Podcast Summary: Dr. Chapa’s Clinical Pearls – "Fetal Dextrogastria"

Episode Date: October 1, 2025
Host: Dr. Chapa
Episode Focus: A practical, evidence-based discussion on fetal dextrogastria, a rare congenital malrotation anomaly, with clinical pearls for students, residents, and practitioners.

Overview of the Episode

This episode provides a comprehensive look at fetal dextrogastria—a rare anomaly where the fetal stomach appears on the right side of the abdomen instead of the left. Dr. Chapa draws from real-world cases and the medical literature to equip listeners with practical diagnostic and management strategies. The discussion emphasizes the rarity, potential associated anomalies, and the need for vigilance in prenatal and postnatal evaluation.

Key Discussion Points and Clinical Insights

1. What is Fetal Dextrogastria?

• Definition & Basic Embryology:

  • Under normal conditions, the fetal stomach is seen on the left side of the abdomen.
  • Dextrogastria refers to the stomach being located on the right side, usually due to an abnormality in midgut rotation during embryological development.
  • Quote: "It's present, but isn't it supposed to be on the other side?" (01:08)
  • Prevalence is approximately 1 in 10,000, but it's likely under-recognized.

• Possible Etiologies:

  • Related to a deviation in the normal embryological rotation of the midgut.
  • May have genetic associations, but these are not well established.

2. Clinical Importance & Associated Conditions

• Associated Anomalies:

  • Dextrogastria can exist in isolation, but is frequently linked with other congenital anomalies:
    • Intestinal atresia
    • Situs inversus
    • Cardiac defects
    • Diaphragmatic hernia
    • Vascular anomalies
    • Asplenia or polysplenia
  • Quote: "At its worst issue is that it carries other friends with it. That could be problematic..." (03:25)

• Potential Complications:

  • Even apparently isolated cases require thorough postnatal evaluation as some anomalies can manifest later.
  • Later-occurring issues can include:
    • Gastroesophageal reflux disease (GERD)
    • Intestinal malrotation and volvulus

3. Diagnostic Approach

• Prenatal Evaluation:

  • Start with detailed 2D ultrasound; move to 3D ultrasound or fetal MRI if needed.
  • Targeted anatomical (level 2) ultrasound is crucial.
  • Quote: "Have a low index of suspicion for 3D ultrasound. Be very thorough in this anatomical scan...make sure we're not missing anything else." (03:40)
  • Postnatal echocardiogram is recommended given high association with cardiac anomalies.

• Postnatal Workup:

  • Consider echocardiography—even if prenatal echo is normal.
  • Monitor for GI symptoms (e.g., bilious vomiting, abdominal pain) indicative of malrotation.

4. Review of the Literature and Notable Case Series

a. 2016 Pediatric Surgery Journal Case Series

• 20 antenatally diagnosed cases studied (2004–2014):
  • 8 elective terminations, 1 intrauterine death, 1 lost to follow-up.
  • Of the 10 live-born:
    • 2 died neonatally due to cardiac disease.
    • 2 developed bilious vomiting; both underwent Ladd’s procedure for malrotation.
    • 1 had significant GERD but no malrotation.
    • 3 had asplenia/polysplenia.
    • 5 not investigated for malrotation by time of chart review.
  • Quote: "Two died secondary to cardiac disease in the neonatal interval. This is why, guys, don't take this lightly." (08:55)

b. 2022 BMC Gastroenterology Single Case

• 19-year-old male, previously undiagnosed:
  • Three months of abdominal pain, two days of vomiting and constipation.
  • Imaging revealed stomach and bowel herniation into right hemithorax—eventration and hiatal hernia.
  • Implication: Fetal dextrogastria may remain asymptomatic for years, but late complications are real.
  • Quote: "Asymptomatic for 19 years. And that isolated dextrogastria was now invading the hemidiaphragm because of a hiatal hernia. Wow." (11:14)

5. Clinical Pearls for Differential Diagnosis

• If no stomach bubble is seen:

  • Double-check fetal position; may be physiologic (empty/contracted) or pathological:
    • Neuromuscular issues (poor swallowing)
    • Mouth or facial malformations (micrognathia, cleft lip)
    • Fluid issues (oligohydramnios)
    • Diaphragmatic hernia

• Key buckets for fetal stomach evaluation:

  1. Side: Is it on the left (normal) or right (dextrogastria)?
  2. Presence: Is a stomach bubble present?
  3. Morphology: Is there a double bubble sign (possible duodenal atresia)?

6. Management and Follow-Up

• Imaging:

  • 2D ultrasound as primary tool; supplement with 3D ultrasound or MRI if indicated.

• Workup for Possible Associated Anomalies:

  • Evaluate the heart, spleen, and intestines closely.
  • Consider postnatal cardiac evaluation even when prenatal studies are normal.

• Long-term Monitoring:

  • May need follow-up through adolescence, as complications (malrotation, hernias) can present late.

Notable Quotes & Memorable Moments

• On rarity and vigilance:
  • "Just because it's rare doesn't mean you don't have to know about it. Because one day you may see, doing a routine second trimester ultrasound, you're like, wait a minute, that stomach bubble looks kind of weird." (01:00)
• On postnatal echo:
  • "Some make that universal call, just get an echo. Even if they had a normal echo during the antepartum evaluation...I'm a fan of doing echo, of course, both prenatally and after delivery." (09:12)
• Pragmatic pearl:
  • "Here's a clinical pearl. Act on it. I mean, do something about it… things that are weird like this, if the stomach bubble is on the incorrect side… that's called dextrogastria. And don't ignore that." (12:25)
• Clinical criteria for assessment:
  • "We got three buckets, basically, right. Number one, is it on the right side...Next bucket is, does it look normal or is it there at all? And then the last bucket is, is it a double bubble sign, which is its own separate issue that typically has to do with an obstruction like duodenal atresia..." (13:46)
• On asymptomatic late presentation:
  • "Could this have been prevented? Maybe. I mean, if the people knew that this young adult, the child had this, could have been screened maybe..." (12:04)

Important Timestamps

• [01:00] Introduction to fetal dextrogastria & clinical significance
• [03:25] Associated congenital anomalies—why thorough workup matters
• [06:43] Embryology, genetics, and current understanding
• [08:55] 2016 Journal review: 20-case series and outcomes
• [11:14] 2022 Case: Adult presentation with diaphragmatic hernia
• [13:46] Assessment "buckets"—how to systematically evaluate the finding

Summary Table: Practical Approach

| Step | What to Look For | Next Action | |------------------------------------|----------------------------------------------------------------|----------------------------------| | Is stomach bubble present? | Yes/No | If No, reassess & consider causes| | Which side is the stomach bubble? | Left (normal) / Right (dextrogastria) | If right, further eval needed | | Does the bubble appear normal? | Normal / Double bubble / Abnormal shape | If abnormal, investigate obstruction (e.g., duodenal atresia)| | Associated findings? | Heart, spleen, intestine, diaphragm abnormalities | Targeted scans, consider MRI/echo| | Postnatal evaluation | Echo, monitor for GI symptoms | Long-term follow-up as needed |

Final Takeaways

• Fetal dextrogastria is rare but clinically significant—don't dismiss an abnormal stomach bubble position.
• Always investigate for additional anomalies, particularly cardiac and splenic defects.
• Use a systematic approach: location, presence, and morphology of the stomach bubble.
• Advise long-term follow-up due to potential for late-onset complications.
• Dr. Chapa sum-up: "Just because you haven't heard of it doesn't mean it doesn't exist. It is out there." (15:35)

This episode is a quick but practical resource, urging clinicians to be observant and thorough, even—as Dr. Chapa repeats—when the finding is “weird” or rare.