The third stage of labor begins immediately after the birth of the baby and concludes with the expulsion of the placenta, often referred to as the “afterbirth.” This stage is relatively short, but its successful management is highly important for maternal health. Following delivery, the uterus must contract rapidly to compress the blood vessels that supplied the placenta, preventing excessive bleeding. This process is managed through two distinct approaches: a natural, expectant method or a medicalized, interventionist method.
Physiological Management of Placenta Delivery
Physiological management is the “hands-off” or expectant approach, allowing the body to expel the placenta naturally without routine medical intervention. This process relies on the mother’s release of oxytocin, which causes the uterus to contract and shear the placenta from the uterine wall. Skin-to-skin contact and initiating breastfeeding soon after birth can help stimulate this natural oxytocin release.
Providers watch closely for several natural signs that indicate the placenta has separated from the uterine lining. These signs include a sudden gush of blood, the umbilical cord lengthening at the vaginal opening, and a change in the shape of the uterus, which becomes firmer and smaller. The cord is typically not clamped or cut until it has stopped pulsating, allowing for continued blood flow to the infant.
Once separation is confirmed, the mother may be encouraged to gently push the placenta out, often with the help of gravity from an upright position. This method involves no routine administration of uterotonic drugs or traction applied to the umbilical cord. Physiological management can take up to an hour to complete, but the time is not a concern as long as the mother is not experiencing heavy bleeding.
Active Management of Placenta Delivery
Active management is a medicalized approach that is the standard of care in many hospital settings globally, as it helps reduce the risk of significant postpartum bleeding. This method uses three main components designed to speed up the delivery of the placenta and ensure effective uterine contraction. The entire process typically takes between five and ten minutes.
The first component is the prophylactic administration of a uterotonic drug, most commonly ten units of oxytocin, usually given by injection into the thigh within one minute of the baby’s birth. This drug causes the uterine muscles to contract strongly and quickly, which helps to separate the placenta from the wall and minimize blood loss. The rapid onset of these strong contractions helps to prevent the most common cause of major postpartum hemorrhage, which is uterine atony.
The second component involves controlled cord traction (CCT), which is a gentle, steady pull on the umbilical cord. The provider performs this action only after the uterus has contracted and signs of placental separation are present. CCT is always accompanied by counter-pressure on the lower abdomen, which supports the uterus and helps prevent a rare but serious complication called uterine inversion.
The third component is uterine massage, performed immediately after the placenta has been delivered. The provider massages the abdomen over the top of the uterus (fundus) to ensure the muscle remains firm and contracted. This manual stimulation is a final measure to close off the blood vessels at the placental attachment site, further reducing the risk of bleeding.
Immediate Post-Delivery Assessment
After the placenta has been delivered, a detailed inspection is performed to ensure maternal safety. The placenta is thoroughly examined to confirm it is complete and that no fragments of tissue remain inside the uterus. The provider checks the maternal surface, which is divided into sections called cotyledons, to ensure the structure is intact.
The fetal membranes and the umbilical cord are also inspected for completeness and any abnormalities. Retained fragments of the placenta or membranes are a common cause of delayed postpartum hemorrhage and infection, making this visual inspection a highly important step. If an accessory placental lobe is suspected to be missing, this requires immediate attention.
The uterus is continuously monitored by checking the firmness and height of the fundus. A firm, well-contracted uterus indicates that the blood vessels are properly clamped down. The fundus is expected to be firm and located near the level of the navel one hour after delivery. Frequent checks are performed in the immediate postpartum period to assess for adequate uterine tone.
Recognizing and Managing Complications
The third stage of labor carries the risk of two major complications requiring prompt intervention: a retained placenta and postpartum hemorrhage (PPH). A retained placenta is diagnosed if the organ has not been expelled after a set time (typically 30 minutes with active management or 60 minutes with physiological management). When this occurs, the risk of severe bleeding increases significantly.
The primary risk of a retained placenta is that it prevents the uterus from contracting fully, leading to PPH. PPH is defined as excessive blood loss, generally over 500 milliliters following a vaginal delivery. The most frequent cause of PPH is uterine atony, which is the failure of the uterus to contract strongly enough to seal the blood vessels.
Interventions for a retained placenta include stronger uterotonic agents. If these fail, manual removal of the placenta may be necessary, which involves the provider inserting a hand into the uterus to detach and remove the tissue. If PPH occurs due to atony, immediate management includes aggressive uterine massage and the use of additional, stronger medications to stimulate uterine contraction.