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ORIGINAL RESEARCH |
From the 1Departments of Obstetrics and Gynecology, Radiology, and Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.
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ABSTRACT |
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 ABSTRACT MATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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METHODS: This was a review of pregnancies complicated by fetal gastroschisis and delivered from January 1998 through June 2006. The last ultrasonogram before delivery was reviewed to determine stomach dilatation, bowel dilatation, or abnormalities of amniotic fluid volume. Neonatal records were reviewed to determine type of closure and any bowel complications.
RESULTS: There were 66 pregnancies with gastroschisis, 1 per 2,000 deliveries. There were three stillbirths and three neonatal deaths. Delayed closure was necessary in 49% who underwent surgery. Birth weight below the third percentile, which occurred in 38%, was associated with need for delayed closure, 64% compared with 25% without growth restriction, P<.001, but was not associated with longer hospital stay or neonatal death. Fetal gastroschisis was diagnosed by prenatal ultrasonography in 58 cases. Bowel complications requiring surgery were more frequent when ultrasonography had demonstrated stomach dilatation (five cases), 60% compared with 10%, P=.002. Fetuses with defects so large that no normal ventral wall could be visualized ultrasonographically (three cases) were at increased risk for neonatal death, 100% compared with 0%, P<.001.
CONCLUSION: Ultrasound findings associated with adverse outcome in fetal gastroschisis included stomach dilatation and a defect so large that no normal ventral wall could be visualized. Fetal growth restriction was common, and such infants were more likely to require delayed gastroschisis closure. Despite more than 90% survival, morbidity with gastroschisis remains high.
LEVEL OF EVIDENCE: II
Given the generally good prognosis for this anomaly, attention has turned to the identification of those fetuses that may be at risk for adverse outcomes. A number of risk factors for poor prognosis have been reported, and include dilatation of the fetal stomach, dilatation of small or large bowel, thickness of bowel wall, fetal growth restriction, or an increased or decreased amount of amniotic fluid. In some centers, presence of one or more of these factors may prompt hospitalization or preterm delivery.6 Importantly, none of these factors has been consistently correlated with adverse outcome. Moreover, when a fetus with gastroschisis is delivered prematurely, the infant may suffer from complications of prematurity in addition to those of the anomaly itself.
Our goal was to review prenatal and postnatal findings of all pregnancies with fetal gastroschisis delivered at our hospital, to describe pregnancy outcomes with fetal gastroschisis, and to characterize ultrasound markers that may improve prediction of neonatal outcome.
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MATERIALS AND METHODS |
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Ultrasound data were obtained by reviewing images and records from our obstetric ultrasonography archive. During the study period, ultrasonography was performed in low-risk pregnancies only as indications arose, in accordance with guidelines from the American College of Obstetricians and Gynecologists and the American Institute of Ultrasound in Medicine.10,11 Gestational age was based on the last menstrual period (LMP), with ultrasonography performed if there were discrepancies between fundal height and LMP or if the LMP was uncertain. This method of gestational age determination has been found to correlate well with ultrasound and pediatric estimates in our population.12
If ultrasonography was performed during the pregnancy, the last examination before delivery was used to evaluate potential prognostic variables. The variables reviewed were chosen based on their prior identification in the literature as potentially useful ultrasound predictors of outcome. Images were evaluated by an investigator blinded to outcome information (P.S.M.). Stomach dilatation was determined based on a gestational age-specific nomogram.16 Bowel dilatation was diagnosed when small bowel diameter exceeded 7 mm or large bowel diameter exceeded 18 mm.17 Using the four-quadrant amniotic fluid index (AFI),18 hydramnios was defined as an AFI of 25.0 cm or greater,19 and oligohydramnios was defined as an AFI of 5.0 cm or less.20 The size of the ventral wall defects was not routinely measured, but defects so extensive that no normal ventral wall was visualized were specifically noted.
Management of pregnancies complicated by gastroschisis included monthly specialized ultrasonography to assess growth, amniotic fluid volume, and the appearance of small and large bowel. Antepartum hospitalization was offered for suspected fetal growth restriction, oligohydramnios, or maternal illness such as hypertension. Hospitalized women underwent fetal testing. Other women were managed as outpatients and, in the absence of maternal or fetal compromise, were permitted to enter labor spontaneously at term. Provided that intrapartum fetal heart rate monitoring was reassuring, that fetal liver was within the abdominal wall, and that there was no other indication for cesarean delivery, it was our practice to deliver these women vaginally.
All infants with gastroschisis were managed in our intensive care nursery, and pediatric surgeons from our medical center performed all the surgical procedures. The infants' surgical operative reports were reviewed. Outcomes of particular interest included whether primary closure was accomplished, whether a silo closure was required, presence of gastrointestinal atresia, and need for bowel resection, as well as the duration of total parenteral nutrition and length of hospital stay. It is the practice of our pediatric surgeons to perform primary closure of the gastroschisis defect whenever possible. The decision to place a silo is generally made at the time of surgery, after primary closure has been attempted, for example if the abdomen is found to be too tightly distended or if ventilator pressures become unacceptably high. The diagnosis of growth restriction was based on birth weight below the third percentile for gestational age, using nomograms from our population that are adjusted for maternal ethnicity and infant sex.12
Categorical data were reported as frequencies, and statistical significance was determined using 
2 tests. Statistical normality was evaluated using the Shapiro-Wilk statistic. Continuous variables that were normally distributed were reported as mean± standard deviation, and two-group comparisons made with Student t test. Variables not normally distributed were reported as median (first and third quartiles), with Wilcoxon rank sum for two-group comparisons. P values less than .05 were considered statistically significant. Statistical analyses were performed using SAS 9 (SAS Institute, Cary, NC).
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RESULTS |
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The maternal age at delivery was 19.9±3.3 years, significantly younger than that of our overall obstetric population during the study period, 25.2±5.8 years, P<.001. The ethnicity distribution for the cohort was 86% Hispanic, 7% African American, and 7% white. Sixty-nine percent of the pregnant women were nulliparous.
Ultrasound findings evaluated in our study are shown in Table 1. These abnormal ultrasound findings were relatively uncommon. For example, five pregnancies had evidence of either hydramnios or oligohydramnios, and 10 fetuses had either stomach or bowel dilatation (or both). Three fetuses had defects so extensive that no normal ventral wall was able to be visualized, with liver, stomach, and bowel completely extruded (Fig. 1A and B).
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There were three fetal deaths of infants weighing 500 g or more (stillbirths). None was found to have growth restriction at last ultrasonography; none had evidence of stomach dilatation, bowel dilatation, oligohydramnios, or hydramnios. One fetal death was attributed to an umbilical cord accident at 38 weeks of gestation. The second occurred at 33 weeks; at autopsy, the infant was found to have intestinal atresia. The third stillbirth occurred at 40 weeks. In this last case, the autopsy documented infection due to group B Streptococcus and Escherichia coli.
Intrapartum outcomes for the 63 liveborn infants are presented in Table 2. The majority of women were delivered at or beyond 34 weeks of gestation (97%, 95% CI 89–99%) with a mean gestational age being 37.0±2.3 weeks (Table 2). Approximately one third were delivered by cesarean, with 68% (95% CI 45–86%) of cesarean deliveries performed for either nonreassuring fetal status or concern about the fetal anomaly (liver involvement). However, most infants were born in good condition, with cord pH less than 7.1 in only 3% (95% CI 0.4–12%). Two infants had nongastrointestinal abnormalities: one had ventriculomegaly requiring shunt placement, and one had a cleft palate. Thirty-eight percent (95% CI 26–51%) of infants had birth weights below the third percentile, using a nomogram derived from our population.12
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Shown in Table 3 are infant outcomes related to the gastroschisis defect. Delayed closure, most often with a silo, was necessary in just under one half of the cases. There were also two infants who underwent primary closure but later required additional surgery for abdominal compartment syndrome. In another infant, the defect was so extensive that surgery was not attempted (Fig. 2A and B). Nine infants (14%, 95% CI 7–25%) needed bowel surgery to repair a bowel atresia, perforation, or necrosis. There were three deaths; in each case, the defect was so extensive that no normal ventral wall had been able to be visualized. Thus, despite significant morbidity, none of the singleton infants with typical gastroschisis defects (which represented 95% of our study) died in the immediate neonatal period.
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Because 38% of the infants were born with evidence of growth restriction, outcomes were evaluated within this subgroup. These growth-restricted infants were significantly more likely to require delayed closure of the gastroschisis defect when compared with normally grown infants, 64% (95% CI 47–79%) compared with 25% (95% CI 10–47%) respectively, P<.001. However, infants with growth restriction did not require longer overall hospitalization, 33 days (first quartile, third quartile: 24 days, 70 days) compared with 38 days (28 days, 48 days) for infants without growth restriction, P=.8. Furthermore, infants with growth restriction did not require a longer duration of total parenteral nutrition, 26 days (20 days, 62 days) compared with 22 days (15 days, 31days) for infants without growth restriction, P=.14. Neonatal death was not significantly more common among infants with growth restriction than among those normally grown, two (8%, 95% CI 1–2%) compared with one (3%, 95% CI 0–13%) respectively, P=.3.
Finally, neonatal outcomes were evaluated according to prenatal ultrasound findings. The five fetuses with stomach dilatation were significantly more likely to require surgical repair of a bowel complication (atresia, perforation, or necrosis) than infants without stomach dilatation, 60% (95% CI 15–95%) compared with 10% (95% CI 4–21%), respectively, P=.002. Among fetuses with stomach dilatation, 60% (95% CI 15–95%) required silo placement with delayed gastroschisis repair, compared with 41% (95% CI 29–55%) of those without stomach dilatation; however, this difference was not statistically significant. Neither abnormalities of amniotic fluid volume nor dilatation of the fetal bowel was significantly associated with either need for delayed gastroschisis closure or a bowel complication. None of these findings was associated with increased risk for fetal death. Only the finding of a defect so large that no ventral wall could be visualized, with all peritoneal organs herniated into the amniotic cavity was significantly associated with neonatal death, 100% compared with 0% without such a large defect, P<.001.
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DISCUSSION |
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Investigators have debated whether ultrasound variables may predict adverse outcomes in fetal gastroschisis for well over a decade. In a recent study of 34 cases of gastroschisis, Aina-Mumuney et al13 identified an association between fetal stomach dilatation and postnatal morbidity and mortality. In that study, stomach dilatation occurred in 38%, whereas it was present in fewer than 10% of ours. One explanation for this difference might be that because we are not a referral center for fetal anomalies, our cohort may have included milder cases not considered to need referral, and the prevalence of fetal stomach dilatation may not be as high as previously described. This may also explain our low prevalence of fetal bowel dilatation. Piper and Jaksic15 recently described a study of 27 infants with gastroschisis, 48% of whom had bowel dilatation greater than 6 mm. In that study, bowel dilatation was associated with slower time to initiation of feeding (an outcome we did not evaluate), but was not associated with length of stay, duration of total parenteral nutrition, or neonatal mortality.
The ultrasound finding most clearly associated with poor outcome in our study was that of a defect so massive that no ventral wall could be visualized, with apparent extrusion of all bowel, stomach, and liver. It may be considered a limitation of our study that such atypical defects were included, or even argued that they were not gastroschisis at all—but rather represented ruptured omphaloceles or atypical cases of body-stalk anomaly. The reason for their inclusion was that in each case, the prenatal diagnosis of gastroschisis was supported by the neonatologists' and pediatric surgeons' assessments after delivery. Despite the large size of the defects, infants were delivered by cesarean, and every effort was made on their behalf. With so few fetuses having such extensive defects, it is not possible to know whether the prognosis will be so poor in all cases, but this is something future study might address.
A somewhat unexpected finding was that such a large percentage of infants with gastroschisis would be born at weights below the third percentile, and that such infants would be more likely to require delayed closure. Japaraj et al14 also documented growth restriction in approximately 40% of those with fetal gastroschisis. Puligandla et al7 found growth restriction in (only) 15% with gastroschisis, but noted that growth-restricted infants had comparable length of hospital stay, duration of total parenteral nutrition, and mortality to normally grown infants with gastroschisis, similar to our findings.
The strengths of our study include the large number of patients in a relatively short study period, when obstetric and surgical management of pregnancies with gastroschisis did not vary over time. Even with nearly 60 patients, our study is limited by the low prevalence of the ultrasound predictors we evaluated. Although this may be encouraging, in that their prevalence is low in a nonreferred population, it limits the conclusions we can draw. However, despite the infrequent ultrasound findings, morbidity in this cohort was significant, because one half the infants in our study were not able to undergo primary closure, and approximately 20% had a serious bowel complication in addition to the gastroschisis.
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Footnotes |
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Financial Disclosure The authors have no potential conflicts of interest to disclose.
doi:10.1097/01.AOG.0000277264.63736.7e
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REFERENCES |
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2. Penman DG, Fisher RM, Noblett HR, Soothill PW. Increase in the incidence of gastroschisis in the south west of England in 1995. Br J Obstet Gynaecol 1998;105:328–31.[Medline]
3. Reid KP, Dickinson JE, Doherty DA. The epidemiologic incidence of congenital gastroschisis in Western Australia. Am J Obstet Gynecol 2003;189:764–8.[Medline]
4. Hertzberg BS, Nyberg DA, Neilsen IR. Ventral wall defects. In: Nyberg DA, McGahan JP, Pretorius DH, Pilu G, editors. Diagnostic imaging of fetal anomalies. 2nd ed. Philadelphia (PA): Lippincott Williams & Wilkins; 2003. p. 507–46.
5. Drewett M, Michailidis GD, Burge D. The perinatal management of gastroschisis. Early Human Dev 2006;82:305–12.[Medline]
6. Vegunta RK, Wallace LJ, Leonardi MR, Gross TL, Renfroe Y, Marshall JS, et al. Perinatal management of gastroschisis: analysis of a newly established clinical pathway. J Pediatr Surg 2005;40:528–34.[Medline]
7. Puligandla PS, Janvier A, Flageole H, Bouchard S, Mok E, Laberge JM. The significance of intrauterine growth restriction is different from prematurity for the outcome of infants with gastroschisis. J Pediatr Surg 2004;39:1200–4.[Medline]
8. Ergun O, Barksdale E, Ergun FS, Prosen T, Qureshi FG, Reblock KR, et al. The timing of delivery of infants with gastroschisis influences outcome. J Pediatr Surg 2005;40:424–8.[Medline]
9. Logghe HL, Mason GC, Thornton JG, Stringer MD. A randomized controlled trial of elective preterm delivery of fetuses with gastroschisis. J Pediatr Surg 2005;40:1726–31.[Medline]
10. ACOG Committee on Practice Bulletins. ACOG Practice Bulletin No. 58. Ultrasonography in pregnancy. Obstet Gynecol 2004;104:1449–58.
11. American Institute of Ultrasound in Medicine. AIUM Practice Guideline for the performance of an antepartum obstetric ultrasound examination. J Ultrasound Med 2003;22:1116–25.
12. McIntire DD, Bloom SL, Casey BM, Leveno KJ. Birth weight in relation to morbidity and mortality among newborn infants. N Engl J Med 1999;340:1234–8.
13. Aina-Mumuney AJ, Fischer AC, Blakemore KJ, Crino JP, Costigan K, Swenson K, et al. A dilated fetal stomach predicts a complicated postnatal course in cases of prenatally diagnosed gastroschisis. Am J Obstet Gynecol 2004;190:1326–30.[Medline]
14. Japaraj RP, Hockey R, Chan FY. Gastroschisis: can prenatal sonography predict neonatal outcome? Ultrasound Obstet Gynecol 2003;21:329–33.[Medline]
15. Piper HG, Jaksic T. The impact of prenatal bowel dilation on clinical outcomes in neonates with gastroschisis. J Pediatr Surg 2006;41:897–900.[Medline]
16. Goldstein I, Reece EA, Yarkoni S, Wan M, Green JL, Hobbins JC. Growth of the fetal stomach in normal pregnancies. Obstet Gynecol 1987;70:641–4.[Medline]
17. Nyberg DA, Mack LA, Patten RM, Cyr DR. Fetal bowel. Normal sonographic findings. J Ultrasound Med 1987;6:3–6.[Abstract]
18. Rutherford SE, Phelan JP, Smith CV, Jacobs N. The four-quadrant assessment of amniotic fluid volume: an adjunct to antepartum fetal heart rate testing. Obstet Gynecol 1987;70:353–6.[Medline]
19. Dashe JS, McIntire DD, Ramus RM, Santos-Ramos R, Twickler DM. Hydramnios: anomaly prevalence and sonographic detection. Obstet Gynecol 2002;100:134–9.
20. Casey BM, McIntire DD, Bloom SL, Lucas MJ, Santos R, Twickler DM, et al. Pregnancy outcomes after antepartum diagnosis of oligohydramnios at or beyond 34 weeks' gestation. Am J Obstet Gynecol 2000;182:909–12.[Medline]
21. Babcook CJ, Hedrick MH, Goldstein RB, Callen PW, Harrison MR, Adzick NS, et al. Gastroschisis: can sonography of the fetal bowel accurately predict postnatal outcome? J Ultrasound Med 1994;13:701–6.[Abstract]
22. Langer JC, Khanna J, Caco C, Dykes EH, Nicolaides KH. Prenatal diagnosis of gastroschisis: development of objective sonographic criteria for predicting outcome. Obstet Gynecol 1993;81:53–6.
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