Neural tube defects
Updates to Article Attributes
A neuralNeural tube defect (NTD) refers to incomplete closure of the neural tube in very early pregnancy.
The The neural tube comprises of a bundle of nerve sheath which closes to form brain at the anterior end and spinal cord at posterior end. The closure should occur at around the 28th day of conception failing which brain or spinal cord doesn't form properly.
Most common form of neural tube defects are:
Spina bifida can involve the spine, brain and / or/or meninges while anencephaly is absence of cranial bones.
Other rare types include:
Epidemiology
Neural tube defects affect approximately 2 - 5-5 per 1000 pregnancies with spina bifida and anencephaly accounting for 95% of these reference required.
Pathology
Causes
Folic acid deficiency is a major cause of anencephaly. By giving supplementation of Folic acid in early pregnancy this defect can be prevented. It is more prevalent in developing countries and in mothers of low socio-economic status.
Associations
- maternal diabetes
*
Markers
- elevated materal serum alpha-fetoprotein (MSAFP) levels
- elevated amniotic fluid acetylcholinesterase (AChE) levels: in an open neural tube defect 3
Radiographic features
These are different for each entity and best discussed under each sub type.
Diagnosis
Most neural tube defects can be diagnosed by one of the following tests:
-
maternal serum alpha fetoprotien (MSAFP):
:a screening test performed in the pregnant woman serum during 16- 18-18 weeks of pregnancy (elevated) -
amniocentesis:
: invasiveinvasive procedure, performed during 15 weeks of pregnancy -
antenatal ultrasound:
:allows detection of anencephaly/acrania at 12 weeks of pregnancy
Treatment and prognosis
Both the management and prognosis is heavily dependent on the type of neural tube defect. The risk for a subsequent pregnancy is thought to be ~ 5 - 10 ~5-10%.
-<p>A<strong> neural tube defect (NTD)</strong> refers to incomplete closure of the <a href="/articles/neural-tube" title="neural tube ">neural tube </a>in very early pregnancy. </p><p> The neural tube comprises of a bundle of nerve sheath which closes to form brain at the anterior end and spinal cord at posterior end. The closure should occur at around the 28<sup>th</sup> day of conception failing which brain or spinal cord doesn't form properly.</p><p>Most common form of neural tube defects are <a href="/articles/spina-bifida" title="spina bifida"></a></p><ul><li><a href="/articles/spina-bifida" title="spina bifida">spina bifida</a> <a href="/articles/anencephaly" title="Anencephaly"></a></li><li><a href="/articles/anencephaly" title="Anencephaly">anencephaly</a> / <a href="/articles/exencephaly" title="exencephaly">exencephaly</a></li></ul><p>Spina bifida can involve the spine, brain and / or meninges while anencephaly is absence of cranial bones.</p><p>Other rare types include</p><ul><li><a href="/articles/iniencephaly" title="Iniencephaly">iniencephaly</a></li></ul><h4><strong>Epidemiology</strong></h4><p>Neural tube defects affect approximately 2 -  5 per 1000 pregnancies with spina bifida and anencephaly accounting for 95% of these <sup>reference required</sup>.</p><h4>Pathology</h4><h5><strong>Causes</strong></h5><p>Folic acid deficiency is a major cause of anencephaly. By giving supplementation of Folic acid in early pregnancy this defect can be prevented. It is more prevalent in developing countries and in mothers of low socio-economic status.</p><h5>Associations</h5><ul><li>maternal diabetes<a href="/articles/fetal-conditions-associated-with-maternal-diabetes" title="Conditions associated with maternal diabetes"> *</a></li></ul><h5>Markers</h5><ul><li>elevated materal serum alpha-fetoprotein (MSAFP) levels </li><li>elevated amniotic fluid acetylcholinesterase (AChE) levels : in an open neural tube defect  <sup>3</sup></li></ul><h4>Radiographic features</h4><p>These are different for each entity and best discussed under each sub type.</p><h4><strong>Diagnosis</strong></h4><p>Most neural tube defects can be diagnosed by one of the following tests</p><ul><li><strong>maternal serum alpha fetoprotien (MSAFP)</strong> : a screening test performed in the pregnant woman serum during 16 - 18 weeks of pregnancy (elevated)</li><li><strong>amniocentesis</strong> : invasive procedure, performed during 15 weeks of pregnancy</li><li><strong>antenatal ultrasound</strong> : allows detection of <a href="/articles/anencephaly" title="Anencephaly">anencephaly</a> / <a href="/articles/acrania" title="acrania">acrania</a> at 12 weeks of pregnancy</li></ul><h4>Treatment and prognosis</h4><p>Both the management and prognosis is heavily dependent on the type of neural tube defect. The risk for a subsequent pregnancy is thought to be ~ 5 - 10 %. </p>- +<p><strong>Neural tube defect (NTD)</strong> refers to incomplete closure of the <a href="/articles/neural-tube">neural tube </a>in very early pregnancy. </p><p> The neural tube comprises of a bundle of nerve sheath which closes to form brain at the anterior end and spinal cord at posterior end. The closure should occur at around the 28<sup>th</sup> day of conception failing which brain or spinal cord doesn't form properly.</p><p>Most common form of neural tube defects are:</p><ul>
- +<li>
- +<a href="/articles/spina-bifida">spina bifida</a> </li>
- +<li>
- +<a href="/articles/anencephaly">anencephaly</a>/<a href="/articles/exencephaly">exencephaly</a>
- +</li>
- +</ul><p>Spina bifida can involve the spine, brain and/or meninges while anencephaly is absence of cranial bones.</p><p>Other rare types include:</p><ul><li><a href="/articles/iniencephaly">iniencephaly</a></li></ul><h4>Epidemiology</h4><p>Neural tube defects affect approximately 2-5 per 1000 pregnancies with spina bifida and anencephaly accounting for 95% of these <sup>reference required</sup>.</p><h4>Pathology</h4><h5>Causes</h5><p>Folic acid deficiency is a major cause of anencephaly. By giving supplementation of Folic acid in early pregnancy this defect can be prevented. It is more prevalent in developing countries and in mothers of low socio-economic status.</p><h5>Associations</h5><ul><li>maternal diabetes</li></ul><h5>Markers</h5><ul>
- +<li>elevated materal serum alpha-fetoprotein (MSAFP) levels </li>
- +<li>elevated amniotic fluid acetylcholinesterase (AChE) levels: in an open neural tube defect <sup>3</sup>
- +</li>
- +</ul><h4>Radiographic features</h4><p>These are different for each entity and best discussed under each sub type.</p><h4>Diagnosis</h4><p>Most neural tube defects can be diagnosed by one of the following tests:</p><ul>
- +<li>
- +<strong>maternal serum alpha fetoprotien (MSAFP):</strong> a screening test performed in the pregnant woman serum during 16-18 weeks of pregnancy (elevated)</li>
- +<li>
- +<strong>amniocentesis:</strong> invasive procedure, performed during 15 weeks of pregnancy</li>
- +<li>
- +<strong>antenatal ultrasound:</strong> allows detection of <a href="/articles/anencephaly">anencephaly</a>/<a href="/articles/acrania">acrania</a> at 12 weeks of pregnancy</li>
- +</ul><h4>Treatment and prognosis</h4><p>Both the management and prognosis is heavily dependent on the type of neural tube defect. The risk for a subsequent pregnancy is thought to be ~5-10%. </p>