Limb abnormalities
Limb malformations are relatively common, affecting approximately one in 700 births (all birth outcomes combined).
There are three types:
reducive malformations,
polydactyly (one or more extra fingers or toes), or
syndactyly (adhesion and fusion of two or more fingers or toes).
These malformations are isolated in the majority of cases, but they may also be associated with other malformations, possibly as part of a polymalformative syndrome. They have multifactorial causes, including chromosomal and genetic factors, as well as teratogenic effects of certain medications, or mechanical causes (e.g., uterine malformation…).
Other anomalies, such as clubfoot (equinus varus) or joint dysplasia, may result from mechanical compression of the fetus against the uterine wall, as well as from genetic predisposing factors. The presence of amniotic bands can also cause harmful constraints on limb development, leading to constriction lines or amputations.
Limb reduction
Limb reduction malformations can be of three types:
transverse,
longitudinal (pre-axial, post-axial, or median), or
intercalary (phocomelia).
In about half of cases, these are transverse amputations. In nearly two-thirds of cases, these are isolated malformations.
Register |
Period |
Births |
Live births |
Stillbirths (excluding IMG) |
IMG |
Total |
Total prevalence/10,000 (95% CI) |
Antilles |
2011–2015 |
47,493 |
16 |
2 |
15 |
33 |
6.9 (4.8–9.8) |
Auvergne |
2011–2015 |
66,381 |
26 |
2 |
27 |
55 |
8.3 (6.2–10.8) |
Brittany |
2011–2015 |
179 180 |
75 |
3 |
75 |
153 |
8.5 (7.2–10.0) |
Paris |
2011–2015 |
128,915 |
61 |
6 |
40 |
107 |
8.5 (7.0–10.3) |
Reunion |
2011–2015 |
71,756 |
33 |
2 |
20 |
55 |
7.7 (5.8–10.0) |
Rhône-Alpes |
2011–2015 |
292,693 |
136 |
11 |
115 |
262 |
9.0 (7.9–10.1) |
