5.4 Common Traps in Medical/Obstetrics/Gynecology
Key Takeaways
- Eclampsia (seizure in pregnancy after 20 weeks) is treated with magnesium sulfate 4 g IV over ~20 minutes, with a repeat 2 g for persistent seizures; magnesium is first-line over benzodiazepines.
- A supine hypotensive third-trimester patient should be placed in the left lateral recumbent position to relieve aortocaval compression by the gravid uterus.
- Shoulder dystocia is managed first with the McRoberts maneuver and suprapubic pressure; fundal pressure is contraindicated because it worsens impaction.
- Prolapsed cord requires the mother in knee-chest or Trendelenburg, a gloved hand elevating the presenting part off the cord, and rapid transport for cesarean section.
- Postpartum hemorrhage is managed with fundal massage, allowing the newborn to nurse, IV fluids, and uterotonics.
5.4 Common Traps in Medical/Obstetrics/Gynecology
Obstetric calls are uncommon but high-acuity, and the NREMT loves the trap where a familiar but harmful maneuver (fundal pressure, aggressive cord handling) is offered as a distractor. Know the normal stages of labor first so you can recognize when something is abnormal.
Stages of labor
- Stage 1 — onset of regular contractions to full cervical dilation (10 cm); the longest stage.
- Stage 2 — full dilation to delivery of the infant; this is when you assist the birth.
- Stage 3 — delivery of the infant to delivery of the placenta (usually within 30 minutes). Do not pull the cord; let the placenta deliver and transport it with the patient.
Normal delivery support: control the head, suction only if obstructing (mouth then nose if needed), check for a nuchal cord (slip over the head or, if tight, clamp-and-cut), deliver the anterior then posterior shoulder, keep the newborn warm and at the level of the perineum, clamp and cut the cord after pulsation slows, and stimulate/dry the baby. Decide quickly whether delivery is imminent — crowning, the urge to push, or strong contractions every 1-2 minutes mean you prepare to deliver on scene rather than risk a delivery in a moving ambulance.
Gather the OB kit, take BSI precautions, and have a plan for two patients (mother and newborn) before the head delivers.
Pre-eclampsia and eclampsia
Pre-eclampsia is new hypertension after 20 weeks gestation with end-organ signs (severe headache, visual disturbance, epigastric/RUQ pain, edema); severe features include BP ≥ 160/110. Eclampsia is the progression to seizures. The first-line drug for an eclamptic seizure is magnesium sulfate 4 g IV over about 20 minutes (diluted), with a repeat 2 g if seizures persist or recur — magnesium is preferred over benzodiazepines for eclampsia.
Watch for magnesium toxicity (loss of deep tendon reflexes, respiratory depression); the antidote is calcium. Control blood pressure per protocol (labetalol or hydralazine) and transport to an obstetric center. A trap is treating the eclamptic seizure as an ordinary seizure with a benzodiazepine alone. Remember the timeline cue: eclampsia can occur antepartum, intrapartum, or up to several weeks postpartum, so a recently delivered woman who seizes is eclamptic until proven otherwise.
OB Complications and Their Correct First Moves
| Complication | Recognition | Correct first action | Trap to avoid |
|---|---|---|---|
| Shoulder dystocia | Head delivers, shoulders stuck ("turtle sign") | McRoberts (hyperflex hips to abdomen) + suprapubic pressure | Never apply fundal pressure — it impacts the shoulder further |
| Prolapsed cord | Cord presents/visible before the baby | Knee-chest or Trendelenburg; gloved hand elevates presenting part off the cord; rapid transport for C-section | Do not push the cord back in |
| Breech | Buttocks/feet first | Support the body, let it deliver spontaneously, avoid traction; if head trapped, form an airway with your fingers (Mauriceau) | Pulling on the body |
| Postpartum hemorrhage (PPH) | > 500 mL bleeding after delivery | Fundal massage, let newborn nurse (releases oxytocin), IV fluids, uterotonics | Ignoring a boggy uterus |
| Supine hypotensive syndrome | Third-trimester hypotension when supine | Left lateral recumbent position | Leaving her flat on the board |
Supine hypotensive syndrome
In the third trimester, lying supine lets the gravid uterus compress the inferior vena cava and aorta (aortocaval compression), dropping venous return and causing hypotension, pallor, and dizziness. The fix is simple and high-yield: roll the patient onto her left side (left lateral recumbent), or if spinal precautions are needed, tilt the backboard 15-30 degrees to the left or manually displace the uterus leftward. This single positioning move can reverse profound hypotension and is a favorite test item.
Postpartum hemorrhage detail
The most common cause of PPH is uterine atony (a soft, "boggy" uterus that fails to clamp down). Treatment escalates through firm fundal massage, encouraging the infant to breastfeed (stimulating endogenous oxytocin), IV crystalloid for volume, and uterotonic medications (oxytocin) per protocol. Treat the mother for shock, keep her warm, and transport rapidly. Retained placenta and lacerations are other causes.
Other OB and GYN emergencies
Not every OB call is a delivery. Ectopic pregnancy (implantation outside the uterus, usually the fallopian tube) presents as a woman of childbearing age with unilateral lower-abdominal pain, vaginal bleeding, and a missed period; a ruptured ectopic causes hemorrhagic shock and is treated as a surgical emergency with fluids and rapid transport.
Placenta previa (painless bright-red bleeding) and placental abruption (painful bleeding with a rigid, tender uterus) are third-trimester hemorrhage causes — both demand gentle handling, large-bore IV access, shock care, and a hands-off-the-vagina approach. Amniotic fluid embolism is a rare, catastrophic intrapartum/postpartum collapse with sudden dyspnea, hypotension, hypoxia, and disseminated intravascular coagulation, requiring aggressive resuscitation.
Across all OB emergencies, the field principles repeat: protect the airway, treat shock with fluids, position to relieve aortocaval compression, keep mother and newborn warm, and transport to an obstetric-capable facility. The NREMT trap in this domain is almost always a maneuver that feels helpful (fundal pressure, pushing a cord back, traction on a breech) but actually harms — when in doubt, choose the gentlest action that buys time to definitive care.
Putting the OB traps together
The recurring distractor structure in this domain is a single tempting-but-wrong move embedded among safe options: fundal pressure for shoulder dystocia, pushing a prolapsed cord back inside, traction on a breech body, aggressive cord traction to "speed" placental delivery, or laying a hypotensive third-trimester patient flat. For each, the protective answer is the same family of gentle, position-based, time-buying actions paired with rapid transport.
Build a quick mental checklist for any OB call: confirm gestational age and gravidity/parity, assess for imminent delivery, screen for hypertension and bleeding, position to relieve aortocaval compression, prepare for both patients, and know that the maneuver that feels most aggressive is usually the one the exam wants you to reject.
A 30-year-old at 36 weeks gestation has a generalized seizure. Her BP is 172/112 mmHg. What is the first-line medication and dose?
During delivery the infant's head emerges but retracts against the perineum (turtle sign) and the shoulders will not deliver. What is the correct first maneuver?
A 38-week pregnant patient becomes hypotensive, pale, and lightheaded when laid flat on the stretcher. What is the most appropriate immediate action?