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Complications during Childbirth

Complications during Childbirth

Labor Labor Labor is the normal physiologic process defined as uterine contractions resulting in dilatation and effacement of the cervix, which culminates in expulsion of the fetus and the products of conception. Normal and Abnormal Labor is defined as regular Regular Insulin, effective uterine contractions resulting in cervical changes that culminate in expulsion of the fetus and products of conception. Complications may arise during childbirth that necessitate prompt recognition and management by the delivering team. Four important complications/topics related to the moments surrounding delivery include episiotomy and lacerations, operative vaginal deliveries ( forceps Forceps Surgical Instruments and Sutures and vacuum-assisted deliveries), shoulder dystocia, and amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity embolism.

Last updated: 18 Oct, 2021

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Contents

Episiotomy and Laceration Repairs

Perineal anatomy

The perineum Perineum The body region lying between the genital area and the anus on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the pelvic diaphragm. The surface area is between the vulva and the anus in the female, and between the scrotum and the anus in the male. Vagina, Vulva, and Pelvic Floor: Anatomy is the space between the vaginal and anal orifices.

  • Perineal muscles:
    • Superficial transverse perineal muscle
    • Bulbocavernosus muscle
  • Anorectal sphincter complex:
    • The entire complex measures approximately 4 cm. 
    • External anal sphincter External anal sphincter Rectum and Anal Canal: Anatomy: 
      • Thick, circular, striated muscle Striated muscle One of two types of muscle in the body, characterized by the array of bands observed under microscope. Striated muscles can be divided into two subtypes: the cardiac muscle and the skeletal muscle. Muscle Tissue: Histology surrounding the anal orifice
      • Responsible for solid, liquid, and gas continence at rest and during rectal distention
      • Under voluntary control
    • Internal anal sphincter Internal anal sphincter Rectum and Anal Canal: Anatomy: 
      • Thin condensation of the smooth muscle of the distal colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy submucosa
      • Responsible for continence at rest
  • Muscular anatomy of the perineum and pelvic floor, external view

    Muscular anatomy of the perineum Perineum The body region lying between the genital area and the anus on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the pelvic diaphragm. The surface area is between the vulva and the anus in the female, and between the scrotum and the anus in the male. Vagina, Vulva, and Pelvic Floor: Anatomy and pelvic floor Pelvic floor Soft tissue formed mainly by the pelvic diaphragm, which is composed of the two levator ani and two coccygeus muscles. The pelvic diaphragm lies just below the pelvic aperture (outlet) and separates the pelvic cavity from the perineum. It extends between the pubic bone anteriorly and the coccyx posteriorly. Vagina, Vulva, and Pelvic Floor: Anatomy, external view

    Image by BioDigital, edited by Lecturio
  • Anorectal anatomy

    Anorectal anatomy

    Image by Lecturio.

Lacerations

Lacerations are spontaneous tears that occur due to the trauma of the infant passing through the vaginal canal during delivery.

  • Epidemiology:
    • Up to 80% of women will sustain some type of laceration Laceration Torn, ragged, mangled wounds. Blunt Chest Trauma at vaginal delivery.
    • Most are 1st- and 2nd-degree tears.
  • Location:
    • Perineal (most common)
    • Periclitoral
    • Periurethral
    • Labial
  • Classifications of perineal lacerations:
    • 1st-degree: 
      • Tear extends to the vaginal epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology and vulva Vulva The vulva is the external genitalia of the female and includes the mons pubis, labia majora, labia minora, clitoris, vestibule, vestibular bulb, and greater vestibular glands. Vagina, Vulva, and Pelvic Floor: Anatomy skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions only.
      • No perineal muscle injury 
    • 2nd-degree:
      • Tear extends to the perineal muscles.
      • No injury to the anal sphincter
    • 3rd-degree:
    • 4th-degree:
  • Risk factors for anal sphincter injury:
    • Operative vaginal delivery
    • Midline episiotomy
    • Macrosomia
    • Primiparity (1st delivery)
  • Prevention of anal sphincter injury:
    • Perineal massage antenatally and intrapartum
    • Manual perineal support at delivery (poor- quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement data, but commonly done)
    • Warm compresses Warm Compresses Chalazion
  • Treatment: 
  • Complications of 3rd- and 4th-degree lacerations:
    • Wound breakdown
    • Fecal incontinence Fecal incontinence Failure of voluntary control of the anal sphincters, with involuntary passage of feces and flatus. Pediatric Constipation
    • Pelvic organ prolapse Pelvic Organ Prolapse Pelvic organ prolapse (POP) is a general term that refers to herniation of 1 or more pelvic organs (e.g., bladder, uterus, rectum) into the vaginal canal, and potentially all the way through the introitus. Weakness and insufficiency of the pelvic floor may result in POP. Pelvic Organ Prolapse
    • Rectovaginal fistulas 
    • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, including dyspareunia Dyspareunia Recurrent genital pain occurring during, before, or after sexual intercourse in either the male or the female. Primary Ovarian Insufficiency
Degrees of perineal lacerations

Degrees of perineal lacerations

Image by Lecturio.

Episiotomy

An episiotomy is an intentional 3–5-cm incision made by the delivering provider to enlarge the vaginal opening at the time of delivery.

Locations of a midline vs. Mediolateral episiotomy

Midline versus mediolateral episiotomy

Image: “Medio-lateral-episiotomy” by Jeremykemp. License: Public Domain, edited by Lecturio.

Related videos

1:50
Labor Stage 3: Laceration and Episiotomy

Operative Vaginal Delivery

Overview

Operative vaginal delivery is the use of obstetric forceps Forceps Surgical Instruments and Sutures or a vacuum extractor to effect delivery of a fetus. 

  • Epidemiology:
    • Overall incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: approximately 3% of deliveries
    • Forceps Forceps Surgical Instruments and Sutures: 0.5% of all vaginal births
    • Vacuum: 2.6% of all vaginal births
  • Indications:
    • Fetal distress in the 2nd stage of labor 2nd stage of labor The period of obstetric labor that is from the complete dilatation of the cervix uteri to the expulsion of the fetus. Normal and Abnormal Labor (2nd stage: time from complete dilation through delivery of the fetus; “pushing”)
    • Prolonged or arrested 2nd stage of labor 2nd stage of labor The period of obstetric labor that is from the complete dilatation of the cervix uteri to the expulsion of the fetus. Normal and Abnormal Labor
    • Shortening of the 2nd stage of labor 2nd stage of labor The period of obstetric labor that is from the complete dilatation of the cervix uteri to the expulsion of the fetus. Normal and Abnormal Labor for maternal medical indications (conditions that prevent safe maternal pushing):
    • Maternal exhaustion
  • Criteria required to perform operative vaginal deliveries:
    • Vertex presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor
    • Ruptured fetal membranes
    • Full cervical dilation Cervical dilation A measurement of the diameter of the cervical canal, reported in centimeters Normal and Abnormal Labor (10 cm)
    • At least +2 station (fetal head is 2 cm below the maternal ischial spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy)
    • Knowledge of the fetal position Fetal position Direction of the fetal head in relation to the maternal pelvis in vertex presentations Normal and Abnormal Labor (e.g., occiput anterior versus posterior)
    • Adequate anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts
    • Empty maternal bladder Bladder A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination. Pyelonephritis and Perinephric Abscess
  • Forceps and vacuum deliveries

    Forceps Forceps Surgical Instruments and Sutures and vacuum deliveries

    Image by Lecturio.
  • Vertex positions

    Fetal head position:
    Position is determined by the location of the fetal occiput (posterior portion of the head located behind the smaller triangular shaped fontanelle Fontanelle Any of six membrane-covered openings between the cranial sutures in the incompletely ossified skull of the fetus or newborn infant. The fontanelles normally close sometime after birth. Skull: Anatomy) relative to the maternal pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy (anterior/posterior and right/left). For example, ROA stands for right occiput anterior and means that the fetal occiput is against the right anterior portion of the maternal pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy.

    Image by Lecturio.
  • Fetal station

    Fetal station Fetal station Refers to how high (or low) the presenting fetal part is compared to the maternal ischial spine, reported in centimeters Normal and Abnormal Labor:
    The presenting fetal part is measured in centimeters from the ischial spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy. Negative numbers denote a higher fetal station Fetal station Refers to how high (or low) the presenting fetal part is compared to the maternal ischial spine, reported in centimeters Normal and Abnormal Labor, while positive numbers denote a lower fetal station Fetal station Refers to how high (or low) the presenting fetal part is compared to the maternal ischial spine, reported in centimeters Normal and Abnormal Labor as the fetus descends in the birth canal Birth canal Pelvis: Anatomy.

    Image by Lecturio.

Vacuum-assisted delivery

  • Technique:
  • Maternal complications
    • 2-fold ↑ risk of 3rd- and 4th-degree perineal lacerations (involves the anal sphincter)
    • Vulvar and vaginal hematomas
    • Urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy injury
    • Lower rates of maternal complications with vacuum as compared with forceps Forceps Surgical Instruments and Sutures and cesarean deliveries
  • Fetal complications:
    • Fetal scalp lacerations
    • Cephalohematoma Cephalohematoma Von Willebrand Disease → hyperbilirubinemia Hyperbilirubinemia A condition characterized by an abnormal increase of bilirubin in the blood, which may result in jaundice. Bilirubin, a breakdown product of heme, is normally excreted in the bile or further catabolized before excretion in the urine. Jaundice
    • Intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage
Intracranial hemorrhage in fetal head

CT scan of fetal head demonstrating an intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage:
This is a potential complication of operative vaginal deliveries.

Image: “Image of computed tomography scan of brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification on postpartum day 23” by University Obstetrics Unit, De Soysa Hospital for Women, Colombo, Sri Lanka. License: CC BY 4.0

Forceps Forceps Surgical Instruments and Sutures-assisted delivery

  • Technique:
  • Maternal complications:
    • 6-fold ↑ risk of 3rd- and 4th-degree perineal lacerations 
    • Vulvar and vaginal hematomas
    • Urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy injury
  • Fetal complications:
    • Facial lacerations
    • Facial nerve injury Nerve Injury Surgical Complications
    • Skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
    • Intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage
Obstetric forceps

Obstetric forceps Forceps Surgical Instruments and Sutures

Image: “Obstetric forceps” by Wellcome Collection gallery. License: CC BY 4.0

Related videos

4:54
Labor Stage 2: Operative Delivery

Shoulder Dystocia

Overview

Shoulder dystocia is when the baby’s anterior shoulder becomes impacted behind the maternal pubic symphysis Pubic Symphysis A slightly movable cartilaginous joint which occurs between the pubic bones. Vagina, Vulva, and Pelvic Floor: Anatomy, preventing delivery of the fetal body. Shoulder dystocia is a true obstetric emergency.

  • Definition: 
    • Failure to deliver the fetal shoulders with gentle downward traction, where additional maneuvers are required to deliver the baby 
    • This is a bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types-on- bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types obstruction → episiotomy will not relieve shoulder dystocia
    • During the dystocia, the fetus is not getting any oxygen. 
  • Epidemiology:
    • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 0.2%–3% of vaginal births in the vertex presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor
    • Risk of recurrence: 10%–16% 
    • Unpredictable and can occur in any laboring woman
  • Risk factors (though shoulder dystocia often occurs in the absence of risk factors):
    • Fetal macrosomia Fetal macrosomia A condition of fetal overgrowth leading to a large-for-gestational-age fetus. It is defined as birth weight greater than 4, 000 grams or above the 90th percentile for population and sex-specific growth curves. It is commonly seen in gestational diabetes; prolonged pregnancy; and pregnancies complicated by pre-existing diabetes mellitus. Wilms Tumor
    • Maternal diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus (pregestational or gestational)
    • Previous shoulder dystocia
    • Maternal obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity 
    • Operative vaginal delivery 
    • Prolonged 2nd stage of labor 2nd stage of labor The period of obstetric labor that is from the complete dilatation of the cervix uteri to the expulsion of the fetus. Normal and Abnormal Labor
  • Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor:
    • Failure of the fetal shoulders to deliver with gentle downward traction on the fetal head
    • Turtle sign: retraction of the fetal head tightly against the maternal perineum Perineum The body region lying between the genital area and the anus on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the pelvic diaphragm. The surface area is between the vulva and the anus in the female, and between the scrotum and the anus in the male. Vagina, Vulva, and Pelvic Floor: Anatomy
    • Abnormal progression of the 2nd stage of labor 2nd stage of labor The period of obstetric labor that is from the complete dilatation of the cervix uteri to the expulsion of the fetus. Normal and Abnormal Labor

Initial management

Shoulder dystocia is an obstetric emergency. 

  • Call for help.
  • Have mother stop pushing.
  • Immediately have mother assume the McRoberts position: 
  • Suprapubic pressure:
    • Attempts to push the shoulder down and inward 
    • Slightly rotates the fetus and dislodges the impacted shoulder
    • Avoid fundal pressure, which may make the dystocia worse.
  • Manual delivery of the posterior arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy 
    • Reduces the bisacromial diameter
    • ↑ Risk of clavicular and/or humerus Humerus Bone in humans and primates extending from the shoulder joint to the elbow joint. Arm: Anatomy fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
  • 95% of shoulder dystocias will be relieved with the management described.
Suprapubic pressure

Suprapubic pressure being used to dislodge and internally rotate an impacted shoulder in shoulder dystocia

Image: “Suprapubic-pressureforSD” by Henry Lerner. License: CC BY 4.0
Mc roberts manv

McRoberts position with suprapubic pressure

Image: “McRoberts maneuver” by geraldbaeck. License: CC0 1.0

Additional maneuvers

Additional maneuvers to attempt if the dystocia persists include:

  • Rotational maneuvers:
    • Attempt to manually rotate the shoulders
    • Rubin’s maneuver: rotate the anterior or posterior fetal shoulder anteriorly toward the fetal face
    • Woods screw maneuver: rotate the posterior fetal shoulder backward
  • Gaskin maneuver:
    • Have mother assume a position on her hands and knees.
    • Repeat above maneuvers in this position.
    • May be helpful in women who are not anesthetized
  • Intentional clavicular fracture Clavicular Fracture Acute Shoulder Pain:
    • Pop the anterior clavicle Clavicle A bone on the ventral side of the shoulder girdle, which in humans is commonly called the collar bone. Clavicle Fracture outward to ↓ the bisacromial diameter.
    • ↑ Risk of injury to vasculature and pulmonary structures
    • Less morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status than procedures of last resort
  • Episiotomy:
    • Episiotomy will not relieve shoulder dystocia.
    • Consider cutting one to allow space to adequately perform the maneuvers.
  • Repeat all above maneuvers several times before moving on to procedures of last resort.
  • Procedures of last resort:
    • Zavanelli maneuver: 
      • Replace the fetal head in the abdomen by reversing the cardinal movements of labor Labor Labor is the normal physiologic process defined as uterine contractions resulting in dilatation and effacement of the cervix, which culminates in expulsion of the fetus and the products of conception. Normal and Abnormal Labor and perform an urgent cesarean delivery Cesarean Delivery Cesarean delivery (CD) is the operative delivery of ≥ 1 infants through a surgical incision in the maternal abdomen and uterus. Cesarean deliveries may be indicated for a number of either maternal or fetal reasons, most commonly including fetal intolerance to labor, arrest of labor, a history of prior uterine surgery, fetal malpresentation, and placental abnormalities. Cesarean Delivery.
      • High morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status
    • Abdominal rescue: 
      • Make a hysterotomy, manually reduce the impacted shoulder, and deliver vaginally.
      • Done when the head is unable to be manually replaced during attempted Zavanelli maneuver
    • Symphysiotomy:
      • Surgical division of the cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology of the pubic symphysis Pubic Symphysis A slightly movable cartilaginous joint which occurs between the pubic bones. Vagina, Vulva, and Pelvic Floor: Anatomy
      • Only used when an OR is unavailable

To remember the management of a shoulder dystocia, remember HELPERR:

  • Call for Help.
  • Consider an Episiotomy (to allow space for maneuvers).
  • Elevate the Legs.
  • Apply suprapubic Pressure.
  • Enter the vagina Vagina The vagina is the female genital canal, extending from the vulva externally to the cervix uteri internally. The structures have sexual, reproductive, and urinary functions and a rich blood supply, mainly arising from the internal iliac artery. Vagina, Vulva, and Pelvic Floor: Anatomy for internal rotational maneuvers.
  • Reliever the posterior arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy.
  • Rotate the woman to hands-and-knees position.

Complications

  • Brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region injury
    • Erb palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies: 
      • Stretching of the C5 and C6 nerves from continuous downward traction on the head
      • Often reversible
      • 75% of brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region injury
    • Klumpke palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies: stretching of C8 and T1 nerves
  • Clavicular fracture Clavicular Fracture Acute Shoulder Pain
  • Humerus Humerus Bone in humans and primates extending from the shoulder joint to the elbow joint. Arm: Anatomy fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
  • Fetal asphyxia Asphyxia A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life. Drowning
  • Contusions and lacerations
Brachial plexus injuries associated with shoulder dystocia

Brachial plexus Brachial Plexus The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (c5-c8 and T1), but variations are not uncommon. Peripheral Nerve Injuries in the Cervicothoracic Region injuries associated with shoulder dystocia

Image by Lecturio.

Related videos

9:10
Labor Stage 2: Shoulder Dystocia

Amniotic Fluid Embolism

Overview

Amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity embolism (AFE) is a complication of labor Labor Labor is the normal physiologic process defined as uterine contractions resulting in dilatation and effacement of the cervix, which culminates in expulsion of the fetus and the products of conception. Normal and Abnormal Labor affecting the mother in the immediate postpartum period Postpartum period In females, the period that is shortly after giving birth (parturition). Postpartum Complications.

  • Caused by entry of amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity into the maternal circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment by:
    • Placental tears
    • Uterine vein rupture
  • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 1 in 40,000 deliveries
  • Mortality Mortality All deaths reported in a given population. Measures of Health Status:

Risk factors

  • Cesarean delivery Cesarean Delivery Cesarean delivery (CD) is the operative delivery of ≥ 1 infants through a surgical incision in the maternal abdomen and uterus. Cesarean deliveries may be indicated for a number of either maternal or fetal reasons, most commonly including fetal intolerance to labor, arrest of labor, a history of prior uterine surgery, fetal malpresentation, and placental abnormalities. Cesarean Delivery
  • Operative vaginal deliveries
  • Placental abnormalities Placental abnormalities Normal placental structure and function are essential for a healthy pregnancy. Some of the most common placental abnormalities include structural anomalies (such as a succenturiate lobe or velamentous cord insertion), implantation anomalies (such as placenta accreta and placenta previa), and functional anomalies (such as placental insufficiency). Placental Abnormalities (e.g., placenta previa Placenta Previa Abnormal placentation in which the placenta implants in the lower segment of the uterus (the zone of dilation) and may cover part or all of the opening of the cervix. It is often associated with serious antepartum bleeding and premature labor. Placental Abnormalities)
  • Preeclampsia Preeclampsia A complication of pregnancy, characterized by a complex of symptoms including maternal hypertension and proteinuria with or without pathological edema. Symptoms may range between mild and severe. Pre-eclampsia usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease. Hypertensive Pregnancy Disorders/ eclampsia Eclampsia Onset of hyperreflexia; seizures; or coma in a previously diagnosed pre-eclamptic patient (pre-eclampsia). Hypertensive Pregnancy Disorders

Pathogenesis

  • Unclear
  • Amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity enters maternal circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment and triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency):
    • Intense pulmonary vasoconstriction Vasoconstriction The physiological narrowing of blood vessels by contraction of the vascular smooth muscle. Vascular Resistance, Flow, and Mean Arterial Pressure:
      • ↑ Pulmonary pressure → right ventricular failure → systemic hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
      • Hypoxemic respiratory failure Hypoxemic Respiratory Failure Respiratory Failure
      • Pulmonary edema Pulmonary edema Pulmonary edema is a condition caused by excess fluid within the lung parenchyma and alveoli as a consequence of a disease process. Based on etiology, pulmonary edema is classified as cardiogenic or noncardiogenic. Patients may present with progressive dyspnea, orthopnea, cough, or respiratory failure. Pulmonary Edema
    • An abnormal immune response:
      • Intense inflammatory response (similar to SIRS) is activated.
      • Inflammatory mediators activate the coagulation cascade Coagulation cascade The coagulation cascade is a series of reactions that ultimately generates a strong, cross-linked fibrin clot. Hemostasis systemically → DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation 
  • DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation leads to:
    • Hemorrhage → further hemodynamic instability
    • Ischemic multiorgan failure
  • Mechanical obstruction Mechanical Obstruction Any impairment, arrest, or reversal of the normal flow of intestinal contents toward the anal canal. Imaging of the Intestines from amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity debris likely does not play a significant role.

Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor

Amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity embolism typically presents dramatically, as sudden onset cardiopulmonary collapse occurring during labor Labor Labor is the normal physiologic process defined as uterine contractions resulting in dilatation and effacement of the cervix, which culminates in expulsion of the fetus and the products of conception. Normal and Abnormal Labor or within 30 minutes after delivery.

  • Signs: 
    • Cardiopulmonary collapse: loss of breathing and pulse
    • Hypoxemia Hypoxemia Neonatal Respiratory Distress Syndrome/ cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination
    • Dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea
    • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
    • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children 
  • Other symptoms:
    • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
    • Mental status changes 
    • Seizure 
  • DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation:
    • Usually develops shortly after an AFE
    • Leads to obstetric hemorrhage
    • Bleeding from catheter sites and mucosal surfaces
  • Fetal heart rate Heart rate The number of times the heart ventricles contract per unit of time, usually per minute. Cardiac Physiology abnormalities indicating distress (e.g., late decelerations, terminal bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias) if still pregnant

Diagnosis

Amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity embolism is a clinical diagnosis based on presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor. 

  • Laboratory evaluation (primarily to help with resuscitation Resuscitation The restoration to life or consciousness of one apparently dead. . Neonatal Respiratory Distress Syndrome):
    • Coagulation profile:
      • ↑ Prothrombin time Prothrombin time Clotting time of plasma recalcified in the presence of excess tissue thromboplastin. Factors measured are fibrinogen; prothrombin; factor V; factor VII; and factor X. Hemostasis
      • ↓ Fibrinogen Fibrinogen Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides a and b, the proteolytic action of other enzymes yields different fibrinogen degradation products. Hemostasis
      • ↑ D-dimer D-dimer Deep Vein Thrombosis
    • CBC:
      • Anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types 
      • Leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus
      • Thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia 
    • Arterial blood gas Arterial blood gas Respiratory Alkalosis:
  • Imaging (once woman is stable enough): 
Amniotic fluid embolism x-ray

Chest x-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests in a woman with amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity embolism:
Diffuse infiltration is evident throughout the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy.

Image: “ X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests” by Department of Emergency and Critical Care, The University of Tokushima Graduate School, Kuramoto Tokushima, 770-8503, Japan. License: CC BY 2.0

Management

Survival depends on prompt diagnosis and effective resuscitation Resuscitation The restoration to life or consciousness of one apparently dead. . Neonatal Respiratory Distress Syndrome.

  • Airway Airway ABCDE Assessment: Secure the airway Airway ABCDE Assessment.
  • Breathing: mechanical ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing
  • Circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment:
    • High- quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement cardiopulmonary resuscitation Cardiopulmonary resuscitation The artificial substitution of heart and lung action as indicated for heart arrest resulting from electric shock, drowning, respiratory arrest, or other causes. The two major components of cardiopulmonary resuscitation are artificial ventilation and closed-chest cardiac massage. Cardiac Arrest ( CPR CPR The artificial substitution of heart and lung action as indicated for heart arrest resulting from electric shock, drowning, respiratory arrest, or other causes. The two major components of cardiopulmonary resuscitation are artificial ventilation and closed-chest cardiac massage. Cardiac Arrest)
    • 2 large-bore IVs → fluid resuscitation Resuscitation The restoration to life or consciousness of one apparently dead. . Neonatal Respiratory Distress Syndrome
    • Transfuse to combat DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation; typically a 1:1:1 ratio of:
    • Vasopressors Vasopressors Sepsis in Children
  • Immediate delivery if woman is still pregnant

Complications

  • Hematologic: DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation
  • Cardiovascular: hemorrhage and cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) arrest
  • Pulmonary-related: pulmonary edema Pulmonary edema Pulmonary edema is a condition caused by excess fluid within the lung parenchyma and alveoli as a consequence of a disease process. Based on etiology, pulmonary edema is classified as cardiogenic or noncardiogenic. Patients may present with progressive dyspnea, orthopnea, cough, or respiratory failure. Pulmonary Edema and ARDS ARDS Acute respiratory distress syndrome is characterized by the sudden onset of hypoxemia and bilateral pulmonary edema without cardiac failure. Sepsis is the most common cause of ARDS. The underlying mechanism and histologic correlate is diffuse alveolar damage (DAD). Acute Respiratory Distress Syndrome (ARDS)
  • Permanent neurologic deficits Neurologic Deficits High-Risk Headaches due to cerebral hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage (85% of survivors)

References

  1. American College of Obstetrics and Gynecology Committee on Obstetrics. (2020). Practice bulletin no. 219: operative vaginal birth. Retrieved March 19, 2021, from https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2020/04/operative-vaginal-birth 
  2. Wegner, E.K., Bernstein, I.M. (2021). Operative vaginal delivery. UpToDate. Retrieved March 19, 2021, from https://www.uptodate.com/contents/operative-vaginal-delivery
  3. American College of Obstetrics and Gynecology Committee on Obstetrics. (2020). Practice bulletin no. 178: shoulder dystocia. Retrieved March 19, 2021, from https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2017/05/shoulder-dystocia 
  4. Rodis, J.R. (2019). Shoulder dystocia: Intrapartum diagnosis, management, and outcome. UpToDate. Retrieved March 19, 2021, from https://www.uptodate.com/contents/shoulder-dystocia-intrapartum-diagnosis-management-and-outcome 
  5. Berkowitz, L.R., Roust-Wright, C.E. (2020). Approach to episiotomy. UpToDate. Retrieved March 20, 2021, from https://www.uptodate.com/contents/approach-to-episiotomy 
  6. Toglia, M.R. (2020). Repair of perineal and other lacerations associated with childbirth. UpToDate. Retrieved March 20, 2021, from https://www.uptodate.com/contents/repair-of-perineal-and-other-lacerations-associated-with-childbirth 
  7. American College of Obstetrics and Gynecology Committee on Obstetrics. (2018). Practice Bulletin No. 198: Prevention and management of obstetric lacerations at vaginal delivery. Retrieved March 20, 2021, from https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/09/prevention-and-management-of-obstetric-lacerations-at-vaginal-delivery 
  8. Baldisseri, M.R., Leigh Clark, S. (2020). Amniotic fluid embolism. UpToDate. Retrieved Mar 17, 2021, from https://www.uptodate.com/contents/amniotic-fluid-embolism 

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