Cerebral Palsy Risk Factors: When is it Caused by a Birth Injury?

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Cerebral Palsy Risk Factors

Cerebral palsy, a collective terminology, describes disorders of movement, balance, and posture caused by brain damage due to events before, during, or after the birth of a child, hampering their brain’s ability to control muscles.

It is one of the most common motor disorders in children and affects the brain’s ability to transmit appropriate signals to neurons controlling muscle tone and power. The condition results in spastic paralysis of muscles in most cases where muscles stiffen and fail to relax, causing immobility.

While symptoms and signs in the early years can warn parents of its presence, there is no permanent cure as the disease causes permanent, irreversible damage to the brain.

Early Symptoms of Cerebral Palsy in Infants and Toddlers

A few symptoms that may hint towards cerebral palsy are:

  • Delayed achievement of developmental milestones (not sitting or rolling over by six months)
  • Stiffened muscles due to spasticity or loss of muscle tone
  • Lack of hand preference
  • Difficulty in swallowing
  • Unable to lift head when lying on stomach

In toddlers, the following symptoms may show:

  • Toewalking due to muscle contractures
  • Not walking by 18 months
  • Inability to speak sentences
  • Unable to follow commands
  • Abnormal posture and gait

While in some cases, the exact cause of cerebral palsy is unknown, other kinds of neurological conditions like erbs palsy is caused by birth trauma to the child. The upper roots of brachial plexus—a network of nerve fibers innervating the arm—are injured due to forced traction applied on the neck during delivery.

The long-term prognosis for some neurological conditions like Erb’s and Klumpke’s palsy is promising in contrast to cerebral palsy, where permanent, irreversible damage occurs to the brain tissues.

Many factors contribute to the development of cerebral palsy, which can be categorized into three divisions based on the timeline of occurrence of events. Let’s take a look!

Prenatal Risk Factors

While most of the cases do not have a definite cause and are regarded as idiopathic, some other prenatal risk factors that might lead to cerebral palsy before birth include fetal exposure to

  • Maternal infections, such as German measles
  • Low birth weight, preterm, premature births
  • Maternal medical conditions
  • Teratogen exposure
  • Multiple gestations

Maternal infections

Some maternal infections pass through the placenta, attacking the fetus and producing developmental abnormalities in the babies.

Infection of cytomegalovirus, chickenpox, rubella, toxoplasmosis, and herpes simplex during pregnancy can cause cerebral palsy in the child. Some of these are preventable with maternal immunizations before pregnancy.

Low birth weight

A healthy baby is born after 37 weeks of gestation, and delivery before 37 weeks is considered preterm birth. Low birth weight is defined as birth weight <2500 grams, and primarily happens due to premature birth. Babies gain most of the weight during the third trimester; therefore, premature delivery is associated with low birth weight, often leading to developmental conditions

Maternal medical conditions

Maternal health and wellbeing play a crucial role in the pregnancy and delivery of the child.

Certain maternal diseases are associated with the development of cerebral palsy in the child, including hypothyroidism, diabetes mellitus, Crohn’s disease, and systemic lupus erythematosus.

Teratogen exposure

Any substance or drug consumed during pregnancy causing birth defects is termed teratogens.

Perinatal and perinatal consumption of teratogens like alcohol, tobacco, or narcotics is associated with birth defects, including cerebral palsy.

Multiple gestations

Twins, triplet pregnancies are high-risk pregnancies that require surplus nutrients and oxygen supply. Also, premature births in multiple gestations account for health problems in babies.

Natal Risk Factors

Factors that predispose the brain to trauma or injury during birth are natal and can be due to OB-GYN negligence, the mother’s medical condition, or neonatal factors. Some of these include,

  • Low oxygen supply
  • Perinatal infections such as chorioamnionitis
  • Placental disease
  • Birth trauma due to vacuum or forceps intervention

Low oxygen supply

Birth asphyxia is low oxygen and blood supply to the fetus during and soon after birth. Causes for birth asphyxia are multifactorial.

Umbilical cord around the neck, heavy bleeding due to placental disorders or trauma, prolonged labor, meconium clogging airways of the neonate and meconium aspiration can lead to birth asphyxia and eventually cerebral palsy.

APGAR score is calculated after 1 and 5 minutes of delivery to rule out the possibility of birth asphyxia. In case of a lower APGAR score which is less than 6, immediate interventions are taken by pediatricians.

Perinatal infections

Infections transmitted during delivery from mother to fetus after membrane rupture can result in neonatal CNS infections.

Placental disease

The placenta is an organ created by mothers to supply oxygen and nutrients to the baby throughout gestation. Its abnormal location can compromise blood and oxygen supply to the fetus, redirecting all of the blood to the mother.

Low oxygen supply inside the uterus increases the risk of developing cerebral palsy.

Birth trauma

Prolonged labor requires assisted delivery with the help of forceps or vacuum. Inappropriate handling of instruments results in birth injuries predisposing the newborn to cerebral palsy.

Postnatal Factors

Factors that contribute to brain trauma after birth until 28 days are classified as postnatal factors. These include,

  • CNS infections
  • Hyperbilirubinemia
  • Head trauma or injury

Hyperbilirubinemia

Physiological jaundice occurs 24 hours after birth and resolves after 5-7 days. Jaundice before or after that period has non-physiological causes.

High levels of bilirubin can cross the blood-brain barrier and harm brain tissue.

The Takeaway

Risk factors predisposing to the development of cerebral palsy do not necessarily culminate in the disease, but it is better to keep a check and avoid the potential risk factors.

Causes of cerebral palsy are multifactorial; however, most of the cases do not have a definite cause or risk factor. It is essential, however, to nullify the chances of cerebral palsy by preventing the modifiable risk factors.