Terminology of Developmental Abnormalities in Common Laboratory Mammals (Version 2)

Abstract

This update (Version 2) of the Terminology ofDevelopmental Abnormalities in Common Laboratory Mammals (Version 1) incorporates improvements and enhancements to both content and organization of the terminology to enable greater flexibility in its application, while maintaining a consistent approach to the description of findings. The revisions are the result of an international collaboration among interested organizations, advised by individual experts and the outcomes of several workshops. The terminology remains organized into tables under the broad categories of external, visceral, and skeletal observations, following the manner in which data are typically collected and recorded in developmental toxicity studies. This arrangement of the tables, as well as other information provided in appendices, is intended to facilitate the process of specimen evaluation at the laboratory bench level. Only the commonly used laboratory mammals (i.e. rats, mice, rabbits) are addressed in the current terminology tables. The inclusion of other species that are used in developmental toxicity testing, such as primates, is considered outside the scope of the present update. Similarly, categorization of findings as, for example, 'malformation' or 'variation' remains unaddressed, in accordance with the overall principle that the focus of this document is descriptive terminology and not diagnosis or interpretation.The skeletal terms have been augmented to accommodate cartilage findings.

Lack of effects on female fertility and prenatal and postnatal offspring development in rats with BNT162b2, a mRNA-based COVID-19 vaccine

“…The remaining fetuses were eviscerated, macerated in potassium hydroxide, and stained with alizarin red [ 29 ] for skeletal examinations. All fetal morphological observations were recorded in general accordance with standardized terminology [ 30 ]. As defined by the Test Facility, fetal observations were classified as either malformations (structural defects that are rare in the control population and are thought to be life threatening or of major physiological consequence), anomalies (minor abnormalities or defects that are relatively rare in the control population and/or are considered not to be of major physiological consequence), or variations (minor abnormalities, defects or alternative forms that are either common in the control population or are of no known physiological consequence).…”

Differences in spontaneous fetal abnormalities among three outbred stocks of Wistar Hannover rats in Japan

“…The terms of morphological abnormalities in the present study were used in accordance with the Terminology of Developmental Abnormalities in Common Laboratory Mammals (Version 2) by Makris et al (2009).…”

NTP Developmental and Reproductive Toxicity Technical Report on the Prenatal Development Studies of 2-((1-(4-Phenoxyphenoxy)propan-2-yl)oxy)pyridine (CASRN 95737-68-1) in Sprague Dawley (Hsd:Sprague Dawley® SD®) Rats and New Zealand White (Hra:NZW SPF) Rabbits

“…In the prenatal developmental toxicity study, fetal examination is expanded to include examination of the fetal viscera, head (soft tissue and skeletal components), and the skeleton for osseous and cartilaginous defects. Abnormalities are separated into malformations that are permanent structural changes that might adversely affect survival, development, or function or variations that are a divergence beyond the usual range of structural constitution that might not adversely affect survival or health, 29 consistent with that described by Makris et al 32 The study design for the prenatal developmental toxicity study in rats is presented in Figure 2, and the study design for the dose range-finding and prenatal developmental toxicity studies in rabbits is presented in Figure 3.…”