Notice bibliographique
Résumé
Trisomy 21, the chromosome abnormality responsible for over 95% of Down syndrome, is one of the most common conditions encountered in the genetic clinic. Recently, the increasing share of pregnancies with advanced maternal age and its impact on the increased incidence of trisomy 21 have been reported in the United States [1-3]. Our hospital is one of main perinatal centers in Tokyo, Japan (about 2,100 deliveries per year). In this study, we examined the recent incidence of trisomy 21 associated with maternal age at our hospital. We reviewed the obstetric records of all Japanese singleton pregnancies at our hospital form January 2005 through January 2011. Demographic information and the characteristics of labor were extracted from patient charts. The conditions of the study patients were Japanese singleton pregnancies whose estimated date of delivery were from January 2006 through December 2011 and managed from 14 weeks or earlier at our hospital. In this study, thus, we have excluded the cases as follows (1) multifetal pregnancies, (2) non-Japanese pregnancies, (3) the time of first visit of our hospital at ≥ 15 weeks’ gestation, and/or (4) spontaneous fetal demise before 22 weeks’ gestation. We examined the maternal age at age of the estimated date of delivery. There were 28 cases of trisomy 21 in 10964 Japanese singleton pregnancies (1/392). In our hospital, there were 39 cases of trisomy 21 in total during this period; however, there were 8 cases of trisomy 21 refereed to our hospital at ≥ 15 weeks’ gestation due to fetal abnormality, 2 non-Japanese cases of trisomy 21 and 1 case of trisomy 21 in twin pregnancy. During this period, the average maternal age of all pregnancies was 32.3 ± 5.5 years old and 35% of the mothers were 35 years old or more at the estimated date of delivery; while the average maternal age in the cases with trisomy 21 was 38.0 ± 4.7 years old. The incidence of trisomy 21 in cases of maternal age of < 35 years (3 cases, average: 27.7 ± 3.5 years), 35 39 years (15 cases, average: 37.5 ± 1.1 years) and ≥ 40 years (10 cases, average: 41.7 ± 1.9 years) were 1/2364, 1/209 and 1/74, respectively. These incidences by maternal age were almost similar to those reported previously in the United States [4]. Of the 28 cases of trisomy 21, 11 cases (39%) were diagnosed as trisomy 21 prenatally using amniocentesis due to maternal request. Ten cases of them (91%) were artificial aborted; thus, the incidence of live births with trisomy 21 was 1/608 (18 cases). The average maternal age in the cases diagnosed prenatally was significant higher than that diagnosed postnatelly (40.1 ± 3.3 vs. 36.6 ± 5.0 years, p < 0.01 by unpaired t-test). The tendency is also similar to that reported in the United States [1-3]. In conclusion, in Japan the recent increased share of pregnancies with advanced maternal age seemed to contribute to the increased incidence of trisomy 21 as observed in other countries.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».