Final answer:
Lochia serosa, the thinner, pinkish vaginal discharge that follows the initial thick, dark discharge called lochia rubra, is present during the second week postpartum.
Step-by-step explanation:
Lochia serosa is present during the postpartum period as the vaginal discharge that occurs after the birth of a child. This type of discharge is a sign that the body is healing following childbirth. Lochia serosa is the thinner, pinkish discharge that follows lochia rubra, the initial thick, dark discharge. It typically appears after the first few days postpartum and continues until about the tenth day. Therefore, lochia serosa is present during the second week postpartum. It is thinner and pinkish in color and typically lasts until about the tenth postpartum day. This discharge is composed of uterine lining cells, erythrocytes, leukocytes, and other debris.