Neural tube defects
Neural tube defects are congenital malformations resulting from the failure of the neural tube to close during the fourth week of embryonic development. This defect can occur at any point along the neural plate, from the cephalic to the caudal end, and over a variable length. This results in abnormalities of the bony structures (vertebrae or skull) and the overlying integument, with varying effects on the underlying nervous tissue (brain or spinal cord).
Depending on the location of the closure defect, we distinguish between anomalies of the cephalic pole (anencephaly/exencephaly and meningomyelocele) and those of the spinal pole (spina bifida).
The known risk factors for neural tube closure are primarily folate deficiency, diabetes, and obesity in women.
Anencephaly
Anencephaly is a lethal congenital anomaly characterized by the total or partial absence of the brain, skull, and scalp and is often associated with the absence of the spinal cord.
Register |
Period |
Births |
Live births |
Stillbirths (excluding IMG) |
IMG |
Total |
Total prevalence/10,000 (95% CI) |
Antilles |
2011–2015 |
47,493 |
1 |
3 |
17 |
21 |
4.4 (2.7–6.8) |
Auvergne |
2011–2015 |
66,381 |
40 |
40 |
6.0 (4.3–8.2) |
||
Brittany |
2011–2015 |
179 180 |
1 |
106 |
107 |
6.0 (4.9–7.2) |
|
Paris |
2011–2015 |
128,915 |
1 |
3 |
54 |
58 |
4.6 (3.5–6.0) |
Reunion |
2011–2015 |
71,756 |
3 |
53 |
56 |
7.8 (5.9–10.1) |
|
Rhône-Alpes |
2011–2015 |
292,693 |
9 |
145 |
154 |
5.3 (4.5–6.2) |
Source: French Registries of Congenital Anomalies, INSEE for births in 2011–2015
It is observed that the prevalence of anencephaly is higher in Réunion than in the areas covered by the other registries. Research from epidemiological, environmental, nutritional, and genetic perspectives is underway to propose appropriate management measures.
For more information: Orphanet (isolated anencephaly/exencephaly)
Spina Bifida
Spina bifida is the most common neural tube defect. The postnatal prognosis and the extent of permanent disability depend on the location and extent of the anomaly, the presence of associated anomalies (extraspinal or, in the case of a chromosomal syndrome, particularly trisomy 21). The disability also depends on upstream consequences (ventricular dilation of the brain, Arnold-Chiari syndrome) as well as downstream consequences (limb immobility, urinary incontinence, clubfoot, etc.).
Register |
Period |
Births |
Live births |
Stillbirths (excluding IMG) |
IMG |
Total |
Total prevalence/10,000 (95% CI) |
Antilles |
2011–2015 |
47,493 |
2 |
14 |
16 |
3.4 (1.9–5.5) |
|
Auvergne |
2011–2015 |
66,381 |
8 |
29 |
37 |
5.6 (3.9–7.7) |
|
Brittany |
2011–2015 |
179 180 |
15 |
3 |
95 |
113 |
6.3 (5.2–7.6) |
Paris |
2011–2015 |
128,915 |
8 |
1 |
55 |
64 |
5.0 (3.8–6.3) |
Reunion |
2011–2015 |
71,756 |
21 |
2 |
71 |
94 |
13.1 (10.6–16.0) |
Rhône-Alpes |
2011–2015 |
292,693 |
44 |
1 |
144 |
189 |
6.5 (5.6–7.4) |
Source: French Registries of Congenital Anomalies, INSEE for births in 2011–2015
It is observed that the prevalence of spina bifida is higher in Réunion than in the areas covered by the other registries. Research from epidemiological, environmental, nutritional, and genetic perspectives is underway to propose appropriate management measures.
For more information: Orphanet (Isolated Spina Bifida)
