Efficacy of folic acid prophylaxis for the prevention of neural tube defects

Research: Prevalence of neural tube defects Khartoum, Sudan August 2014-July 2015

Background

Neural tube defects (NTDs) are birth defects that results from failure of the neural tube to develop properly during early pregnancy.

Methods

We studied the prevalence of neural tube defects in newborns admitted to the NICU in Soba University and Omdurman Maternity hospitals, during the period 1st August 2014 to 31st July 2015. A cross-sectional hospital based study, involved all newborns with any type of neural tube defect admitted to the NICU in the study area during the study period. Data was collected using a questionnaire reviewing the medical, social history and clinical examination.

Results

Out of the 36,785 delivered newborns during the study period, the prevalence of NTDs was 2.8:1000. Females were 56 (54.4%) predominated males 47 (45.6%). History of neural tube defects was found in 11 (10.7%) of the affected newborns siblings. Sixty-eight (66%) of the studied mothers received folic acid during pregnancy with the current child, of those who received folic acid 66 (97.1%) started folic acid after conception, 36 (54.5%) in the first trimester and 39 (57.4%) had no regular intake of the folic acid. The types of NTDs include myelomeningocele 49 (47.6%), anencephaly 18 (17.5%), encephalocele 14 (13.6%), myelomeningocele and hydrocephalus 11 (10.7%) and meningocele 8 (7.8%).

Conclusion

The prevalence of neural tube defects is 2.8:1000. Myelomeningocele is the commonest encountered NTD. The use of preconception folic acid needs to be advocated.

Folic acid calls to poison centers in Texas, 1998-2003

Folic acid (folacin, pteroylglutamic acid) is a monoglutamate form of the water-soluble B vitamin that is involved in the synthesis of nucleotides and amino acids and the normal maturation of red blood cells. This study describes the folic acid calls received by Texas poison centers during 1998-2003. There were 650 calls involving folic acid as a single-ingredient product, of which 55.1% were human exposures. Children age <6 years accounted for 80.1% of the human exposures. Patients were managed outside of the health care facilities in 92.1% of the cases. Of those cases with a known medical outcome, 94.8% had no clinical effects. This study found folic acid exposures reported to poison centers were unlikely to have more than minor adverse affects.

Maternal Stress, Social Support, and Risk of Neural Tube Defects Among Mexican Americans

BACKGROUND

Studies suggest that maternal psychologic stress can increase the risk of congenital malformations, including neural tube defects (NTDs). We examined whether maternal stress and lack of social support contribute to NTD risk in a population living along the Texas-Mexico border.

METHODS

Case mothers (N = 184) were Mexican-American women with NTD-affected pregnancies who delivered during 1995 to 2000 in one of the 14 Texas counties bordering on Mexico. Control mothers (N = 225) were randomly selected from Mexican-American women residing in the same area and delivering normal live births. We measured maternal stress by tallying the number of job changes, residential moves, and major injuries occurring during the year before conception. Social support was measured using social integration and perceived emotional support scales.

RESULTS

Mothers who experienced one or more stressful life events during the year before conception had increased risks for NTDs (odds ratio [OR] = 2.9; 95% confidence interval [CI] = 1.8-4.7) compared with mothers experiencing no events. Mothers who scored low on emotional support had an elevated risk compared with those who scored high (OR = 4.6; CI = 2.2-9.7). Social support measures, such as network size and satisfaction, group interactions, and church attendance, were unrelated to NTD risk. The estimated effects were not modified or confounded by age, education, country of birth, income, obesity, vitamin supplements, dietary folate, cigarette smoking, or alcohol consumption.

CONCLUSION

In this Mexican-American population, the occurrence of stressful life events was associated with NTD risk. These findings suggest that stress may exacerbate risk in populations with poor nutritional status and meager economic resources.

Trends in neural tube defect prevalence, folic acid fortification, and vitamin supplement use

In this review, the authors analyze international trends in rates of neural tube defects (NTDs) during the past three decades. Population-based data sources include the Metropolitan Atlanta Congenital Defects Program and other US birth defects surveillance programs in the National Birth Defects Prevention Network, the International Clearinghouse for Birth Defects Monitoring Systems, and US and Canadian vital records. To analyze trends in vitamin consumption, we review data from the US National Health and Nutrition Examination Surveys and international surveys of multivitamin use. We discuss the role of factors associated with historic and continuing declines in NTD rates in most countries. These factors include the introduction and increased utilization of prenatal diagnosis, recommendations for multivitamin use in women of childbearing age, and population-wide increases in blood folate levels that have occurred since food fortification was mandated. We also discuss research needs for further NTD prevention. This is a US government work. There are no restrictions on its use.

The Chilean flour folic acid fortification program reduces serum homocysteine levels and masks vitamin B-12 deficiency in elderly people

Hyperhomocysteinemia is considered a risk factor for cardiovascular disease and is prevalent in the elderly. Supplementation with folic acid, vitamin B-6 and B-12 lowers homocysteine levels. In January 2000, the Chilean government initiated a flour folic acid fortification program to decrease the occurrence of neural tube defects. The aim of this study was to evaluate the effect of this program on serum homocysteine and folate levels in elderly subjects after 6 mo. A total of 108 elderly people were studied. We measured serum folate, homocysteine and vitamin B-12 levels before the fortification started and 6 mo later. At baseline, folate deficiency (<6.8 nmol/L) was present in 1.8%, vitamin B-12 deficiency (<165 pmol/L) in 27.6% and hyperhomocysteinemia (>14 micromol/L) in 31% of the sample. Six months later, serum folate levels increased from 16.2 +/- 6.2 to 32.7 +/- 7.1 nmol/L (P < 0.001), homocysteine levels decreased from 12.95 +/- 3.7 to 11.43 +/- 3.6 micromol/L (P < 0.001) and vitamin B-12 levels were unchanged. Flour fortification with folic acid had a moderate lowering effect on homocysteine levels. Given that vitamin B-12 deficiency was more common than folate deficiency, it may be more appropriate to add vitamin B-12 to food, at least in foods for this age group.