A study on limb reduction defects in six European regions

Limb reduction defects (LRD) gained especial attention after the thalidomide tragedy in 1962, LRD are common congenital malformations which present as obvious congenital anomalies recognized at birth, Therefore it might be assumed that they are well documented, However classification of LRDs is disputed as the identification of the exact site of the reduction (s) is hindered by imprecise information, This study was undertaken in 6 European countries to evaluate the use of the new classification proposed by EUROCAT for the epidemiologic and genetic study of LRD. The total number of births including livebirths, stillbirths and terminations, surveyed during 7 years by the 6 registries of congenital anomalies participating to this study was 611.150, The total prevalence of LRD was 7.06 per 10.000 births including the following categories prevalence : terminal transverse, 3.97, longitudinal, 1.75, proximal-intercalary, 0.10, split hand/foot 0.54 and multiple types 0.70, The prevalence of LRD was statistically higher in Basque Country, Odense, Strasbourg and Groningen than in Belfast and Emilia Romagna. Six per cent of the cases were chromosomal anomalies, including 15 trisomies 18 out of 26 cases, 49.5 % (201 cases) were isolated LRD and 50.5 % (206 cases) had other major non LRD associated malformations. Sex ratio and maternal age were not statistically different between regions and from the normal population. Multiply malformed with LRD had statistically significantly lower birthweight and lower gestational age than isolated cases with LRD, where available prenatal detection of LRD was higher in multiple malformed children with LRD than in isolated cases, 19.9 % and 4.8 % respectively. The precurrence risk was 1 in 37

Evaluation of the prenatal diagnosis of neural tube defects by ultrasonographic examination in different centres across Europe.

OBJECTIVE: Evaluation of prenatal diagnosis of neural tube defects by ultrasound examination in unselected populations across Europe. SETTING: Prenatal ultrasound units in areas that report to contributing congenital malformation registers. METHODS: All cases with a suspected or confirmed neural tube defect and delivered within the 30 month study period were identified from 18 Congenital Malformation Registers from 11 European countries. Data on the pregnancy, prenatal scans, outcome of pregnancy, and information on different screening policies for each country were analysed. RESULTS: 670766 deliveries occurred in the area covered by the registers during the study period. A neural tube defect was diagnosed at delivery in 542 cases. In 84% of these, the lesion was isolated (166 anencephaly, 252 spina bifida, 35 encephalocele). Of the 166 isolated cases with anencephaly, 96% were correctly identified prenatally; one was missed on scan, two were wrongly diagnosed, and four were not scanned (sensitivity 98%). 84% of the prenatal diagnoses were made before 24 weeks' gestation; 86% of isolated anencephalic pregnancies were terminated. Of the 252 cases of isolated spina bifida, 171 (68%) were correctly identified prenatally; 66% of these before 24 weeks' gestation. The diagnosis was missed on scan in 60 cases and 21 were not scanned (sensitivity 75%). The mean reduction in birth prevalence because of termination of pregnancy for spina bifida was 49% (range 6-100%). There was a wide variation between centres in prenatal detection rate (33-100%), termination of pregnancy of prenatally diagnosed cases (17-100%), and gestation both at diagnosis and termination of pregnancy. CONCLUSION: A high prenatal detection rate for anencephaly was reported by all registers. There is a large variation in prenatal detection and termination rates for spina bifida between centres, reflecting differences both in policy and culture