Chills and shivering are frequently reported experiences during childbirth, leading many expectant parents to wonder if this physical response signals the beginning of labor. This involuntary shaking is often a normal physiological reaction to the tremendous effort and change occurring in the body. The meaning of chills can vary significantly, ranging from a common side effect of labor to a potential warning sign requiring medical attention. This article clarifies the reasons behind labor-related chills and provides the definitive signs that indicate labor is truly underway.
Understanding Shivering and Chills During Labor
The experience of uncontrollable shivering, often described as a “labor shake,” is a common occurrence, particularly during the active phase of labor or immediately following delivery. This phenomenon is not typically a sign that labor is about to begin, but rather a response to the intense physiological changes occurring as labor progresses. Many women experience this shaking, which can range from mild trembling to full-body chattering.
One major factor is the sudden and significant shift in hormones, particularly the surge of adrenaline and endorphins released during intense contractions. The body’s “fight-or-flight” response, triggered by the stress of labor, floods the system with hormones that can cause muscles to tremble uncontrollably. This surge is part of the body’s natural mechanism to cope with childbirth.
Physical exhaustion from the strenuous work of labor also contributes to the shaking, as the muscles react to fatigue and immense energy expenditure. Furthermore, the use of epidural or spinal anesthesia can influence the body’s ability to regulate its temperature. The medications can open up blood vessels near the skin, leading to heat loss and triggering a shivering response.
The chills are generally temporary and tend to resolve relatively quickly, often within 20 to 30 minutes after the baby is born. This non-pathological shivering should not be confused with the deep, bone-aching chills that accompany a fever. These labor shakes are considered a normal, temporary response to the dramatic hormonal, physical, and pharmacological changes of delivery.
The Definitive Signs of Active Labor
Because chills are an ambiguous symptom, knowing the verifiable signs of active labor is essential for determining when to seek medical care. The most reliable indicator is the pattern of true contractions, which are distinct from the practice contractions known as Braxton Hicks. True labor contractions establish a consistent rhythm and gradually increase in frequency, duration, and intensity over time.
A true contraction typically lasts for 60 seconds or longer and occurs at increasingly shorter intervals, following a predictable pattern. Unlike false labor, which often subsides with a change in position or activity, true labor contractions will persist regardless of movement. The discomfort of true labor often starts in the lower back and radiates forward, whereas Braxton Hicks are usually felt only in the front of the abdomen.
Another definitive sign is the rupture of membranes, commonly referred to as the “water breaking.” This may be a sudden gush of fluid or a slow, steady trickle, but the fluid is clear and distinct from urine. The loss of the mucus plug, a thick, jelly-like discharge that seals the cervix, can also signal that the cervix is beginning to change.
The combination of regular, intensifying contractions and progressive cervical changes defines the onset of active labor. These changes can only be confirmed by a healthcare provider. While the loss of the mucus plug or the water breaking can happen before contractions start, the consistent rhythm and increasing power of the uterine tightening are the most practical indicators for someone at home.
When Chills Signal a Medical Concern
While non-feverish shivering is common during labor, chills accompanied by an elevated temperature can signal a serious medical complication. A maternal fever during labor, defined as 100.4°F (38.0°C) or higher, requires immediate evaluation by a medical professional. This elevated temperature, especially when paired with chills, may indicate an infection.
The primary concern is chorioamnionitis, an infection of the amniotic fluid and surrounding membranes. This condition is often caused by bacteria ascending from the vagina into the uterus, and the risk increases when the amniotic sac has been ruptured for an extended period. Other symptoms accompanying an infection include a rapid heart rate in the mother or fetus, foul-smelling amniotic fluid, or uterine tenderness.
If chills are experienced along with a fever, contact the healthcare provider immediately for assessment and potential treatment. Early diagnosis of a possible infection is important because chorioamnionitis poses risks to both the parent and the baby. Treatment typically involves administering intravenous antibiotics to manage the infection and improve outcomes.
Other infections, such as pyelonephritis (a kidney infection), can also cause chills and fever during pregnancy and labor, making prompt diagnosis important. Any instance of fever combined with chills must be investigated. The presence of a deep, flu-like ache along with the shivering warrants urgent attention, as it differs from the normal, temporary labor shake.