Prolaps Tali Pusat

01Pathophysiology

The fundamental concept is straightforward: the umbilical cord is the sole lifeline between the fetus and the placenta. When the cord slips ahead of or alongside the fetal presenting part, it becomes trapped between the presenting part and the bony pelvis or cervix. This mechanical compression occludes the umbilical vessels, cutting off blood flow, oxygen delivery, and carbon dioxide removal.

The reason this happens relates to how the presenting part fits into the pelvis. In a normal vertex presentation with an engaged head, the fetal skull acts like a plug that fills the lower uterine segment and pelvic inlet completely, leaving no room for the cord to slip past. When the presenting part is abnormal (breech, transverse lie) or unengaged, there is a gap between the presenting part and the pelvic wall. Once the membranes rupture, the sudden rush of amniotic fluid can carry the cord downward through this gap.

Polyhydramnios increases risk because the large volume of fluid generates a stronger "wash-down" effect at membrane rupture. Prematurity contributes because the small fetal size leaves more space in the pelvis. Amniotomy performed when the presenting part is still high is an iatrogenic risk factor that students must recognize, since it combines the force of fluid release with a non-engaged head.

Once the cord is compressed, the fetal response is immediate. Umbilical vein occlusion reduces oxygenated blood return to the fetus, while umbilical artery occlusion prevents the fetus from offloading CO2. The resulting hypoxemia triggers a vagal response leading to fetal bradycardia. If the compression is intermittent (as with contractions), the CTG shows variable decelerations. If the compression is sustained, the result is prolonged bradycardia that rapidly progresses to acidosis, hypoxic-ischemic injury, and fetal death within minutes if not relieved.

The connection between pathophysiology and exam presentation is critical: a vignette describing sudden fetal heart rate changes immediately following membrane rupture, in a patient with known risk factors, should immediately trigger the thought of cord prolapse.

02Classification and Clinical Manifestation

Difference By type

03Diagnostic Workup

The diagnosis of overt cord prolapse is primarily clinical, not laboratory-based. The moment a patient with ruptured membranes develops sudden fetal bradycardia, the next best step is a vaginal examination, not ordering labs or imaging. When the examiner feels a soft, pulsating loop of cord in the cervical canal, the diagnosis is confirmed. No further testing is needed before initiating emergency management.

Continuous electronic fetal monitoring (CTG) is the screening tool that first raises the alarm. The classic pattern is a sudden-onset, prolonged bradycardia immediately after spontaneous or artificial rupture of membranes. Variable decelerations are also characteristic because they reflect intermittent cord compression. The key to the exam is understanding that variable decelerations are caused by cord compression (as opposed to late decelerations, which reflect uteroplacental insufficiency).

For occult prolapse, the cord is not palpable, so the diagnosis is inferred from CTG findings. Recurrent variable decelerations in a patient with risk factors for prolapse should raise suspicion. Repositioning the mother and amnioinfusion may relieve the compression; if the pattern does not improve, operative delivery is indicated.

Ultrasound plays a limited role in the acute emergency but is valuable in the antepartum period for identifying cord presentation (funic presentation) before membranes rupture. Color Doppler can show the cord lying over the internal cervical os.

There is no role for laboratory tests (blood gas, CBC, coagulation panel) in making the diagnosis. However, umbilical cord blood gas analysis is performed after delivery to assess the degree of fetal acidosis and document the neonatal outcome.

04Management and Treatment

Acute stabilization begins the moment the diagnosis is made. The single most important action is manual elevation of the presenting part. The examiner places a hand in the vagina and pushes the presenting part (usually the fetal head) upward and away from the cord. This is the intervention that buys time. Students must understand that this hand does not come out until the baby is delivered by cesarean.

Positioning is the next step. The knee-chest position (patient on hands and knees with chest down) or steep Trendelenburg (head-down, feet elevated) uses gravity to move the presenting part cephalad. This is simple, immediately available, and effective.

Bladder filling is a bridge maneuver. By inserting a Foley catheter and instilling 500 to 750 mL of warm saline, the distended bladder physically pushes the presenting part up. This technique allows the examiner to safely remove the hand from the vagina during transport to the operating room. The catheter is clamped to keep the bladder full until the cesarean incision is made.

Tocolysis with terbutaline (a beta-2 agonist, 0.25 mg given subcutaneously) halts uterine contractions. Each contraction pushes the presenting part down and compresses the cord further, so stopping contractions is a temporizing measure. This is a single dose, not ongoing therapy.

Emergency cesarean delivery is the definitive treatment in nearly all cases. The goal is a decision-to-delivery interval of under 30 minutes, though faster is always better. The only scenario where vaginal delivery is acceptable is when the cervix is fully dilated, the presenting part is at the pelvic floor, and delivery can be accomplished within minutes using vacuum or forceps.

After delivery, neonatal resuscitation should be immediately available. Umbilical cord blood gas analysis is sent to document the degree of acidosis. The neonate is assessed with Apgar scores and may require advanced resuscitation depending on the duration and severity of the hypoxic insult.

Contraindication note: Terbutaline should be used cautiously in patients with cardiac disease or uncontrolled hyperthyroidism. In such cases, the team may choose to omit tocolysis and proceed directly to cesarean without delay.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on cord prolapse questions is by failing to recognize the clinical scenario when it is presented indirectly. The classic trap vignette does not say "cord prolapse." Instead, it describes a patient with a known risk factor (breech presentation, polyhydramnios, or premature infant) who undergoes amniotomy or experiences spontaneous rupture of membranes, followed immediately by fetal bradycardia. The question asks for the "next best step in management." Students who do not link the fetal bradycardia to the membrane rupture event will choose "continue monitoring" or "administer oxygen to the mother" instead of the correct answer: perform a vaginal examination.

A second frequent trap involves the management sequence. After the diagnosis is confirmed, students sometimes select "emergency cesarean section" as the immediate next step. While cesarean is the definitive treatment, the immediate next step is manual elevation of the presenting part. The cesarean is being prepared simultaneously, but the question is testing whether you know to relieve the cord compression first.

Another tested concept is the distinction between overt and occult prolapse. A vignette showing recurrent variable decelerations without a palpable cord on exam is testing your ability to recognize occult prolapse and manage it appropriately (repositioning, amnioinfusion, or cesarean if unresponsive).

Finally, students must remember: never attempt to push the cord back into the uterus, and never handle the cord excessively, as both can cause vasospasm and worsen fetal compromise. The cord should be kept warm and moist, and the focus should be on lifting the presenting part, not manipulating the cord itself.

The core competency being tested is your ability to recognize an obstetric emergency from indirect clinical cues, perform the correct immediate intervention (vaginal exam followed by manual elevation), and understand the stepwise temporizing measures (positioning, bladder filling, tocolysis) that bridge to definitive surgical delivery.