The right upper quadrant (RUQ) is the area of the abdomen beneath the ribs on the right side. Pain here is concerning during pregnancy because this region houses important organs, including the liver, gallbladder, and a portion of the pancreas. While discomfort is often related to the harmless physical changes of a growing pregnancy, the involvement of these underlying organs means RUQ pain can also signal a more serious medical condition. Understanding the full spectrum of potential causes, from mechanical pressure to complex systemic disorders, is necessary for appropriate monitoring and care.
Benign Causes of Discomfort
The physiological and mechanical adaptations required to accommodate a developing fetus are frequent, non-serious sources of RUQ discomfort. As the uterus expands, it pushes surrounding organs upward, causing pressure against the diaphragm and rib cage. This mechanical crowding often leads to a persistent, dull ache or a feeling of fullness directly under the right ribs, especially in later pregnancy.
Hormonal changes also cause benign gastrointestinal distress felt in the RUQ. Increased progesterone levels cause smooth muscles throughout the body, including those of the digestive tract, to relax. This relaxation slows down the movement of food, known as delayed gastric emptying. As a result, trapped gas, bloating, or severe indigestion (heartburn) can manifest as pain or pressure in the upper abdomen.
Another common cause of sharp, sudden pain is the stretching of the round ligaments that support the uterus. These cord-like structures connect the front of the womb to the groin area. As the uterus grows rapidly, the ligaments are put under tension and can spasm when a person moves suddenly, such as when coughing, sneezing, or rolling over. This pain is typically brief, sharp, and often felt on the right side, considered a normal, intermittent part of the second trimester.
Non-Obstetric Medical Conditions
RUQ pain may also stem from conditions affecting the organs in that area regardless of pregnancy, though pregnancy can increase the risk. A common non-obstetric cause is cholelithiasis, or the formation of gallstones. Pregnancy hormones, particularly estrogen, increase cholesterol saturation in the bile, while progesterone slows down gallbladder motility. These factors create conditions favorable for stone formation.
If a gallstone blocks a bile duct, it can lead to acute cholecystitis, involving inflammation and severe, steady RUQ pain that may radiate to the back or right shoulder. This pain is often accompanied by nausea, vomiting, and sometimes a low-grade fever. A related condition is pancreatitis, or inflammation of the pancreas, often triggered by gallstones passing into the common bile duct.
Pancreatitis is a serious but rare event in pregnancy, typically presenting with severe upper abdominal pain that can radiate straight through to the back. Non-obstetric viral infections, such as acute viral hepatitis (Hepatitis A, B, or E), can also cause liver inflammation resulting in RUQ pain. Viral hepatitis symptoms are often non-specific and can include fatigue, nausea, vomiting, fever, and jaundice (yellowing of the skin and eyes).
Urgent Pregnancy Syndromes
The most concerning causes of RUQ pain are conditions unique to or severely complicated by pregnancy, requiring immediate medical intervention. Severe preeclampsia and its related disorder, HELLP syndrome, are high-risk conditions where RUQ pain is a hallmark symptom. HELLP syndrome is defined by hemolysis (breakdown of red blood cells), elevated liver enzymes, and low platelet count.
In both severe preeclampsia and HELLP syndrome, RUQ pain originates from the liver due to damage to the hepatic blood vessels. This damage leads to fibrin deposits, blocked blood flow, and localized bleeding, resulting in liver swelling. The pain is caused by the stretching of Glisson’s capsule, the thin, fibrous membrane that encases the liver. This stretching causes intense, persistent, or colicky pain in the epigastric area or RUQ.
HELLP syndrome usually occurs in the third trimester. The pain is frequently accompanied by severe, unrelenting headache, blurred vision, and nausea and vomiting. A life-threatening complication of HELLP is a subcapsular hematoma—a collection of blood under the liver capsule that can spontaneously rupture, causing sudden, catastrophic pain and internal bleeding.
Acute Fatty Liver of Pregnancy (AFLP) is another rare, life-threatening liver disorder typically presenting late in the third trimester. This condition is characterized by an excessive accumulation of fat within the liver cells, likely due to a defect in the fetus’s ability to process fatty acids. AFLP causes RUQ pain, often alongside non-specific symptoms like profound fatigue, persistent nausea, and vomiting. As the disease progresses, signs of liver failure emerge, including jaundice, confusion, and dangerously low blood sugar levels. The only definitive treatment for both HELLP and AFLP is immediate delivery, regardless of gestational age.
Warning Signs and Seeking Care
While minor aches are common in pregnancy, distinguishing benign discomfort from a medical emergency is important. Pain that is sudden, sharp, and unrelenting, or that rapidly increases in severity, should prompt immediate medical evaluation. Benign pains, such as round ligament pain, are typically fleeting and relieved by changing position.
Specific accompanying symptoms serve as red flags that necessitate urgent care. These include a persistent fever or chills, which can indicate infection such as cholecystitis or pyelonephritis. Persistent, severe vomiting that prevents keeping liquids down is also a concerning sign.
Signs related to the urgent pregnancy syndromes require immediate professional medical help. These symptoms include a severe, throbbing headache not relieved by standard pain medication, sudden changes in vision such as blurriness or seeing flashing lights, and new, sudden swelling in the face or hands. Any RUQ pain combined with these signs, or with symptoms of jaundice (yellowing skin or eyes), must be relayed to a healthcare provider immediately. When contacting a provider, specify the onset of the pain, its location, its severity, and any associated symptoms experienced.