Braxton Hicks Contractions (BHCs) are episodes of uterine tightening often called “practice labor.” These contractions are a common, normal physiological occurrence during gestation as the uterus prepares for childbirth. While they can be startling, BHCs are generally harmless. Understanding the difference between these warm-up tightenings and actual labor is a frequent concern for expectant mothers.
Defining Braxton Hicks Contractions
Braxton Hicks contractions are the sporadic tightening and relaxing of the uterine muscle fibers. They are named after John Braxton Hicks, the English physician who first described them in 1872. This intermittent uterine activity occurs throughout pregnancy but is usually not felt until the second or third trimester.
The sensation manifests as a firming across the abdomen, sometimes described as the stomach “balling up.” Unlike true labor, BHCs do not cause the progressive thinning or dilation of the cervix. Physicians believe these contractions play a role in toning the uterine muscle and promoting blood flow to the placenta.
Normal Frequency and Characteristics
The pattern of Braxton Hicks contractions is characterized by irregularity, infrequency, and a lack of progression. They are usually brief, lasting anywhere from 30 to 60 seconds, though some can extend up to two minutes. They should not become consistently longer, stronger, or closer together over time.
A normal frequency involves contractions occurring only a few times a day, or perhaps once or twice an hour. BHCs are considered normal if they occur fewer than four to six times within a single hour. Common triggers can intensify these contractions, including physical activity, dehydration, a full bladder, or increased fetal movement. Addressing these triggers, such as resting or drinking water, will usually cause the contractions to fade or disappear.
Key Differences from True Labor
The distinction between Braxton Hicks and true labor lies in the pattern and progression of the contractions. BHCs are unpredictable and non-rhythmic, often varying in intensity and duration. True labor contractions establish a consistent and predictable interval, becoming progressively more frequent, intense, and longer-lasting.
The location of the sensation is another distinguishing factor. Braxton Hicks are often felt primarily in the front of the abdomen or the top of the uterus. True labor contractions commonly begin as a dull ache in the lower back that wraps around to the front of the abdomen. BHCs are easily disrupted; they often stop or lessen if you change activity, walk around, or lie down. True labor contractions persist and intensify regardless of positional changes, rest, or hydration.
Warning Signs and When to Seek Medical Attention
Contractions that become regular and occur six or more times in one hour, especially if this pattern continues despite resting and drinking water, warrant a call to a healthcare provider. This frequency, particularly before 37 weeks of gestation, may indicate the possibility of preterm labor.
Immediate medical attention is necessary if contractions are accompanied by other physical signs of labor or complications. These warning signs include vaginal bleeding or spotting heavier than light pink or brown discharge. A sudden gush or steady trickle of fluid from the vagina suggests that the amniotic sac may have ruptured, often called the water breaking.
Other severe symptoms to report immediately are a noticeable decrease in fetal movement, severe pain that prevents talking, or intense, persistent lower back pain. If the contractions are lasting longer than two minutes each, contacting a medical professional allows for proper evaluation.