Why do babies cry during sleep?

Why Babies Cry During Sleep

Babies cry during sleep due to normal developmental processes including arousal mechanisms, which are protective physiological responses to stressors during sleep, and should not be perceived as poor sleep quality or a medical concern in most cases.

Normal Developmental Causes of Crying During Sleep

Protective Arousal Mechanisms

• Infants have a natural ability to arouse from sleep as a protective physiological response to stressors 1
• These arousals are often accompanied by crying and are completely normal
• Physiologic studies show that infants are more likely to arouse when sleeping in the supine (back) position compared to prone position 1
• This increased arousal capability is actually beneficial for infant safety and SIDS prevention

Normal Sleep Cycles

• Infants cycle through different sleep states more frequently than adults
• When transitioning between sleep cycles, babies may briefly wake and cry before returning to sleep
• An infant who wakes frequently is exhibiting normal behavior and should not be perceived as a poor sleeper 1

Medical Causes (Less Common)

In a minority of cases, crying during sleep may be associated with:

Discomfort Related to Feeding

• Gastroesophageal reflux - only if accompanied by frequent vomiting (approximately five times per day) 2
• Food allergies - cow's milk and other food allergies may cause irritability 2

Medication Withdrawal

• Infants exposed to certain medications in utero may exhibit withdrawal symptoms including sleep disturbances
• These can include irritability, hyperactivity, tremors, high-pitched cry, and excessive sucking 1
• Medications that may cause withdrawal symptoms include:
  • SSRIs (selective serotonin reuptake inhibitors) - symptoms appear within hours to days after birth 1
  • Alcohol - symptoms include hyperactivity, crying, irritability, and poor sleep patterns 1
  • Barbiturates - can cause disturbed sleep and excessive crying 1

Management Approaches

For Normal Developmental Crying

1. Educate parents about normal infant sleep patterns

   • Explain that frequent waking and crying are normal protective mechanisms 1
   • Reassure that an infant's ability to arouse from sleep is important for their safety

2. Maintain safe sleep practices

   • Always place infants on their back to sleep 1
   • Avoid the prone (stomach) or side sleeping positions which reduce protective arousals 1
   • Do not elevate the head of the crib as this may compromise respiration 1

3. Help parents develop consistent settling approaches

   • Recognize when the baby is tired 2
   • Apply a consistent approach to settling 2
   • Help baby deal with discomfort through a baby-centered approach 2

For Parents

• Accept that crying during sleep is normal and not a sign of poor parenting
• Encourage parents to accept help from friends and family to manage fatigue 2
• If parents are unable to manage their baby's crying, consider referral to a parenting center or local hospital 2

Important Considerations

When to Be Concerned

• Excessive crying accompanied by other symptoms like vomiting, fever, or unusual behavior
• Crying that suddenly increases or changes in character
• Signs of pain or discomfort that persist when the baby is awake

Common Pitfalls to Avoid

1. Mistaking normal arousal for a medical problem

   • Most crying during sleep is developmental, not pathological 2
   • Less than 5% of excessively crying infants have an underlying organic cause 3

2. Changing to prone sleeping position

   • Parents may be tempted to place babies on their stomachs to reduce crying
   • This significantly increases SIDS risk and should be strongly discouraged 1

3. Overmedication or unnecessary dietary changes

   • Avoid prescribing medications or altering diet without clear indications 4
   • The assumption that crying reflects pain or discomfort is often incorrect in a normally growing infant 4

Remember that for most infants, crying during sleep is a normal developmental phenomenon that will improve with time, typically peaking at around 6 weeks and abating by 12-16 weeks of age 2.