Time mating guinea pigs by monitoring changes to the vaginal membrane throughout the estrus cycle and with ultrasound confirmation

Guinea pig development in utero is more similar to humans than any other rodent species. As such, their importance to reproductive studies is evident, particularly those studies focused on therapeutic interventions to improve human pregnancy outcome. Tracking the guinea pig estrus cycle is imperative to ensuring appropriately timed mating and can be performed by monitoring the guinea pig vaginal membrane. Here, we describe, and provide picture representation, of changes to the guinea pig vaginal membrane throughout the estrus cycle. Utilization of this monitoring enabled a 100% pregnancy success rate on the first mating attempt in a cohort of five guinea pigs. This approach, along with early pregnancy ultrasounds as a secondary method to confirm pregnancy, offers a cost effective and reliable approach to timed-mating in the guinea pig.