Neural tube defect

Under the generic term neural tube defect ( NTD ) are those malformations summarized in which it has come in embryonic development in an incomplete closure of the neural tube.

Among the most common Neuralrohrfehlbildungen include anencephaly ( in which substantial parts of the brain, the meninges and the overlying skull bones and skin does not develop ) and spina bifida ( a corresponding varying degrees of deformity of the spine ).

Embryology

The critical period is that from 22 to 28 days ( the incipient organ formation ), which begins with the " primary neurulation " in the CNS. Once under the influence of the notochord from the ectoderm, the ( wider cranial ) neural plate is formed, are still forming during the third week of the edges of the neural plate, the neural folds, between which is now a neural groove. From the 22nd day these neural folds approach each other and merge to form the neural tube, from the lumen of the ventricular system of the brain and spinal cord form.

Frequency

Neural tube defects occur ( regionally varying frequency ) on at 1 to 5/ 1000 live births. The overall incidence, there would probably be valued much higher, it would also include pregnancies that are terminated prematurely (due to the diagnostic evaluation in the context of pregnancy tests).

In addition, there are regional differences in the frequency, for example, because an association between exposure to car exhaust fumes in early pregnancy and the occurrence of neural tube defects could be found.

Diagnosis

Already in 1983 it was shown that the ultrasound examination of mothers at high risk for neural tube defects - ie Allows sufficiently accurate statements about the existence of a malformation - women with elevated alpha -1 -fetoprotein

The ICD -10 code O35.0 is specified in the care of the expectant mother in " suspected malformation of the central nervous system to the unborn child ( anencephaly or spina bifida aperta ) ". When child himself comes as a diagnostic key Q00 ( " Anencephaly and similar malformations " ) are used.

Folic acid

The intake of folic acid in early pregnancy reduces the likelihood of the emergence of a Neuralrohrfehlbildung the child considerably, taking an appropriate preparation must begin even before the pregnancy or within the first four weeks of pregnancy to be effective. Thus, the pregnancy in the decisive period is often not yet known.

In Canada, from 1994, is trying to reduce open neural tube defects by folic acid before conception, with their frequency ( in Nova Scotia ) was not statistically significant from 2:55 per 1000 births (live births and stillbirths in the period 1991-1994) to 2.61 / 1000 (1995-1997) increased (RR 1.02). Only with the enrichment of grain products from November 1998 whose occurrence was significantly reduced ( 1:17 per 1000 births in 1998-2000, RR 0:46 ).

In the United States since 1996 by the FDA enrichment of bread, cereals, flour and other grain products required.

Swell

• Malformation
• Disease in neurology