5.2 Protocol 24: Pregnancy / Childbirth / Miscarriage

5.2 Protocol 24: Pregnancy / Childbirth / Miscarriage

Quick Answer: Protocol 24 structures emergency dispatch for obstetric emergencies across all three trimesters. In early pregnancy (<14 weeks), the primary life threat is ruptured ectopic pregnancy, presenting with unilateral abdominal pain, syncope, and hypovolemic shock. In late pregnancy (>28 weeks), dispatchers must distinguish between painful abruptio placentae and painless placenta previa, while preventing supine hypotensive syndrome through left lateral positioning. When contractions occur less than 2 minutes apart, or when the caller reports crowning (head visible) or the urge to push / have a bowel movement, delivery is imminent. This mandates an immediate DELTA dispatch and an instantaneous shunt to Protocol F (Childbirth Pre-Arrival Instructions).

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Anatomical and Physiological Considerations in Obstetric Dispatch

Pregnancy induces profound anatomical and cardiovascular adaptations that alter both baseline maternal vital signs and clinical vulnerability during acute illness or trauma:

• Maternal Hypervolemia: Circulating blood volume increases by 40% to 50% (approximately 1.5 liters), accompanied by physiological anemia (erythrocyte volume expands only 20% to 30%).
• Masked Hypovolemic Shock: Because of expanded blood volume, a pregnant mother can lose up to 30% to 35% of her total blood volume before displaying classic signs of decompensated shock (hypotension, marked tachycardia). Uterine hypoperfusion occurs long before maternal blood pressure drops, placing the fetus in extreme danger while the mother appears stable.
• Diaphragmatic Displacement: In the late second and third trimesters, the cephalad displacement of the diaphragm by the expanding uterus reduces functional residual capacity by 20%, predisposing the mother to rapid arterial desaturation and hypoxemia.

Supine Hypotensive Syndrome

When a pregnant woman past 20 weeks of gestation lies completely flat on her back (supine), the massive weight of the gravid uterus and fetus compresses the inferior vena cava (IVC) and descending abdominal aorta against the lumbar spine:

• Pathophysiology: Venous return to the right atrium drops precipitously, reducing cardiac output by 25% to 30%. The patient experiences severe dizziness, lightheadedness, nausea, clammy diaphoresis, and sudden syncope. Uteroplacental perfusion plummets, causing profound fetal bradycardia and distress.
• EMD Intervention: The dispatcher must immediately direct the caller to position the mother on her left side (left lateral recumbent position) or place a firm rolled pillow, folded blanket, or coat under her right hip to create a 15 to 30 degree tilt, shifting uterine mass off the great vessels.

+-------------------------------------------------------------------------+
|                    SUPINE HYPOTENSIVE SYNDROME TRAP                     |
|                                                                         |
|   Mechanism:    Gravid uterus compresses IVC against lumbar spine       |
|   Hemodynamics: Venous return drops -> CO drops 30% -> Syncopal arrest  |
|   Mandate:      NEVER leave late-term pregnant patient supine!          |
|   Position:     LEFT LATERAL RECUMBENT (or tilt right hip 15-30 deg)    |
+-------------------------------------------------------------------------+

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Trimester-Specific Triage & Pathologies

Obstetric dispatch triage requires rapid identification of gestational age, categorizing patients into distinct anatomical risk zones:

1. First Trimester (Weeks 1 to 13)

• Ectopic Pregnancy: Implantation of the blastocyst outside the uterine endometrium, occurring in over 95% of cases within the ampulla or isthmus of the fallopian tube. Between weeks 6 and 10, embryonic growth stretches and ruptures the non-elastic tubular wall, tearing branches of the uterine and ovarian arteries.
  • Clinical Triad: Sudden, severe unilateral lower pelvic/abdominal pain; vaginal spotting or bleeding; and amenorrhea (missed period).
  • Diaphragmatic Hemoperitoneum (Kehr's Sign): Massive intra-abdominal hemorrhage accumulates under the diaphragm, irritating the phrenic nerve and producing referred pain to the tip of the shoulder.
  • Dispatch Rule: Any female of childbearing age (typically 12 to 50) presenting with sudden severe lower abdominal pain, syncope, and dizziness must be treated as a ruptured ectopic pregnancy until proven otherwise in an operating room.
• Miscarriage (Spontaneous Abortion): Non-viable loss of pregnancy prior to 20 weeks gestation. Characterized by crampy midline suprapubic pain, vaginal bleeding, and passage of clots or fetal tissue.

2. Second Trimester (Weeks 14 to 27)

Characterized by late pregnancy losses, cervical incompetence, premature rupture of membranes (PPROM), and early onset of severe gestational hypertensive disorders.

3. Third Trimester (Weeks 28 to 40+)

• Abruptio Placentae (Placental Abruption): Premature separation of a normally implanted placenta from the uterine decidua prior to delivery. Tears maternal spiral arteries, leading to retroplacental hematoma formation.
  • Presentation: Sudden, severe, constant abdominal and back pain; dark red vaginal bleeding; and a characteristically rigid, board-like ("wooden") uterus with unremitting contraction tone.
  • Concealed Abruption: In 20% of cases, the hemorrhage is completely trapped behind the placenta (concealed), presenting with excruciating uterine agony and maternal shock without any visible external vaginal bleeding.
• Placenta Previa: The placenta implants low in the uterine cavity, partially or completely covering the internal cervical os. As the lower uterine segment thins and the cervix dilates in late pregnancy, placental attachments tear.
  • Presentation: Sudden, profuse, painless, bright red vaginal bleeding; the uterus remains soft, non-tender, and relaxed.
  • Clinical Caution: Digital vaginal examinations or packing the vagina are strictly prohibited, as manual manipulation can provoke catastrophic, uninhibited exsanguination.
• Preeclampsia and Eclampsia: Preeclampsia is multisystem gestational endothelial dysfunction characterized by hypertension (SBP >= 140 or DBP >= 90), proteinuria, persistent frontal headache, visual disturbances (scotoma, photopsia), and right upper quadrant/epigastric pain (hepatic capsule stretch). When a preeclamptic patient develops generalized tonic-clonic convulsions, the condition is classified as Eclampsia (shunts immediately to Protocol 12 with obstetric transport protocols).

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Comparative Triage: Third-Trimester Hemorrhage vs. Ectopic Crisis

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Labor Stages and Imminent Delivery Assessment

The physiological process of parturition is divided into three distinct clinical stages:

1. Stage 1 (Dilation Phase): Begins with regular uterine contractions and ends when the cervix is fully dilated (10 centimeters) and effaced (100%).
2. Stage 2 (Expulsion Phase): From full cervical dilation to the complete delivery of the neonate.
3. Stage 3 (Placental Phase): From the delivery of the neonate to the complete expulsion of the placenta and fetal membranes.

The Three Imminent Delivery Diagnostic Triggers

In Protocol 24 Key Questions, the EMD interrogates three primary physical markers to identify whether delivery will occur before field paramedics arrive:

                    IMMINENT DELIVERY TRIAGE CHECKLIST
                                    |
      +-----------------------------+-----------------------------+
      |                             |                             |
1. CONTRACTIONS              2. CROWNING / HEAD            3. RECTAL PRESSURE
  "< 2 minutes apart?"         "Can you see any             "Feeling like having
  "Continuous bearing down?"    part of baby?"               a bowel movement?"
      |                             |                             |
      +-----------------------------+-----------------------------+
                                    |
                    ANY SINGLE POSITIVE INDICATOR
                                    |
                  IMMEDIATE 24-D-2 / 24-D-3 DISPATCH
                                    +
               INSTANT SHUNT TO PROTOCOL F (CHILDBIRTH DLS)

1. Contraction Interval: "How far apart are the contractions?"
   • Contractions occurring less than 2 minutes apart (measured from the start of one contraction to the start of the next) indicate late active labor or transition into the second stage.
2. Crowning / Presentation of the Baby: "Can you see any part of the baby coming out?"
   • If the caller observes the baby's head (crowning), hair, feet, or buttocks bulging at the vaginal opening, delivery is actively occurring within minutes.
3. Urge to Push or Defecate: "Does she feel like she has to push or have a bowel movement?"
   • As the fetal presenting part descends deep into the pelvic canal, it exerts direct mechanical pressure on the rectal vault and sacral plexus. This stimulates an involuntary, overwhelming maternal urge to bear down. A mother in late labor who insists she "needs to use the toilet" must NEVER be allowed into the bathroom—precipitous delivery over a toilet bowl creates severe neonatal trauma and cold-water asphyxiation.
4. Parity Multiplier: Women who have delivered children previously (multiparous) progress through second-stage labor in a fraction of the time required by first-time mothers (primiparous). A multiparous mother with contractions 3 minutes apart and an urge to push is in imminent delivery.

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Protocol 24 Determinant Hierarchy

+-------------------------------------------------------------------------+
|                    PROTOCOL 24 DETERMINANT CLASSIFICATION               |
|                                                                         |
|   24-D-1:  Breech or cord (presenting part is not the head)             |
|   24-D-2:  Head visible / out (crowning)                                |
|   24-D-3:  Imminent delivery (> 6 months / 24 weeks)                    |
|   24-D-4:  3rd trimester hemorrhage                                     |
|   24-D-5:  High risk complications                                      |
|   24-D-6:  Baby born (complications with baby)                          |
|   24-D-7:  Baby born (complications with mother)                        |
|   24-D-8:  Possible MISCARRIAGE with signs of life                      |
|   24-C-1:  2nd trimester hemorrhage or miscarriage                      |
|   24-C-2:  1st trimester SERIOUS hemorrhage                             |
|   24-C-3:  Abdominal pain / cramping (< 6 months / 24 weeks)            |
|   24-C-4:  Baby born (no complications)                                 |
|   24-B-1:  Labor (delivery not imminent, > 6 months / 24 weeks)         |
|   24-B-2:  Unknown status / other codes not applicable                  |
|   24-A-1:  1st trimester hemorrhage or MISCARRIAGE                      |
|   24-A-2:  Confirmed STILLBIRTH situation (no complications)            |
|                                                                         |
|   Suffix M is appended for a MULTIPLE BIRTH.                            |
+-------------------------------------------------------------------------+

Whenever 24-D-1 (Breech or cord), 24-D-2 (Head visible/out), or 24-D-3 (Imminent delivery) is selected, the EMD performs parallel dispatch and instantly shunts to Protocol F (Childbirth — Delivery) without asking remaining Key Questions. Note the trap in the low-acuity codes: early labor that is not imminent is 24-B-1, while 24-A-1 is 1st trimester hemorrhage or MISCARRIAGE — the opposite of what many candidates guess.

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Miscarriage Management and Emotional Caller Care

Spontaneous abortion (miscarriage) occurs in 15% to 20% of clinically recognized pregnancies, representing an acute physiological and psychological crisis for the caller:

• Quantitative Bleeding Assessment: The EMD must determine the severity of blood loss: "How many sanitary pads has she soaked through in the last hour?" Soaking through more than two heavy maxi-pads per hour for two consecutive hours indicates massive vaginal hemorrhage.
• Clot and Tissue Protocol: Instruct the caller to save any passed tissue or large clots in a clean plastic bag or covered container for pathology examination at the emergency department. Never allow tissue to be flushed down the toilet.
• Direct Instructions: Instruct the mother to lie quietly on her side. Advise her: "Use clean sanitary pads to absorb the blood. Do not use tampons, and do not put anything inside the vagina."
• Compassionate Communication: Callers experiencing pregnancy loss are engulfed by guilt, grief, and panic. The EMD must maintain calm authority, validate their distress without offering empty medical guarantees (e.g., avoid saying "I'm sure the baby will be fine" or "You're young, you can try again"), and provide grounded reassurance: "Help is on the way. I am staying right here on the phone with you."