Uterine atony: Clinical sciences

Uterine atony is the failure of the uterus to contract adequately after childbirth. This occurs due to a poor response to oxytocin resulting in failure of myometrial contraction. Uterine atony can occur after either vaginal delivery or cesarean section and is the number one cause of postpartum hemorrhage. Some methods can be used to prevent uterine atony, including active management during the third stage of labor, such as prophylactic uterotonics, uterine massage, and placental delivery.

Your first step in evaluating a postpartum patient who presents with a chief concern suggesting uterine atony is to perform CABCDE assessment. If the patient is unstable, you should stabilize their airway, breathing, and circulation right away. This means you may need to intubate the patient and obtain IV access. Ideally, two large bore IVs will already be present to allow for adequate resuscitation. Finally, you should continuously monitor their vitals.

Once these important steps are done, you can move on to focused history and physical exam. Also, obtain labs like CBC, PT, INR, PTT, and fibrinogen. Now, patients may report feeling dizzy or anxious and may experience tunnel vision after giving birth. When taking history, be sure to see if the patient has any risk factors for uterine atony. These include high parity, multiple gestation such as twins or triplets, fetal macrosomia, chorioamnionitis, polyhydramnios, as well as general anesthesia, and prolonged oxytocin use.

When it comes to a physical exam, it typically reveals hypotension and tachycardia, as well as an altered mental status to the point of being unconscious. Patients may look pale and their skin may feel cold or clammy due to the acute blood loss. On abdominal exam, the uterus will be soft, boggy, and poorly contracted, which will result in continuous bleeding from the uterus. Okay, let’s move on to labs. They typically reveal anemia and may also show thrombocytopenia, elevated coagulation studies, and low fibrinogen as coagulation factors are consumed.