Neural Tube Birth Defects Research Articles

Use of genetic counselling services for neural tube defects.

Genetic counselling is recommended for parents of children with neural tube defects (NTDs) to inform them of the recurrence risks and the option of prenatal diagnosis. British Columbia provides an excellent site to examine the use by parents of genetic counselling services for NTDs. Genetic services for the entire province are centralized, and there is virtually complete ascertainment of all NTD births. The results from this study indicate that use of genetic counselling services is influenced by the type of NTD present and whether the index case was live or stillborn. Genetic counselling is most often sought after the birth of a liveborn infant with spina bifida.

The impact of screening for open neural tube defects in England and Wales

Using information derived from the voluntary system of notification of congenital malformations in England and Wales, the birth prevalence of anencephaly and spina bifida was estimated to have declined by 80 per cent from 31.5 to 6.2 per 10,000 between 1964-1972 and 1985. Over the same period, notified terminations of pregnancy with a suspected fetal central nervous system abnormality increased from less than 1 per cent to 56 per cent of neural tube defect births and central nervous system terminations combined, accounting for 31 per cent of the decline in births. Routinely collected national statistics provide a method for monitoring the impact of screening for open neural tube defects. However because they are incomplete and lack detail an alternative method of monitoring is needed. This paper includes an outline of such a method, together with the results of a pilot study designed to assess the feasibility of monitoring screening in the Oxford Region.

A review of the theories of vertebrate neurulation and their relationship to the mechanics of neural tube birth defects*

ABSTRACT All of the published theories of neurulation, (some of them forgotten but never disproved), are reviewed for the purpose of assessing just where we are in coming to a satisfactory explanation of this critical step in the formation of the brain and spinal cord, whose occasional failure leads to neural tube birth defects. A new approach to evaluating these theories is introduced, namely finite element analysis, along with a discussion of its promise and present limitations. ‘To think that heredity will build organic beings without mechanical means is a piece of unscientific mysticism’ (His, 1888).

The impact of maternal serum alpha fetoprotein screening on open neural tube defect births in North‐East Scotland

Over the three years period 1980-1982, 18 256 pregnancies in the Grampian Region of N-E Scotland including the islands of Orkney and Shetland were screened for raised levels of maternal serum alpha fetoprotein (MSAFP) in the second trimester. Thirty six cases of fetal open neural tube defect in singletons were detected (18 anencephaly and 18 spina bifida). Four additional cases of open spina bifida were associated with normal MSAFP levels although two of these were detected by amniotic fluid AFP measurement when amniocentesis was carried out because of previous NTD history. A further three cases of open spina bifida and two of anencephaly occurred in unscreened pregnancies. The MSAFP screening programme alone was thus instrumental in reducing the birth incidence of open neural tube defects by 36 out of 45 cases (80 per cent) in singletons.

The relationship of supplemental iodine to neural tube defects in Rochester, New York, 1924-1932.

The geographic distribution of infants born with anencephaly and spina bifida in Rochester, New York, in 1924-1932, was examined to test the hypothesis that iodine supplemented water may have reduced the prevalence of these defects. During this period the region had a high prevalence of iodine deficiencies. Comparing the prevalence of neural tube defects in an area with iodine supplemented water to one without iodine supplementation, we found no significant difference in prevalence at birth of neural tube defects. Because the prevalence rates for these defects in children of foreign-born parents (except the Irish) was low, we reexamined the data, excluding these cases. There remained no differences in rates. Iodine supplemented water thus appears to have had no effect on the occurrence of neural tube defects.

Descriptive epidemiology of neural tube defects, Rochester, New York, 1918-1938.

This study examines the secular distribution of births, sex, and age at death of 330 cases of anencephaly and spina bifida and 62 cases of "monstrosity" recorded on City of Rochester death certificates between 1918 and 1938. The results show that death certificates may be used as a source of data (with inherent biases) and that persons diagnosed as monstrosity had similar epidemiologic characteristics to those diagnosed as anencephalic during this period. In Rochester the rise in prevalence at birth of neural tube defects was similar to, and occurred at approximately the same years as, the rises reported in Boston and Providence.