Birth sequence in mice.
Succession of deliveries at parturition was determined in mice following a marker injection in utero. The data failed to refute the hypothesis of a random birth order, as delivery from either uterine horn was found to be unpredictable. In addition, significantly more females delivered the first pup from the right uterine horn, supporting the concept of a "physiological dominance" for the right side of the mouse reproductive tract.
D000818:Animals; D001722:Birth Order; D036861:Delivery, Obstetric; D005260:Female; D007743:Labor, Obstetric; D051379:Mice / Q000502:physiology*; D011247:Pregnancy