The umbilical cord serves as the essential connection between a developing fetus and the placenta during pregnancy. It facilitates the exchange of oxygen, nutrients, and waste products for the growing baby. After birth, the cord is clamped and cut, but a portion remains connected to the placenta, which is still inside the mother’s uterus.
Understanding the Placenta’s Role
The placenta is a temporary organ that forms within the uterus during pregnancy. This organ attaches to the uterine wall and connects to the fetus via the umbilical cord. Through this connection, the placenta delivers oxygen and nutrients from the mother’s bloodstream to the baby.
Beyond its role in nutrient and oxygen supply, the placenta also removes carbon dioxide and waste products from the baby’s blood. It acts as the baby’s lungs, kidneys, and liver until birth, and produces hormones that support the pregnancy. The placenta additionally transfers antibodies from the mother to the baby, providing immunity. After birth, the placenta, with the remaining umbilical cord attached, must be expelled.
The Third Stage of Labor: Placental Expulsion
The third stage of labor begins immediately after the baby is born and concludes with the delivery of the placenta. This process involves the placenta detaching from the uterine wall and being expelled through the vagina. Uterine contractions, which continue after birth, play a significant role in this separation and expulsion.
Healthcare providers look for several signs indicating placental detachment. These signs include a gush of blood from the vagina, a noticeable lengthening of the umbilical cord, and the uterus becoming more globular in shape and firmer upon palpation. The uterus also tends to rise higher in the abdomen as the detached placenta descends into the lower uterine segment.
The management of this stage can vary, falling into two main approaches: physiological (or expectant) management and active management. Physiological management allows the placenta to be expelled naturally through uterine contractions and maternal pushing efforts, often without immediate cord clamping or uterotonic medications. Active management involves administering a uterotonic agent, like oxytocin, to encourage strong uterine contractions, often combined with controlled cord traction and early cord clamping to hasten placental delivery. Spontaneous expulsion of the placenta occurs within 5 to 30 minutes, though active management can expedite this process.
Post-Delivery Care and Examination
After the placenta and its attached umbilical cord are expelled, care focuses on the mother’s well-being. The uterus begins a process called involution, where it contracts to return to its pre-pregnancy size. These ongoing contractions are important as they compress blood vessels at the site where the placenta was attached, helping to prevent excessive bleeding.
Medical staff carefully examine the expelled placenta and umbilical cord. This inspection ensures that the placenta is complete and that no fragments remain inside the uterus, as retained placental tissue can lead to postpartum hemorrhage or infection. The examination includes checking the maternal surface for completeness of its lobes and inspecting the fetal membranes. The umbilical cord is also assessed for its length, insertion point, and the number of blood vessels present, providing information about the pregnancy’s course.