A 10-day-old male came to clinic for his health supervision visit. He was a term infant who was reported to be breastfeeding well. His parents were only concerned as they had noted that above his umbilicus there seemed to be a bulge when he was straining. They had noted it in the newborn nursery but wanted to discuss it again. He didn’t seem bothered by it.
The pertinent physical exam showed an interactive male with a weight of 3.285 kg which was up 110 grams since his 4-day weight check appointment and was above birthweight by 20 grams. His physical examination was normal. He had no umbilical hernia noted, but when he did seem to strain above his umbilicus the rectus muscles were slightly splayed (about 1 cm in lateral width) with a mild bulge (proximal to distal about 2 cm in length). This coincided with what the parents had noticed as well. On palpation there was no palpable opening along the linea alba noted from his sternum to umbilicus and his rectus muscles also were normal with palpation.
The diagnosis of a mild diastis recti abdominis was noted. The parents were counseled that this often spontaneously resolved within a few weeks and it had resolved by the time of his 2-month health supervision visit.
Ventral wall hernias are common. They can be congenital or acquired and it is estimated that approximately 25% of people will have one at some point in their life. True hernias have a fascial defect and therefore contents can protrude through and potentially become incarcerated and/or strangulated.
Common ones include:
- Epigastric occurs between the sternum and umbilicus. It can appear midline or slightly off-center. In children they can spontaneously resole.
- Umbilical occurs around the umbilical structures. These again often spontaneously resolve.
- Spigelian occurs in anterior abdominal wall adjacent to the semilunar line lateral to the rectus abdominus muscles. Most are in the lower abdominal wall
- Inguinal occurs in the inguinal canals
- Femoral occurs in the deeper femoral canals
- Lumbar occurs through a defect of the posterolateral abdominal wall
- Incisional – occurs within the surgical incision.
- Parastomal – occurs near an created opening (like an incision) in the abdominal wall such as a stomal appliance or other surgery or trauma.
- Gastroschisis occurs when there is abnormal development of the umbilical cord ring resulting in non-closure of the anterior abdominal wall. It occurs usually left and lateral to the umbilicus. Abdominal contents are seen to protrude and are not covered by membranes.
An image of common locations can be found here
Diastasis recti abdominis (DRA) is an abnormal increased separation between the rectus abdominus muscles that results in weakness of the anterior abdominal wall often noted as an abdominal bulge. The collagen fibers crossing between rectus abdominus muscles creates the linea alba centrally. Stretching and thinning of these fibers creates the potential problem. It is not a true abdominal wall hernia as it does not have a true fascial defect. Therefore it does not risk incarceration. The bulging maybe better shown with the patient in a semi-fetal position, rather than during a headlift maneuver to try to provoke the bulge.
DRA may cause no problems, or can be associated with abdominal wall dysfunction and back pain. It commonly occurs in pregnant and post-partum women (where it can actually increase compared to during pregnancy), and is also associated with obesity, previous abdominal surgeries, and potentially aneurysmal arterial disease. Obviously strenuous activities which increase intraabdominal pressure can make this worse. Congenital RDA is commonly seen in newborns, where spontaneous resolution usually occurs within a few weeks after birth. Other times it can be associated with problems and syndromes which have abdominal wall problems such as Beckwith-Wiedemann syndrome, Cantrell pentalogy, Opitz syndrome, Prune Belly Syndrome, or other problems associated with midline congenital defects.
DRA often spontaneously resolves or can be treated with exercise, weight loss and physical therapy. For those that do not improve, surgical techniques include plication and modified hernia repairs.
Normal variations occur and often > 2 cm separation of inter-rectal muscle distance (IRD) measured at 2-3 cm above the umbilicus is considered the definition of abnormal for DRA. The IRD changes depending on where it is measured. A 2022 paper using an asymptomatic adult population who were undergoing abdominal computed tomography for appendicitis or renal issues showed IRD measured at 3 cm above the umbilicus was considered normal up to 34 mm.
Questions for Further Discussion
1. What are different types of diaphragmatic hernias?
2. What is the role and type of medical imaging in management of ventral abdominal hernias?
3. How common are inguinal and femoral hernias?
- Symptom/Presentation: Abdominal Mass
- Age: Newborn
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
To view videos related to this topic check YouTube Videos.
Nahabedian M, Brooks DC. Rectus abdominis diastasis. UptoDate. Rev 10/20/21. Accessed 10/9/2022.
Brooks DC, Petro CC. Management of Ventral Hernias. Rev 4/21/22. Accessed 10/9/2022.
Hall H, Sanjaghsaz H. Diastasis Recti Rehabilitation. In: StatPearls. StatPearls Publishing; 2022. Accessed October 10, 2022. http://www.ncbi.nlm.nih.gov/books/NBK573063/
Kaufmann RL, Reiner CS, Dietz UA, Clavien PA, Vonlanthen R, Kaser SA. Normal width of the linea alba, prevalence, and risk factors for diastasis recti abdominis in adults, a cross-sectional study. Hernia. 2022;26(2):609-618. doi:10.1007/s10029-021-02493-7
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa