Figure 3.

Weight changes in the guinea pig throughout gestation. Noticeable increases in gestational weight are not reliable until mid-pregnancy in the guinea pig. Healthy fetuses were confirmed in all the animals at gestational day 30 using an ultrasound, except for one animal (#1) in which blood in the vaginal lumen was observed at gestational day 24 and was associated with a decrease in cumulative weight gain. At post mortem, #3 had four fetuses, #5 had three fetuses, #2 and #4 had two fetuses, and #1 was not pregnant.