Braxton Hicks contractions are a normal part of late pregnancy, often described as “practice contractions” as the uterus prepares for childbirth. Many pregnant individuals may undergo monitoring at some point, and understanding how these contractions appear on a monitor can help reduce anxiety. This guide will clarify the visual characteristics of Braxton Hicks contractions on a monitor and help differentiate them from true labor.
Understanding Braxton Hicks Contractions
Braxton Hicks contractions serve as a physiological preparation for true labor, essentially toning the uterine muscles. These contractions typically begin in the second or third trimester, though they often become more noticeable in the later months of pregnancy. They are generally characterized by an uncomfortable but usually painless tightening sensation across the abdomen. Unlike true labor, Braxton Hicks contractions are irregular, tend not to increase in intensity or frequency over time, and do not cause cervical changes.
How Contraction Monitoring Works
Uterine contractions are monitored using a non-invasive device called an external tocodynamometer, often referred to as a “toco.” This device is placed on the abdomen and secured with a belt. The tocodynamometer functions by measuring changes in abdominal pressure as the uterus contracts and relaxes. These pressure changes are then converted into an electrical signal, which is translated into a line graph displayed on a fetal monitor.
Visualizing Braxton Hicks on the Monitor
On a fetal monitor, Braxton Hicks contractions appear as low, irregular peaks. The line on the monitor might show a slight elevation or a small, rounded hump, which quickly returns to the baseline. These peaks typically do not demonstrate a consistent pattern of increasing intensity or frequency. Braxton Hicks contractions often appear sporadically, lacking the clear, sustained “hill” or “mountain” pattern usually associated with stronger, more coordinated uterine activity. Their intensity on a toco reading is generally lower, often ranging from 5 to 25 mmHg.
Distinguishing Braxton Hicks from True Labor
Differentiating Braxton Hicks from true labor on a monitor involves observing distinct patterns. True labor contractions manifest as more pronounced, symmetrical peaks that progressively increase in intensity, duration, and frequency over time. These contractions typically follow a regular pattern, becoming closer together and stronger. In contrast, Braxton Hicks contractions are irregular, inconsistent, and often subside with a change in activity or position. While the monitor provides objective data, the subjective experience, including pain levels, regularity, and progression, remains crucial for accurate differentiation.
When to Seek Medical Advice
Even when experiencing what seem like Braxton Hicks contractions, it is important to know when to contact a healthcare provider. Seek medical advice if contractions become regular, increase in intensity or frequency, or are accompanied by other concerning symptoms. These include vaginal bleeding, a gush or continuous leakage of fluid, or a noticeable decrease in fetal movement.