHD. The most common defect is Trisomy 21, but Trisomy.13, Trisomy 18 and the 45X0 (Turners syndrome) can also be involved2-7. Pnmaiy environmentalfactors are the etiological cause in the remaining 2-3% cases7. These include the drug Thalidomide andrubella virus as the classical causes of CHD. As a result of cultural and religious factors not permittingautopsies, lack of population studies and limited resources very few reports on, CHD am available,from Asian and African countries including Pakistan. Yet it is important to find out the possible role ofvarious environmental and -genetic factors and to determine antenatal risk factors for CHD in ourpopulation. Similarly information on the prevalence and spectrum of CHD is necessary to developeffective paediatnc cardiology services for their management and treatment among Pakistani newborninfants.Methodology Retrospective analysis of all live births with CHD delivered at the Aga Khan University Hospitalbetween July, 1987 and December, 1992 were analysed and case control analysis done on CHD caseswithout chromosomal anomalies. All live births who during the neonatal period (initial hospitalizationand first postnatal visit, between 2 1-28 days of age) were clinically suspected to have CHD andsubsequently confirmed to have a significant cardiovascular malformation by echocardiography wereincluded. For each case, a control was identified as the next consecutive live birth without anycongenital malformation, matched for sex and weight. Premature infants with patent ductus arteriosus(PDA) were excluded from the study. Maternal and neonatal data was collected from the medical filesusing data extraction sheets. Data was analyzed using the statistical package for social sciences (SPSS)(Windows 6.1 1994 Chicago, USA). Umvariate methods were used forcalculationof odds ratio andcorresponding 96% confidence intervals and analysis of variance employing the two-tailed students t-test was used for evaluation of continuous data, Significance was set at 5%.Results A total of 34 new borns were diagnosed to have a significant congenital heart disease (CHD) during theneonatal period out of a total of 8331 live births. The prevalence of CHD in neonates was found to be 4per 1000 live births. The most common cardiovascular malformation detected was ventricular septaldefect(VSD) (n=10) followed by patent ductus arteriosus (PDA) (n=7) (Table I).There were 8 cases with chromosomal abnormalities, of which there were 7 cases of Trisomy 21 and 1ofTrisomy 18. Congenital rubella syndrome was the etiological cause in 2 cases, while in the remainingcases no definite etiology could be ascertained.Table II lists maternal risk factors and neonatal characteristics at birth for non-chromosomalcardiovascular malformations. No association of CHD was found with antenatal conditions such asabortions, still-births and maternal diabetes mellitus. Consanguinity was also not significantlyassociated with cardiovascular malformations. Affected newborn infants were morç likely to havelowerapgar scores of 1 and 5 minutes at birth however, there was no significant difference in the birthweight or gestation of the cases.Discussion The 4 per 1000 live birth prevalence of CHD among Pakistani newborn infants delivered at thishospital may be considered as an under-estimate of the actual figure. Firstly, many cases of CHD suchas those with minimal pulmonic stenosis or very small ventricular or atrial defects, may not becomeclinically evident in the neonatal period and therefore not be diagnosed by ordinary clinicalexamination2. Secondly only 40-50% of cases with CHD are diagnosed in the first week and 50-60% inthe first month after birth2. Since our study only included cases diagnosed during the neonatal period, asignificant number of cases which were diagnosed after the first month of birth, may have been missed.Another important factor in assessing the actual incidence of CHD is the fact that the incidence appearsto be approximately 5 times higher in still-born fetuses and abortuses than in live born infants2.However, the malformations in abortuses and intrauterine deaths are usually excluded from estimatesof prevalence of CHD in birth cohorts. By not considering the incidence of CHD in pre-natal deaths, inchildren with minimal CHD and those cases detected after the neonatal period, the potential importanceof genetic and chromosomal factors is grossly under-estimated. At the same time the importance ofenvironmental teratogens may be incorrectly assessed. However, even though this figure may be anunder-estimate of the actual incidence, it still represents a significant thsease’burden on the healthsystem.The spectrum and incidence of various cardiac lesions in this series is similar to what has been reportedelsewhere. According to Hoffman2 various social, religious and economic factors may prevent infantreceiving medical care and autopsies in several Asian and African countries. Therefore, serious cardiaclesions that cause early death and very mild lesions may be under represented in reported series fromthese countries. This may be one of the possible explanations for the difference in distribution ofvarious cardiac lesions in this study as compared to other reports. For example, the difference in theincidence of the most common lesion i.e., ventricular septal defect (VSD) between different reports, isbecause clinically inevident defects, only detectable by invasive methods, were included in several ofthe studies. Differences in the incidence rate of rare lesions can also be due to relatively small numbersof these lesions in each series. However, prevalence rate of CHD reported here is similar to the figurescited from a population based study of live births by Ferencz et al14, although lower figures have beenreported among a review of over a million live births fmm the New England Regional Infant CardiacProgramme15. The prevalence of cardiovascular malformations in Trisomy 21 is reported to be about40~50%8-10. While the incidence of Trisomy 21 in reported series of children with CHD ranged from3.2 to 10.4%, none of them mentioned maternal age, in any detail2. In this study of live births withCHD, 20% of the cases had Trisomy 21, whereas the proportion of mothers older than 35 years of agewas 6% of the total maternal population. It is therefore difficult to attribute the greater proportion ofcases with CHD due to Trisomy 21 in this sample, to agreater number of elderly mothers ortoalternative undetermined factors.In this study certain maternal conditions of the cases without chromosomal abnormalities during theprevious and current pregnancies were investigated to evaluate their association with CHD. Of thesefactors maternal abortions, still-births, consanguinity and maternal diabetes inellitus16 were notassociated with a significant risk of CHD. However, newborns with CHD were overall found to bemore depressed at birth in our study in comparison with controls. Several other workers have alsofailed to identify any clear etiological factors for CHD17. The intake of drugs during early pregnancy ishazardous because they are responsible for 1.5% of all congenital anomalies and most drugs have notbeen tested in humans5. Known cardiogenic teratogens include lithium, hydantoin, retinoic acid,amphetamines and maternal hormonal therapy5. Several reports have suggested that amphetamines andsalicylate intakes could also cause cardiovascular malformations15,16. Maternal drug intake could notbe ascertained as a possible risk factor in this series because of incomplete documentation in themedical record. It is important to monitor and document all maternal drug intake during the antenatalperiod and to avoid unnecessary use of drugs, especially during the first trimester. This survey from awell defined obstetric population with neonatal follow-up suggests that CHD represents a significantburden of congenital malformations. The present data does represent some differences from the patternof congenital heart disease among referred children in other series fmrn Pakistan, which containedmostly older children18,19. Thus rates of PDA are proportionately higher in this series than tetralogy ofFallot. Considering the additional children who acquire heart disease from rheumatic fever each year,these data represent a substantial burden of heart disease in the paediatric age group. This has importantimplications in the future development of paediatric cardiac services including the training ofpediatricians inPakistan.It is also essential to carry out further multi-center and population basedstudies to determine and validate various maternal and neonatal risk factors for CHD in Pakistanipopulation at large.References 1. Hayward, R. and Swanton, H. Congenital cardiovascular abnormalities. Br. J. Hosp. Med..1981;43:211-219.2. Hoffman, J.I.E. Congenital heart disease: Incidence and inheritance. Pediatr. Clin.North Am.,1990;37:25-43.3. Mayberry, J.C., William, A. S. and Stanley, J.G. Increased birth prevalence of cardiac defects inYuma, Arizona. Am. 3. Cardiol., 1990;16:1696-1700.4. Sadiq, M. and Silove, E.D. A higher prevalence of congenital heart disease in U.K. immigrants ofIndian subcontinent; implication in development of pediatriccardiacservices in Pakistan. Pak. Pediatr,J., 1994; 18:153-159.5. Ferencz, C., Neil, C.A., Boughman, J.A. et al. Congenital cardiovascular malformations associatedwith chromosome abnormalities. An Epidemiologic study. 3. Pediatr. 1989;114:79- 86,6. Chandramouli, B. The neonate with congenital heart disease: Diagnosis and management. IndianJ.Pediatr., 1991;58:453-469.7. Tikkanen, J. and Heinonen, OP. Congenital heart disease in the offspring and maternal habits andhome exposures during pregnancy. Teratology, 1992,46:447454.8. Hoe, TS., Chan, K.C. and Boo, N.Y. Cardiovascular malformations in Malaysian neonates withDown’s syndrome. Singapore Med. J., 1990;31:474-476.9. Clark, SB. Congenital cardiovascular defects in infants with Down’s syndrome (Commentary).Pediatr.. Rev., 1989;11:99-100.10. Hoe, T. S., Boo, N.Y. and Clyde, MM. Incidence ofDown’s syndrome in a large Malaysianmaternity hospital over an 18, month period. Singapore Med. J., 1989;30:24.6-248.11. Singh, M. and Sharma, N.K. Spectrum of congenital malformation in the newbprn. Indian 3.Pediatr., 1980;4:239-244.12. Hegazy, SI., Al-Beyari, T.H., Al-Amari, A.H. et al. Congenital malformations in primary health carein Al Qassini region. Ann. Saudi Med., 1995;15:48-53.13. Thein M.M., Koh, D., Tan, K.L. et al. Descriptive profile of birth defects among live births inSingapore. Teratology, 1992;4.6:277-284.14. Ferencz, C., Rulein, J.D., MeCarter, R.J, et al. Cardiac and non- cardiac malformations:Observations in a population based study. Teratology, 1987;35:367-78.15. Fyler, D.C., Buckley, L.P.,Hellenbrand, W. et al. Report of the New England Regional InfantCardiac Program. Pediatrics, 1980;65(Suppl):377-461.16. Chung, CS. and Myrianthopoulos, NC. Factors affecting risks of congenital malformations. 1-Analysis of epidemiologic features in congenital malformations: Report from the collaborativeperinatal project. Birth Defects, 1975;11:1-22.17. Pycritz, RE. and Murphy, E.A. Genetics and congenital heart disease: Perspectives and prospective.J. Am. CoIl. Cardiol., 1989; 13:1458-68.18. Rahirntoola, R.J., Majid, I., Shafqat, H. et al. Congenital heartdisease in children visiting JPMC.Pak. Heart 3., 1980; 13:21.19. Aziz, K. Incidence of heart disease in children at the National Institute of Cardiovascular Diseasesin children. Karachi Shakoorsons, 1991. pp. 1-5.

Profile and risk factors for congenital heart disease

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Profile and risk factors for congenital heart disease

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