Neural tube defect

Classification according to ICD-10
O35.0	Care of the mother in case of (suspected) malformation of the central nervous system in the fetus
Q00	Anencephaly and related malformations
ICD-10 online (WHO version 2019)

The generic term neural tube defect (NRD) summarizes those malformations in which the embryonic development has resulted in an incomplete closure of the neural tube .

The most common neural tube malformations include anencephaly (in which essential parts of the brain , the meninges and the overlying cranial bones and skin do not develop) and the spina bifida aperta (a corresponding, differently pronounced malformation in the area of ​​the spine).

embryology

The decisive period is that from the 22nd to the 28th day (when organs begin to develop ), which begins in the area of ​​the CNS with "primary neurulation ". Once under the influence of the notochord from the ectoderm , the ( cranial wider) neural plate has emerged the third week of the edges of the neural plate formed yet during the neural folds, between which now has a neural groove is located. From the 22nd day onwards, these neural folds approach each other and merge to form the neural tube , from whose lumen the ventricular system of the brain and spinal cord will be formed.

frequency

Neural tube defects occur in 1 to 5/1000 live births (with regional differences). The overall incidence would have to be set much higher if one were to include pregnancies that are terminated prematurely (based on the diagnostic clarification in the context of the pregnancy examinations).

There are also regional differences in the frequency, for example because a connection between exposure to car exhaust fumes in early pregnancy and the occurrence of neural tube defects could be found.

diagnosis

As early as 1983 it could be shown that the ultrasound examination of mothers with a high risk of neural tube defects - i.e. H. Women with elevated alpha-1 fetoprotein - enables sufficiently accurate statements about the presence of a malformation.

The ICD-10 code O35.0 is given when caring for the expectant mother in the event of "suspected malformation of the central nervous system in the unborn child ( anencephaly or spina bifida aperta )".
Q00 ("Anencephaly and similar malformations") is used as the diagnosis code for the child itself.

Folic acid

Taking folic acid in early pregnancy significantly reduces the likelihood of neural tube malformations in the child, although the taking of a corresponding preparation must start in advance of pregnancy or within the first four weeks of pregnancy in order to be effective. However, the pregnancy in the crucial period is often not even known.

Since 1994, attempts have been made in Canada to reduce open neural tube defects by administering folic acid before conception, although the frequency (in Nova Scotia ) is not statistically significant at 2.55 per 1000 births (live and stillbirths in the period from 1991 to 1994) 2.61 / 1000 (1995-1997) increase ( RR 1.02). It was only with the enrichment of cereal products from November 1998 that their occurrence was significantly reduced (1.17 per 1000 births in the period 1998–2000, RR 0.46).

In the USA, fortification of bread, cereals, flour and other grain products has been prescribed by the FDA since 1996 .

See also

• Koussef syndrome

swell

1. ^ Kohei Shiota, John M. Opitz: Neural tube defects and maternal hyperthermia in early pregnancy: Epidemiology in a human embryo population. In: American Journal of Medical Genetics. 12, 1982, p. 281, doi: 10.1002 / ajmg.1320120306 .
2. ↑ Guidelines for the prevention of neural tube defects through periconceptional folic acid substitution. Austrian Society for Pediatrics and Adolescent Medicine, Nutrition Commission and Austrian Society for Pre- and Perinatal Medicine A. Pollak et al
3. ↑ AM Padula, IB Tager, SL Carmichael, SK Hammond, F. Lurmann, GM Shaw: The Association of Ambient Air Pollution and Traffic Exposures With Selected Congenital Anomalies in the San Joaquin Valley of California. In: American Journal of Epidemiology. (2013); 177 (10), pp. 1074-1085. doi: 10.1093 / aje / kws367 .
4. ^ CJ Roberts et al .: Diagnostic effectiveness of ultrasound in detection of neural tube defect. The South Wales experience of 2509 scans (1977-1982) in high-risk mothers. In: Lancet. 1983. PMID 6138609 .
5. ↑ L. Vidia include: Incidence of open neural tube defects in Nova Scotia after folic acid fortification. In: CMAJ. 2002 (Nova Scotia: frequency of open neural tube defects before and after grain fortification with folic acid; engl.)
6. ↑ S. Daly, JL Mills, et al. a .: Minimum effective dose of folic acid for food fortification to prevent neural-tube defects. In: Lancet. Volume 350, Number 9092, December 1997, pp. 1666-1669, ISSN  0140-6736 . doi: 10.1016 / S0140-6736 (97) 07247-4 . PMID 9400511 .
7. ↑ SW Junod (FDA): Folic Acid Fortification: Fact and Folly . accessed on 2012-Sep-11

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !