How Stress During Pregnancy Affects a Baby’s Growth and Development

What Is Stress During Pregnancy?

Stress is the body’s natural response to a perceived challenge or threat. When stressed, the body releases hormones such as cortisol and adrenaline, triggering the fight-or-flight response. During pregnancy, hormonal and physical changes are already significant and added emotional or psychological stress can feel overwhelming.

Common triggers of stress during pregnancy include:

• Financial worries
• Job-related pressure
• Relationship conflicts
• Health complications
• Previous pregnancy loss
• Lack of social support

Occasional stress is normal and does not harm the baby. Concern arises primarily with chronic, severe or unmanaged stress.

Is All Stress Harmful to the Baby?

No. Short-term stress, such as feeling nervous before a medical appointment or managing a busy day at work, is unlikely to cause harm. The body is equipped to handle these small stress responses.

Problems arise when stress becomes constant and intense. Long-term anxiety, depression, domestic conflict or traumatic events can keep stress hormones elevated for prolonged periods, which may affect the pregnancy environment.

How a woman perceives and copes with stress also matters. Two people can experience the same event but respond differently. Support systems, resilience and access to care significantly influence outcomes.

Can Stress During Pregnancy Cause Low Birth Weight?

Yes. Significant or chronic stress during pregnancy has been linked to a higher risk of low birth weight (LBW), defined as a baby weighing less than 2.5 kilograms at birth. Stress can affect fetal growth through several pathways:

• Hormonal changes: Stress triggers the release of cortisol and corticotropin-releasing hormone (CRH), which can influence fetal development and increase the risk of preterm labour and LBW.
• Reduced uterine blood flow: Stress may redirect blood away from the uterus, limiting oxygen and nutrient delivery to the fetus.
• Lifestyle effects: Stress can lead to unhealthy coping mechanisms, such as poor diet, disrupted sleep or smoking, which further impact fetal growth.
• HPA axis dysregulation: Chronic stress can alter the maternal stress-response system, potentially affecting long-term development of the baby’s stress regulation.

While stress alone is rarely the sole cause of LBW; other factors like maternal health, infections and lifestyle choices also play a role, managing stress is an important part of supporting healthy fetal growth.

Recognise stressors, seek professional support and practice relaxation techniques like deep breathing, mindfulness or gentle exercise.

Does Stress Affect a Baby’s Brain Development?

Yes, research suggests that chronic or high levels of maternal stress during pregnancy may influence the developing baby’s brain, although effects vary and are not guaranteed. The baby’s brain grows rapidly throughout pregnancy, especially in the second and third trimesters, making it sensitive to environmental influences.

When a pregnant woman experiences ongoing stress, stress hormones and related physiological responses can cross the placenta or affect the intrauterine environment. Studies have found associations between higher prenatal stress and:

• Alterations in fetal brain growth and structure, including changes in hippocampal volume and cortical development.
• Differences in brain connectivity and neural development, which have been observed using fetal imaging techniques.
• Greater risk of later behavioural and emotional regulation challenges, as prenatal stress influences neurodevelopmental processes.

However, these findings do not mean that stress guarantees developmental problems. Many children born to mothers who experienced stress during pregnancy develop normally. Multiple factors, such as genetics, the postnatal environment, supportive caregiving and social resources, play powerful roles in shaping long-term outcomes.

Is There a Link Between Stress and Preterm Birth?

Yes, several studies suggest that severe stress during pregnancy may increase the risk of preterm birth (delivery before 37 weeks of gestation).

Possible mechanisms include:

• Stress-related inflammation
• Hormonal changes that trigger early labour
• Impact on immune function

Women experiencing significant life stressors, trauma or untreated mental health conditions may be at higher risk. This highlights the importance of screening for anxiety and depression during antenatal visits. Early identification and support can reduce risks and improve outcomes.

How Can Maternal Stress Influence Long-Term Health?

High maternal stress during pregnancy can affect a child’s long-term health through multiple pathways:

• Hormonal exposure: Cortisol crosses the placenta, impacting brain regions controlling emotion, attention and memory.
• Epigenetic changes: Stress can alter gene expression, affecting health trajectories.
• Brain structure and function: May influence the amygdala, hippocampus and frontal cortex.
• Immune system and microbiome: Increases risk of inflammation, allergies and gastrointestinal issues.

Potential long-term outcomes:

• Behavioural and emotional: anxiety, depression, ADHD, temperament challenges
• Cognitive: attention, memory and language difficulties
• Metabolic: obesity, insulin resistance, metabolic dysfunction
• Neurodevelopmental: possible developmental delays

What Are the Signs of High Stress in Pregnancy?

Pregnancy stress can show up in many ways, affecting your emotions, body and daily behaviour. Common signs include:

Emotional and Mental Signs:

• Persistent anxiety or uncontrollable worry
• Mood swings, irritability or sudden sadness
• Trouble focusing or “brain fog”
• Panic attacks or intense fear

Physical Signs:

• Difficulty sleeping or excessive fatigue
• Headaches, muscle tension or palpitations
• Changes in appetite or digestive issues

Behavioural Signs:

• Social withdrawal or avoiding activities
• Unhealthy coping, such as increased smoking or alcohol use
• Fear or reluctance about childbirth

If these symptoms persist for more than two weeks or interfere with daily life, professional support from a healthcare provider is strongly recommended. Early intervention can protect both maternal and fetal well-being.

How Can You Manage Stress During Pregnancy?

Managing stress during pregnancy does not require perfection. Small, consistent changes can help regulate the nervous system and promote emotional well-being.

• Prioritise rest: Sleep is essential for emotional balance. Aim for a consistent bedtime routine.
• Gentle physical activity: Walking, prenatal yoga or stretching can reduce cortisol levels and improve mood.
• Mindfulness and breathing exercises: Simple breathing techniques can calm the stress response within minutes.
• Social support: Talking openly with a partner, friend or family member reduces feelings of isolation.
• Limit information overload: Constant exposure to negative news or online forums can heighten anxiety.
• Professional support: Counselling, cognitive behavioural therapy or antenatal mental health services can provide structured coping strategies.

When Should You Seek Professional Help?

One should consider speaking to the healthcare provider if you experience:

• Persistent low mood
• Panic attacks
• Thoughts of self-harm
• Inability to function at work or home
• Severe relationship conflict or domestic violence

Obstetricians, midwives and general practitioners are trained to support mental health during pregnancy. Early intervention improves outcomes for both mother and baby.

Conclusion

Stress during pregnancy is normal, but chronic or severe stress can affect fetal growth, preterm birth risk and long-term development. The key is managing stress through rest, gentle movement, mindfulness, supportive relationships and professional help when needed. You cannot control every stressor, but how you respond matters. With awareness, self-compassion and healthy coping strategies, both mother and baby can thrive.