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Risk Factors for Omphalocele

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Birth Defect Risk Factor Series: Omphalocele

Introduction

Omphalocele is a birth defect where some of a baby’s organs protrude through the abdominal muscles.  It occurs in about 2 out of every 10,000 births in the United States.  Studies to determine the risk factors for omphalocele have had mixed results. 

Figure 1.  A picture of a baby with omphalocele.

Omp_ills

 

Content Source: Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities

What is a birth defect?

As a baby grows inside the mother, problems sometimes happen.  These problems, called birth defects, may affect how a baby looks or functions when it is born.  Birth defects may be discovered during pregnancy and are usually found within the baby’s first year.  Some birth defects are mild and the baby will be fine if it gets the proper treatment.  Other birth defects are very severe and lead to death.

Genetics and birth defects

Some, but not all, defects occur because of a genetic problem.  Genetics has to do with genes and how they are passed from parent to child.  Genes are the basic unit of inheritance and determine a person’s looks, personality, intelligence and other traits. Our genes are contained in chromosomes inside the cells of our bodies.  A chromosome can be thought of as a long, tightly coiled string of genes.

Chromosomes are made of long strands of DNA (Deoxy-ribo-nucleic Acid).  DNA is a molecule found in our cells that provides the instructions for how we operate.  It is made of 2 strands that wind around each other to form a shape called a double helix.   Each gene is a specific section of the DNA molecule.  (See Figure 2).  Humans have around 23,000 genes in their cells.

Figure 2.  The make up of a chromosome.

Gene

Courtesy: National Human Genome Research Institute

Chromosomes occur in pairs and there are 23 pairs found inside cells in the human body. A baby receives one half of each pair from its mother and one half of each pair from its father.  Genetic disorders can happen when there is a mutation or change in one or more genes.  Chromosomal defects such as missing pieces, extra pieces, or the wrong number of chromosomes can also result in a genetic disorder.  The result may be a birth defect.

What is omphalocele?

Omphalocele (om-FA-lo-seal) is a birth defect in which a baby’s organs stick out beyond the abdominal muscles in the area of the belly button.  “Omphalo” means umbilicus (also called navel or belly button) and “cele” means hernia.  A hernia is when part of the body sticks out through the wall that is supposed to keep it in.   Therefore Omphalocele means a hernia at the umbilicus.

The exposed organs are covered by a thin film or membrane.  Sometimes this membrane may have broken and this defect may be mistaken for a similar defect called gastroschisis (ga-stros-KI-sis).

 Infants with omphalocele tend to have other birth defects, including chromosomal defects (most often trisomy 13, trisomy 18, and trisomy 21).  They often have a lower survival rate than infants with gastroschisis (2, 3, 6, 9, 26, 31, 38, 44, 47, 60, 62).  Babies with omphalocele are often born early, have restricted growth while in the womb and have a low birth weight (35, 42, 48, 50, 57).  Extremely high birth weights are not common in babies with omphalocele (66).

When does omphalocele occur?

In normal development, the intestine of the fetus should stick out or herniate into the umbilical cord by the 10th week of pregnancy.  Between weeks 10 and 12, the intestine should pull back into the belly.  If this does not happen, omphalocele may result.

Figure 3: Timeline showing when omphalocele occurs during pregnancy

Pregnancy timeline

Table 1. Estimated number of Omphalocele cases in 2005 based on number of cases for every 10,000 live births

 

 

Number of Cases for every 10,000 Live Births

Number of Live Births in 2005

Estimated Number of  Omphalocele Cases

Texas

2.13

385,537

82

United States

2.07

4,138,349

857

 

How is omphalocele diagnosed?

A Woman carrying a fetus with omphalocele has high levels of a substance called alpha-fetoprotien in her body.(11)  Testing the mother for this substance along with an ultrasound of the fetus allow doctors to spot omphalocele while the baby is inside the mother. (64)

Early detection along with voluntary termination of the pregnancy has reduced the number of babies born with omphalocele in areas where voluntary termination is allowed (3, 8, 9, 15, 27, 29, 44; 47, 50, 57, 58, 59).  

Why does omphalocele occur?

Risk factors are things that may cause an increased danger of a baby developing omphalocele.  There is little clear evidence about what the risk factors for omphalocele are. Some possible risk factors have stronger evidence than others.  Figures 3 and 4 show the number of scientific studies for and against the connection of a possible risk factor with developing omphalocele.

Demographic risk factors

Age of Mother:

Studies looking at the connection between a mother’s age and risk for a baby having omphalocele have found different results.  Being an older mother seems to be linked to a higher risk of omphalocele development.  The information linking being a young mother and omphalocele is not as clear.

  • Five studies found that the highest risk for omphalocele occurs in the youngest and oldest mothers (8, 39, 52, 55, 60). 
  • Four studies found that the risk increases as the mother’s age increases (26, 28, 47, 62).
  •  One found a higher risk in younger but not older mothers (49).      
  • Three studies have reported no clear relationship between omphalocele risk and maternal age (7, 41, 57).

Older mothers may have an increased risk because of omphalocele's association with chromosomal abnormalities.  These abnormalities occur more frequently with advanced maternal age.  The risks associated with low birth weight and early delivery for babies with omphalocele is the same for both younger and older mothers (53). 

Sex of the baby:

 Most studies have found that boys have a higher risk for omphalocele than girls (3, 6, 9, 12, 28, 50, 60).  There are, however, some studies that have found no differences in risk between boys and girls (26, 57, 71).

Race/Ethnicity:

Most studies have found no relationship between race or ethnicity and omphalocele (26, 36, 52, 56, 70, 71).  However, one study did find that black infants were at a higher risk of omphalocele than white infants (55).

Previous births:        

There is no evidence that having given birth before increases the risk of having a baby with omphalocele (8, 28).  However, the risk of early birth in a baby with omphalocele is higher for women who have given birth before versus women who have not (54).  

Multiple Birth Pregnancy

Twins, triplets and other multiple births may have a greater risk of omphalocele compared to single babies (23, 40, 50). However one study reported no association between omphalocele and multiple baby pregnancies (32).

Other Risk Factors:

The number of babies born with omphalocele varies widely by geographic location (26, 28, 52, 60, 74). There is some evidence that babies born in rural areas are at higher risk for omphalocele than those born in cities (55).

Time of year a baby is born and being born at high altitudes are not risk factors for omphalocele (4, 14).   

Babies born to parents who are related do not seem to be at higher risk of omphalocele (51).

Omphalocele Risk Factors: Demographic

Factors in lifestyle or environment

Obesity: 

Babies of obese mothers are at greater risk of having omphalocele. (43, 67, 68, 69).

Babies born to mothers with hypothyroidism do not appear to have an increased risk of omphalocele (34). Hyperthyroidism is a condition of producing too much thyroid hormone which may cause weight loss,

Living Environment:

Living close to hazardous waste sites or industrial sites has not been found to increase risk of omphalocele (13, 22).  One study did find that living close to landfill sites has been associated with a slightly increased risk of abdominal wall defects such as omphalocele (24). Water chlorination does not appear related to abdominal wall defect (33).

Smoking:

One study found that maternal smoking is not associated with omphalocele (63). However another study found a moderately elevated risk for omphalocele in women who are heavy smokers and who used alcohol during the first trimester of pregnancy (37).

Prescription medication:

The use of antibiotics or benzodiazepines do not seem to be a risk factor for omphalocele (18, 19, 20, 21, 25).  Antibiotics are used to treat bacterial infections and benzodiazepines (ben-zo-dye-AZ-a-peens) are a class of drugs used to treat such things as insomnia and anxiety.

 There is some evidence that Selective Serotonin Reuptake Inhibitors (SSRIs) in early pregnancy may increase the risk of omphalocele (1). But at least oen study did nto find that risk (30).  SSRIs are medications used to treat depression.

Misoprostol is not associated with a risk of omphalocele (46).  Misoprostol is a drug mainly used to treat stomach ulcers but may also induce labor and induce abortion in elective terminations.

Prenatal Vitamins

Taking multivitamins that contain folic acid before and during pregnancy may help prevent omphalocele. (5,45).  However, this evidence is mixed as some studies have found no effect of taking folic acid on reducing the risk of omphalocele (16, 17).  Folic acid is very important in preventing other types of birth defects.

Other Risk Factors

Being poor may increase the risk of having a baby with omphalocele (65), and mothers who work in service work may have a slightly higher risk for omphalocele compared to homemakers and farmers' wives (28).

Omphalocele Risk Factors: Lifestyle & Environmental

What is the treatment for omphalocele?

The treatment and outcome for a baby with omphalocele depends on what other health problems it has.  Omphalocele is often occurs with other birth defects and other developmental problems like low birth weight.  Parents and their doctor must determine the best treatment for each child.

References

  1. Alwan S, Reefhuis J, Rasmussen SA, Olney RS, Friedman JM. Use of selective serotonin-reuptake inhibitors in pregnancy and the risk of birth defects. N Engl J Med 2007; 356: 2684-2692.
  2. Baird PA, MacDonald EC. An epidemiologic study of congenital malformations of the anterior abdominal wall in more than half a million consecutive live births. Am J Hum Genet 1981;33:470- 478.
  3. Barisic I, Clementi M, Hausler M, Gjergja R, Kern J, Stoll C, The Euroscan Study Group. Evaluation of prenatal ultrasound diagnosis of fetal abdominal wall defect by 19 European registries. Ultrasound Obstet Gynecol 2001;18:309-316.
  1. Botto LD, Olney RS, Erickson JD.  Vitamin supplements and the risk for congenital anomalies other than neural tube defects. Am J Med Genet C Semin Med Genet 2004; 125C: 12-21.
  1. Bound JP, Harvey PW, Francis BJ. Seasonal prevalence of major congenital malformations in the Fylde of Lancashire 1957-1981. J Epidemiol Community Health 1989;43:330-342.
  2. Bugge M, Hauge M.. Gastroschisis og omphalocele i Danmark. Ugeskr Laeg 1983;145:1323- 1327.
  3. Bugge M, Holm NV. Abdominal wall defects in Denmark, 1970-89. Paediatr Perinat Epidemiol 2002;16:73-81.
  4. Byron-Scott R, Haan E, Chan A, Bower C, Scott H, Clark K. A population-based study of abdominal wall defects in South Australia and Western Australia. Ped Perinatal Epidemiol 1998;12:136-151.
  5. Calzolari E, Bianchi F, Dolk H, Milan M, EUROCAT Working Group. Omphalocele and gastroschisis in Europe: a survey of 3 million births 1980-1990. Am J Med Genet 1995;58:187- 194.
  6. Canfield MA, Honein MA, Yuskiv N, Xing J, Mai CT, Collins JS, Devine O, Petrini J, Ramadhani TA, Hobbs CA, Kirby RS. National Estimates and Race/Ethinc-Specific Variation of Selected Birth Defects in the United States, 1999-2001. Birth Defects Res A Clin Mol Teratol 2006; 76:747-756.
  7. Canick JA, Saller DN. Maternal serum screening for aneuploidy and open fetal defects. Obstet Gynecol Clin North Am 1993;20:443-454.
  8. Carpenter MW, Curci MR, Dibbins AW, Haddow JE. Perinatal management of ventral wall defects. Obstet Gynecol 1984;64:646-651.
  9. Castilla EE, Campana H, Camelo JS. Economic activity and congenital anomalies: an ecologic study in Argentina. Environ Health Perspect 2000;108:193-197.
  10. Castilla EE, Lopez-Camelo JS, Campana H. Altitude as a risk factor for congenital anomalies. Am J Med Genet 1999;86:9-14.
  11. Chi LH, Stone DH, Gilmour WH. Impact of prenatal screening and diagnosis on the epidemiology of structural congenital anomalies. J Med Screen 1995;2:67-70.
  12. Czeizel A. A case-control analysis of the teratogenic effects of co-trimoxazole. Reprod Toxicol 1990;4:305-313.
  13. Czeizel AE, Toth M, Rockenbauer M. Population-based case control study of folic acid supplementation during pregnancy. Teratology 1996;53:345-351.
  14. Czeizel AE, Rockenbauer M. A population-based case-control teratologic study of oral oxytetracycline treatment during pregnancy. Eur J Obstet Gynecol Reprod Biol 2000;88:27-33.
  15. Czeizel AE, Rockenbauer M, Sorensen HT, Olsen J. Use of cephalosporins during pregnancy and in the presence of congenital abnormalities: a population-based, case-control study. Am J Obstet Gynecol 2001a;184:1289-1296.
  16. Czeizel AE, Sorensen HT, Rockenbauer M, Olsen J. A population-based case-control teratologic study of nalidixic acid. Int J Gynaecol Obstet 2001b;73:221-228.
  17. Czeizel AE, Rockenbauer M, Sorensen HT, Olsen J. A population-based case-control teratologic study of ampicillin treatment during pregnancy. Am J Obstet Gynecol 2001c;185:140-147.
  18. Dolk H, Vrijheid M, Armstrong B, Abramsky L, Bianchi F, Garne E, Nelen V, Robert E, Scott JE, Stone D, Tenconi R. Risk of congenital anomalies near hazardous-waste landfill sites in Europe: the EUROHAZCON study. Lancet 1998;352:423-427.
  19. Doyle PE, Beral V, Botting B, Wale CJ. Congenital malformations in twins in England and Wales. J Epidemiol Community Health 1991;45:43-48.
  20. Elliott P, Briggs D, Morris S, de Hoogh C, Hurt C, Jensen TK, Maitland I, Richardson S, Wakefield J, Jarup L. Risk of adverse birth outcomes in populations living near landfill sites. BMJ 2001;323:363-368.
  21. Eros E, Czeizel AE, Rockenbauer M, Sorensen HT, Olsen J. A population-based case-control teratologic study of nitrazepam, medazepam, tofisopam, alprazolum and clonazepam treatment during pregnancy. Eur J Obstet Gynecol Reprod Biol 2002;101:147-154.
  22. Forrester MB, Merz RD. Epidemiology of abdominal wall defects, Hawaii, 1986-1997. Teratology 1999a;60:117-123.
  23. Forrester MB, Merz RD. Impact of demographic factors on prenatal diagnosis and elective pregnancy termination because of abdominal wall defects, Hawaii, 1986-1997. Fetal Diagn Ther 1999b;14:206-211.
  24. Hemminki H, Saloniemi I, Kyyronen P, Kekomaki M. Gastroschisis and omphalocele in Finland in the 1970s: prevalence at birth and its correlates. J Epidemiol Comm Health 1982;36:289-293.
  25. Heydanus R, Raats MA, Tibboel D, Los FJ, Wladimiroff JW. Prenatal diagnosis of fetal abdominal wall defects: A retrospective analysis of 44 cases. Prenat Diagn 1996;16:411-417.
  26. Källén B, Olausson P. Maternal use of selective serotonin re-uptake inhibitors in early pregnancy and infant congenital malformations. Birth Defects Res A Clin Mol Teratol 2007; 79: 301-308.
  27. Kallen B, Mastroiacovo P, Robert E. Major congenital malformations in Down syndrome. Am J Med Genet 1996;65:160-166.
  28. Kallen B. Congenital malformations in twins: a population study. Acta Genet Med Gemellol (Roma) 1986;35:167-178.
  29. Kallen BA, Robert E. Drinking water chlorination and delivery outcome-a registry-based study in Sweden. Reprod Toxicol 2000;14:303-309.
  30. Khoury MJ, Becerra JE, d'Almada PJ. Maternal thyroid disease and risk of birth defects in offspring: a population-based case-control study. Paediatr Perinat Epidemiol 1989;3:402-420.
  31. Khoury MJ, Erickson JD, Cordero JF, McCarthy BJ. Congenital malformations and intrauterine growth retardation: a population study. Pediatrics 1988;82:83-90.
  32. Leck I, Lancashire RJ. Birth prevalence of malformations in members of different ethnic groups and in the offspring of matings between them, in Birmingham, England. J Epidemiol Community Health 1995;49:171-179.
  33. Mac Bird T, Robbins JM, Druschel C, Cleves MA, Yang S, Hobbs CA. Demographic and environmental risk factors for gastroschisis and omphalocele in the National Birth Defects Prevention Study. J Pediatr Surg 2009; 44: 1546-51.
  34. Mann L, Ferguson-Smith MA, Desai M, Gibson AA, Raine PA. Prenatal assessment of anterior abdominal wall defects and their prognosis. Prenat Diagn 1984;4:427-435.
  35. Martinez-Frias ML, Salvador J, Prieto L, Zaplana J. Epidemiological study of gastroschisis and omphalocele in Spain. Teratology 1984;295:377-382.
  36. Mastroiacovo P, Castilla EE, Arpino C, Botting B, Cocchi G, Goujard J, Marinacci C, Merlob P, Metneki J, Mutchinick O, Ritvanen A, Rosano A. Congenital malformations in twins: an international study. Am J Med Genet 1999;83:117-124.
  37. Materna-Kiryluk A, Wiśniewska K, Badura-Stronka M, Mejnartowicz J, Wieckowska B, Balcar-Boroń A, Czerwionka-Szaflarska M, Gajewska E, Godula-Stuglik U, Krawczyński M, Limon J, Rusin J, Sawulicka-Oleszczuk H, Szwalkiewicz-Warowicka E, Walczak M, Latos-Bieleńska, A. Parental age as a risk factor for isolated congenital malformations in a Polish population. Paediatr Perinat Epidemiol 2009; 23: 29-40.
  38. Mili F, Edmonds LD, Khoury MJ, McClearn AB. Prevalence of birth defects among low-birth- weight infants. A population study. Am J Dis Child 1991;145:1313-1318.
  39. Moore LL, Singer MR, Bradlee ML, Rothman KJ, Milunsky A. A prospective study of the risk of congenital defects associated with maternal obesity and diabetes mellitus. Epidemiology 2000;11:689-694.
  40. Morrow RJ, Whittle MJ, McNay MB, Raine PAM, Gibson AAM, Crossley J. Prenatal diagnosis and management of anterior abdominal wall defects in the West of Scotland. Prenat Diagn 1993;13:111-115.
  41. Mulinare J, Erickson JD, James LM, Berry RJ. Does periconceptional use of multivitamins reduce the occurrence of birth defects? Am J Epidemiol 1995:141:S3.
  42. Orioli IM, Castilla EE. Epidemiological assessment of misoprostol teratogenicity. BJOG 2000;107:519-523.
  43. Rankin J, Dillon E, Wright C. Congenital anterior abdominal wall defects in the North of England, 1986-1996: Occurrence and outcome. Prenat Diagn 1999;19:662-668.
  44. Rasmussen SA, Moore CA, Paulozzi LJ, Rhodenhiser EP. Risk for birth defects among premature infants: A population-based study. J Pediatr 2001;138:668-673.
  45. Reefhuis J, Honein MA. Maternal age and non-chromosomal birth defects, Atlanta 1968-2000: Teenager or thirty-something, who is at risk? Birth Defects Res A Clin Mol Teratol 2004; 70:572-579.
  46. Riley MM, Halliday JL, Lumley JM. Congenital malformations in Victoria, Australia, 1983-95: an overview of infant characteristics. J Paediatr Child Health 1998;34:233-240.
  47. Rittler M, Liascovich R, Lopez-Camelo J, Castilla EE. Parental consanguinity in specific types of congenital anomalies. Am J Med Genet 2001;102:36-43.
  48. Roeper PJ, Harris J, Lee G, Neutra R. Secular rates and correlates for gastroschisis in California (1968-1977). Teratology 1987;35:203-210.
  49. Salihu HM, Emusu D, Aliyu ZY, Pierre-Louis B, Druschel CM, Kirby RS. Omphalocele, advanced maternal age, and fetal morbidity outcomes. Am J Med Genet A 2005; 135:161-165.
  50. Salihu HM, Emusu D, Sharma PP, Aliyu ZY, Oyelese Y, Druschel CM, Kirby R.  Parity effect on preterm birth and growth outcomes among infants with isolated omphalocele.  Eur J Obstet Gynecol Reprod Biol 2006; 128: 91-96.
  51. Salihu HM, Pierre-Louis B, Druschel C, Kirby R. Omphalocele and Gastroschisis in the State of New York, 1992-1999. Birth Defects Res A Clin Mol Teratol 2003; 67:630-636.
  52. Shaw GM, Carmichael SL, Nelson V. Congenital malformations in offspring of Vietnamese women in California, 1985-97. Teratology 2002a;65:121-124.
  53. Stoll C, Alembik Y, Dott B, Roth MP. Risk factors in congenital abdominal wall defects (omphalocele and gastroschisis): a study in a series of 265,858 consecutive births. Ann Genet 2001;44:201-208.
  54. Stoll C, Dott B, Alembik Y, Roth MP. Evaluation of routine prenatal diagnosis by a registry of congenital anomalies. Prenat Diagn 1995;15:791-800.
  55. Stoll C, Alembik Y, Dott B, Roth MP, Finck S. Evaluation of prenatal diagnosis by a registry of congenital anomalies. Prenat Diagn 1992;12:263-270.
  56. Tan KH, Kilby MD, Whittle MJ, Beattie BR, Booth IW, Botting BJ. Congenital anterior abdominal wall defects in England and Wales 1987-93: Retrospective analysis of OPCS data. BMJ 1996;313:903-906.
  57. Texas Department of State Health Services. Texas birth defects registry report of birth defects among 1999-2005 deliveries. 2008.
  58. Torfs C, Curry C, Roeper P. Gastroschisis. J Pediatr 1990;116:1-6.
  59. Van Den Eeden, SK, Karagas MR, Daling JR, Vaughan TL. A case-control study of maternal smoking and congenital malformations. Paediatr Perinat Epidemiol 1990;4:147-155.
  60. Vintzileos AM, Campbell WA, Nochimson DJ, Weinbaum PJ. Antenatal evaluation and management of ultrasonically detected fetal anomalies. Obstet Gynecol 1987;69:640-660.
  61. Vrijheid M, Dolk H, Stone D, Abramsky L, Alberman E, Scott JE. Socioeconomic inequalities in risk of congenital anomaly. Arch Dis Child 2000;82:349-52.
  62. Waller DK, Keddie AM, Canfield MA, Scheuerle AE. Do infants with major congenital anomalies have an excess of macrosomia? Teratology 2001;64:311-317.
  63. Waller DK, Shaw GM, Rasmussen SA, Hobbs CA, Canfield MA, Siega-Riz A, Gallaway M, Correa A. Prepregnancy obesity as a risk factor for structural birth defects. Arch Pediatr Adolesc Med 2007; 161:745-750.
  64. Watkins M, Honein M, Rasmussen S. Maternal obesity and abdominal wall defects. Paediatr Perinat Epidemiol 2001;15:A35-A36.
  65. Watkins  ML, Rasmussen SA, Honein MA, Botto LD, Moore CA. Maternal obesity and risk for birth defects. Pediatrics 2003; 111:1152-1158.
  66. Yang P, Beaty TH, Khoury MJ, Chee E, Stewart W, Gordis L. Genetic-epidemiologic study of omphalocele and gastroschisis: Evidence for heterogeneity. Am J Med Genet 1992; 44:668-675.
  67. Yang P, Khoury MJ, Stewart WF, Beaty TH, Chee E, Beatty JC, Diamond EL, Gordis L. Comparative epidemiology of selected midline congenital abnormalities. Genet Epidemiol 1994;11:141-15.
  68. Martin JA, Hamilton BE, Sutton PD, Ventura SJ, Menacker F, Kirmeyer S, Munson ML. Births: Final data for 2005, National Vital Statistics Reports 2007; 56(6).
  69. Texas DSHS Vital Statistics.  2005 Annual Report.  Accessed 11/02/2009 at www.dshs.state.tx.us/CHS/VSTAT/vs05/nnatal.shtm.
  70. GoldBaum G, Daling J, Milham S. Risk factors for gastroschisis. Teratology 1990; 42:397-403.
Last updated April 19, 2013