ABSTRACT
Fetal period of time during which the fetus grows rapidly and the organs are formed. The prenatal and postnatal analyses of the fetal structure provide information as to fetal growth, growth retardation, gestational age and congenital malformations. The development of the skeletal system during the intrauterine period takes place in an orderly manner as it also does in other systems. It was aimed that the morphometric development of the forearm in human fetuses during the period between 20-40 gestational weeks be radiologically investigated and that its clinical importance be evaluated, as well. A total of 100 fetal forearms (50 fetuses: 23 male, 27 female), the ages of which varied between 20-40 gestational weeks, without having any external pathology or anomaly were incorporated into the study. The fetuses were separated into groups according to weeks, trimesters and months. After the general external measurements of the fetuses had been performed, the mammographies and forearm radiographies of the fetuses were shot in the way that the forearms would remain in a prone position. Morphometric measurements pertaining to forearm structures were taken from the forearm radiographies that were shot with the help of a digital compass. Later on, the morphometric measurements in question were statistically evaluated. The mean values and the standard deviations of the measured parameters were determined according to gestational weeks, trimesters and months. There was a significant correlation between the measured parameters and the gestational age (p<0.001). In the comparison of the measured parameters between trimesters and months, it was observed that there was a statistically significant difference between the groups (p<0.05). Separately, it was also determined that there was no statistically significant difference in the comparison of the parameters, which was made between genders and right-left forearms (p>0.05). As for the results obtained in our study, we are of the opinion that the data obtained during this study period will be beneficial for the involved clinicians, such as those in charge of gynecology, radiology, forensic medicine and perinatology, in terms of evaluating the clinical studies related to the morphometric development of the forearm throughout the fetal period, in determining the fetal age and sex, and also in determining the pathologies and variations regarding the development of fetal skeletal system.
El período fetal es el tiempo en el cual el feto crece rápidamente y se forman los órganos. Los análisis prenatal y postnatal de la estructura fetal proporcionan información sobre el crecimiento fetal, el retraso de crecimiento, la edad gestacional y las malformaciones congénitas. El desarrollo del sistema esquelético, como también el de otros sistemas durante el período intrauterino, avanza de manera ordenada. Se investigó radiológicamente el desarrollo morfométrico del antebrazo en fetos humanos durante el período comprendido entre 20-40 semanas gestacionales y se evaluó su importancia clínica. Un total de 100 antebrazos fetales (50 fetos: 23 de sexo masculino, 27 de sexo femenino), cuya edad varió entre 20-40 semanas de gestación, sin patología externa o anomalía, fueron incluidos en el estudio. Los fetos fueron separados en grupos de semanas, trimestres y meses. Después de realizar las mediciones externas generales de los fetos, las mamografías y las radiografías fueron realizadas de tal manera que los antebrazos permanecieran en pronación. Las radiografías de las medidas morfométricas correspondientes a las estructuras del antebrazo se tomaron con apoyo de una compás digital; posteriormente, las medidas fueron tratadas estadísticamente. Los valores medios y las desviaciones estándar de los parámetros medidos se determinaron de acuerdo con las semanas de gestación, los trimestres y los meses. Hubo una correlación significativa entre los parámetros medidos y la edad gestacional (p <0,001). En la comparación de los parámetros medidos entre los trimestres y los meses, se observó una diferencia estadísticamente significativa entre los grupos (p <0,05). Se determinó también que no hubo diferencias estadísticamente significativas en la comparación de los parámetros, que se realizó entre los sexos y los antebrazos derecho-izquierdo (p> 0,05). En cuanto a los resultados de nuestro estudio, los datos obtenidos durante este período de estudio serán beneficiosos para los clínicos, como también para profesionales de las áreas de ginecología, radiología, medicina forense y perinatología, en la evaluación de estudios clínicos relacionados con el desarrollo morfométrico del antebrazo durante todo el período fetal, determinación de la edad y el sexo fetal, así como en la determinación de variaciones en el desarrollo del sistema esquelético fetal.
Subject(s)
Humans , Male , Female , Pregnancy , Embryonic and Fetal Development , Forearm/diagnostic imaging , Forearm/embryology , Skeleton/embryologyABSTRACT
ABSTRACT The development of DBA/2J mouse strain embryos is nearly 12 h - or 6 somite pairs - delayed as compared to the outbred NMRI mouse embryos of the same age on gestation days (GD) 8-12. To evaluate inter-strain differences in susceptibility to teratogens, dams were treated with methylnitrosourea (MNU, 5 mg/kg body weight i.p.) on defined gestation days (NMRI: GD 9, 91/2 or 10; DBA/2J: GD 10 or 101/2). Skeletal anomalies produced by MNU on both mouse strains varied with the GD of treatment. The pattern of anomalies produced by MNU on a given GD markedly differed between the two mouse strains, yet they were similar -with a few exceptions- when exposures at equivalent embryonic stages are compared. Findings from this study indicated that strain-dependent differences in the developmental stage of mouse embryos of the same gestational age occur, a possibility that has been often neglected when inter-strain differences in susceptibility to developmental toxicants are interpreted.