Lower stomach pain during pregnancy is extremely common and usually caused by the normal stretching and shifting happening inside your body. The most likely explanation depends on how far along you are, where exactly the pain is, and what it feels like. Most causes are harmless, but a few require urgent attention, so understanding the differences matters.
Round Ligament Pain
The most common reason for lower abdominal pain in pregnancy is round ligament stretching. Your uterus is anchored to your lower abdominal wall by two rope-like bands, each about 10 to 12 centimeters long. As your uterus grows, these ligaments get longer and wider to keep up, and that stretching can hurt.
Round ligament pain typically shows up during the second trimester (weeks 14 through 27), though it can start earlier or linger later. It tends to feel like a sharp, stabbing, or pulling sensation on one or both sides of your lower belly. It can also come as aches, cramps, or spasms. The pain often flares with sudden movements like standing up quickly, rolling over in bed, coughing, or laughing. It usually passes within seconds to minutes.
Digestive Slowdown and Constipation
Pregnancy hormones, particularly progesterone, relax the smooth muscles throughout your body, including the ones that push food through your intestines. The result is slower digestion, more gas, bloating, and constipation, all of which can cause cramping and pressure in your lower belly.
About one in three pregnant people experience constipation. The rate is lowest in the first trimester (around 21%) and peaks in the second trimester at roughly 34%. Staying hydrated, eating fiber-rich foods, and keeping physically active all help keep things moving. The discomfort from digestive issues tends to feel dull, come and go, and improve after a bowel movement or passing gas.
Braxton Hicks Contractions
Starting as early as the second trimester but most noticeable in the third, Braxton Hicks contractions can feel like your entire abdomen tightens and hardens. They start at the top of the uterus and spread downward, sometimes making your belly look strangely contorted or almost pointy.
These “practice contractions” are irregular, unpredictable, and non-rhythmic. They typically last 15 to 30 seconds, though occasionally up to two minutes. The key difference from real labor contractions: Braxton Hicks don’t get stronger, closer together, or more painful over time. They taper off and disappear, especially if you change positions or drink water. For most people they’re more uncomfortable than truly painful, though some do find them intense.
Pelvic Girdle and Pubic Bone Pain
Pain that feels like it’s in your lower stomach can actually originate from your pelvis. Symphysis pubis dysfunction (SPD) affects the joint at the front of your pelvis and causes shooting pain right at the pubic bone that radiates into the lower abdomen, groin, thighs, and back. It often comes with a clicking or grinding sensation in the joint.
This kind of pain is worse with movement: walking, climbing stairs, standing on one leg, or turning over in bed. It gets better with rest. If this sounds familiar, a few adjustments can help. Avoid sitting or standing in one position for more than 30 minutes, keep your knees together when getting in and out of the car, and sleep with a pillow between your legs. Avoid heavy lifting, crossing your legs, or standing on one foot. Paracetamol (acetaminophen) is considered safe in pregnancy and can be taken in regular doses if the pain is persistent.
Urinary Tract Infections
UTIs are more common during pregnancy and can cause lower abdominal pressure, burning with urination, and an urgent need to pee. Between 2% and 10% of pregnant people have bacteria in their urine without any symptoms at all, a condition called asymptomatic bacteriuria. Left untreated, it can progress to a kidney infection and has been linked to higher rates of preterm delivery and low birth weight. This is why a urine culture is a routine part of prenatal care.
If the infection reaches the kidneys, symptoms escalate to fever (100°F or higher), flank pain, and feeling generally unwell. Kidney infections in pregnancy are typically treated in the hospital. A straightforward bladder infection is treated with a short course of antibiotics and resolves quickly.
When Lower Stomach Pain Is Serious
Most pregnancy-related abdominal pain is benign, but certain patterns signal something that needs immediate medical attention.
Ectopic Pregnancy (First Trimester)
If you’re in early pregnancy and haven’t yet had an ultrasound confirming the pregnancy is in your uterus, sharp pelvic pain combined with vaginal bleeding could indicate an ectopic pregnancy, where the embryo implants outside the uterus, usually in a fallopian tube. Symptoms often start subtly and worsen as the embryo grows. Shoulder pain or a sudden urge to have a bowel movement can occur if there’s internal bleeding irritating nearby nerves. This is a medical emergency.
Placental Abruption (Late Pregnancy)
In the second half of pregnancy, sudden, severe abdominal pain with a rigid or tender uterus may indicate placental abruption, where the placenta separates from the uterine wall before delivery. This is often accompanied by vaginal bleeding, though not always. It requires emergency care.
Red Flags at Any Stage
The CDC identifies several urgent warning signs during pregnancy that warrant immediate medical care:
- Severe belly pain that doesn’t go away, especially if it starts suddenly, is sharp or stabbing, or worsens over time
- Vaginal bleeding heavier than light spotting
- Fluid leaking from your vagina, or discharge with a foul smell
- Fever of 100.4°F or higher
- Severe swelling, redness, or pain in one leg, which could signal a blood clot
Simple Relief for Common Pain
For the everyday aches of a growing uterus, a few strategies help. Changing positions slowly rather than jumping up from a chair or bed reduces round ligament flare-ups. Gentle stretching, staying active with walks or prenatal exercise, and getting adequate rest all make a difference. When resting, lying on your less painful side with a pillow under your bump and another between your knees takes pressure off your ligaments and pelvis.
Avoid sitting or standing in one position for long stretches. If you’re dealing with constipation-related cramping, focus on water intake and high-fiber foods before reaching for supplements. A warm (not hot) bath or a heating pad on a low setting over your lower belly can ease muscle tension, though you should keep heat application brief.
If your pain is new, worsening, or doesn’t match the patterns described above, trust your instinct. Pain that is persistent, one-sided, or accompanied by bleeding, fever, or changes in your baby’s movement pattern is worth a call to your provider, even if it turns out to be nothing.