EMS Prehospital Deliveries

Anatomy and Physiology

Pelvic Girdle

The pelvis forms a bony ring, which the fetus must pass through during delivery. The size and shape of the maternal bony pelvis, in correlation with fetal size and position, significantly impact the ease of delivery. In up to 3% of deliveries, the anterior fetal shoulder unexpectedly gets stuck behind the maternal pubic bone during delivery, resulting in an obstetric emergency called shoulder dystocia.[8][9]

Uterus

The uterus is a hollow, pear-shaped muscle in a female's pelvis. It houses the fetus, placenta, and fluid-filled amniotic sac during pregnancy. During labor, the uterus generates powerful rhythmic muscular contractions, forcing the baby through the pelvis outlet and ultimately out of the vaginal opening.[9]

Cervix

The cervix is a fibromuscular tubular structure that forms the opening of the uterus, leading into the vagina. During labor, uterine contractions push the fetal head against the cervix, helping it to dilate and thin out (ie, efface), which allows passage of the fetus out of the uterus and into the vagina.[9]

The cervix is assessed on a vaginal exam using a sterile technique to monitor labor progress during labor. Cervical dilation is measured in centimeters through digital examination with 2 fingers. Full dilation is typically defined as reaching a dilation of 10 centimeters. Effacement is measured as a percentage of thinning; a cervix that is 100% effaced refers to a cervix that has become paper-thin.[9] In active labor, before full dilation and effacement, the cervix can be felt as a rim of tissue on top of the infant's presenting body part, usually the head. When the cervix is fully dilated and effaced, it falls behind the fetal presenting part and is no longer palpable. Delivery may be imminent if the cervix is no longer palpable and the fetal head can be seen at the vaginal introitus.[9]

Fundal Height

The fundus is the upper part of the uterus, easily felt during an abdominal examination as a firm, rounded dome. Fundal height is the distance, measured in centimeters, from the top of the fundus to the top of the pubic bone. It's a quick way to estimate gestational age during the later stages of pregnancy. When the fundal height aligns with the umbilicus, it suggests around 20 weeks of gestation. For each centimeter above the umbilicus, another week is added to estimate gestational age. This method helps calculate the approximate gestational age based on fundal height.[8][10][8]

After delivery of the infant, the uterus should contract down, beginning its return to a nonpregnant size. As the uterus contracts down, it clamps off small blood vessels in the uterine muscle and significantly slows postpartum bleeding. Massaging the fundus can help stimulate this contraction and is useful in managing postpartum bleeding and hemorrhage.[11]

Placenta and Umbilical Cord

The placenta is the vital organ that links the fetus to the mother, facilitating the exchange of nutrients and gases. One side of the placenta adheres to the uterine wall, while the other side faces the infant. Typically, the umbilical cord attaches to the center of the placenta. After the baby is born, the uterus continues to contract, aiding in the detachment and expulsion of the placenta. Placental delivery is recognized by a sudden flow of blood and the lengthening of the umbilical cord. However, if the placenta separates prematurely, it can lead to fetal and maternal hemorrhage, and if the umbilical cord gets torn, it can cause rapid blood loss in the baby.[11] 

Stages of Labor

There are 3 stages of labor. Delivery of the fetus occurs in the second stage of labor.

• Stage 1: Begins with the onset of regular uterine contractions and cervical change and concludes when the cervix is fully dilated (ie, 10 cm). Labor tends to progress more slowly for women during their first delivery and faster with each subsequent delivery, but there are wide variations in what is considered normal. Active labor typically refers to when a patient's cervix begins to dilate quickly over time, which may not occur until 6 cm.[12][9]
• Stage 2: Begins when the cervix is fully dilated at 10 cm and concludes after delivery of the fetus. Once the cervix is fully dilated, the average time to delivery in a woman laboring for the first time without an epidural is 36 minutes. The median time decreases with each successive delivery, up until the third delivery, to an average of 12 minutes with the second delivery and 6 minutes for any delivery after that.[12] 
• Stage 3: Begins immediately after delivery of the infant and ends after delivery of the placenta. Placental delivery usually occurs within 9 minutes of infant delivery on average. A retained placenta is typically defined as one that has not been delivered after 30 minutes.[11]

Indications

Indications that delivery is imminent include:

• A strong, reflexive maternal urge to push or defecate[13]
• Intense contractions at regular intervals, ≤2 minutes apart
• Bulging perineum
• Crowning of the fetal head (ie, the fetal head is visible at the vaginal opening) or spontaneous separation of the labia by the presenting fetal part[14][15][16]

Contraindications

There are few contraindications to unplanned prehospital delivery. The EMS healthcare practitioner can do little to delay or prevent delivery during spontaneous labor. If the EMS practitioner is close to the hospital, discouraging the woman from pushing may delay the delivery for a short while, depending on her dilation and the number of previous deliveries. During a precipitous delivery, uterine contractions are involuntary and are often strong enough to deliver an infant without much additional maternal effort. A strong and reflexive urge to bear down that the patient may be unable to suppress is usually present. Therefore, delivery may occur regardless of the patient's intentions, so EMS healthcare professionals must be prepared to deliver the infant en route to the hospital.

Two relative contraindications to vaginal delivery that EMS clinicians should be aware of are umbilical cord prolapse and breech, especially footling breech presentations. Umbilical cord prolapse, in which the umbilical cord is the presenting part, results in compression of the umbilical cord, which can lead to complications such as hypoxic brain injury and cerebral palsy. An emergent cesarean delivery is typically preferred; therefore, decompression of the cord should be attempted consisting of manual elevation of the fetal presenting part using 2 fingers or the whole hand through the vagina and placing the patient in a steep Trendelenburg or knee-chest position until experienced clinicians can perform a cesarean delivery in a hospital setting.[17]

A frank breech (ie, when the infant's buttocks are the presenting part) or a footling breech (ie, when the infant's foot is the presenting part) presentation occurs more frequently in preterm pregnancies and has a higher risk of complications compared to infants with a cephalic presentation. These patients also often require a cesarean delivery. EMS personnel should not perform any traction, and patients should be instructed to pant during contractions until the hospital can be reached, as specialized expertise is essential for these types of deliveries.[18][19]

Equipment

For most uncomplicated deliveries, minimal equipment is necessary. Ideally, in the prehospital setting, emergency medical professionals should have something to clamp and cut the umbilical cord and a dry cloth to dry and stimulate the infant, such as a towel. In emergency settings, typical obstetric and gynecological equipment may not be available, but if possible, EMS personnel should have the following items ready:

• Personal protective equipment (eg, a mask with face shield, gown, booties, sterile gloves)
• Towels or clean, dry cloths
• Blankets and infant hat
• Two umbilical cord clamps or hemostats
• Medical scissors or scalpel to cut the cord
• Container for the placenta
• Bulb suction
• Supplemental oxygen
• IV access equipment and crystalloid fluid
• Oxytocin
• Infant ventilation bags or a manometer to monitor inflating pressures during ventilation[7]

Equipment should be quickly and easily accessible to EMS healthcare practitioners or their assistants. Often, these items can be stored in an ambulance as part of an emergency delivery kit. However, equipment storage capacity within an ambulance is often limited, and some equipment may not be considered cost-effective. Furthermore, stocking may vary among different EMS systems.[8][7] Clean clothing can dry, stimulate, and warm the infant if no medical equipment is available during delivery.[7]

Personnel

In a prehospital delivery, the EMS practitioner must make do with the personnel available. Ideally, the emergency medical professional performing the delivery should have at least 1 assistant. Hospital clinicians (eg, emergency, neonatologist, and obstetric physicians and nurses) should be notified ahead of the patient's arrival so that they may prepare necessary equipment for treatment (eg, infant warmers).[8][10]

Preparation

History and Physical Examination

The initial evaluation of a laboring patient by EMS is primarily to determine whether the patient is stable for transport to a hospital; a patient who demonstrates clinical signs of imminent delivery is considered unstable, and EMS may decide to perform a field delivery before transporting the patient and neonate to the hospital. Upon arrival, EMS personnel should attempt to rapidly obtain a focused history and physically examine the laboring patient to make this determination.[20][13] Important information to obtain from the history includes:

• The estimated due date and gestational age of the pregnancy, if known. The first day of the last menstrual period to calculate an estimated due date and gestational age may be used if the patient does not know an estimated due date.[8]
• Number of pregnancies and the number of prior vaginal and cesarean deliveries
• Any pregnancy complications in current or prior pregnancies
• The onset of the contractions and their frequency 
• If and when the membranes ruptured (ie, water breaking) and the color of the fluid
  • Clear yellow: normal
  • Bloody: may indicate placental abruption or placenta previa
  • Green: consistent with meconium, which increases the neonatal risk for respiratory complications [8]
• If and where the patient received prenatal care
• Number of fetuses (singleton or twins) and perceived fetal movement
• Any nonobstetric health problems, allergies, and medications
• If the position of the fetus is known from a recent assessment (eg, recent ultrasound) [8]

Maternal vital signs should be obtained in patients not delivered when EMS arrives, and fetal heart tones should be auscultated if a fetal heart Doppler is available.[10] In addition to a focused chest examination, a rapid fundal height assessment should be performed to estimate the gestational age of the pregnancy. The diagnosis of active labor is beyond the scope of practice for EMS clinicians. Laboring patients should be transported to facilities with obstetric capabilities unless delivery appears imminent. This should be evaluated through visual inspection of the perineum if the patient has symptoms of rectal pressure, an urge to push, or contractions less than 2 minutes apart. EMS clinicians noting signs of an imminent delivery, including distention of the perineum by the presenting fetal part or the emergence of the fetal head past the vaginal introitus with contractions, should be aware that these are indications of an impending delivery and that preparation for a field procedure is required.[13] 

Unless intervention is indicated due to a breech delivery or prolapsed umbilical cord, a sterile digital examination of the vagina is typically not needed until the patient can be triaged by hospital clinicians who will assess cervical dilation and effacement, identify the presenting fetal part, and gauge the descent (ie, station) of the fetus.[13] Especially when there's noticeable vaginal bleeding, it's important to refrain from performing a digital examination until placenta previa can be ruled out as a potential cause.[10] Examination of the perineum is most accessible for the EMS practitioner to perform with the patient in the dorsal lithotomy position (ie, supine with flexed hips and knees).[21]

Patient Positioning

Common Western delivery positions include the left-tilted dorsal lithotomy or semi-Fowler positions. Nevertheless, safe delivery can occur in various positions, such as left lateral decubitus, kneeling, squatting, or on hands and knees. EMS personnel should prioritize the mother's comfort, ensure accessibility for healthcare practitioners, and establish a secure area for the baby to prevent birth-related neonatal falls, which have been documented as causing birth trauma.[22][21]

However, pregnant patients should not lie flat on their backs because this can reduce uteroplacental blood flow and the fetus due to aortic compression. Therefore, if lying supine, they should always have a rolled-up towel tucked under the left hip to tilt the patient or have the patient in a semi-reclined posture, sitting up at a 45-degree angle.[21]

Technique or Treatment

In general, the goals of the delivering clinician are to reduce the risk of pelvic floor trauma for the parturient, provide initial neonatal support and resuscitation, and manage maternal and neonatal complications to optimize outcomes. If only 1 trained EMS practitioner is available, assistance from the patient's family, friends, or another nonclinical person to assist with the birth and provide maternal support is an option.[15] In preparation for delivery, available supplies or the emergency delivery kit should be readily accessible to the EMS clinician assisting. Women delivering in the semirecumbent or left-tilted dorsal lithotomy positions should flex their hips and legs to open up the pelvic inlet.[9] The perineum and area below the patient's buttocks should be draped with clean towels. If time allows, the perineum and vaginal area should be quickly swabbed with a povidone-iodine solution.[10]

Active Pushing

As the fetal head emerges from the vaginal introitus, laboring patients will feel the urge to push or bear down due to the increased rectal pressure from the fetal head as it descends. Parturients delivering outside of a hospital should be encouraged to push when they feel a contraction begin. This typically will occur reflexively.[15] Additionally, parturients should be encouraged to breathe in a natural way, which often includes pushing with an open glottis (eg, moaning or screaming while bearing down) instead of pushing with a closed glottis (eg, Valsalva pushing). Although a common technique has been to coach parturients to push for 3 sets of 10 seconds while holding a deep breath, there is no evidence to suggest this approach provides any clinical benefit over parturient-driven pushing.[23] It is important to note that a mother's perception of her birth experience depends on their clinician's empathy and interpersonal skills as much as their clinical abilities. Patients should be offered verbal encouragement to help keep them calm and focused while pushing with their preferred method.[24][25] 

Approach to Delivery 

The majority of EMS-assisted deliveries involve quick and straightforward vaginal births. In this scenario, the primary responsibility of the EMS clinician is to assist in safely guiding and managing the baby's delivery to prevent any harm to the mother or the newborn.[10][9] Traditionally, the delivering clinician places 1 hand on the fetal head as it emerges and provides very gentle counter pressure, preventing the rapid expulsion of the fetus, while the other gloved hand is at the perineum, applying moderate manual pressure to provide perineal support as the fetal head emerges. However, studies have not shown this method to be any more beneficial than allowing the fetal head to emerge on its own using a hands-off approach.[26][10][9] Routine use of episiotomy is not recommended and should not be performed.[27][9]

Usually, the fetal head emerges either facing down towards the maternal rectum or, less commonly, facing up towards the maternal abdomen during delivery. As the fetal body moves through the pelvis, a natural process called restitution occurs, where the head automatically turns to face one of the maternal thighs. This rotation usually takes a few seconds.

Once the fetal head has fully emerged and this rotation occurs, the delivering clinician should sweep their fingers around the fetal neck and feel for a nuchal cord. A nuchal cord is an umbilical cord wrapped around the neonate's neck. A nuchal cord, if present, may be wrapped more than once, tightly or loosely. If the umbilical cord is felt wrapped around the neck, the EMS clinician should attempt to reduce it by gently pulling the cord over the infant's head, taking care not to lacerate or avulse the cord; this should be repeated until all loops have been removed.[10][9] If the nuchal cord is too tight to pull over the infant's head, it may be left in place if delivery of the rest of the neonate is not impeded and removed from the neck as soon as the neonate is delivered. If a tight nuchal cord prevents the delivery from proceeding, the cord can be doubly clamped and cut before the body delivers. This should be an option of last resort; delivery of the anterior shoulder should be attempted first before clamping and cutting a tight nuchal cord to avoid neonatal asphyxia in case shoulder dystocia is encountered.[28]

After delivery of the fetal head and restitution, the neonate's shoulders will be delivered. With the infant's head facing 1 of the maternal thighs, the EMS clinician should gently grasp both sides of the head with a hand on each side. The delivering clinician should then apply gentle posterior traction (ie, toward the maternal rectum) to help guide the infant's anterior shoulder underneath the pubic bone. Immediately following delivery of the anterior shoulder, the neonate should be guided upwards (ie, toward the maternal abdomen) to deliver the posterior shoulder. From there, the passage of the rest of the body should happen quickly; clinicians should hold tightly to the neonate's head and body as it delivers, placing it gently on the maternal abdomen.[10][9]

Delayed Umbilical Cord Clamping

There is no rush for the prehospital clinician to clamp the umbilical cord. Evidence shows that except for infants requiring immediate cardiopulmonary resuscitation (CPR), the umbilical cord should not be clamped until it has stopped pulsating, approximately 30 to 60 seconds following delivery. Some professional organizations recommend waiting up to 3 minutes.[29][30] Delayed cord clamping allows for the autotransfusion of up to 100 mL of oxygenated blood within the first 3 minutes after birth and is especially beneficial for preterm infants.[29] Therefore, in most cases, the initial care (eg, clearing the airway, drying, stimulating, and warming the infant) and assessment of the newborn (eg, respiratory effort, tone, and heart rate [HR]) may be performed before clamping the cord.

To safely cut the cord, 2 clamps are placed on the umbilical cord, and the cord is transected between the clamps. Generally, it is advised that the proximal umbilical clamp be placed approximately 10 centimeters from the umbilicus. If necessary, this provides an adequate cord distance to place an umbilical catheter once the neonate reaches the hospital if they require resuscitation. The second clamp should be placed approximately 5 cm beyond the first, allowing adequate space to safely cut the umbilical cord with a sharp, ideally sterile, pair of scissors or scalpel.[10][9] 

The cord should be kept clean and dry. If a standard aseptic technique (eg, use of sterile gloves, clamps, and scissors) was used to cut the cord, keeping the remaining umbilical stump clean typically does not require antiseptics (eg, chlorhexidine or alcohol swabs). However, antiseptics may be reasonable to prevent infection, depending on the delivery environment, such as in settings where sterile equipment is unavailable or if the cord becomes contaminated (eg, falling in the dirt).[31]

Immediate Postpartum Neonatal Evaluation

The AAP, among other international societies, recommends newborn care immediately following birth, including drying and stimulating the neonate, clearing the airway of secretions, ensuring adequate respiratory effort, and keeping them warm. After the infant is delivered, the EMS clinician should gently wipe the infant's nose and mouth to clear the mucus as they are placed directly skin-to-skin on the mother's chest or abdomen; bulb suctioning may not routinely be needed.[32][33] The infant should be dried and rubbed vigorously within the first 60 seconds of birth with a clean towel or cloth to help stimulate the infant to breathe and cry, allowing it to clear its lungs from any remaining amniotic fluid. Most infants will have a strong respiratory effort after this initial stimulation. After ensuring the baby is dry and has a robust respiratory drive, it's essential to wrap them in a warm, dry towel or cloth. If a cloth isn't available, having direct skin-to-skin contact fosters bonding and helps maintain the infant's warmth.[32] A food- or medical-grade, heat-resistant plastic bag can be used if skin-to-skin contact can not be maintained.[32]

Immediately after this initial drying and stimulating, or if additional help is available, the infant should be assessed on the maternal abdomen within 30 to 60 seconds of birth to determine if the neonate requires further resuscitative efforts. Key factors to consider include:

• Heart rate: An average newborn HR should be ≥100 bpm; it can be assessed by auscultation or palpation at the base of the umbilical cord.
• Respiratory effort: Normal effort should appear as vigorous crying or nonlabored breathing without gasping or apnea. An average newborn respiratory rate is 40 to 60 breaths/min.
• Color: The newborn's skin should be assessed for cyanosis. Any cyanosis should be documented in the record and carefully monitored, as cyanosis of the trunk or lips may indicate cardiorespiratory abnormalities. Isolated cyanosis of the distal extremities (ie, blue hands or feet) is common in the first few minutes of life and typically resolves within a few minutes.
• Tone: Newborns should display active movement in all their limbs and have regular muscle tone, meaning they should not appear limp.
• Reflex irritability (grimace response): The infant should spontaneously grimace, cough, sneeze, or vigorously cry in response to stimulation.[34][35]

Additional assessments of the HR, respiratory effort, color, tone, and reflex irritability, components of the APGAR score, should be performed at 5 and 10 minutes of life. Findings from these initial assessments are essential for hospital clinicians and must be documented in the record.[34][35] Infants who can breathe without difficulty and have good muscle tone typically do not require any additional immediate intervention. About 10% of infants may require additional stimulation beyond routine drying, which can be accomplished by rubbing the newborn's trunk or back or gently slapping the soles of the feet. Infants with difficulty breathing or an HR less than 100 bpm require additional neonatal resuscitation maneuvers.[34][35] See the Complications section below.

After the initial assessment is complete and the infant and mother are determined to be stable, breastfeeding can be encouraged, which will help the infant maintain its blood glucose levels. Infants at risk for hypoglycemia should have their blood sugar level checked within the first hour of life, and they need to be monitored closely for evidence of hypoglycemia for the first few days. Infants at high risk for hypoglycemia include those born to mothers with diabetes, gestational or pregestational, and large or small infants of gestational age.[34][35]

The infant should be reassessed every 30 to 60 minutes during the first 4 to 8 hours after birth and have a full general assessment within the first 24 hours of life. Therefore, neonates should be transferred into the care of clinicians trained in newborn care after an unplanned prehospital delivery.[34][35] 

 Delivering the Placenta

The placenta often will deliver after the neonate has been successfully delivered and initially assessed to be stable. This typically occurs between 5 and 15 minutes after delivery but may take up to 30 minutes. Therefore, the patient and newborn should be transported at this time if a field delivery has been performed; the placenta does not have to be delivered first. If the placenta has not been delivered within 30 minutes, the patient should be transferred to an obstetric clinician to assist with removing the placenta, which may have implanted abnormally. These patients are at high risk for bleeding. In most cases, the placenta can deliver spontaneously with maternal effort alone.[36] 

While gentle traction on the umbilical cord reduces the risk of some postpartum hemorrhages and, therefore, is typically used by trained birth attendants to help deliver the placenta, cord traction can also result in cord avulsion and uterine inversion, which, although rare, can lead to significant morbidity.[37][38] Due to these risks and the somewhat limited benefits, controlled cord traction for placental delivery typically is not needed during prehospital deliveries by nonobstetric clinicians who lack dedicated training in this particular skill. [38] EMS clinicians should never pull on the cord. The placenta should naturally detach from the uterine wall as the uterus contracts following delivery; it should not require external force to separate.

If the placenta shows signs of separation from the uterine wall, the patient may be asked to bear down to deliver the placenta. Signs of placental separation include:

• The uterus becomes firmer.
• A sudden gush of blood from the vagina is noted.
• The umbilical cord begins to lengthen.[37] 

When the placenta is visible at the vaginal opening, it may be grasped by the cord as the patient pushes and gently guided outward. Once the placenta has been delivered, it needs to be inspected for any missing pieces because if the placenta is not intact, the retained products must be removed to prevent bleeding or infection.[36] Therefore, the placenta should be kept in a container that can be transferred to hospital staff for evaluation by trained obstetric clinicians upon arrival.

Complications

Obstetric Lacerations

Lacerations are common after vaginal deliveries, especially with the first delivery. Lacerations may involve the perineum, vagina, vulva, periclitoral, or periurethral tissue. Perineal tears are the most common and are classified by degrees of severity as follows:

• First degree: laceration of the perineal skin only
• Second degree: extension of a laceration from the perineal skin to the perineal muscles 
• Third degree: laceration involving the anal sphincter
• Fourth degree: laceration extending from the perineal skin through to the anal sphincter complex and anal epithelium [39]

Nonperineal lacerations are often superficial and do not need to be repaired unless actively bleeding; however, if performed, repair of lacerations requires appropriate training, lighting, visualization, and pain control. ACOG recommends that the judgment of an obstetrically trained clinician be used to determine whether or not a first or second-degree laceration should be repaired.[39] Most second-degree lacerations are repaired, but no evidence supports surgical repair over expectant management. However, a trained obstetric clinician should surgically repair third- and fourth-degree lacerations. If significant bleeding from a laceration is identified, it typically can be conservatively managed by applying pressure until an appropriately trained clinician can evaluate and provide treatment as indicated.[39] 

Breech Delivery

Breech presentations are the most common type of malposition encountered. Breech vaginal deliveries are associated with higher levels of neonatal morbidity and mortality.[40] This is because the fetal head, the largest and hardest fetal body part to move through the maternal pelvis, can become entrapped within the pelvis after the body delivers. During this time, the umbilical cord can become compressed as it runs alongside the fetal head, and the fetus is deprived of oxygen until the head is delivered. Whenever feasible, these patients should be taken to the hospital for delivery. Even if a fetal foot or buttock is visible at the vaginal opening, reaching a hospital facility for a safer delivery may still be possible. However, once the fetus has been delivered to the level of the neonatal umbilicus, a breech delivery is imminent, and the EMS clinician should be prepared for on-scene delivery.[10]

For the delivering clinician to perform the maneuvers of a breech delivery, the mother should be placed in the semi-recumbent position. The infant should be allowed to deliver spontaneously, without any assistance from the EMS clinician, to the level of the neonatal umbilicus. The EMS clinician can then hook their fingers around the infant's hips and apply downward traction; additionally, if not already facing down, the infant should be rotated so that its spine is facing up. As the fetal body continues to deliver, the delivering clinician may support the fetal body on their forearm and deliver the legs, 1 at a time, by grasping the thigh and sweeping the leg up and out while flexing the knee.[10] When the scapulas are visible, the neonate should be rotated 90 degrees to face 1 of the maternal thighs. The EMS clinician should then sweep their fingers over the anterior arm, bending at the elbow and moving it down and across the infant's chest until the arm is out of the vagina. The infant should then be rotated 180 degrees to the other side, and the process should be repeated to deliver the second arm.[10]

To deliver the head, the infant should be placed so that it is lying on the forearm of the delivering clinician with the fetal legs straddling the forearm. The clinician should use the other hand to grasp the shoulders and apply downward traction until the back of the head is visible. At this point, the index and middle fingers of the bottom hand should be placed on the infant's face to apply downward pressure to the infant's maxilla while an assistant applies firm maternal suprapubic pressure. These maneuvers should allow the fetal head to flex and move under the pubic bone. Keeping downward pressure on the face and suprapubic pressure on the maternal abdomen, the delivering clinician elevates the infant's body straight up into the air toward the maternal abdomen, with the infant held between the clinician's 2 forearms, allowing the face and the entire head to deliver.[10]

Shoulder Dystocia

Shoulder dystocia occurs when the infant's shoulder becomes impacted behind the maternal pubic bone, causing the infant's body to get stuck in the birth canal. This complication is difficult to anticipate, but risk factors include macrosomia, maternal diabetes, maternal obesity, and fetal postdates. Recognizing and managing this complication quickly is crucial because prolonged dystocia can result in severe fetal morbidity (eg, asphyxiation, clavicle fracture, and brachial plexus injury).[41]

Shoulder dystocia can be expected when, following the delivery of the fetal head, it either firmly retracts against the perineum or starts moving back into the vagina during the intervals between contractions. This is known as the turtle sign because it can appear like a turtle pulling its head back into its shell. This occurs because the fetal head is expelled as the mother pushes, but because the fetal shoulder is stuck behind the pelvic brim when the mother stops pushing, the head gets pulled back into the vaginal canal. The delivering clinician should call for additional help when this sign is observed.[42]

Several maneuvers can be used to resolve the dystocia. Before attempting maneuvers, the delivering clinician should check for a nuchal cord and remove it if possible. If a tight nuchal cord is noted, the cord can be doubly clamped and cut before the body delivers. This should be an option of last resort; the anterior shoulder should be delivered before clamping and cutting a tight nuchal cord to avoid neonatal asphyxia due to shoulder dystocia.[28]

The first maneuver to attempt should be the McRoberts maneuver.[43] To perform this maneuver, assistants should sharply flex the parturient's thighs up onto her abdomen/chest (resulting in hyperflexion at the hips). If no one is available to help, the mother can be instructed to "pull your knees up to your armpits" or "pull your thighs onto your chest." This position alters the angles within the pelvis, allowing more room for the shoulders to move through the pelvis.[44] Simultaneously with or immediately after a short trial in the McRoberts position, the assistant should be asked to apply pressure above the maternal pubic bone to help manually dislodge the impacted shoulder.[45] If both of these maneuvers are unsuccessful, the delivering clinician can reach their hand into the posterior vagina and attempt to grasp the posterior forearm of the fetus, flexing it at the elbow. Then, the clinician can sweep the arm up and across the fetal chest, delivering the posterior arm. This alters the angle of the shoulder girdle and is often enough to relieve the dystocia.[28][43] They can also attempt to rotate the fetus in the birth canal by pushing on the back side of the anterior fetal shoulder and rotating 30 degrees toward the fetal face.[28][43] If the infant still has not been delivered, the mother can be flipped onto her hands and knees, and these maneuvers can be repeated in the new position.

Umbilical Cord Prolapse

Umbilical cord prolapse is when a loop of the umbilical cord gets stuck below the head of the fetus. This is concerning because the fetal head can compress the cord as the delivery progresses, preventing oxygenated blood from getting to the baby. These patients should be taken to a facility capable of performing a cesarean delivery. If the EMS clinician feels a pulsating cord of tissue consistent with a prolapsed umbilical cord on the vaginal exam, the mother should be instructed to stop pushing and be placed in the Trendelenburg position. The delivering clinician should attempt to decompress the cord by placing their hand into the vagina and pushing the fetal presenting part, typically the head, back up into the vagina and holding it there until instructed to remove their hand by the delivering surgeon at the hospital.[18] The clinician elevating the head should be prepared to maintain that position with the patient in the operating room.[28]

Postpartum Hemorrhage

Postpartum hemorrhage (PPH) is when the mother loses more than 500 mL of blood after a vaginal delivery.[46] It is one of the leading causes of pregnancy-related maternal death worldwide.[47] Much of the treatment involves getting the patient to a hospital that provides obstetric care. Still, there are several things the prehospital delivering clinician can do to assist in this situation.

EMS personnel should take the patient's vitals, establish IV access, and administer fluids similar to any traumatic hemorrhage. EMS clinicians should communicate to the receiving hospital that postpartum hemorrhage is suspected so that preparations for management can be made (eg, massive transfusion protocol).[11] They should also attempt to identify the cause of the hemorrhage so they can attempt to stop the bleeding. The most common cause of PPH is uterine atony, which causes 70% to 80% of cases.[48] Usually, the uterus begins to contract spontaneously after the baby has been successfully delivered. Thus, the myometrium effectively clamps down on the hemorrhaging spiral arteries, preventing further blood loss. Vigorous massage of the uterine fundus can stimulate this uterine contraction. If this is insufficient, bimanual uterine massage can be done by placing 1 hand within the vagina and the other on the maternal abdomen over the uterine fundus and compressing the uterus between their hands, similar to putting pressure on a wound.[49]

In a hospital setting, administering oxytocin immediately following the delivery of the infant is the most critical intervention for reducing the risk of PPH. For this reason, ACOG, the World Health Organization, and the American Academy of Family Physicians all recommend the universal administration of a uterotonic agent, usually oxytocin, following all births by obstetric clinicians.[48] 

Estimation of maternal blood loss (EBL) should be recorded. Typical vaginal deliveries have an EBL of less than 500 mL, and blood loss may be significantly less. (One standard soda can is approximately 300 mL.) Estimating blood loss can be difficult, as up to several hundred milliliters of amniotic fluid may be mixed with the blood. In general, bleeding should slow significantly within the first few minutes after delivery, especially after delivery of the placenta. If bleeding persists at a significant rate or if large blood clots, such as those the size of an apple, are observed, clinicians should be concerned about the possibility of a postpartum hemorrhage. Uterine massage should be continued until bleeding improves, or hospital clinicians can administer oxytocin. It can be administered intramuscularly (IM) or by slow IV infusion. IV bolus has been associated with cardiovascular collapse. A standard dosage is either 10 units administered IM or 5 to 10 units given as an IV bolus. It can be given at any time after the delivery of the infant's anterior shoulder, as there is no clearly defined optimal timing for its administration.[48][11] If the patient has IV access, up to 30 units can be added to 500 to 1000 mL of fluid and given as a continuous infusion.[48]

In addition to uterine atony, other less common causes of PPH include heavy bleeding from lacerations, retained placental fragments or membranes, or an acute coagulopathy (eg, disseminated intravascular coagulation). Therefore, a careful pelvic exam and rapid transfer to a hospital with obstetric clinicians are also appropriate.[11]

Neonatal Resuscitation

About 1% of infants struggle with the transition to extrauterine life and require some level of CPR beyond standard warming, drying, and stimulation (eg, rubbing the trunk).[50] Neonatal resuscitation is similar to standard CPR for a young infant. It may include positive pressure ventilation (PPV), endotracheal intubation and airway suctioning, chest compressions, and other interventions. Neonates should be assessed to determine if they require further resuscitative interventions within the first 60 seconds after birth. The following are indications that further resuscitation is required: a preterm neonate, absence of vigorous crying or effective breathing, and poor muscle tone. The following resuscitation protocol is recommended by the AAP, ACOG, the American Heart Association (AHA), and a 2022 international consensus for neonates demonstrating difficulty with birth transition.[50][32]

• Repeat initial resuscitation steps:
  • Clear the airway (eg, suction with a bulb syringe).
    • Bulb suction the mouth first, then the nose, to prevent aspiration if the neonate gasps during nasal suctioning. 
    • Avoid vigorous suctioning of the posterior pharynx. This may cause reflex bradycardia and damage the mucosa, which can interfere with feeding.
  • Warm, dry, and stimulate the neonate by replacing wet towels or cloths and rubbing with a dry towel.
• If the infant demonstrates labored breathing or persistent cyanosis:
  • Monitor blood oxygen saturation (SPO₂). The target SPO₂ increases with increasing minutes since birth. The target SPO₂ at 1 minute of life is only 60% to 65%; this target increases by 5% every minute for up to 5 minutes. At that point, the SPO₂ target is 80% to 85%; at 10 minutes of life, it is 85% to 95%.
  • Consider continuous positive airway pressure.[32][50]
• If the infant's HR is <100 bpm, or if the infant is gasping or apneic:
  • Initiate PPV.
    • Most term babies do not require supplemental oxygen with PPV.
    • Supplemental oxygen should be used judiciously and guided by pulse oximetry readings and target SPO₂ levels. Adequate ventilation alone is usually enough to restore HR in newborn infants.
  • Monitor SPO₂ with pulse oximetry.
  • Consider electrocardiography (ECG) monitoring.
  • If the HR stays <100 bpm despite PPV, check ventilation and consider intubation.[32][50]
• If the infant's HR is <60 bpm:
  • Start chest compressions, coordinated with PPV.
  • Perform neonatal intubation if not done already.
  • Give 100% oxygen.
  • Perform ECG monitoring.
  • If there is no response after 45 to 60 seconds of effective compressions, give epinephrine 0.1 to 0.3 mL/kg of 1:10,000 solution IV, equaling 0.01 to 0.03 mg/kg.[32][50]

Neonatal Hypothermia

Neonatal hypothermia is associated with increased mortality, and this risk increases as the neonate's temperature drops further from 97.7 °F (36.5 °C).[51] This risk is even more pronounced in premature infants. Hypothermia may also be associated with intraventricular hemorrhage and neonatal respiratory issues. Additionally, the temperature of infants (without asphyxiation) on admission strongly predicts morbidity and mortality.

The AHA 2022 CPR guidelines recommend maintaining infant temperatures between 97.7 °F (36.5 °C) and 99.5 °F (37.5 °C) for optimal outcomes.[50] The best options for maintaining normal temperatures include the following:

• Skin-to-skin contact, covered by a blanket with healthy neonates.
• Use of a radiant warmer, if available.
• Placing the infant in a clean, food-grade plastic bag up to the neck level, swaddling them, and holding them against the warm bodies of appropriate adults (eg, parent, EMS personnel) may be beneficial in highly low-birth-weight infants.
• Getting the baby into a warm, temperature-controlled room or increasing the temperature in the room to ≥78.8 °F (23 °C).[50] 

Clinical Significance

While prehospital deliveries are rare for EMS practitioners, the practitioners must have a solid understanding of proper delivery techniques and how to manage common emergency complications. Ideally, laboring patients should be transported to a medical facility equipped for obstetric and neonatal care before delivery takes place. However, there are situations where there isn't enough time for transportation, and the delivery occurs either upon EMS arrival or during transport.[3]

Unplanned prehospital deliveries have been linked to increased perinatal mortality and morbidity for both the newborn and the mother.[4][5][6][1] This is often due to insufficient training among EMS personnel in managing emergent deliveries, handling common intrapartum complications, and providing basic recommended neonatal resuscitation.[3][7] Therefore, healthcare practitioners should continually update their knowledge, skills, and strategies for promptly identifying complications, performing effective interventions, and coordinating care. This ensures that EMS clinicians remain composed during prehospital deliveries and strive for the best possible outcomes for the mother and the newborn.

Typically, uncomplicated deliveries require minimal intervention from EMS personnel, mainly providing support and conducting basic assessments. Critical aspects of the delivery process include assisting with expulsing the fetal head and anterior shoulder and performing the initial steps of neonatal resuscitation. EMS clinicians should also be able to address common complications that may arise during childbirth, such as shoulder dystocia, umbilical cord prolapse, postpartum hemorrhage, and neonatal respiratory distress, until the patient can be safely transported to a hospital.

Enhancing Healthcare Team Outcomes

When responding to a call for assistance during labor, the initial priority should be to swiftly transport the mother to a hospital equipped with obstetric care. It's essential to notify hospital clinicians, including emergency, neonatologists, obstetric physicians, and nurses, before the patient's arrival so they can prepare the necessary equipment, such as infant warmers, and be ready for treatment if required. In a hospital setting, trained obstetric professionals can conduct the delivery in a controlled environment, equipped to handle any potential complications.[8][10]

However, circumstances may not always allow sufficient time to transport the mother to the appropriate facility. In such cases, EMS practitioners must be well-versed in the proper delivery techniques.[22][52] To optimize patient outcomes, it is essential to maintain detailed documentation of the EMS team's interventions and ensure sound clinical care to facilitate effective communication between healthcare professionals. This is crucial because the delivery circumstances and the newborn's initial condition can influence how physicians or other advanced practitioners manage these patients upon their transfer to the hospital. Additionally, EMS clinicians should be capable of providing a verbal report when transferring patients to hospital-based clinicians.