What is Infant Head Lag?
Babies usually have a big head in comparison to the size of their body, and their neck muscles are quite weak when they’re born. That’s why their heads tend to wobble or lag, particularly during the first few weeks. During this time, it’s normal for parents and caregivers to support the baby’s head until they learn how to control their neck.
The development of motor skills in babies generally progresses from the head down to the feet, with the baby learning to stabilize their body, which means they can balance their body weight whether they’re moving or still. This gradual strengthening of the neck and body muscles typically develops quickly during infancy. For example, when a baby is moved from lying down to a sitting position, they should be able to keep their head in line with their shoulders instead of letting it flop around.
Several studies suggest that by 3-4 months, a baby should have enough control over their neck muscles to prevent this head lag. At this point, a typical baby actively participates in their own handling by using their emerging neck strength to counterbalance the pull from their body when being picked up.
If a baby still has a head lag after 4 months, it may indicate some problems with their neurological development. This is most commonly observed in babies born prematurely or those with a condition called cerebral palsy, and can give us some indication of how their physical and mental abilities might develop. However, head lag by itself may not necessarily predict future neurological outcomes since it only evaluates one aspect of the baby’s reactions. To make more accurate predictions, it is suggested to combine assessments of several neonatal responses such as reflex reactions, posture and muscle tone.
Research also suggests that head lag, along with other early quirks in physical development, may be linked to a higher risk of autism, especially in babies who already have a sibling with autism. It’s also been found that babies with autism often have difficulties with maintaining posture and may have lower than average muscle strength around their body’s core.
What Causes Infant Head Lag?
When a baby can’t hold their head up, this is often referred to as ‘head lag’. There are two types of head lag – physiological and pathological. Physiological head lag is normal and simply occurs because the baby’s motor control pathways are still developing. On the other hand, pathological head lag happens if there are issues with the baby’s muscles or nerves, which can make it difficult for them to maintain their posture and leaves them with less control over their body.
Sometimes, head lag happens because of problems with a baby’s sensory system. This can prevent the baby from noticing that their head position has changed and from adjusting their movements accordingly.
Various medical and environmental factors can affect a baby’s ability to control their head and neck. These factors can include being born prematurely, sustaining a brain injury, low birthweight, or needing to be on a ventilator for a long period after birth. Head lag can also tell us about a premature baby’s muscle control. If a baby was born early and experiences a delay in gaining control over their head movement, this might simply be because their muscle control isn’t fully developed yet. Even if they don’t have any other neurological problems, premature babies might have worse motor development than babies born at term, and they may show signs of head lag for longer.
Risk Factors and Frequency for Infant Head Lag
Head lag, or difficulty in maintaining the position of the head, is especially common in babies who are born prematurely. By the time they reach the expected full-term date, most babies born on time can hold their heads up during a pull-to-sit test.
- A study in the American Journal of Occupational Therapy found 90% of babies born before 30 weeks had head lag at 30 weeks.
- About 60.5% of these infants still had head lag at 34 weeks.
- And, 57.8% at the age corresponding to a full-term birth.
- More head lag was seen in infants with complications around the time of birth.
Another study conducted at the Hadassah Medical Centre in Jerusalem, Israel, concluded the issue of head lag was not as prevalent in babies born on time, with only 4% experiencing this. However, for 20% of these infants, other risk factors like vacuum delivery, possible sepsis, and congenital malformations were present. For the other 80% who did not have these risk factors, 62.5% had mild head lag and 37.5% had moderate-to-severe head lag.
Signs and Symptoms of Infant Head Lag
During a baby’s routine check-up, doctors assess muscle tone, including the baby’s ability to control their head and neck. It’s normal for newborns to have some degree of head lag, that is, the baby’s head falling back when picked up from a lying position. This usually goes away on its own. However, if persistent and severe head lag continues beyond the age of 3 to 4 months, it may indicate conditions related to low muscle tone and weakness.
A thorough medical history is important to help doctors narrow down the possible causes of low muscle tone, including:
- Pregnancy and birth history
- Post-natal period
- Developmental milestones
- Family health history
Certain risk factors may also contribute to low muscle tone, including:
- Being born prematurely
- Excess amniotic fluid during pregnancy (polyhydramnios)
- Breech birth
- Older parental age
- Exposure to harmful substances or infections
- Maternal health conditions (like epilepsy or diabetes)
- Newborn infections (TORCHES)
- Challenges shortly after birth (like sepsis and prolonged stay in the neonatal intensive care unit)
A comprehensive physical exam can help identify related conditions or syndromes causing the low muscle tone. For instance, signs like certain facial features or droopy eyelids can suggest problems with the nervous system or muscle function respectively.
When checking muscle tone, it’s helpful if the baby is calm, alert, and not crying. Muscle tone in the neck and core is examined using special tests. In one test, the baby is held horizontally and should be able to keep their back straight, their head up and their arms and legs bent. In another test, an energetic baby should be able to keep their head up while sitting.
Head lag can be classified into three levels of severity. Mild head lag is when the baby tries to hold their head up when moved from lying to sitting. Moderate head lag is when the baby doesn’t try to hold their head up during this movement, but can hold their head up while sitting. Severe head lag is when the baby can’t lift their head during the movement or hold it up while sitting.
Testing for Infant Head Lag
If a newborn is displaying signs of head lag, it’s essential to evaluate the baby thoroughly. This process typically begins with a detailed medical examination and discussing the baby’s history. If the baby experiences occasional head lag before they are three to four months old and shows no other signs of low muscle tone (hypotonia) or distinctive facial features linked to genetic syndromes, then further testing might not be necessary. However, if the head lag is continuous, very noticeable, or accompanied by other signs of hypotonia, more intensive examination is required.
Doctors in Israel discovered a “feeding test” that helps distinguish normal, expected head lag from the kind that may indicate a health concern. In this study, healthy newborns were fed and then re-examined for head lag after eating. About 92% of the infants showed either a reduction or complete disappearance of head lag 15 minutes after feeding, likely due to increased blood sugar levels. Those who continued to experience head lag were later diagnosed with conditions such as Soto syndrome, hypothyroidism, and cerebral palsy.
If your doctor believes your newborn’s head lag is a sign of an underlying health issue, they may recommend several diagnostic tests. These can include blood tests for thyroid function (TSH and free T4), electrolyte levels, and indicators of infection. More specialized tests might include CT or MRI scans of the baby’s head and neck, electroencephalogram (EEG) to measure brain activity, genetic testing (karyotype), analysis of the baby’s urine and blood for abnormal levels of certain acids, liver function tests, and tests for certain enzymes like aldolase and creatine kinase. Your baby might also be referred to a neurologist for further consultation.
Treatment Options for Infant Head Lag
When a young baby can’t hold up their head by themselves, it’s known as “head lag.” In newborns, it’s perfectly normal and usually goes away by the time they’re around four months old. But if it continues past this point, or if it’s severe before this age, it could be a sign of a more serious problem and will require attention from a team of specialists. This team could include a children’s doctor (pediatrician), a brain specialist for children (child neurologist), a geneticist who studies how certain traits or conditions are passed down through families (medical geneticist), and therapists who work on physical and occupational tasks. Working together, they can provide the best care possible.
Research shows that early intervention is the best way to help children who are at risk of developing motor disorders, which are conditions that affect the ability to control muscle movement. Parents are taught how to help their child’s development through specific training routines and programs. Therapists also play a crucial role in developing a baby’s sensorimotor skills, which link the sensory experiences (things the child sees, hears, or touches) with motor actions, helping improve their participation in different activities.
Some of these training routines might include home exercises like reverse cradling (holding the baby in a certain way that helps build neck strength), tummy time, using toys, and specifically working on strengthening the neck muscles.
What else can Infant Head Lag be?
If a baby has trouble keeping their head up, it could be due to several health conditions related to low muscle tone, or hypotonia. Such conditions should be taken into account while diagnosing a baby with consistently poor head control. These include:
- Chromosomal disorders, like Prader Willi syndrome
- Injuries that limit oxygen or blood flow to the brain or spinal cord
- Abnormal brain development
- Spinal muscular atrophies
- Congenital hypomyelination neuropathy, a condition affecting the nerves
- Familial dysautonomia, a nervous system disorder present from birth
- Infantile neuronal degeneration, a type of neurodegenerative disease
- Infections that affect the brain, like meningitis and encephalitis
- Infantile botulism, a rare but serious illness
- Congenital and transient myasthenia gravis, a condition that causes muscle weakness
- Muscular dystrophies, a group of genetic diseases that cause muscle weakness and loss
- Metabolic myopathies like hypothyroidism that affect muscle function
- Central core disease or other congenital myopathies which are disorders present at birth that affect muscle function
The parents should consult with a healthcare provider to conduct relevant tests and arrive at an accurate diagnosis.
What to expect with Infant Head Lag
Generally, healthy babies who show signs of a natural head lag tend to get better on their own without any treatment. However, head lag that’s caused by health problems usually needs early physical therapy and treatment of the root cause to improve.
Possible Complications When Diagnosed with Infant Head Lag
Babies who can’t control their head well may struggle with breastfeeding because they can’t latch on properly. Additionally, they might face other issues related to the underlying cause of their head lag. For instance, infants with a condition known as infantile myasthenia gravis might have trouble breathing.
Problems may include:
- Difficulty in breastfeeding
- Poor latching during breastfeeding
- Issues related to secondary causes like infantile myasthenia gravis
- Respiratory distress or breathing difficulties
Preventing Infant Head Lag
Checking for any delays in a baby’s ability to hold up their head, often referred to as ‘head lag,’ should be a regular part of a child’s checkups during the first six months of life. It’s crucial that parents understand when their child should be reaching certain physical milestones, like being able to keep their head steady. This knowledge can help parents avoid worrying unnecessarily and from jumping to conclusions about their child’s development. It also keeps them informed about when they might need to seek further medical advice.
If a baby still has head lag after four months, this might signal a need for further investigation. Starting early therapy at home, which involves the parents and helps to improve the baby’s physical skills, has been proven to improve results.
