Postpartum hemorrhage (PPH) refers to excessive blood loss after childbirth, a serious complication. It is a significant cause of maternal mortality globally, contributing to preventable deaths. This article informs readers about PPH and the factors that increase its likelihood.
Understanding Postpartum Hemorrhage
Postpartum hemorrhage is categorized into two main types based on when bleeding occurs. Primary PPH happens within the first 24 hours after birth. Secondary PPH refers to bleeding that develops between 24 hours and up to 12 weeks postpartum. While definitions vary, PPH generally involves significant blood loss or any amount accompanied by signs of hypovolemia.
The underlying physiological reasons for PPH are summarized by the “Four T’s”: Tone, Trauma, Tissue, and Thrombin. Uterine atony, or “Tone,” refers to the uterus failing to contract adequately after the placenta is delivered. Normally, uterine contractions compress blood vessels at the placental attachment site, preventing excessive bleeding. When the uterus remains soft and weak, these vessels continue to bleed freely, making uterine atony the most common cause of PPH, accounting for up to 80% of cases.
“Trauma” involves injuries to the birth canal, such as lacerations of the cervix, vagina, or perineum, or even uterine rupture. These tears can lead to significant blood loss. “Tissue” refers to retained placental fragments or blood clots within the uterus. Any remaining tissue prevents the uterus from effectively contracting, leading to continued bleeding. This category also includes conditions like placenta accreta, where the placenta is abnormally attached and fails to detach properly.
“Thrombin” relates to blood clotting disorders (coagulopathies). If a woman’s blood does not clot efficiently, even minor bleeding can become excessive and difficult to control. Conditions like pre-eclampsia and HELLP syndrome can affect clotting factors and platelets, increasing the risk of PPH.
Key Factors Increasing Risk
Many factors can increase a woman’s likelihood of experiencing postpartum hemorrhage, stemming from her health, pregnancy, and the delivery process. Certain maternal medical conditions can elevate this risk. For instance, pre-eclampsia and gestational hypertension are associated with a higher incidence of PPH. Anemia, obesity, and pre-existing bleeding disorders like von Willebrand disease also contribute to an increased risk. Some medications, such as anticoagulants or magnesium sulfate, can interfere with blood clotting or uterine contractions, raising the risk.
Pregnancy-related factors can predispose a woman to PPH. Carrying multiple babies overdistends the uterus, making it harder for the muscle to contract effectively after delivery. Polyhydramnios can also lead to uterine overdistension. Grand multiparity can weaken the uterine muscle over time, increasing the risk of atony.
Placental abnormalities, including placenta previa or placental abruption, increase PPH risk. A previous PPH also raises the chance of recurrence in subsequent pregnancies.
Factors during labor and delivery also contribute to PPH risk. Prolonged or rapid labor can exhaust the uterine muscles, making them less effective at contracting post-delivery. Induced labor can sometimes desensitize the uterus to its contracting effects. Operative vaginal deliveries using forceps or vacuum extraction, as well as Cesarean sections, are associated with increased blood loss due to trauma or their surgical nature.
A large baby, or macrosomia, also contributes to uterine overdistension. Infections within the uterus can impair uterine contractility, increasing PPH risk.
Specific placental issues can directly cause PPH. Retained placental tissue, where parts of the placenta remain inside the uterus after delivery, is a common cause of continued bleeding. More severe conditions like placenta accreta, increta, or percreta involve abnormal adherence of the placenta to the uterine wall, sometimes invading the uterine muscle or beyond. These conditions make placental detachment extremely difficult and are associated with a high risk of severe hemorrhage, often requiring surgical intervention, including hysterectomy, to control the bleeding.
Recognizing and Managing PPH
Recognizing postpartum hemorrhage promptly is important for effective management. The most obvious sign is persistent, heavy vaginal bleeding, which may include passing several large blood clots. Beyond visible bleeding, signs of hypovolemic shock can develop, such as dizziness, lightheadedness, a rapid heart rate (tachycardia), and a drop in blood pressure. The uterus may also feel soft and boggy (atonic) upon examination, rather than firm and contracted, or it may appear enlarged.
Upon identification, immediate medical response focuses on rapid assessment and intervention. Initial steps often include vigorous uterine massage to stimulate contractions and expel any remaining clots or tissue. This is followed by the administration of uterotonic medications, such as oxytocin, which help the uterus contract and compress bleeding vessels. Fluid resuscitation with intravenous fluids is also started immediately to help stabilize the woman’s blood pressure and circulating volume. PPH is an emergency requiring swift, coordinated action from the medical team to control bleeding and prevent further complications.
Proactive Measures to Reduce Risk
Proactive measures are implemented to reduce the risk of postpartum hemorrhage, starting even before labor begins. During antenatal care, addressing conditions such as anemia is important, as improving a woman’s blood count before delivery can enhance her ability to tolerate potential blood loss. Management of chronic medical conditions throughout pregnancy also helps optimize overall health and reduce associated PPH risks.
During labor and delivery, active management of the third stage of labor is a recommended strategy to prevent PPH. This approach involves coordinated interventions. A key component is the administration of a uterotonic drug, most commonly oxytocin, shortly after the baby’s delivery. This medication helps the uterus contract strongly, reducing the likelihood of atony.
Another element of active management is controlled cord traction, where gentle tension is applied to the umbilical cord to assist in the expulsion of the placenta once it has separated. Following placental delivery, uterine massage is performed to ensure the uterus remains firm and contracted. Continuous monitoring of the woman’s bleeding and vital signs during and after delivery allows for early detection of any issues. Hospitals also maintain readiness for PPH by having protocols and necessary resources in place to respond quickly if excessive bleeding occurs.