Gastroschisis

Gastroschisis:

A defect in the anterior abdominal wall through which the intestinal contents freely protrude.

Baby’s intestines stick outside of the baby’s body, through a hole beside the belly button. Organs, such as the stomach and liver, can also stick outside of the baby’s body.

Unlike an Omphalocele, the intestines are not covered in a protective sac and are exposed to the amniotic fluid, the bowel can become irritated, causing it to shorten, twist, or swell.


Causes


High-risk pregnancies such as those complicated by infection, young maternal age, smoking, drug abuse, or anything that contributes to low birth weight can increase the incidence of gastroschisis, which is more frequent in newborns who are small for gestational age. Whether the intrauterine growth retardation can facilitate the apparition of gastroschisis or the abdominal wall defect impairs fetal growth is not clear yet.

A change in paternity (childbearing with different fathers) has been implicated as a risk factor in a recent study, suggesting that the immune system of the mother may play a role in the development of gastroschisis.[2]

Gastroschisis as a stand-alone congenital defect is usually inherited in an autosomal recessive manner. It may begin as a sporadic mutation, can be associated with non-genetic congenital disorders, but has also been observed to be autosomal dominant.[3]

Genetic counseling and further genetic testing, such as amniocentesis, may be offered during the pregnancy, as this and other abdominal wall defects are associated with genetic disorders. If there are no additional genetic problems or birth defects, surgery soon after birth can often repair the opening.


An In-Depth Look


At least six hypotheses have been proposed:

  1. Failure of mesoderm to form in the body wall[4]
  2. Rupture of the amnion around the umbilical ring with subsequent herniation of bowel[5]
  3. Abnormal involution of the right umbilical vein leading to weakening of the body wall and gut herniation[6]
  4. Disruption of the right vitelline (yolk sac) artery with subsequent body wall damage and gut herniation[7]
  5. Abnormal folding of the body wall results in a ventral body wall defect through which the gut herniates[8]
  6. Failure to incorporate the yolk sac and related vitelline structures into the yolk sac[9]

The first hypothesis does not explain why the mesoderm defect would occur in such a specific small area. The second hypothesis does not explain the low percentage of associated abnormality compared with omphalocele. The third hypothesis was criticized due to no vascular supplement of anterior abdominal wall by umbilical vein. The fourth hypothesis was commonly accepted, but it was later shown that the right vitelline artery (right omphalomesenteric artery) did not supply the anterior abdominal wall in this area.[10]More evidence is needed to support the fifth hypothesis.[8]


Risks & Outcomes


Recently, CDC researchers have reported important findings about some factors that affect the risk of having a baby with gastroschisis:

  1. Younger age: teenage mothers were more likely to have a baby with gastroschisis than older mothers, and White teenagers had higher rates than Black or African-American teenagers.2
  2. Alcohol and tobacco: women who consumed alcohol or were a smoker were more likely to have a baby with gastroschisis.3
  3. Certain medications: use of ibuprofen during pregnancy increased the risk for gastroschisis.4
  4. Infections: women who reported a genitourinary tract infection just before or during early pregnancy were shown to have an increased risk of having a baby with gastroschisis.4

CDC continues to study birth defects like gastroschisis in order to learn how to prevent them. If you are pregnant or thinking about getting pregnant, talk with your doctor about ways to increase your chance of having a healthy baby.

Soon after the baby is born, surgery will be needed to place the abdominal organs inside the baby’s body and repair the defect.

If the gastroschisis defect is small (only some of the intestine is outside of the belly), it is usually treated with surgery soon after birth to put the organs back into the belly and close the opening. If the gastroschisis defect is large (many organs outside of the belly), the repair might done slowly, in stages. The exposed organs might be covered with a special material and slowly moved back into the belly. After all of the organs have been put back in the belly, the opening is closed.

Babies with gastroschisis often need other treatments as well, including receiving nutrients through an IV line, antibiotics to prevent infection, and careful attention to control their body temperature.


References


  1. ^ Schwartz’s principles of surgery: self assessment and board review, 8th edition, chapter 38, page 278; textbook p.1493
  2. ^ Chambers, Christina D.; Chen, Brian H.; Kalla, Kristin; Jernigan, Laura; Jones, Kenneth Lyons (2007). “Novel risk factor in gastroschisis: Change of paternity”.American Journal of Medical Genetics Part A 143A (7): 653–659.doi:10.1002/ajmg.a.31577PMID 17163540.
  3. ^ Yang, Ping; Beaty, Terri H.; Khoury, Muin J.; Chee, Elsbeth; Stewart, Walter; Gordis, Leon (1992). “Genetic-epidemiologic study of omphalocele and gastroschisis: Evidence for heterogeneity”. American Journal of Medical Genetics 44 (5): 668–675.doi:10.1002/ajmg.1320440528PMID 1481831.
  4. ^ Duhamel, B. (1963). “Embryology of Exomphalos and Allied Malformations”.Archives of Disease in Childhood 38: 142–7. doi:10.1136/adc.38.198.142.
  5. ^ Shaw, Anthony (1975). “The myth of gastroschisis”. Journal of Pediatric Surgery 10(2): 235–44. doi:10.1016/0022-3468(75)90285-7PMID 123582.
  6. ^ Devries, Pieter A. (1980). “The pathogenesis of gastroschisis and omphalocele”.Journal of Pediatric Surgery 15 (3): 245–51. doi:10.1016/S0022-3468(80)80130-8.PMID 6445962.
  7. ^ Hoyme, H; Higginbottom, M; Jones, K (1981). “The vascular pathogenesis of gastroschisis: Intrauterine interruption of the omphalomesenteric artery”. The Journal of Pediatrics 98 (2): 228–31. doi:10.1016/S0022-3476(81)80640-3.PMID 6450826.
  8. a b c Feldkamp, Marcia L.; Carey, John C.; Sadler, Thomas W. (2007). “Development of gastroschisis: Review of hypotheses, a novel hypothesis, and implications for research”. American Journal of Medical Genetics Part A 143A: 639–52.doi:10.1002/ajmg.a.31578.
  9. ^ Stevenson, RE; Rogers, RC; Chandler, JC; Gauderer, MWL; Hunter, AGW (2009). “Escape of the yolk sac: a hypothesis to explain the embryogenesis of gastroschisis”.Clinical Genetics 75 (4): 326–33. doi:10.1111/j.1399-0004.2008.01142.x.PMID 19419415.
  10. ^ Curry, Cynthia; Boyd, Ellen; Stevenson, Roger E. (2006). “Ventral Wall of the Trunk”. In Stevenson, Roger E.; Hall, Judith G.. Human Malformations and Related Anomalies. Oxford: Oxford University Press. pp. 1023–49. ISBN 978-0-19-516568-5.