Gas and digestive changes can be an early signal that your body is preparing for labor, but on their own, they don’t mean labor is imminent. At 38 weeks, your body is producing higher levels of hormones called prostaglandins that ripen the cervix for delivery. These same hormones stimulate the smooth muscle in your intestines, which can cause gas, loose stools, and general digestive upset in the days before labor begins.
That said, gas is also extremely common throughout the third trimester for reasons that have nothing to do with labor. Here’s how to tell the difference and what to actually watch for.
Why Gas Increases Before Labor
The hormones that prepare your cervix to soften and dilate don’t limit their effects to your uterus. Prostaglandins act on smooth muscle throughout your body, including the walls of your digestive tract. When they ramp up in the days leading to labor, they can speed up digestion, cause cramping in your intestines, and produce noticeable gas and diarrhea. Many women report a “clearing out” feeling 24 to 48 hours before contractions start.
Progesterone also plays a role earlier in pregnancy. High progesterone levels slow digestion throughout pregnancy, leading to constipation and trapped gas. As progesterone begins to drop relative to rising estrogen and prostaglandins near the end of pregnancy, the shift can cause a sudden change in your bowel habits. So if you’ve been constipated for weeks and things suddenly loosen up at 38 weeks, that shift is worth paying attention to.
Gas That Isn’t Related to Labor
At 38 weeks, your uterus is taking up most of your abdominal space. The physical compression of your stomach and intestines alone causes bloating, gas, and discomfort that has no connection to labor. Eating larger meals, swallowing air while eating quickly, or consuming gas-producing foods like beans, broccoli, or carbonated drinks will make this worse regardless of where you are in pregnancy.
If your gas feels the same as it has for weeks, comes and goes without any pattern, and isn’t accompanied by other changes, it’s most likely just a normal late-pregnancy symptom rather than a labor sign.
Other Signs That Labor Is Close
Gas becomes more meaningful as a labor signal when it shows up alongside other pre-labor changes. According to the American College of Obstetricians and Gynecologists, the key signs that labor is approaching include:
- Lightening: The baby drops lower into your pelvis, which can happen a few weeks to a few hours before labor. You may feel less pressure on your diaphragm and find it easier to breathe, but you’ll likely notice more pressure on your bladder.
- Loss of the mucus plug: A thick plug of mucus that sealed your cervix during pregnancy gets pushed out as dilation begins. You might see a clear, pink, or slightly bloody discharge several days before labor or right at the start.
- Rupture of membranes: Your water breaking, which can be a gush or a slow trickle.
- Regular contractions: Not the irregular tightening of Braxton Hicks, but contractions that come at consistent intervals and get progressively closer together and stronger.
If you’re experiencing gas or diarrhea along with one or more of these signs, your body is likely gearing up. If gas is your only symptom, it’s less reliable as a predictor.
Gas Pains vs. Contractions
It can be genuinely hard to tell the difference between intestinal gas cramps and early contractions, especially if this is your first pregnancy. Braxton Hicks contractions feel like a tightening in a specific area of your abdomen, similar to mild menstrual cramps. They come and go without a regular pattern, and they typically stop if you change positions or drink water.
Gas pain tends to feel sharper and more localized, often in the lower abdomen or sides. It usually improves after passing gas or having a bowel movement. True labor contractions, by contrast, wrap around from your back to your front, grow stronger over time, and don’t ease up with movement or rest. Timing them is the most reliable way to tell: if the tightening comes every 5 to 7 minutes and each one lasts about 30 to 60 seconds, that pattern points to real labor rather than gas.
Easing Gas Discomfort at 38 Weeks
Smaller, more frequent meals put less pressure on your compressed digestive system than three large ones. Sticking with bland, low-fat foods like plain rice, toast, broiled chicken, and yogurt can help if your stomach is already upset. Drinking plenty of water and staying gently active, even just walking, keeps things moving through your intestines and reduces trapped gas.
Avoid carbonated drinks and straws, both of which introduce extra air into your digestive tract. Eating slowly and chewing thoroughly also reduces the amount of air you swallow. If constipation has been building up and is now resolving on its own, that’s normal and may actually bring relief.
When Belly Pain Needs Attention
Most gas at 38 weeks is harmless, but certain types of abdominal pain warrant a call to your provider. The CDC identifies severe belly pain that doesn’t go away, starts suddenly, or worsens over time as an urgent maternal warning sign. This is especially true if the pain is sharp or stabbing rather than the dull, crampy feeling of gas.
Other warning signs that can accompany abdominal discomfort include a severe headache that won’t respond to rest or fluids, vision changes like flashing lights or blurriness, and extreme swelling in your hands or face. These can indicate conditions like preeclampsia or placental abruption, which require immediate evaluation. Steady, worsening pain that doesn’t come in waves and doesn’t improve after passing gas or changing position is not typical of either gas or normal labor contractions, and that distinction matters.
What 38 Weeks Means for Delivery
At 38 weeks, you’re classified as “early term,” a designation that covers 37 weeks through 38 weeks and 6 days. Full term starts at 39 weeks. In a healthy pregnancy, outcomes for both the baby and mother are best when delivery happens at 39 weeks or later, which is why planned deliveries before that point are generally reserved for situations where continuing pregnancy poses health risks.
That said, spontaneous labor at 38 weeks is completely normal and doesn’t carry the same concerns as an elective early delivery. If your body goes into labor on its own at this point, your baby is well-developed and ready. So while gas alone isn’t a reliable countdown timer, being alert to the full picture of labor signs at 38 weeks makes sense. Your body may be telling you it’s almost time.