Breech Presentation

1. THE 2-MINUTE PHYSIOLOGY (Rapid Pathophysiology)

• Mechanical Mismatch: Unlike cephalic presentation where the hard, symmetric fetal skull acts as an optimal, gradual dilating wedge, breech presentation features the softer, smaller, and irregular fetal buttocks or lower extremities entering the lower uterine segment first. This fails to dilate the maternal cervix adequately for the passage of the largest fetal part.
• The Head Entrapment Mechanism: Because the pelvis and lower extremities deliver first, they can easily slip through an incompletely dilated cervix (frequently seen in pre-term or precipitous deliveries). The fetal head, which is the largest and least compressible part, then becomes trapped behind the constricting cervix or the bony maternal pelvis, resulting in rapid, severe fetal asphyxia.
• Umbilical Cord Compression & Prolapse: In cephalic deliveries, the fetal head occupies the entire pelvic inlet, preventing the umbilical cord from slipping past. In breech—especially footling or incomplete breech—the presenting part does not fill the pelvic inlet, allowing the umbilical cord to prolapse into the vagina. Furthermore, as the fetal body delivers, the umbilical cord is compressed between the descending head/pelvis and the maternal pelvis, cutting off fetoplacental blood flow and driving severe hypoxia.
• Premature Fetal Respiration: As the fetal torso delivers and is exposed to cold ambient air, the tactile and thermal stimulation can trigger a premature gasping reflex while the head is still trapped in the birth canal, leading to fatal aspiration of amniotic fluid or vaginal secretions.

2. THE BEDSIDE ACTION PLAN (Rapid ER Management)

Immediately activate a multidisciplinary emergency resuscitation team, including Emergency Medicine, Obstetrics, and Neonatology/Pediatrics.

• AIRWAY & STABILIZATION:
• Establish two large-bore IV lines above the diaphragm.
• Ensure the neonatal resuscitation cart is fully equipped and active at the bedside, including a warm mattress, suction, and neonatal bag-valve mask.
• THE TRANSFER CRITERIA:
• If time permits, transfer the patient immediately to the Labor and Delivery (L&D) suite for a cesarean section.
• Imminent Delivery Assessment: Labor is unpredictable; clinical judgment is required. Perform a pelvic exam to ensure precipitous delivery is not imminent. If the fetus is crowning or the cervix is fully dilated, transfer is contraindicated; prepare for immediate delivery in the ED.
• MATERNAL POSITIONING:
• Place the patient in the lithotomy position with her buttocks at the very edge of the stretcher. This allows gravity to assist in drawing the fetal body downward.
• THE "HANDS-OFF" PROTOCOL (Crucial):
• Allow the fetus to deliver spontaneously up to the level of the umbilicus. DO NOT touch, pull, or apply traction to the fetus during this stage. Premature traction triggers a fetal Moro reflex, causing the arms to extend above the head (nuchal arms) and the neck to hyperextend, locking the head in the pelvis.
• UMBILICAL CORD LOOP:
• Once the umbilicus delivers, gently reach in and pull down a loose loop of the umbilical cord to relieve traction and cord compression.
• DELIVERY OF THE LEGS (Pinard's Maneuver):
• If the legs do not deliver spontaneously, insert two fingers into the vagina, apply digital pressure in the popliteal fossa of each knee to flex the joint, and gently sweep the legs laterally out of the vagina.
• DELIVERY OF THE ARMS (Løvset's Maneuver):
• If the arms are extended, grasp the fetus by the bony pelvis (thumbs on the sacrum) and rotate the body 180 degrees. This brings the posterior arm under the maternal pubic symphysis, allowing it to sweep out. Rotate 180 degrees in the opposite direction to deliver the other arm.
• DELIVERY OF THE HEAD (Mauriceau-Smellie-Veit Maneuver):
• Place the fetal body straddling your non-dominant arm.
• Insert the index and middle finger of your non-dominant hand into the fetal mouth or onto the maxilla (malar bones) to pull the chin down and maintain neck flexion (do not pull on the jaw).
• Place your dominant hand on the fetal shoulders, with your index and middle fingers on either side of the neck.
• Apply gentle traction downward and outward while a bedside assistant applies suprapubic pressure (never fundal pressure) to maintain head flexion and guide the head through the pelvis.
• Sweep the fetal body upward toward the mother's abdomen to deliver the face.
• MANAGING HEAD ENTRAPMENT:
• Uterine Relaxants: Administer Nitroglycerin 50 to 200 mcg IV push (or sublingual) or Terbutaline 0.25 mg SC to rapidly relax the cervix.
• Dührssen Incisions: If medical relaxation fails, perform surgical incisions on the cervix at 2, 6, and 10 o'clock using bandage scissors to enlarge the opening and relieve head entrapment. Critical: Avoid 3 and 9 o'clock where the uterine arteries run.

3. THE DIAGNOSTIC GRID (Differential Diagnosis & Workup)

Top 4 Critical "Can't-Miss" Differential Diagnoses:

1. Face / Brow Presentation: Can feel soft on digital examination and be mistaken for buttocks. Differentiated by palpating facial landmarks (nose, mouth, bony orbital ridges) rather than the anus and ischial tuberosities.
2. Shoulder Dystocia: Occurs in cephalic presentations; the head delivers but the shoulders are trapped behind the pubic symphysis. Unlike breech, the head is already delivered, and you will see the classic "turtle sign."
3. Transverse Lie / Shoulder Presentation: Fetus lies horizontally across the pelvis. A hand or shoulder may prolapse. Vaginal delivery is mechanically impossible; mandates emergency cesarean section.
4. Umbilical Cord Prolapse: The cord delivers ahead of the presenting part, leading to severe fetal bradycardia.

Prioritized Diagnostic Workup Strategy:

• Pelvic Examination: Perform immediately to assess cervical dilation, effacement, and fetal station, and to ensure precipitous delivery is not imminent.
• Fetal Heart Rate (FHR) Monitoring: Initiate continuous cardiotocographic monitoring to rule out fetal distress or preterm labor.
• Maternal Labs: Type and screen, CBC, and coagulation profile (fibrinogen, PT/INR) if hemorrhage or abruption is suspected.

4. THE VISUAL BOARD (ECG / POCUS / Imaging)

• Point-of-Care Ultrasound (POCUS):
• Presentation View: Place the low-frequency transducer transabdominally just superior to the maternal pubic symphysis. Scan for presentation. In breech, you will visualize the soft, irregular fetal pelvis (buttocks/genitals) or lower extremities in the lower uterine segment instead of the classic hypoechoic, round, hard fetal skull (with its highly echogenic midline falx echo).
• Fundal Scan: Scan the uterine fundus to locate the fetal head, which will appear as a highly echogenic round structure with a bright skull table.
• Fetal Heart Rate and Placenta: Use POCUS to assess fetal viability and evaluate for placental location to rule out placenta previa or abruption.
• Maternal Imaging:
• Pelvic radiographs or CT scans are completely contraindicated during active labor. If the patient is a trauma victim, do not withhold necessary CT scans, but prioritize clinical assessment and POCUS first.

5. THE SCORING MATRIX (Risk Stratification & Guidelines)

• EMTALA Stabilization Guidelines:
• Under the Emergency Medical Treatment and Labor Act (EMTALA), a patient is considered unstable if delivery is imminent or in progress.
• Gestational Age and Viability Guidelines:
• Below 24 weeks' gestation, the chances of fetal survival are less than 50%. If the fetus is viable (\(\geq\) 22-24 weeks), continuous fetal monitoring is mandatory.
• Breech Type Classification:
• Frank Breech (hips flexed, knees extended): Lowest risk of cord prolapse; most common type.
• Complete Breech (hips flexed, knees flexed): Intermediate risk of cord prolapse.
• Incomplete / Footling Breech (one or both feet presenting): Highest risk of cord prolapse (\(\sim\)15-20%); absolute indication for emergency cesarean section if delivery is not imminent.

6. THE DANGER ZONE (Pitfalls & Critical Actions)

Deadly Cognitive Traps & Trainee Errors:

• The "Traction Trap": Trainees instinctively want to pull on the fetal legs or buttocks as soon as they appear. This is a deadly mistake. Traction before the scapulae/shoulders have delivered causes the arms to wrap behind the head (nuchal arms) and extends the fetal neck, causing immediate, catastrophic head entrapment. Keep your hands off the fetus until the umbilicus delivers!
• The Fundal Pressure Error: Applying pressure to the maternal uterine fundus to "help push the baby out" pushes the extended head further into the pelvis, locking the chin behind the pubic symphysis and worsening entrapment. Only apply suprapubic pressure to keep the head flexed.
• Incorrect Dührssen Incision Locations: Making cervical incisions at 3 and 9 o'clock will lacerate the uterine arteries, causing catastrophic maternal hemorrhage. Only make incisions at 2, 6, and 10 o'clock.

Board-Mandated Critical Actions:

• Manual Leftward Displacement of the Uterus: If the patient is still pregnant and the fundus is \(\geq\) 20 weeks' gestation, place her in the left lateral tilt position or perform continuous manual leftward displacement of the uterus.
• The 4-Minute Hysterotomy Rule: If maternal cardiac arrest occurs and the uterus is \(\geq\) 20 weeks' gestation (at or above the umbilicus), resuscitative hysterotomy (perimortem cesarean section) must be initiated by 4 minutes and completed within 5 minutes of no ROSC.

7. MCQ MASTERCLASS (Written Exam Tips)

• Buzzwords to Identify Breech Presentation:
• "Ischial tuberosities and anus palpated on digital exam" \(\rightarrow\) Frank breech.
• "Mauriceau-Smellie-Veit maneuver" \(\rightarrow\) Malar flexion and shoulder traction to deliver the head.
• "Dührssen incisions" \(\rightarrow\) Surgical relief for entrapment by an incompletely dilated cervix.
• High-Yield Facts:
• Most common type of breech presentation: Frank breech.
• Breech type with the highest risk of cord prolapse: Footling / Incomplete breech.
• First-line pharmacologic agent for cervical entrapment: Nitroglycerin IV or sublingual.
• Deciphering Distractors:
• Exams will ask about the correct location for Dührssen incisions. Distractors will include 3 and 9 o'clock. Avoid 3 and 9 o'clock because the uterine arteries run there, and incising them can cause fatal maternal exsanguination.
• Exams will try to suggest that applying fundal pressure is useful during breech delivery. This is a trap—fundal pressure is contraindicated; only suprapubic pressure should be applied.

8. THE BOARDROOM SCRIPT (OSCE & Oral Board Tips)

Mandatory OSCE Communication Actions:

• Activate the Multidisciplinary Team Immediately: State, "I am immediately activating the emergency obstetric resuscitation team, including Obstetrics, Anesthesia, Neonatology, and the ICU. I am requesting that the neonatal resuscitation cart be fully prepared".
• Verbalize Priority: State, "My primary goal is maternal stabilization and rapid assessment of fetal delivery status to determine if emergency cesarean section is indicated or if precipitous delivery is imminent".

High-Yield Phrasing to Use under High-Stress Testing:

• On Patient Presentation (Imminent Breech Delivery):
• "I am placing the patient in the lithotomy position at the very edge of the bed. I am establishing two large-bore IVs above the diaphragm".
• "I am performing a rapid pelvic exam to assess cervical dilation, effacement, and fetal station".
• On Hands-Off Declaration:
• "The buttocks are delivering. I am maintaining a strict hands-off approach. I will not apply any traction or pull on the fetus to prevent premature extension of the arms and head."
• On Leg and Arm Delivery:
• "The umbilicus has delivered. I am gently pulling down a loop of the umbilical cord. I am applying pressure in the popliteal fossa to deliver the legs via Pinard's maneuver. Since the arms are extended, I am holding the baby's bony pelvis and rotating the body 180 degrees to deliver the anterior arm via Løvset's maneuver, then rotating back to deliver the other arm."
• On Head Delivery:
• "To deliver the head, I am placing the baby straddling my non-dominant arm and putting my fingers on the maxilla to flex the neck. I am placing my other hand on the shoulders and directing my assistant to apply firm suprapubic pressure to keep the head flexed as I guide it out using the Mauriceau-Smellie-Veit maneuver."
• On Managing Cervical Entrapment:
• "The head is trapped by a tight cervix. I am administering 100 mcg of Nitroglycerin IV push to relax the cervix. If this fails, I am using bandage scissors to perform Dührssen incisions at 2, 6, and 10 o'clock on the cervix, taking care to avoid the uterine arteries at 3 and 9 o'clock."