Abstract
A retrospective study of neural tube defects (NTDs) was carried out among elective terminations of pregnancies, stillbirths and live births to women residing in two regions of Quebec, in 1992. Primary data sources included the hospital administrative data system MEDECHO, stillborn and infant death certificates, and the list of patients seen at three spina bifida clinics. Hospital records were reviewed. A total of 30 NTD cases were identified. The prevalence rate was 1.41 per 1,000, indicating a threefold reduction in frequency during the last three decades. All 17 cranial defects but only 5 of 13 spinal defects were diagnosed during pregnancy. Elective terminations were performed at an average gestation of 18 weeks (range 11 to 21 weeks). The MEDECHO file allows a complete identification of NTD cases, but diagnostic categories are not very specific and coding errors are present.
Résumé
Une étude rétrospective des anomalies de fermeture du tube neural (AFTN) a été réalisée parmi les interruptions médicales de grossesse, les mortinaissances et les naissances vivantes de mères résidant dans deux régions du Québec, en 1992. Les sources d’information primaires ont été le système médico-administratif MEDECHO, les certificats de mortinaissances et de décès infantiles, ainsi que la liste de patients suivis dans trois cliniques de spina bifida. Les dossiers hospitaliers ont été consultés. Au total, 30 cas d’AFTN ont été identifiés. Le taux de prévalence est de 1,41 pour mille, ce qui indique une réduction par un facteur 3 durant les trois dernières décennies. Les 17 cas de malformation crânienne ont été détectés en début de grossesse, mais seulement 5 des 13 cas de malformation de la colonne vertébrale. Les interruptions de grossesse ont été pratiquées en moyenne à 18 semaines de gestation (valeurs extrêmes: 11 et 21 semaines). Le fichier MEDECHO permet une identification complète des cas d’AFTN, mais les catégories diagnostiques sont peu spécifiques et il existe des erreurs de codification.
Footnotes
This study was supported by the “Direction de la planification du Ministère de la Santé et des Services sociaux du Québec” and the “Direction de la Santé publique, de la planification et de l’évaluation de la Régie régionale de la Santé et des Services sociaux de la Montérégie”.
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