Neural tube defects, maternal cohorts, and age: a pointer to aetiology (original) (raw)
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High incidence of neural tube defects in Bursa, Turkey
Paediatric and Perinatal Epidemiology, 1988
Summary. A radiological survey of 1204 members of the population of Bursa revealed a high prevalence of spina bifida occulta (16.3%). Hospital deliveries in the area also showed a high incidence of anencephalus and spina bifida aperta (5.8 per 1000 total births) in the years 1983 to 1986. In the first 6 months of 1987, however, there was an increase in incidence to 20 per 1000 births (P<0.01). The possibility is raised that the Chernobyl disaster of May 1986 might have resulted in the elevation of the rate in an already susceptible population.
Survival and disability in a cohort of neural tube defect births in Dublin, Ireland
Birth Defects Research Part A-clinical and Molecular Teratology, 2008
BACKGROUND:Neural tube defects (NTDs) are a major cause of death and disability. Periconceptional folic acid prevents up to 70% of these malformations but public health campaigns to increase use of supplements have had disappointing results: The proposed mandatory fortification of bread products in Ireland has raised concerns about possible side effects. We examined data collected on a cohort of children born with NTDs in an era before fortification/supplementation to illustrate the serious consequences in terms of survival and disability.Neural tube defects (NTDs) are a major cause of death and disability. Periconceptional folic acid prevents up to 70% of these malformations but public health campaigns to increase use of supplements have had disappointing results: The proposed mandatory fortification of bread products in Ireland has raised concerns about possible side effects. We examined data collected on a cohort of children born with NTDs in an era before fortification/supplementation to illustrate the serious consequences in terms of survival and disability.METHODS:All 623 infants born with NTDs in the Dublin area between 1976 and 1987 were included. Information was collected on mortality and length of survival for those who died, and for those who survived at least 5 years, interview-based data were collected on age, place of residence, prevalence of hydrocephalus, degree of disability, schooling, and IQ.All 623 infants born with NTDs in the Dublin area between 1976 and 1987 were included. Information was collected on mortality and length of survival for those who died, and for those who survived at least 5 years, interview-based data were collected on age, place of residence, prevalence of hydrocephalus, degree of disability, schooling, and IQ.RESULTS:Seventy-four births (12%) were stillborn. Of the livebirths only 41% were alive at 5 years. Factors associated with mortality were type of lesion, level of lesion, presence of other defects, hydrocephalus, year of birth, and gestation. Of the children who survived to 5 years or more, 75% had a disability and 56% were severely disabled. Type of lesion and level of lesion influenced disability risk.Of the survivors, 51% of children had mobility limitations, 59% were incontinent, 42% had hydrocephalus, and 17% had intellectual disability.Seventy-four births (12%) were stillborn. Of the livebirths only 41% were alive at 5 years. Factors associated with mortality were type of lesion, level of lesion, presence of other defects, hydrocephalus, year of birth, and gestation. Of the children who survived to 5 years or more, 75% had a disability and 56% were severely disabled. Type of lesion and level of lesion influenced disability risk.Of the survivors, 51% of children had mobility limitations, 59% were incontinent, 42% had hydrocephalus, and 17% had intellectual disability.CONCLUSIONS:These findings illustrate the devastating consequences of NTDs and underline the importance of effective intervention programs with folic acid for prevention. Birth Defects Research (Part A) 2008. © 2008 Wiley-Liss, Inc.These findings illustrate the devastating consequences of NTDs and underline the importance of effective intervention programs with folic acid for prevention. Birth Defects Research (Part A) 2008. © 2008 Wiley-Liss, Inc.
Introduction: Several congenital malformations affect developing fetuses, among which Neural tube defect (NTD) is most common. Folic acid supplementation brought decline in the incidence of NTDs. The present study aims at finding the incidence of NTDs in a tertiary care hospital and compares the results with the similar Indian studies published earlier. Materials and Methods: The study was done at Chettinad Hospital & Research Institute (CHRI), Kelambakkam. The total number of deliveries was recorded for a period of five years from 2009 to 2013. Fetuses which were still born with neural defect were collected and observed in detail externally for the sex, type of NTD and other associated anomalies. Indian studies published between 1987 and 2014 reporting the incidence of NTDs among the births occurred were retrieved from the Internet and their various observations were used for comparison. R esults: The number of deliveries conducted between 2009 and 2013 at CHRI was 3220. Of these, babies born with NTDs were nine (5 males and 4 females). The incidence of fetuses with meroanencephaly, holoanencephaly, craniorachischisis, encephalocele and myelocele were 0.62, 0.62, 0.93, 0.31 and 0.31 per 1000 births respectively. Overall incidence of NTDs in the present study was 2.79/1000 births. Fetuses with NTDs also had the following anomalies – Club foot, cleft lip and palate and exomphalos. C onclusion: Comparing the results with the previous studies it is clearly evident that the incidence of NTDs have significantly reduced from 11.42/1000 births to 2.79/1000 births. In most of the previous studies NTDs had a female preponderance whereas present study has a male preponderance.In older studies, spina bifida was the most common NTDs followed by anencephaly. But in the present study anencephaly was the common NTD than spina bifida. Incidence of NTDs has reduced due to various reasons like prenatal screening for fetal anomalies and folic acid supplementation.
Incidence of neural tube defects in Ontario, 1986-1999
CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 2002
Prenatal screening and the promotion of folic acid intake could affect the incidence of neural tube defects (NTDs). We examined trends in the total NTD incidence, as detected in live births, stillbirths and therapeutic abortions, from 1986 to 1999 in Ontario. To capture cases of NTDs we used data from the Canadian Congenital Anomalies Surveillance System and hospital data on therapeutic abortions. We calculated the total incidence of NTDs by combining the numbers of NTDs occurring in live births, stillbirths and therapeutic abortions. The total NTD incidence rate increased from 11.7 per 10,000 pregnancies in 1986 to 16.2 per 10,000 in 1995, and it subsequently decreased to 8.6 per 10,000 by 1999. The NTD birth rate (live births and stillbirths) decreased from 10.6 per 10,000 births in 1986 to 5.3 per 10,000 in 1999. The rate of therapeutic abortions with an NTD or hydrocephalus rose from 17.5 per 10,000 abortions in 1986 to 50.7 per 10,000 in 1995 and fell to 28.7 per 10,000 abortio...
Neural tube defects in New South Wales, Australia
Journal of Medical Genetics, 1978
Cases of spina bifida cystica, encephalocele, and anencephaly occurring over a 9-year period, 1965 to 1973, in New South Wales, Australia, were identified. A low frequency of 1 1 for spina bifida and encephalocele (SB) and 0-9 for anencephaly (A) was found. Secular trends parallel to those observed in the northern hemisphere were noted. Detailed analysis of 1575 cases showed an excess of births in spring, corresponding with conception in the summer months, after correction for shorter gestation in anencephalus, which varies from the peak of spring conceptions observed in British studies. An excess of female cases for each abnormality and a social class effect with a deficit of cases in classes I and II and an excess in classes IV and V and ex-nuptial births were apparent. The first birth rank for younger mothers did not show a significantly increased risk; however, the effect of high birth rank and older maternal age was more significant. Migration studies showed that in migrating from areas of high incidence these parents maintain a higher risk than the Australian population. The highest risk group was that in which both parents were born in the UK, and the next highest that in which an English-born mother was married to an Australian father. Mothers from Malta, and either or both parents from Lebanon, Egypt, and Austria were also at high risk. Part-aboriginal children had a higher risk rate for ASB than white Australian children. The proportion of older sibs affected was 4.12% of sibs of both sexes of an index case of spina bifida, and 3.19% of an index case of anencephaly. The abnormalities alternate or recur in families. An increased perinatal mortality rate in sibs was shown. Twin studies showed a higher concordance rate for monochorionic pairs. A sequential interaction in an excess of opposite sex sib before an index case was apparent. The results of this study support a multifactorial aetiology for ASB resulting from genetic environmental interaction. New South Wales is the eastern coastal state of Australia, with an area of 309 433 square miles and a population of 4 640 800 at the 1971 Census. The continent is geographically isolated with a large migrant population, seasonal reversal, and a hot climate. Methods Records for 1965 to 1967 were incomplete; further cases were identified by examination of labour ward There were 712 cases of anencephalus identified from registers in obstetric hospitals and by letter to country stillbirth and neonatal death registrations at the NSW centres. Registrar General's Department International Classifi-One hundred and forty-two cases of encephalocele cation of Disease (ICD) 7409. Cases registered as (ICD 7430), and 721 of meningomyelocele (7410, 'monster' and 'multiple congenital abnormalities' were 7419), stillborn, and registered as perinatal deaths or excluded unless definite anatomical evidence of neural deaths aged 1 month to 9 years from 1 January 1965 tube malformation could be confirmed. to 30 December 1975, were obtained from the Bureau of Census and Statistics and the Registrar General's
Decline in Prevalence of Neural Tube Defects in a High-Risk Region of the United States
Pediatrics, 2000
Objectives. To conduct surveillance for neural tube defects (NTDs) in a high-risk region of the United States and to prevent occurrence and recurrence of NTDs through the periconceptional use of folic acid supplements. Design. Active and passive methods were used for surveillance of NTD-affected pregnancies and births during a 6-year period (October 1992-September 1998). Individual genetic counseling was used to prevent NTD recurrences and a public awareness campaign was used to reduce NTD occurrences. Setting. State of South Carolina. Patients. All cases of spina bifida, anencephaly, and encephalocele identified among 278 122 live births and fetal deaths to South Carolina residents during 1992-1998 were included. Main Outcome Measure. Changes in occurrence and recurrence rates during a 6-year period. Results. Over the 6 years of surveillance, the prevalence rates for NTDs decreased from 1.89 to .95 cases per 1000 live births and fetal deaths. The prevalence decrease is explained primarily by a decrease in cases of spina bifida. Isolated NTDs accounted for 297/360 (82%) NTDs and 63/360 (18%) had at least 1 other structural anomaly. Females predominated among isolated NTDs but the sex distribution was equal among NTD cases with other anomalies. Prevalence rates for whites (1.48 cases per 1000 live births and fetal deaths) were higher than rates for blacks (.87 cases per 1000 live births and fetal deaths). There were no NTD recurrences in 113 subsequent pregnancies to mothers of infants with isolated NTDs who took periconceptional folic acid. The rate of periconceptional folic acid use among women of childbearing years increased from 8% to 35% during the 6-year project period. Conclusion. The prevalence of NTDs in a high-risk region has declined coincident with the increased periconceptional use of folic acid supplements among women of childbearing age. Pediatrics 2000;106:677-683; neural tube defects, high-risk region, birth defects, folic acid, spina bifida, anencephaly, encephalocele.
Teratology, 1991
In the period 1980-1987, neural tube defects were two to three times more prevalent in populations covered by EUROCAT registries in the United Kingdom and Ireland (UKI) than in Continental Europe and Malta (CEM). 1864 NTD cases in a total population of 580,000 births in UKI and 455 cases in a population of 380,000 births in CEM were analysed to find if there were differences in the ratio of prevalence rates between UKI and CEM according to site of the defect and association with non-central nervous system (CNS) anomalies. The prevalence rate ratio was high for anencephaly with accompanying spina bifida, iniencephaly, and upper spina bifida, and low for encephalocele, lower spina bifida, and anencephaly without other neural tube defects. There was a greater female excess for anencephaly with accompanying spina bifida, iniencephaly, and upper spina bifida than for other defects in both geographic areas. There was a female excess for encephalocele in UKI but a male excess in CEM. Certain sites (anencephaly with accompanying spina bifida, iniencephaly, and encephalocele) were more likely to have accompanying non-CNS anomalies. The prevalence rate ratio of multiply malformed NTD was in general lower than for isolated NTD but showed the same pattern by site. The prevalence rate ratio was high for multiply malformed anencephaly with accompanying spina bifida, iniencephaly, and upper spina bifida. The sex ratio was similar between isolated and multiply malformed cases when site of the defect is taken into account. It is concluded that the geographic prevalence pattern and sex ratio differ according to site of NTD but do not differ substantially according to whether NTD is isolated or associated with non-CNS anomalies.
Date of conception and prevention of neural tube defects
Clinical Genetics, 2008
The authors studied the time of conception of 280 fetuses and liveborns with anencephaly or spina bifida seen in a French Canadian population during a period of six years. There is an evident seasonal variation in the conception of NTD fetuses. Using a wave statistical model applied to data recorded over a six year period the authors have rejected the "no variation between the six two-month intervals" hypothesis at a P I0.005 level. It is postulated that, in any vitamin intake or environment program to prevent NTD in families at risk, one must take into account the annual and seasonal variations, ethnic groups identity and the date of conception in the choice of control mothers.