October 15, 2026 Author : Noémia Nunes (obstetrics-gynecology ) Placental abruption (abruptio placentae) is a pregnancy complication in which : The placenta partially or completely separates from the wall of the uterus during pregnancy; It can compromise the supply of oxygen and nutrients to the baby; The mother's symptoms vary according to the severity of the abruption; Treatment depends on the stage of pregnancy and the severity of the abruption and aims to protect the health of both the baby and the mother. What is the placenta and what is placental abruption? The placenta is a temporary organ that develops only during pregnancy . It forms inside the uterus, attaches to the uterine wall, and connects to the baby through the umbilical cord. Through the placenta and umbilical cord, oxygen and nutrients are delivered to the baby, while waste products from the baby's metabolism are removed. The placenta also plays a role in fetal protection and hormone production. Under normal circumstances, the placenta remains firmly attached to the uterine wall throughout pregnancy and separates only after the baby is born . Following delivery, the uterus contracts strongly, causing the placenta to detach from the uterine wall and be expelled through the vagina during the so-called third stage of labor, usually within the first 30 minutes after birth. One complication that may occur during pregnancy is premature placental abruption, meaning the partial or complete separation of the placenta from the uterine wall before delivery. Placental abruption occurs most frequently during the third trimester of pregnancy, particularly in the final weeks before birth. However, it can occur from 20 weeks of gestation onwards. It can be a serious condition because it may compromise the baby's supply of oxygen and nutrients and cause severe bleeding in the mother . When the placenta separates from the uterine wall, it disrupts the maternal blood vessels responsible for blood circulation between the mother and the placenta, leading to bleeding inside the uterus and/or externally through the vagina. What causes placental abruption and which pregnant women are at higher risk? It is not always possible to identify an exact cause of placental abruption. However, several medical conditions and behaviors are known to increase the risk, including : Chronic hypertension; Gestational hypertension and pre-eclampsia; History of placental abruption in a previous pregnancy; Smoking and illicit drug use; Abdominal trauma; Premature rupture of membranes; Multiple pregnancy; Pregnancy at advanced maternal age; Certain blood vessels or blood clotting conditions. What are the symptoms of placental abruption? Symptoms may appear suddenly. The most common are : Vaginal bleeding; Persistent abdominal pain; Lower back pain; Uterine contractions; Uterine tenderness or a feeling of a hard, rigid uterus; Decreased fetal movements. These symptoms may not all be present , and their severity depends on the extent of the placental abruption. Furthermore, they may also occur in other pregnancy complications or, in some cases, have other causes. Even in cases of significant placental abruption, vaginal bleeding may not occur because blood can remain trapped between the placenta and the uterine wall. How is placental abruption diagnosed and treated? Diagnosis is based on the woman symptoms and on tests that assess fetal wellbeing , such as ultrasound and cardiotocography (CTG). Ultrasound may help confirm the diagnosis and allows evaluation of both placental status and fetal wellbeing. Blood tests may also be needed to assess the extent and consequences of bleeding and to identify clotting disorders. The placenta cannot be reattached to the uterine wall. Therefore, treatment focuses on protecting the health and wellbeing of both the baby and the mother and determining the safest time for delivery . Management depends on the severity of the abruption, the gestational age, and the clinical condition of both mother and baby. If the abruption is minor and the pregnancy is still far from term, hospitalization for maternal and fetal monitoring or more frequent obstetric follow-up may be required. In more severe cases, with significant bleeding or evidence of fetal distress, the best option may be urgent delivery, often by caesarean section. Remember Partial or complete separation of the placenta from the uterine wall before the baby is born is a potentially serious obstetric complication that requires urgent medical evaluation. Therefore, a pregnant woman should contact her doctor immediately or go to a hospital obstetric emergency department if she experiences : Vaginal bleeding; Severe or persistent abdominal or lower back pain; Frequent and painful contractions, uterine tenderness, or a sensation of uterine tightening; Reduced fetal movements. Meet the obstetrics-gynecology clinical team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item. English translation generated with AI and reviewed by the editorial team.
