What is an open neural tube defect (NTD)?
Sep 09, 2022
Source: Cainiu Health
Dr. Yang Jun
Introduction
Open neural tube defects (NTD) refer to developmental malformations of the brain, spinal cord, or spine that occur while the baby is growing in the mother's uterus. The neural tube is essentially fully formed by days 28 to 32 of pregnancy. If the neural tube fails to close completely—either entirely or partially—it results in an open neural tube defect. Types of open neural tube defects include spina bifida, anencephaly, and encephalocele.
Open neural tube defects (NTDs) are congenital malformations affecting the brain, spinal cord, or spine that occur during fetal development in the mother’s uterus. The neural tube is typically fully formed by days 28–32 of gestation. If the neural tube fails to close completely—either partially or entirely—an open NTD results. The three main types of open NTDs are spina bifida, anencephaly, and encephalocele.
1. Spina Bifida
Spina bifida is the most common type of open NTD. It may lead to a range of congenital complications in newborns, including paralysis, urinary and fecal incontinence, clubfoot, hydrocephalus, and intellectual disability.
2. Anencephaly
Anencephaly is characterized by the incomplete formation of major portions of the brain and skull. Fetuses affected by anencephaly typically experience intrauterine fetal demise after 20 weeks of gestation.
3. Encephalocele
Encephalocele occurs when brain tissue or its surrounding membranes protrude through an opening in the skull, commonly occurring in the frontal region of the skull, near the nose and sinuses. Common clinical manifestations include paralysis, intellectual disability, and epilepsy.
Currently, diagnostic methods for open NTDs primarily include maternal serum screening, prenatal ultrasound examination, and amniocentesis.
