Body weight as a diagnostic method of pregnancy in Wistar rats

Abstract

Introduction: The methods used in the diagnosis of pregnancy in rats mostly have disadvantages, such as: the need for a high degree of professional expertise, material costs, the need for anesthesia and the impossibility of diagnosing on the first days. However, the determination of body weight is easily obtained data, supported by a simple and non-invasive technique, which represents an advantage over other methods. Objective: To determine on which day of gestation the increase in body weight reaches sufficient significance to establish the diagnosis of pregnancy in Wistar rats. Material and Methods: It is an observational, prospective, longitudinal study. A total of 37 females were selected and divided into two groups: 24 pregnant rats (RG) and 13 non-pregnant rats (RNG). Both groups were weighed on gestation days 0, 2, 6, 9, 13 and 16. The variation in body weight was analyzed through the days. Results: Despite the body differences between groups on days 2 and 6, the results were inconclusive for this stage. The GR reached a minimum average increase of 27.5 g towards day 9, for this same day the average increase in the GR and RNG was 36.1 g and 9.17 g, respectively. Conclusions: Body weight from day 9 of gestation reaches sufficient relevance for the diagnosis of pregnancy in heterozygous Wistar rats, but not before day 6.

Keywords

• diagnóstico de preñez en ratas
• peso corporal
• apareamiento programado
• diagnosis of pregnancy in rats
• body weight
• timed mating