Labor often involves intense, uncontrollable shaking, known medically as rigors. These episodes are involuntary shivering, chattering, or full-body trembling that can occur before, during, or immediately following delivery. Labor shakes are a very common and usually normal physiological response during the childbirth process. Understanding the underlying cause helps demystify the symptom and provides a pathway for seeking relief.
The Physiology Behind Labor Shakes
The primary drivers of labor shakes are complex and often occur simultaneously within the body. Significant hormonal shifts happen as the body transitions into active labor, particularly surges in stress hormones like adrenaline and cortisol. These sudden fluctuations, combined with the release of oxytocin to stimulate contractions, can trigger an involuntary physical response that manifests as shaking.
A second major factor involves the body’s temperature regulation system. The massive energy expenditure of uterine contractions and pushing causes a rapid consumption of glucose, which can temporarily disrupt the internal thermal balance. The body’s core temperature may fluctuate, leading the hypothalamus to initiate shivering as a way to generate heat.
Epidural anesthesia represents another distinct cause, often leading to shivering due to its effect on the nervous system and blood flow. The anesthetic blocks nerve signals, causing the blood vessels in the lower half of the body to relax and widen, a process called vasodilation. This action shifts warm blood from the core to the periphery, triggering a shivering response to compensate.
External factors, such as receiving room-temperature intravenous fluids, can also contribute to a drop in core temperature. The cumulative effect of physical effort, hormonal changes, and medical interventions makes the body highly susceptible to these temporary thermal dysregulations.
Immediate Comfort Measures for Relief
Addressing the physical sensation of cold is often the most effective immediate step for comfort, even if the core issue is non-thermoregulatory. Warm blankets, especially those heated in a hospital warmer, should be placed over the body and legs to provide external heat and a sense of physical weight. Wearing warm socks or having a heat pack applied to the feet or lower back can assist in regulating the peripheral temperature.
Support people can implement relaxation techniques to reduce the adrenaline-driven component of the shaking. Focused, slow breathing patterns help calm the nervous system and manage the intensity of involuntary movements. Gentle massage or counter-pressure applied to the arms and legs can offer a grounding sensation and temporary distraction from the shaking.
Changing positions frequently, such as shifting from side-lying to sitting on a birth ball, may help redistribute blood flow and relieve muscle tension. After delivery, immediate skin-to-skin contact with the newborn is a powerful comfort measure. The baby’s warmth and hormone release help regulate the birthing person’s body temperature and stress hormones.
Medical Interventions for Severe Rigors
When non-medical comfort measures are insufficient or the rigors are severe, the medical team can employ specific interventions. For shivering related to an epidural or IV fluid administration, utilizing warmed intravenous fluids is a direct method to counter thermal loss. Studies have shown that administering parenteral fluids and local anesthetics at warmer temperatures can significantly reduce the incidence of shivering.
In cases where the shaking is severe, continuous monitoring of the patient’s oxygen saturation may be necessary. Intense, prolonged shivering dramatically increases the body’s oxygen consumption, which can be problematic for individuals with pre-existing cardiac conditions. If oxygen levels drop, supplemental oxygen is administered via a mask to ensure adequate saturation.
Some medications, such as the opioid Meperidine, are known to have anti-shivering properties. Their use is often limited in labor due to potential side effects for both the birthing person and the baby. Medical staff will assess the overall condition to determine if the benefit of a pharmacological intervention outweighs the associated risks.
When Shaking Requires Clinical Attention
While most labor shakes are a normal part of the process, certain accompanying symptoms warrant immediate clinical attention from the care team. Shaking accompanied by a fever, defined as a temperature of 100.4°F (38°C) or higher, is a primary concern. An elevated temperature may signal a developing infection, such as chorioamnionitis, which requires prompt evaluation and antibiotic treatment.
The duration and intensity of the rigors are also important indicators to report to the nurse or doctor. Shaking that is violent, exceptionally distressing, or persists for more than one or two hours after the delivery of the baby is atypical for normal labor rigors. Persistent shivering can be a sign of a more serious systemic issue, like sepsis, and should never be ignored.
Any shaking paired with other concerning symptoms, such as severe pain unrelated to contractions, confusion, or a sustained, rapid heart rate, necessitates immediate medical assessment. The clinical team will use these details to distinguish between a benign physiological tremor and a potentially serious complication requiring intervention.