Birth injury is damage that occurs as a result of physical pressure during the birthing process, usually during transit through the birth canal.
- Many newborns have minor injuries during birth.
- Infrequently, nerves are damaged or bones are broken.
- Most injuries resolve without treatment.
A difficult delivery, with the risk of injury to the baby, may occur with extremely large fetuses. Doctors recommend cesarean delivery (C-section) when they estimate the baby weighs more than 11 pounds (more than 10 pounds when the mother has diabetes). Injury is also more likely when the fetus is lying in an abnormal position in the uterus before birth (see Figure: Position and Presentation of the Fetus).
Birth injuries are most commonly due to the natural forces of labor and delivery. In the past, when risks of cesarean delivery were high, doctors did difficult deliveries by pulling the fetus out using forceps (a surgical instrument with rounded edges that fit around the fetus's head). However, bringing the fetus down from high in the birth canal with forceps had a high risk of causing birth injury. Today, forceps are used only in the final stages of delivery and rarely cause injury. Overall, the rate of birth injuries is much lower now than in previous decades because of improved prenatal assessment with ultrasonography, the limited use of forceps, and because doctors often do cesarean delivery if they foresee an increased risk of birth injury.
(See also Overview of General Problems in Newborns.)
Position and Presentation of the Fetus
Toward the end of pregnancy, the fetus moves into position for delivery. Normally, the position of a fetus is facing rearward (toward the woman’s back) with the face and body angled to one side and the neck flexed, and presentation is head first.
An abnormal position is facing forward, and abnormal presentations include face, brow, breech, and shoulder.
Did You Know...
Head and brain injuries during birth
Head injury is the most common birth-related injury.
Head molding is not an injury. Molding refers to the normal change in shape of the baby's head that results from pressure on the head during delivery. In most births, the head is the first part to enter the birth canal. Because a fetus's skull bones are not rigidly fixed in position, the head elongates as it is pushed through the birth canal, which allows the fetus to pass through more easily. Molding does not affect the brain and does not cause problems or require treatment. The head shape gradually becomes more rounded over several days.
Swelling and bruising of the scalp is common but not serious and generally resolves within a few days.
Scalp scratches can occur when instruments (such as monitor leads attached to the scalp, forceps, or vacuum extractors) are used during a vaginal delivery.
Bleeding outside of the skull bones can lead to an accumulation of blood either above or below the thick fibrous covering (periosteum) of one of the skull bones.
A cephalhematoma is blood accumulation below the periosteum. Cephalohematomas feel soft and can increase in size after birth. Cephalohematomas disappear on their own over weeks to months and almost never require any treatment. However, they should be evaluated by the pediatrician if they become red or start to drain liquid. Sometimes some of the blood calcifies and leaves a hard lump in the scalp. The lump is not dangerous, is usually hidden by hair, and requires no treatment.
A subgaleal hemorrhage is bleeding directly under the scalp above the periosteum covering the skull bones. Blood in this area can spread and is not confined to one area like a cephalohematoma. It can cause significant blood loss and shock, which may even require a blood transfusion. A subgaleal hemorrhage may result from the use of forceps or a vacuum extractor, or may result from a blood clotting problem.
Fracture of one of the bones of the skull may occur before or during the birth process. Unless the skull fracture forms an indentation (depressed fracture), it generally heals rapidly without treatment.
Did You Know...
Bleeding in and around the brain
Bleeding in and around the brain (intracranial hemorrhage) is caused by the rupture of blood vessels and may be caused by
- Birth injury
- Significant illness in the newborn that decreases delivery of blood or oxygen to the brain
- A blood clotting problem
Prematurity increases the risk of intracranial hemorrhage.
Sometimes, intracranial hemorrhage occurs after a normal delivery in an otherwise well newborn. The cause of bleeding in these cases is unknown.
Bleeding in the brain is much more common among very premature infants. Newborns who have bleeding disorders (such as hemophilia) are also at increased risk of bleeding in the brain.
Most infants with bleeding do not have symptoms, whereas others can be sluggish (lethargic), feed poorly, and/or have seizures.
Bleeding can occur in several places in and around the brain:
- Subarachnoid hemorrhage is bleeding below the innermost of the two membranes that cover the brain. This is the most common type of intracranial hemorrhage in newborns, usually occurring in full-term newborns. Newborns with a subarachnoid hemorrhage may occasionally have apnea (periods when they stop breathing), seizures, or lethargy during the first 2 to 3 days of life but usually ultimately do well.
- Subdural hemorrhage is bleeding between the outer and the inner layers of the brain covering. It is now much less common because of improved childbirth techniques. A subdural hemorrhage can put increased pressure on the surface of the brain. Newborns with a subdural hemorrhage may develop problems such as seizures.
- Epidural hematoma is bleeding between the outer layer (dura mater) of tissue covering the brain (meninges) and the skull. An epidural hematoma may be caused by a skull fracture. If the hematoma increases the pressure in the brain, the soft spots between skull bones (fontanelles) may bulge. Newborns with an epidural hematoma may have apnea or seizures.
- Intraventricular hemorrhage is bleeding into the normal fluid-filled spaces (ventricles) in the brain.
- Intraparenchymal hemorrhage occurs into the brain tissue itself. Intraventricular hemorrhages and intraparenchymal hemorrhages usually occur in very premature newborns and occur more typically as a result of an underdeveloped brain rather than a birth injury. Most of these hemorrhages do not cause symptoms, but large ones may cause apnea or a bluish gray discoloration to the skin, or the newborn's entire body may suddenly stop functioning normally. Newborns who have large hemorrhages have a poor prognosis, but those with small hemorrhages usually survive and do well.
Newborns who have a hemorrhage may be admitted to a neonatal intensive care unit (NICU) for monitoring, supportive care (such as warmth), fluids given by vein (intravenously), and other treatments to maintain body function.
Bleeding Around the Brain
Bleeding may occur in several areas in and around the brain.
Nerve injuries may occur before or during delivery. These injuries usually cause weakness of the muscles controlled by the affected nerve. Nerve injuries may involve the
- Facial nerve: Lopsided facial expression
- Brachial plexus: Arm and/or hand weakness
- Phrenic nerve: Difficulty breathing
- Spinal cord (rare): Paralysis
Facial nerve injury is evident when the newborn cries and the face appears lopsided (asymmetric). This injury is caused by pressure against the nerve due to
- The way the fetus was positioned in the uterus before birth
- The nerve being pressed against the mother's pelvis during delivery
- Forceps used to assist the delivery
No treatment of facial nerve injury is needed, and the muscle weakness usually resolves by 2 to 3 months of age. However, sometimes facial nerve weakness is caused by a congenital disorder rather than an injury and does not resolve.
The brachial plexus is a group of large nerves located between the neck and shoulder, leading to each arm. During a difficult delivery, one or both of the baby's arms can be stretched and injure the nerves of the brachial plexus (see Plexus Disorders) and cause weakness or paralysis of part or all of the baby's arm and hand. Weakness of the shoulder and elbow is called Erb palsy, and weakness of the hand and wrist is called Klumpke palsy. About half of the cases of brachial plexus injuries are related to difficult deliveries, typically involving large babies, and about half occur in babies with normal deliveries. Brachial plexus injury is less frequent in babies delivered by cesarean delivery. Extreme movements at the shoulder should be avoided to allow the nerves to heal. Many milder injuries resolve over a few days. If the abnormality is more severe or lasts for more than 1 or 2 weeks, physical therapy or occupational therapy for proper positioning and gentle movement of the arm are recommended. If there is no improvement over 1 or 2 months, doctors typically recommend the baby be evaluated by a pediatric neurologist and/or orthopedist at a pediatric specialty hospital to see whether surgery may be beneficial.
The phrenic nerve, which is the nerve going to the diaphragm (the muscular wall that separates the organs of the chest from those of the abdomen and assists in breathing), is occasionally damaged, resulting in paralysis of the diaphragm on the same side. In this case, the newborn may have difficulty breathing and sometimes requires assistance with breathing. Injury of the phrenic nerve usually resolves completely within a few weeks.
Spinal cord injuries due to overstretching during delivery are extremely rare. These injuries can result in paralysis below the site of the injury. Damage to the spinal cord is often permanent. Some spinal cord injuries that occur high up in the neck are fatal because they prevent the newborn from breathing properly.
Other nerves, such as the radial nerve in the arm, the sciatic nerve in the lower back, or the obturator nerve in the leg, also may be injured during delivery.
Bones may be broken (fractured) before or during delivery even when the delivery is normal.
- A fracture of the collarbone (clavicle) is relatively common, occurring in 1 to 2% of newborns. Sometimes these fractures are not recognized until several days after birth when a lump of tissue forms around the fracture. Clavicle fractures do not seem to bother newborns and need no treatment. Healing is complete over a few weeks.
- Fractures of the upper arm bone (humerus) or upper leg bone (femur) sometimes occur. Doctors usually apply a loose splint to limit movement. These fractures may cause pain with movement in the first few days. These fractures usually heal well unless the head of the bone (where growth occurs) is involved.
- Fractures of multiple bones can occur in newborns with certain genetic conditions in which the bones are very fragile.
Injuries to the skin and soft tissues
The newborn’s skin may have minor injuries after delivery, especially areas that receive pressure during contractions or that first emerge from the birth canal during delivery. Instruments needed for delivery, such as forceps, can injure the skin. Swelling and bruising may occur around the eyes and on the face during face-first deliveries and on the genitals after breech deliveries (see Abnormal Presentations). No treatment for these bruises is needed.
Use of instruments during delivery and stress on the newborn (such as caused by asphyxia) can injure the fat under the skin (called subcutaneous fat necrosis of the newborn). This skin injury can look like red, firm, raised areas on the trunk, arms, thighs, or buttocks. This type of injury usually resolves on its own over weeks to months.
Perinatal asphyxia is a decrease in blood flow to the baby's tissues or a decrease in oxygen in the baby's blood before, during, or just after delivery. Some common causes include the following:
- Separation of the placenta from the uterus before delivery (placental abruption)
- Obstruction of umbilical cord blood flow
- Abnormal development of the fetus (for example, when there is a genetic abnormality)
- Severe infection in the fetus
- Exposure to certain drugs before birth
- Severe maternal hemorrhage
- Severe maternal illness
Sometimes the exact cause of perinatal asphyxia cannot be identified.
Regardless of the cause, affected newborns appear pale and lifeless at birth. They breathe weakly or not at all and have a very slow heart rate. They need to be revived (resuscitated) after delivery. Resuscitation may include use of a resuscitation bag and mask to push air into the lungs or insertion of a breathing tube in the newborn's throat (endotracheal intubation). If asphyxia resulted from rapid blood loss, the newborn may be in shock. They are immediately given fluids by vein, and sometimes a blood transfusion.
Newborns with asphyxia may show signs of injury to one or more organ systems, including the following:
- Heart: Poor color, low blood pressure
- Lungs: Difficulty breathing and low oxygen levels
- Brain: Lethargy, seizures, or even coma
- Kidneys: Reduced output of urine
- Liver: Difficulty making proteins that are needed for blood to clot normally
- Intestines: Difficulty digesting milk
- Blood forming system: Low platelet count and bleeding
Newborns may need drugs to help their heart function and a mechanical ventilator to support their breathing. Some newborns who have been revived may benefit from having their body temperature lowered below the normal temperature of 98.6° F (37° C) for 72 hours. Blood cell transfusions and plasma may be necessary to manage problems with the blood forming system. Most of the organs damaged by perinatal asphyxia recover over a week, but brain damage may persist.
Survivors who have minimal injury to the brain may be completely normal. Survivors who have moderate to severe injury to the brain may have permanent signs of damage, ranging from mild learning disorders to delayed development to cerebral palsy. Some severely asphyxiated infants do not survive.