Final answer:
Bleeding during pregnancy can occur from benign causes such as varicose veins, nose bleeds, or the 'bloody show,' as well as from serious conditions. Postpartum, women experience a type of bleeding called lochia. Increased blood volume and circulatory changes throughout pregnancy support fetal development but can also lead to these bleeding events.
Step-by-step explanation:
Bleeding in pregnancy can have several causes and varies in seriousness. Throughout pregnancy, the circulatory system undergoes significant changes: a substantial increase in blood volume by 30 percent, which can lead to conditions such as varicose veins or hemorrhoids, contributing to blood loss. Nasal congestion and nose bleeds may occur due to swollen respiratory mucosa. Another benign source of bleeding is the expulsion of a mucus plug from the cervical canal, a phenomenon known as the "bloody show," signaling that labor may soon begin. Pathological blood loss might be associated with conditions like hookworm infestation, peptic ulcer, or cancer.
During childbirth, Rh* fetal erythrocytes can leak into maternal blood. Postpartum, uterine contractions help limit blood loss. Nonetheless, new mothers experience a vaginal discharge called lochia, consisting initially of lochia rubra (red lochia) and then transitioning to lochia serosa and finally lochia alba over up to three weeks.