Are Hernias Associated with Pregnancy?

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A hernia is the protrusion of part of an internal organ through the wall of a body cavity. Often, what is penetrated is a wall, due to its connective tissue or muscle being weak in some region. During pregnancy, various types of hernia can occur, because of the growing uterus. This increases pressure in all directions over time, so the walls of body cavities are pushed.

Types of hernias provoked by pregnancy

One type of hernia that pregnancy can produce, or exacerbate, is an inguinal hernia, in which a section of intestine, or omentum (an apron-shaped layer of membrane that is attached to abdominal organs), protrudes into what’s called the inguinal canal in the groin. A less common type of groin hernia is a femoral hernia. In a femoral hernia, a weakened abdominal wall and pressure from the growing womb causes abdominal contents to protrude into what’s called the femoral canal.

Protrusion of abdominal contents through abdominal wall muscles, not into a canal, is called a ventral hernia. One type of ventral hernia is called an incisional hernia, which is characterized by protrusion of organ parts through a healed incision line, such as the incision that you may have had for a cesarean section for a previous pregnancy.

An umbilical hernia is the protrusion of abdominal contents through the umbilicus (the “belly button”). This develops commonly in pregnancy, due to forward pressure from the growing womb against an abdominal wall that is weakened right around the umbilicus. Umbilical hernia is fairly common among mothers-to-be, developing in approximately 8 out of 1,000 pregnancies.

A diaphragmatic hernia occurs when organ parts protrude through the diaphragm that separates the abdominal and chest (thoracic) cavities. The most common type of diaphragmatic hernia is called hiatal hernia, in which the stomach protrudes upward through what’s called the esophageal hiatus (a hole in the diaphragm through which the esophagus passes on its way to the stomach. Diaphragmatic hernias are fairly rare during pregnancy, but they can lead to severe complications when they do occur.

Hernias are diagnosed, first based on your history, your symptoms, and then signs that the doctor can find on physical examination. This process can point to a likely hernia, which imaging studies can then reveal. In the case of an umbilical hernia, for instance, the umbilicus would bulge, and this would worsen when you cough. If intestines begin to become strangulated, you also would feel abdominal pain and tenderness centered on the umbilicus, which would be surrounded by reddened skin. Constipation or vomiting also might occur. With a hiatal hernia, you would feel heartburn, you may experience regurgitation of food, you may have difficulty swallowing, shortness of breath, and sore throat, plus you may have darkened stools, which are indicative of bleeding in the stomach. Organs, such as intestines, also can become incarcerated in a hernia, meaning that they can’t get out without surgery, no matter how the tissues are pulled or manipulated from the outside, kind of like a Chinese finger trap.

Hernias can lead to various complications for both the mother and her fetus. Umbilical and incisional hernias can entrap loops of intestine, for instance, leading to life threatening situations. Since the fetus is in the abdominal cavity of the mother, strangulation or incarceration of organs can cause, not only maternal problems, but also fetal problems, requiring immediate surgery. In such cases, there is elevated risk of premature delivery and spontaneous abortion (miscarriage).

Hiatal hernia can lead to, or exacerbate, gastroesophageal reflux disease (GERD), meaning that acid from the stomach reaches the esophagus, causing a burning sensation, sometimes coughing, and, if it continues for a long time, long term damage. This situation is treated with agents that reduce acid production, called H-2 antihistamines cimetidine, famotidine, nizatidine, ranitidine. Stronger medications, called proton pump inhibitors include lansoprazole and omeprazole. Ranitidine, cimetidine, and famotidine are considered to be fairly safe in pregnancy, as are lansoprazole and omeprazole. These medications are generally considered safe in women who are breastfeeding, even if tiny amounts of the drugs enter the milk. Many hernias can be managed with a watchful waiting approach with restrictions on physical activities, but surgery is typically required when strangulation, incarceration, and other complications develop.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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