J Clin Ultrasound 24:48-50, January 1996 CCC 0091-27511961010048-03 0 1996 by John Wiley & Sons, Inc.

A Twin Gestation Complicated by Gastroschisis in Both Twins

Armando Fuentes, MD, Kathy B. Porter, MD, Benjamin A. Torres, MD, Sandra Saadeh, MD, Kirsten Duesenberg, MS, and William F. O'Brien, MD

Gastroschisis is a congenital defect of the anterior abdominal wall resulting in the evisceration of abdominal contents. The defect usually involves the paraumbilical region on the right side, and the herniated contents are usually limited to the intestines. The prevalence of this finding is ap- proximately 1 in 10,000 births.' Environmental and certain other factors such as maternal age, cigarette smoking, and alcohol consumption have been implicated in the development of gastroschi- sis.' A hereditary component has not been found, although familial recurrences have been de- ~c r ibed .~

Reports of gastroschisis in both twins are very rare. There are two case reports in monozygotic twins and one report in dizygotic A he- reditary factor may explain the finding in monozygotic twin pregnancy. In the reported case of dizygotic twins, the authors speculated that al- cohol may have played a role. We report the pre- natal diagnosis of a case of dizygotic twins com- plicated by gastroschisis in both infants.

CASE REPORT

A 33-year-old white woman, gravida 2 para 1, was referred to our institution for evaluation of elevated maternal serum alpha- fetoprotein (MSAFP) in a spontaneous twin gestation at 19 weeks, menstrual age (MA). The MSAFP at 15 weeks, MA, measured 11.73 multiples of median (MOM), and a repeat sample measured 13.27 MOM. A targeted ultrasound examination re- vealed a diamniotic gestation and gastroschisis in both twins (Figure 1). The only abdominal organs noted to be herniated were intestines. No other

From the Department of Obstetrics and Gynecology, Univer- sity of South Florida, College of Medicine, Tampa, Florida. For reprints contact Armando Fuentes, MD, Arnold Palmer Hos- pital For Children and Women, 105 West Miller Street, Or- lando, Florida 32806-2036.

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abnormalities were detected, and the amniotic fluid volume was normal in each sac. Two placen- tas were visualized, and twin B was noted to be a female.

The patient underwent genetic counseling, and a complete family history was obtained. No cases of gastroschisis were identified in her family. A daughter had a hiatal and an umbilical hernia. The father had been adopted, so no paternal fam- ily history was available. The mother smoked one to three cigarettes per day. Her only exposure to alcohol was limited to 24 ounces of beer early in the first trimester. She had no exposure t o drugs or medicines except for an occasional tablet of acetaminophen.

The presence of a congenital anomaly in a twin gestation raised the suspicion of chromosomal eti- ology, and an amniocentesis was performed. The karyotype of both twins was 46 XX. Twin A had an amniotic fluid AFP of 21.70 MOM and twin B had an AFP of 25.85 MOM. The acetylcholines- terase determination was strongly positive for both twins. The mother elected to continue the pregnancy.

At 26 weeks, MA, the patient presented with premature rupture of membranes and active la- bor. Twin A was delivered vaginally and twin B by cesarean section due to malpresentation. Twin A weighed 780 grams with Apgars of 2 ,5 , and 8. Twin B weighed 690 grams with Apgars of 1, 5, and 8. The only physical finding was a herniation of the intestines through the anterior abdominal wall. Shortly after birth, both twins underwent primary closure of the abdominal wall with no complications. Histologic examination of the pla- centa confirmed the gestation as diamniotic, di- chorionic. Blood samples from the infants were obtained; DNA analysis revealed dizygosity.

DISCUSSION Gastroschisis is a congenital defect of all the lay- ers of the anterior abdominal wall. Commonly

JOURNAL OF CLINICAL ULTRASOUND

GASTROSCHISIS IN TWINS

FIGURE 1. Transverse image through the fetal abdomen showing a gastroschisis in both twins

found on the right side of the midline, it does not involve the umbilicus. The defect is sporadic and the pathogenesis is uncertain. One theory postu- lates the etiology as an abnormal involution of the right umbilical vein and another as a disorder of the omphalomesenteric artery.637 Several tera- togenic factors such as tobacco, alcohol, and viral illnesses have been implicated.2 However, in a study by Werler, et al,' no association with to- bacco was found. Recently, pseudoephedrine, an ingredient of commonly used decongestants, has been associated with the development of gastros- chisis.*

In the two published reports of simultaneous occurrence of gastroschisis in monozygotic twins, no environmental cause could be identified sug- gesting a genetic etiology. The only previously reported case of gastroschisis in dizygotic twins implied a causative role for alcohol and heavy to- bacco use.

In the present case, a single exposure to a rel- atively small amount of alcohol and tobacco use of less than five cigarettes daily was reported. The mother denied the use of antihistamines or decon- gestants. Although a history of a previous child

with an umbilical hernia was elicited, this finding does not necessarily suggest a familial tendency.

Familial occurrences of abdominal wall defects have been reported previously. Hershey et a13 de- scribed a mother who gave birth to a son with an omphalocele. Subsequent pregnancies with a dif- ferent husband resulted in one stillbirth with par- tial atresia of the colon and one liveborn infant with gastroschisis.

A disruption of the distal right omphalomesen- teric artery during embryogenesis, which sup- plies the umbilical ring and the yolk sac, may weaken the umbilical region and result in a her- niation. The proximal portion of the omphalome- senteric artery, which becomes the superior mes- enteric artery, can be another site of disruption resulting in bowel atresia.

This report suggests that, despite the general lack of association with other malformations, some cases of gastroschisis may be associated with a hereditary or familial syndrome of abdom- inal wall and intestinal malformations. The asso- ciation between smoking, alcohol consumption, and certain medications also imply a multifacto- rial etiology.

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CASE REPORT: FUENTES ET AL.

BIBLIOGRAPHY

1. Werler MM, Mitchell AA, Shapiro, S: Demographic, Reproductive, Medical and Environmental Factors in Relation to Gastroschisis. Teratology 45:353-360, 1992.

2. Goldbaum G, Daling J, Milham S: Risk factors for gastroschisis. Teratology 42:397-403, 1990.

3. Hershey DW, Haesslein HC, Marr CC, et al: C. Fa- milial abdominal wall defects. Am J Med Genet 34:

4. Sarda P, Bard H: Gastroschisis in a case of dizygotic twins: the possible role of maternal alcohol con- sumption. Pediatrics 74:94-95, 1984.

174-176,1989.

5. Gorczyca DP, Lindfors KK, Giles KA, et al: Prena- tally diagnosed gastroschisis in monozygotic twins. J Clin Ultrasound 17:216-218, 1989.

6. DeVries PA: The pathogenesis of gastroschisis and omphalocele. J Pediatr Surg 15245-251, 1980.

7. Hoyme HE, Higginbottom MC, Jones KI: The vas- cular pathogenesis of gastroschisis: intrauterine in- terruption of the omphalomesenteric artery. J Pedi- atrics 98:228-231, 1981.

8. Werler MM, Mitchell AA, Shapiro S: First trimester maternal medication use in relation to gastroschisis. Teratology 45:361-367, 1992.

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