10/11/2025
Adrenaline in labour and birth
Adrenaline (also called epinephrine) is a key stress hormone released by the adrenal glands. During labour and birth, its role is complex and varies depending on timing, maternal condition, and intrapartum events. Here’s an overview of its physiology, clinical implications, and practical considerations for obstetric care.
Key physiological roles in labour and birth
Maternal physiological response to stress and pain
Adrenaline is released in response to pain, fear, anxiety, hypoxia, and exertion.
It increases heart rate, blood pressure, and bronchodilation, helping to maintain maternal oxygen delivery.
Uterine activity
Adrenaline can modulate uterine contractions. Higher levels may blunt contractions, potentially leading to slower labour progression or secondary arrest.
In some contexts, mild sympathetic stimulation can help coordinate contractions, but excessive catecholamines may inhibit uterine activity.
Fetal well-being
Adrenaline crosses the placenta in small amounts; fetal adrenal response contributes to fetal adaptation during stress.
Excess maternal catecholamines have been associated with reduced placental blood flow and potential fetal distress in extreme scenarios.
Situations that raise adrenaline during labour
Pain management (especially with inadequate analgesia)
Physical exertion and prolonged labour
Maternal cold exposure or hypoglycemia
Acute distress, fear, or emergency situations
Clinical implications and management
Pain relief and anxiety control
Adequate analgesia (e.g., neuraxial analgesia like an epidural or intrathecal analgesia) can reduce the maternal sympathetic surge and limit excessive adrenaline release.
Non-pharmacological comfort measures and supportive care also help minimize stress responses.
Labour progression
Inadequate analgesia or high stress may contribute to slower labour or a stagnation phase.
Hypnobirthing can reduce the production of adrenaline and potentially speed labour up
