The range of neural tube defects in southern India

Understanding the Mothers of Children with Spina Bifida and Hydrocephalus in Tanzania

OBJECTIVE

To identify if there are cultural, medical, educational, economic, nutritional and geographic barriers to the prevention and treatment of spina bifida and hydrocephalus.

METHODS

The mothers of infants with spina bifida and hydrocephalus admitted to Muhimbilli Orthopaedic Institute, Dar Es Salaam, Tanzania, between 2013 and 2014 were asked to complete a questionnaire. A total of 299 infants were identified: 65 with myelomeningoceles, 19 with encephaloceles, and 215 with isolated hydrocephalus. The questionnaire was completed by 294 of the mothers.

RESULTS

There was a high variation in the geographic origin of the mothers. Approximately 85% traveled from outside of Dar Es Salaam. The mean age was 29 (15-45) years old with a parity of 3 (1-10). The rates of consanguinity, obesity, antiepileptic medication, HIV seropositivity, and family history were 2%, 13%, 0%, 2%, and 2%, respectively. A maize-based diet was found in 84%, and only 3% of woman took folic acid supplementation, despite 61% of mothers stating that they wished to conceive another baby. Unemployment was high (77%), a low level of education was common (76% not attended any school or obtaining a primary level only), and 20% were single mothers. Hospital only was the preferred method of treatment for 94% of the mothers, and 85% of the babies were born in a hospital.

CONCLUSIONS

Our study highlights some of the cultural, educational, geographic, nutritional, and economic difficulties in the prevention and management of spina bifida and hydrocephalus in Tanzania.

Folic acid, dietary habits, and homocysteine levels in relation to neural tube defects: A case-control study in North India

PURPOSE

The present study attempts to understand the complex contribution of biochemical (plasma homocysteine) and nutritional parameters (dietary pattern and folate supplementation) to the neural tube defects (NTDs) affected pregnancies and controls in North Indian population.

METHODS

Case-control study design was adopted to assess the role of folic acid, dietary habits, and homocysteine in relation to NTD births. The subjects comprised of 130 mothers of affected children (cases) and 233 mothers of healthy children (controls), who were either carrying NTD fetus or gave birth to NTD child.

RESULTS

The mean homocysteine levels were elevated in cases (15.71 ± 8.35 μmol/L) as compared to controls (12.87 ± 5.95 μmol/L) but were lower among the non-vergetarians (13.55 ± 6.64 μmol/L) than the vegetarians (14.78 ± 7.93 μmol/L). Vegetarian dietary habit increased the NTD risk by 1.6 fold (95% CI = 1.0-2.7) while folic acid supplementation demonstrated a protective effect for conceptions (OR = 0.59; 95% CI = 0.3-0.9). Consumption of folic acid with non-vegetarian diet witnessed lowering of homocysteine in cases (12.88 ± 6.81 μmol/L) and in controls (11.85 ± 5.54 μmol/L), with an odds ratio depicting a 3.1 fold risk for consuming vegetarian diet without folic acid supplementation during the peri-conceptional period.

CONCLUSION

It is suggested that plasma hyperhomocysteinemia bears negative impact on child-bearing women group, of north Indian ancestry, in modulating the risk of NTDs. Efforts should be made to enhance awareness regarding folic acid and vitamin B12 (non-vegetarian diet) supplementations alongwith proper nutritional intake among women, especially those consuming vegetarian diet to control homocysteine levels in order to reduce the risk of NTDs.

Evidence for potential underestimation of clinical folate deficiency in resource-limited countries using blood tests

Although a low serum folate concentration is a useful biomarker of pure folate deficiency, the presence of vitamin B12 deficiency or hemolysis or both in individuals with low folate status predictably raises serum folate levels. Therefore, in resource-limited settings where dietary folate deficiency can coexist with vitamin B12 deficiency or malaria or both, the serum folate concentration can range from normal to high, leading to serious underestimation of tissue folate status. This review traces the genesis of an inappropriate overreliance on the serum folate concentration to rule out folate deficiency in vulnerable populations of women and children. Of significance, without due consideration of a chronically inadequate dietary folate intake, authors of influential studies have likely wrongly judged these populations to have an adequate folate status. Through repetition, this error has led to a dangerous entry into the contemporary medical literature that folate deficiency is rare in women and children. As a consequence, many millions of under-resourced women and children with mild to moderate tissue folate deficiency may have been deprived of folate replacement. This review uses historical documents to challenge earlier conclusions and re-emphasizes the need for contextual integration of clinical information in resource-limited settings.

Epidemiology of the neural tube defects in Kashmir Valley

Introduction/Background:

Neural tube defects (NTD) are the most common congenital malformations affecting the brain and spinal cord and have a multifactorial etiology. Genetic and environmental factors have been found to cause these defects, both individually and in combination.

Aims and Objectives:

The aim of this study was to determine the incidence, types, demographics, risk factors, and other associated anomalies relevant to NTDs in Kashmir Valley.

Materials and Methods:

A 2-year hospital-based prospective study was carried out from November 2013 to October 2015. A detailed history of the mother was taken along with detailed clinical examination of neonate including measurement of head circumference and checking the status of fontanella, whether - lax/full/bulging/or tense, type of NTD. Investigations that were done included were X-ray skull: Anteroposterior (AP) and lateral, X-ray spine: AP and lateral, ultrasonography abdomen, magnetic resonance imaging: Spine and brain.

Results:

The total number of babies with NTD's was 125 with an overall incidence of 0.503. District Kupwara was having the highest incidence (1.047) and district Srinagar the lowest incidence of NTD's (0.197). The majority of NTD's (116 cases, 92.8%) were found in the rural areas. Among the different types of NTD's, spina bifida had an incidence of 0.342 (85 cases, 68%), and anencephaly had an incidence of 0.113 (28 cases, 22.4%). There was a slight preponderance of females over males with NTD's. There were70 females (56%) and 55 males (44%) respectively with a male:female ratio of 0.8:1.

Conclusions:

The incidence rates of NTDs are very high for Kashmir Valley. Geographical distribution of NTDs at this place confirms a relationship between the socioeconomic status, educational status, maternal age and environmental factors for the development of an NTD. The results of this study point to the importance establishing a health policy to prevent NTDs in Kashmir Valley.

Epidemiology of the neural tube defects in Kashmir Valley

BACKGROUND

Neural tube defects (NTDs) are the most common congenital malformations affecting the brain and spinal cord and have a multifactorial etiology. Genetic and environmental factors have been found to cause these defects, both individually and in combination.

METHODS

A 2-year hospital-based prospective study was carried out from November 2013 to October 2015 to determine the incidence, types, demographics, risk factors, and other associated anamolies relevant to NTDs in Kashmir Valley. A detailed history of the mother was taken along with detailed clinical examination of neonate including measurement of head circumference and checking the status of fontanella, whether lax/full/bulging/or tense, type of NTD. Investigations that were done included were X-ray skull: Anterior-posterior (AP) and lateral, X-ray spine: AP and lateral, ultrasonography abdomen, magnetic resonance imaging: Spine and brain.

RESULTS

The total number of babies with NTD's was 125 with an overall incidence of 0.503. Kupwara district was having the highest incidence (1.047) and Srinagar district the lowest incidence of NTD's (0.197). Majority of NTD's (116 cases, 92.8%) were found in the rural areas. Among the different types of NTD's, spina bifida had an incidence of 0.342 (85 cases, 68%) and anencephaly had an incidence of 0.113 (28 cases, 22.4%). There was a slight preponderance of females over males with NTD's. There were 70 females (56%) and 55 males (44%), respectively, with a male: female ratio of 0.8:1.

CONCLUSIONS

The incidence rates of NTDs is very high for Kashmir Valley. Geographical distribution of NTDs at this place confirms a relationship between the socioeconomic status, educational status, maternal too young or advanced age, and environmental factors for the development of a NTD. The results of this study point to the importance establishing a health policy to prevent NTD in Kashmir Valley.

Global Birth Prevalence of Spina Bifida by Folic Acid Fortification Status: A Systematic Review and Meta-Analysis

BACKGROUND

Birth defects remain a significant source of worldwide morbidity and mortality. Strong scientific evidence shows that folic acid fortification of a region's food supply leads to a decrease in spina bifida (a birth defect of the spine). Still, many countries around the world have yet to approve mandatory fortification through government legislation.

OBJECTIVES

We sought to perform a systematic review and meta-analysis of period prevalence of spina bifida by folic acid fortification status, geographic region, and study population.

SEARCH METHODS

An expert research librarian used terms related to neural tube defects and epidemiology from primary research from 1985 to 2010 to search in EMBASE and MEDLINE. We searched the reference lists of included articles and key review articles identified by experts.

SELECTION CRITERIA

Inclusion criteria included studies in English or French reporting on prevalence published between January 1985 and December 2010 that (1) were primary research, (2) were population-based, and (3) reported a point or period prevalence estimate of spina bifida (i.e., prevalence estimate with confidence intervals or case numerator and population denominator). Two independent reviewers screened titles and abstracts for eligible articles, then 2 authors screened full texts in duplicate for final inclusion. Disagreements were resolved through consensus or a third party.

DATA COLLECTION AND ANALYSIS

We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses, or PRISMA, abstracting data related to case ascertainment, study population, folic acid fortification status, geographic region, and prevalence estimate independently and in duplicate. We extracted overall data and any subgroups reported by age, gender, time period, or type of spina bifida. We classified each period prevalence estimate as "mandatory" or "voluntary" folic acid fortification according to each country's folic acid fortification status at the time data were collected (as determined by a well-recognized fortification monitoring body, Food Fortification Initiative). We determined study quality on the basis of sample representativeness, standardization of data collection and birth defect assessment, and statistical analyses. We analyzed study-level period prevalence estimates by using a random effects model (α level of < 0.05) for all meta-analyses. We stratified pooled period prevalence estimates by birth population, fortification status, and continent.

RESULTS

Of 4078 studies identified, we included 179 studies in the systematic review and 123 in a meta-analysis. In studies of live births (LBs) alone, period prevalences of spina bifida were (1) lower in geographical regions with mandatory (33.86 per 100,000 LBs) versus voluntary (48.35 per 100,000 LBs) folic acid fortification, and (2) lower in studies of LBs, stillbirths, and terminations of pregnancy in regions with mandatory (35.22 per 100,000 LBs) versus voluntary (52.29 per 100,000 LBs) fortification. In LBs, stillbirths, and terminations of pregnancy studies, the lowest pooled prevalence estimate was in North America (38.70 per 100,000). Case ascertainment, surveillance methods, and reporting varied across these population-based studies.

CONCLUSIONS

Mandatory legislation enforcing folic acid fortification of the food supply lags behind the evidence, particularly in Asian and European countries. This extensive literature review shows that spina bifida is significantly more common in world regions without government legislation regulating full-coverage folic acid fortification of the food supply (i.e., Asia, Europe) and that mandatory folic acid fortification resulted in a lower prevalence of spina bifida regardless of the type of birth cohort. African data were scarce, but needed, as many African nations are beginning to adopt folic acid legislation.

A Study on The Incidence of Neural Tube Defects in A Tertiary Care Hospital Over A Period of Five Years

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.

RESULTS

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.

CONCLUSION

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.

Systematic review of birth prevalence of neural tube defects in India

BACKGROUND

Neural tube defects are one of the most prevalent congenital anomalies. Data on the total birth prevalence, live birth and stillbirth prevalence of neural tube defects in India are lacking. The objective of this study is to conduct a systematic review of birth prevalence of neural tube defects in India and compare it with existing estimates.

METHODS

A PubMed search identified 463 articles, of which 19 articles were eligible for inclusion in the review. Meta-analysis was used to estimate the overall birth prevalence of neural tube defects and to investigate the variation among studies identified by this review.

RESULTS

The 19 articles reported a total of 308,387 births, among which 1310 cases of neural tube defects were reported, giving an overall birth prevalence of 4.1 per 1000 (95% confidence interval [CI], 3.1-5.4). The live birth and stillbirth prevalence of neural tube defects was 1.3 per 1000 births (95% CI, 0.9-1.8) and 1.7 per 1000 births (95% CI, 0.7-4.0), respectively. Among the neural tube defects, the reported prevalence of anencephaly was highest at 2.1 per 1000 births (95% CI, 1.6-2.8) followed by spina bifida at 1.9 per 1000 births (95% CI, 1.4-2.7).

CONCLUSION

The systematic review suggests that neural tube defects contribute to a significant number of live births and stillbirths in India, suggesting that preconception folic acid supplementation should be an essential element of reproductive health services.

Maternal serum second trimester screening for chromosomal disorders and neural tube defects in a government hospital of North India

OBJECTIVE

Down syndrome (DS) has major resource implications especially in developing countries being third most important cause of mental handicap. Maternal serum screening for chromosomal aneuploidies and neural tube defects (NTDs) is practiced worldwide in many countries and has been integrated into mainstream health care, while it is gradually gaining momentum in Asian countries.

METHODS

This prospective cohort study was carried out in pregnant women undergoing triple screening test between January 2007 and December 2010 after informed consent. Biomarkers alpha-fetoprotein, human-chorionic-gonadotropin and unconjugated-estriol were tested, and risk of pregnancy being affected with DS, Edward's syndrome or NTDs were calculated. Screen-positive patients were referred for detailed ultrasonography and confirmatory amniocentesis. Follow-up record was maintained until delivery.

RESULTS

Of 7400 pregnant women enrolled, 419(5.7%) were screen-positive, including 339 positive for DS, two for trisomy 18, and 62 for NTDs. Total eight cases of DS were eventually diagnosed in the population (prevalence of DS = 1 : 925), seven of which were detected in utero following diagnostic evaluation for positive serum screen (DR of DS screen = 87.5%). Total five cases of NTD were observed, yielding NTD prevalence of 0.67/1000.

CONCLUSIONS

Triple screening in the second trimester is reasonably effective for the detection of major chromosomal defects and NTDs, and can be implemented successfully also in India.

Parental consanguinity and associated factors in congenital talipes equinovarus

BACKGROUND

The cause of congenital talipes equinovarus (CTEV) is multifactorial and, consanguinity could be one of the causative factors in its development. The purpose of this study was, to determine the prevalence of parental consanguinity in CTEV and other factors like associated, congenital anomalies, maternal and fetal factors and also the severity of CTEV in these patients.

METHODS

The above factors were studied in 54 patients of less than 1 month of age with parental, consanguinity and 91 feet were evaluated for its severity using Dimeglio classification at the time of presentation.

RESULTS

Out of 174 children presented to our department with CTEV, 54 (31%) children were born out, of consanguineous marriage. Thirty seven (68.5%) patients had bilateral CTEV. Twenty five (46.3%), patients had associated congenital anomalies and myelomeningocele being the commonest anomaly, associated. Out of 91 feet 61 (67%) were of grade 4 severity.

CONCLUSION

High grade of severity observed in both idiopathic and non idiopathic CTEV suggests the, probable role of consanguinity as an etiological factor in the development of CTEV especially in our, part of the world.

Association between MTHFR A1298C polymorphism and neural tube defect susceptibility: a metaanalysis

OBJECTIVE

To determine whether 5,10-methylenetetrahydrofolate reductase A1298C polymorphism is associated with neural tube defect susceptibility.

STUDY DESIGN

Computerized literature searches of the PubMed, Embase, and Medline database were conducted to identify all eligible articles. Study subjects were classified as neural tube defect patients, mothers with neural tube defect offspring and fathers with neural tube defect offspring. The pooled odds ratios with 95% confidence interval (CI) were calculated by fixed-effects model or random-effects model.

RESULTS

Twenty-three case-control studies were finally included. The pooled results showed no significant association between 5,10-methylenetetrahydrofolate reductase A1298C polymorphism and neural tube defect susceptibility in any genetic contrast among the 3 groups, except 1 (AC vs AA in neural tube defect patients: odds ratio, 1.16; 95% CI, 1.10-1.32; P = .03), which, however, turned out to be of no statistical significance in the subgroup of the white population (odds ratio, 1.14; 95% CI, 0.98-1.31; P = .08).

CONCLUSION

This metaanalysis suggests that 5,10-methylenetetrahydrofolate reductase A1298C polymorphism is not associated with neural tube defect susceptibility in the white population.

Folate supplementation, MTHFR gene polymorphism and neural tube defects: a community based case control study in North India

The present study analyses the potential role of MTHFR gene polymorphism, folate supplementation and dietary pattern among the mothers of NTD neonates and controls in heterogeneous populations of North India, with the special focus on their ethnic labels. Results indicated significant increased risk for neural tube defects with respect to low folic acid supplementation and vegetarian diet in univariate and multivariate analyses. There was no significant difference in the genotypic or allelic distribution of MTHFR C677T polymorphism, however, high frequency of CT genotype, as observed, among controls suggests heterozygous advantage probably due to supplementary folate. Among the two communities, Muslim NTD mothers had higher TT genotype showing increased risk for neural tube defects (adjusted OR: 12.9; 95% CI: 1.21-136.8) and lower folic acid supplementation (adjusted OR: 3.5; 95% CI: 1.18-10.22). Whereas, marginal increased risk for NTDs with vegetarian diet was observed among Hindus. Cultural and ethnic variation in the risk factors for neural tube defects is highlighted in the study.

Dyslipidemia in pregnancy may contribute to increased risk of neural tube defects -a pilot study in north Indian population

Neural tube defects are congenital structural abnormalities of the brain and vertebral column resulting from improper or non-timely closure of the neural tube. Prevalence of neural tube defects is reported to be higher among women with diabetes mellitus and obesity. This study was designed to investigate the relation between the presence of dyslipidemia in antenatal patients and the risk of fetal neural tube defects. The present study was an observational, cross-sectional study involving 129 pregnant women in 16 to 18 weeks gestation period. Of these, 80 women had normal pregnancies and 49 were clinically high-risk cases for neural tube defects. Fasting blood samples were analyzed for blood sugar and lipid profile by enzymatic assay and alpha-fetoprotein levels using Enzyme Immunoassay. Alpha-fetoprotein (AFP) values were converted to Multiples of Median (MoM) appropriate for the gestational age. Based on AFP values, women were labeled as screen negative (AFP <2 MoM, n= 102) and screen positive (AFP > 2 MoM, n =27). Screen positive women were further evaluated by ultrasound and 21 women were found to carry a neural tube defects positive pregnancy. Statistical analysis was done on SPSS software. Body weight of the women showed a significant positive correlation with serum triglycerides, plasma sugar and AFP MoM values. A significant difference was observed in serum cholesterol levels (p= 0.038), triglycerides (p=0.001) and plasma sugar levels (p=0.002) between normal women and those with neural tube defects positive pregnancy. The Odds ratio for neural tube defects risk in dyslipidemic cases was 24.23 (CI 4.73 - 148.60) with a relative risk of 12.12. Dyslipidemia especially hypertriglyceridemia was found to be significantly associated with fetal neural tube defects.

MTHFR 677C-->T and 1298A-->C polymorphisms: evaluation of maternal genotypic risk and association with level of neural tube defect

BACKGROUND

Neural tube defects (NTDs) are common birth defects (1 in 1,000) leading to significant morbidity and mortality. Periconceptional folic acid supplementation helps in prevention of 70% of NTDs. Recently, polymorphisms in genes encoding enzymes of the folate pathway have been implicated in causation of NTDs. Since the closure of neural tube occurs at multiple sites, the etiology of defect at different sites may be different - which explains the failure of folic acid supplementation to prevent all NTDs.

METHODS

Molecular analysis of methylenetetrahydrofolate reductase polymorphisms was carried out using polymerase chain reaction and restriction enzyme digestion. We studied the association of these polymorphisms in mothers with a previous child with NTD and further refined the risk by stratification based on level of defect.

RESULTS

The frequency of 677C-->T homozygotes was higher in mothers with a previous child with NTD than the controls (OR = 1.6 (0.38-6.7), 95% CI, p = 0.72) but the difference was statistically insignificant. There was a significant difference in frequency of T alleles among mothers with a previous child with a 'lower' type of defect compared to controls (OR = 2.15 (1.13-4.1), 95% CI, p = 0.02). We did not find any significant association of 1298A-->C polymorphism with the level of NTDs.

CONCLUSIONS

We conclude that in the North Indian population, the 677C-->T allele of the MTHFR gene may be associated with the occurrence of a lower type of NTD. This points towards the differential role of thermolabile MTHFR at different sites of neural tube closure.

Neural tube defects in Pondicherry

OBJECTIVE

This study was carried out to identify the trend and the frequency of neural tube defects from July 1998 to June 2004.

METHODS

A total of 310 babies were born with neural tube defects with the overall frequency of 5.7/1000 births compared to 2.3/1000 births observed earlier in our hospital.

RESULTS

The most common defect was spina bifida (54.8%) followed by anencephaly (31.6%), and encephalocele (11.6%). More neural tube defects were observed in female and low birth weight babies, still births and unbooked mothers. Neural tube defect was significantly higher among babies born to parents of consanguineous marriage (p< 0.01). Associated congenital defects were observed in thirty nine (12.6%) cases.

CONCLUSION

The rise in the frequency of NTDS may indicate the current trend of NTDs in Southern India. A further prospective study is desired to measure the effectiveness of regular folic acid supplementation in bringing down this frequency.

Birth order and neural tube defects: a reappraisal

There is evidence that late birth order is associated with some complex disorders. For neural tube defects (NTDs) there is no consensus as to whether first or increased birth order is associated or not. A meta-analysis of published data on NTDs was carried out to ascertain whether there is an increased risk for children first born or of high birth order to have NTDs. All data available with information regarding the frequency of live births and NTDs cases by birth order (1, 2, 3, and 4 or more) were included in the analysis. Effect sizes calculations were performed. Children with higher birth order are more likely to have spina bifida but not anencephaly. This same effect was also seen for all NTDs combined, which probably reflects the association with spina bifida. These results suggest the compilation of anencephaly and spina bifida data can be the explanation for the controversies seen in the literature.

Breech presentation and tossing a coin: heads or tails

Through a retrospective review of our own materials and data from peer-reviewed journals, among medical entities a greater probability than 0.5 was not found for breech presentation. Submitting the occurrence of breech presentation to the classical laws of probability means that each fetus in breech presentation has its 'pair' in cephalic presentation. Among medical entities with a probability of less than 0.5 for breech presentation, the group of fetuses in cephalic presentation consist of two subgroups: (1) fetuses which are by chance in cephalic presentation and whose number is identical to the number of fetuses in breech presentation, (2) fetuses which are in cephalic presentation because of the postural development. Likewise, introducing a medical entity with a small number of cases does not allow a conclusion to be drawn about a relationship between that entity and breech presentation.

Endogamy, consanguinity and community genetics

The population of India is composed of many thousands of subpopulations, divided by geography, language, religion and caste or biraderi (patrilineage) boundaries, with endogamous marriage the norm. The net effect has been the creation of multiple genetic isolates with individual mutation profiles, but to date the clinical consequences of this highly complex differentiation have been largely ignored. In contrast, the topic of consanguinity continues to attract attention among medical and population geneticists, clinicians and social scientists. The significant progress made in India in improving childhood nutritional status and combating infectious disease means that genetic disorders have assumed ever-increasing importance. In populations where consanguineous marriage is widely practised, recessive genetic disorders will continue to gain greater prominence in the overall spectrum of ill health. At the same time this increase will in part be negated by urbanization and the move to smaller family sizes, which predictably will result in a decline in the prevalence of consanguineous unions. Developing an understanding of these changes will require a wide-ranging and multidisciplinary investigative approach for which community genetics is ideally suited.

Importance of folate in human nutrition

From a public health perspective, some of the new insights into folic acid nutrition are of significance. Folate intake recommendations vary under different conditions. Intake of 350 microg is required to maintain plasma homocysteine levels, 650 microg for those with elevated plasma homocysteine, about 400 microg for women planning to become pregnant and 4000 microg for those with history of neural tube defect affected pregnancy. This raises the question whether the folate intake is adequate for the general population, particularly in the vulnerable groups or whether there is a need for scientists to take a fresh view of the requirements, recommended dietary intakes, and consider intervention measures which will have impact on the folate nutritional status. The recommendations should provide a margin of safety to allow for decreased intake, increased requirements, individual variability and bioavailability of natural food folates. The folate intake and nutriture in relation to India and other developing countries needs careful consideration to reduce anemia, neural tube defects and possibly impact on the high incidence of cardiovascular diseases.

Spina bifida cystica: selective management in Zaria, Nigeria

Management of spina bifida cystica in Zaria, Nigeria is selective. Over a period of 11 years, 77 children with this defect, 54 meningocoeles and 23 myelomeningocoeles, 66 (86%) situated in the lumbosacral region, were treated operatively. Forty-two (55%) had surgery in the neonatal period and 91% within 6 months of birth. Postoperative complications occurred in 19 of 68 patients (28%), including mild hydrocephalus, which resolved spontaneously (six, 9%), wound infection (six, 9%), leakage of cerebrospinal fluid (four, 6%) and meningitis (three, 4%). Mortality was 3% from both meningitis and cardiac arrest. Of 32 patients followed up for 3-5 years, 20 with meningocoeles were normal. Of 12 with myelomeningocoele, four had varying degrees of lower limb weakness, three double incontinence, two faecal incontinence, two had progressive hydrocephalus plus paralysis and double incontinence, and one had urinary incontinence. Therefore, 38% were functionally disabled and could not be adequately rehabilitated owing to poor facilities. While management of spina bifida cystica is more aggressive now in most developed countries, ours remains selective due to difficulty with multidisciplinary care and rehabilitation. Even with our selective management, the care of patients with functional handicap remains a challenge.

Neural tube defect among Palestinians: a hospital-based study

A preliminary study was undertaken to estimate the incidence of neural tube defect (NTD) among Palestinians living in East Jerusalem and the southern part of the West Bank (600,000 inhabitants). Between 1 January 1986 and 31 December 1993, all NTD in fetuses weighing more than 500 g or of more than 22 weeks gestation, whether the product of abortion, therapeutic termination, stillborn or liveborn, were included. Mothers' data recorded included age, parity, residential area, gestational age, obstetrical history and consanguinity. The study included 26,934 consecutive newborns registered at Makassed Hospital in the study period. There were 148 cases of NTD, an incidence of 5.49 per 1000 births. The female to male ratio was 1.5:1. The incidences of spina bifida, encephalocele and anencephaly were 2.23, 0.44 and 2.41 per 1000, respectively. The incidence of NTD increased with maternal age. This preliminary report reveals a high incidence of NTD in the Palestinian community and further monitoring is necessary to confirm these findings and implement suitable policies for the detection and prevention of NTD.

Consanguinity and its effect on fetal growth and development: a south Indian study

The effect of consanguinity on fetal growth and development was studied in 3700 consecutive births (live and stillborn); 26% of the total births were to consanguineous couples. Hindus had a higher frequency of consanguineous marriages, uncle-niece unions being the commonest type, whereas Moslems preferred first cousin marriages. The incidence of congenital malformations was 39.1/1000 births with a significantly higher incidence among the consanguineous group (8.01%) as against the nonconsanguineous group (2.42%) (p less than 0.001). The incidence of malformations was higher in the uncle-niece matings (9.34%) compared to the first cousin marriages (6.18%) (p less than 0.01). Malformations of major systems were significantly more frequent among the consanguineous couples, whereas malformations of the eyes, ears, and skin did not show any significant effect of consanguinity. Stillbirth rates were significantly higher in the consanguineous group, irrespective of the mother's socioeconomic status, and were higher in uncle-niece matings compared to first cousin and beyond first cousin unions in both the poor and middle/upper class. A significant decrease in the mean birth weight and head circumference of babies born to consanguineous parents was noted in both the poor and middle/upper socioeconomic class. The mean length was less in babies born to consanguineous parents belonging to the poor social class only.