Ultrasound prediction of birthweight and growth restriction in fetal gastroschisis

Estimating fetal weight in gastroschisis: A 10 year audit of outcomes at the National Maternity Hospital

OBJECTIVE

To identify whether conventional methods of estimating fetal growth (Hadlock's formula), which relies heavily on abdominal circumference measurements, are accurate in fetuses with gastroschisis.

METHODS

A retrospective cohort study was performed between the period January 1, 2011 and December 31, 2021 in a tertiary referral maternity hospital identifying all pregnancies with a diagnosis of gastroschisis. Projected fetal weight was obtained using the formula (EFW [Hadlock's formula] + 185 g × [X/7]) where X was the number of days to delivery.

RESULTS

During the study period 41 cases were identified. The median maternal age was 25. The median BMI was 25 and 63% were primiparous women (n = 26). Median gestation at diagnosis was 21 weeks. Median gestation at delivery was 36 weeks. A total of 4.8% of mothers had a history of drug use (n = 2). The rate of maternal tobacco use was 21.9% (n = 9). A total of 4.8% of fetuses had additional congenital anomalies including amniotic band syndrome and myelomeningocele (n = 2). Estimated fetal weight (EFW) and birth weight data were available for 34 cases. A Wilcoxon signed-rank test showed projected EFW using Hadlock's formula did not result in a statistically significant different birth weight (Z = -1.3, P = 0.169). Median projected weight and actual birth weight were 2241.35 and 2415 g respectively. Median difference was 0.64 g (95% CI: -148 to -28.5).

CONCLUSION

Our data showed accuracy using standard formulae for EFW in fetuses with gastroschisis.

Perinatal Outcomes of Neonates with Complex and Simple Gastroschisis after Planned Preterm Delivery-A Single-Centre Retrospective Cohort Study

This research analysed early neonatal outcomes of complex and simple gastroschisis following planned elective preterm delivery in relation to prenatal ultrasound assessment of bowel conditions. A retrospective study of 61 neonates with prenatal gastroschisis diagnosis, birth, and management at a single tertiary centre from 2011 to 2021 showed a 96.72% survival rate with no intrauterine fatalities. Most cases (78.7%) were simple gastroschisis. Neonates with complex gastroschisis had longer hospital stays and time to full enteral feeding compared to those with simple gastroschisis-75.4 versus 35.1 days and 58.1 versus 24.1 days, respectively. A high concordance of 86.90% between the surgeon's and perinatologist's bowel condition assessments was achieved. The caesarean delivery protocol demonstrated safety, high survival rate, primary closure, and favourable outcomes compared to other reports. Prenatal ultrasound effectively evaluated bowel conditions and identified complex gastroschisis cases.

Prediction of Neonatal Growth Restriction in Fetuses With Gastroschisis by Early Third Trimester Ultrasonography Utilizing Contemporary Birth Weight Percentiles

OBJECTIVE

To identify the estimated fetal weight (EFW) formula and threshold for the optimal prediction of fetal growth restriction (FGR) at 26-34 weeks' in fetuses with gastroschisis.

METHODS

Late second and third trimester ultrasound data were used to calculate the EFW utilizing eight different formulas: Hadlock I-IV, Honarvar, Shepard, Siemer, and Warsof. EFW and birth weight percentiles were assigned from US population growth curves. FGR and small for gestational age (SGA) were defined as EFW and birth weight less than the tenth percentile for gestational age; Receiver operating characteristic (ROC) curves were used to compare formula performance for FGR diagnosis at 26-34 weeks' to identify an SGA birth weight.

RESULTS

There were 170 newborns with gastroschisis; 46 (27%) were SGA. The mean gestational age at the time of ultrasound was 30.8 ± 1.7 weeks. The mean gestational age at birth was 36.3 ± 1.7 weeks. ROC curve analysis found the Hadlock III formula had the largest area under the curve (AUC) of 0.813 closely followed by Hadlock IV (AUC = 0.811) and Hadlock II (AUC = 0.808) for diagnosis of FGR correlating to neonatal SGA diagnosis. Hadlock II, Hadlock III, and Hadlock IV had the highest diagnostic accuracies when compared to the other EFW formulas.

CONCLUSIONS

The Hadlock II, Hadlock III, and Hadlock IV formulas have comparable predictive performance in the optimal identification of FGR in fetuses with gastroschisis at 26-34 weeks'. A threshold of an EFW less than the 25.2th percentile is suggested.

Accuracy of Ultrasound to Predict Neonatal Birth Weight Among Fetuses With Gastroschisis: Impact on Timing of Delivery

OBJECTIVES

To determine the accuracy of ultrasound estimation of fetal weight among fetuses with gastroschisis and how the diagnosis of fetal growth restriction (FGR) affects the timing of delivery.

METHODS

This was a retrospective cohort study including all fetuses with a diagnosis of gastroschisis at our institution from November 2012 through October 2017. We excluded multiple gestations, pregnancies with major structural or chromosomal abnormalities, and those for which prenatal and postnatal follow-up were unavailable. Performance characteristics of ultrasound to predict being small for gestational age (SGA) were calculated for the first and last ultrasound estimations of fetal weight.

RESULTS

Our cohort included 75 cases of gastroschisis. At the initial ultrasound estimation, 15 of 58 (25.9%) fetuses met criteria for FGR; 48 of 70 (68.6%) met criteria at the time of the last ultrasound estimation (median, 34.7 weeks). Cesarean delivery was performed for 37 of 75 (49.3%), with FGR and concern for fetal distress as the indication for delivery in 17 of 37 (45.9%). Only 6 of 17 (35.3%) of the neonates born by cesarean delivery for an indication of FGR and fetal distress were SGA. The initial ultrasound designation of FGR corresponded to SGA at birth in 8 of 15 (53.3%), whereas the last ultrasound estimation corresponded to SGA in 17 of 48 (35.4%). The initial ultrasound estimation agreed with the last ultrasound estimation before delivery with the diagnosis of FGR in 13 of 15 (86.7%).

CONCLUSIONS

Ultrasound in the third trimester was sensitive but had a low positive predictive value and low accuracy for the diagnosis of SGA at birth for fetuses with gastroschisis. A large proportion of fetuses were born by cesarean delivery with indications related to FGR or fetal concerns.

Interval growth across gestation in pregnancies with fetal gastroschisis

BACKGROUND

Gastroschisis is often complicated by fetal growth restriction, preterm delivery, and prolonged neonatal hospitalization. Prenatal management and delivery decisions are often based on estimated fetal weight and interval growth; however, appropriate interval growth from week to week across gestation for these fetuses is poorly understood.

OBJECTIVE

This study aimed to determine the median increase in overall estimated fetal weight and individual biometric measurements across each week of gestation in pregnancies with fetal gastroschisis and to assess whether lower in utero fetal weight gain is predictive of postnatal growth or adverse neonatal outcomes.

STUDY DESIGN

This was a retrospective cohort study of pregnancies with gastroschisis evaluated at 5 institutions of the University of California Fetal-Maternal Consortium from December 2014 to December 2019. The inclusion criteria were prenatally diagnosed gastroschisis with at least 1 ultrasound performed at a University of California Fetal-Maternal Consortium institution. Estimated fetal weight and individual biometric measurements were recorded for each ultrasound performed at a University of California Fetal-Maternal Consortium institution from the time of gastroschisis diagnosis to delivery. Median estimated fetal weight and biometric measurements were calculated for each gestational age in 1-week increments. Neonatal outcomes collected were birthweight, length of stay, complications of gastroschisis (bowel atresia, bowel stricture, ischemic bowel before closure, or severe pulmonary hypoplasia), and growth failure at discharge.

RESULTS

We identified 95 pregnancies with fetal gastroschisis who, in aggregate, had 360 growth ultrasounds at a University of California Fetal-Maternal Consortium institution. The median interval growth was 130 g/wk. The median estimated fetal weight and abdominal circumference in fetal gastroschisis cases were approximately the tenth percentile on the Hadlock growth curve across gestation. Moreover, the median biparietal diameter, head circumference, and femur length measurements remained below the 50th percentile on the Hadlock growth curve across gestation. The median birthweight for neonates with less than the median weekly prenatal weight gain was less than for those with greater than the median weekly prenatal weight gain (2185 g vs 2780 g; P<.01). There was no difference in prenatal weight gain trajectory when comparing neonates who had or did not have bowel complications of gastroschisis.

CONCLUSION

In this multicenter cohort of pregnancies with fetal gastroschisis, the median interval growth was 130 g/wk, and overall, in utero growth closely followed the tenth percentile on the Hadlock curve. Poor prenatal growth in cases of fetal gastroschisis correlates with lower neonatal weights but did not predict a more complicated course.

Accuracy of estimated fetal weight assessment in fetuses with abdominal wall defects

BACKGROUND

Gastroschisis and omphalocele are congenital abdominal wall defects in which the bowel and other abdominal contents extrude from the fetal abdominal cavity. Standard formulas for estimated fetal weight using ultrasound include fetal abdominal circumference measurement and have a range of error of approximately 10%. It is unknown whether the accuracy of estimated fetal weight assessment is compromised in fetuses with abdominal wall defects because of the extrusion of abdominal contents.

OBJECTIVE

This study aimed to assess the accuracy of standard estimated fetal weight assessment in fetuses with abdominal wall defects by comparing prenatal assessment of fetal weight with actual birthweight.

STUDY DESIGN

A retrospective cohort study of fetuses diagnosed with gastroschisis or omphalocele was performed at a single center from 2012 to 2018. Fetuses with additional anomalies or confirmed chromosome abnormalities were excluded. Estimated fetal weight was calculated using the Hadlock formula. Published estimates of fetal growth rate were used to establish a projected estimated fetal weight at birth from the final growth ultrasound, and the percent difference between projected estimated fetal weight at birth and actual birthweight was calculated. The Wilcoxon rank-sum test was used to examine the difference between projected estimated fetal weight and actual birthweight.

RESULTS

We had complete data for 112 fetuses with abdominal wall defects, including 85 with gastroschisis and 27 with omphalocele. The median (interquartile range) projected estimated fetal weight was similar to median birthweight, at 2283 g (interquartile range, 2000-2810) and 2306 g (interquartile range, 1991-264), respectively, which did not represent a statistically significant difference between projected estimated fetal weight and actual birthweight (P=.32). The median percent error was 6.8 (3.1-12.8). In addition, we did not find any statistical difference between projected estimated fetal weight and actual birthweight in patients with gastroschisis (P=.52) or omphalocele (P=.35) individually. Estimated fetal weight was underestimated in most cases (n=68 [60.7%]).

CONCLUSION

In fetuses with abdominal wall defects, standard measurement of fetal weight shows an accuracy that is at least comparable with previously established margins of error for ultrasound assessment of fetal weight. Standard estimated fetal weight assessment remains an appropriate method of estimating fetal weight in these fetuses.

Development of a prenatal clinical care pathway for uncomplicated gastroschisis and literature review

BACKGROUND

Gastroschisis is an abdominal wall defect wherein the bowel is herniated into the amniotic fluid. Controversy exists regarding optimal prenatal surveillance strategies that predict fetal well-being and help guide timing of delivery. Our objective was to develop a clinical care pathway for prenatal management of uncomplicated gastroschisis at our institution.

METHODS

We performed a review of literature from January 1996 to May 2017 to evaluate prenatal ultrasound (US) markers and surveillance strategies that help determine timing of delivery and optimize outcomes in fetal gastroschisis.

RESULTS

A total 63 relevant articles were identified. We found that among the US markers, intraabdominal bowel dilatation, polyhydramnios, and gastric dilatation are potentially associated with postnatal complications. Prenatal surveillance strategy with monthly US starting at 28weeks of gestational age (wGA) and twice weekly non-stress testing beginning at 32wGA is recommended to optimize fetal wellbeing. Timing of delivery should be based on obstetric indications and elective preterm delivery prior to 37wGA is not indicated.

CONCLUSIONS

Close prenatal surveillance of fetal gastroschisis is necessary due to the high risk for adverse outcomes including intrauterine fetal demise in the third trimester. Decisions regarding the timing of delivery should take into consideration the additional prematurity-associated morbidity.

Predicting birth weight in fetuses with gastroschisis

OBJECTIVE

To determine the accuracy of commonly utilized ultrasound formulas for estimating birth weight (BW) in fetuses with gastroschisis.

STUDY DESIGN

A retrospective review was conducted of all inborn pregnancies with gastroschisis within the five institutions of the University of California Fetal Consortium (UCfC) between 2007 and 2012. Infants delivered at ⩾28 weeks who had an ultrasound within 21 days before delivery were included. Prediction of BW was evaluated for each of the five ultrasound formulas: Hadlock 1 (abdominal circumference (AC), biparietal diameter (BPD), femur length (FL) and head circumference (HC)) and Hadlock 2 (AC, BPD and FL), Shepard (AC and BPD), Honarvar (FL) and Siemer (BPD, occipitofrontal diameter (OFD), and FL) using Pearson's correlation, mean difference and percent error and Bland-Altman analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the ultrasound diagnosis of intrauterine growth restriction (IUGR) were assessed.

RESULTS

We identified 191 neonates born with gastroschisis within the UCfC, with 111 neonates meeting the inclusion criteria. The mean gestational age at delivery was 36.3±1.7 weeks and the mean BW was 2448±460 g. Hadlock (1) formula was found to have the best correlation (r=0.81), the lowest mean difference (8±306 g) and the lowest mean percent error (1.4±13%). The Honarvar and Siemer formulas performed significantly worse when compared with Hadlock 1, with a 13.7% (P<0.001) and 3.9% (P=0.03) difference, respectively, between estimated and actual BW. This was supported by Bland-Altman plots. For Hadlock 1 and 2, sensitivity was 80% with a NPV of 91%.

CONCLUSION

The widely used Hadlock (1) and (2) formulas provided the best estimated BW in infants with gastroschisis despite its inclusion of abdominal circumference. Furthermore, this formula performs well with diagnosis of IUGR.

Utility of third trimester sonographic measurements for predicting SGA in cases of fetal gastroschisis

OBJECTIVE

To assess the accuracy of different sonographic estimated fetal weight (EFW) cutoffs, and combinations of EFW and biometric measurements for predicting small for gestational age (SGA) in fetal gastroschisis.

STUDY DESIGN

Gastroschisis cases from two centers were included. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated for different EFW cutoffs, as well as EFW and biometric measurement combinations.

RESULTS

Seventy gastroschisis cases were analyzed. An EFW<10% had 94% sensitivity, 43% specificity, 33% PPV and 96% NPV for SGA at delivery. Using an EFW cutoff of <5% improved the specificity to 63% and PPV to 41%, but decreased the sensitivity to 88%. Combining an abdominal circumference (AC) or femur length (FL) z-score less than -2 with the total EFW improved the specificity and PPV but decreased the sensitivity.

CONCLUSION

A combination of a small AC or FL along with EFW increases the specificity and PPV, but decreases the sensitivity of predicting SGA.

High mortality among children with gastroschisis after the neonatal period: A long-term follow-up study

BACKGROUND

During the last decades neonatal outcomes for children born with gastroschisis have improved significantly. Survival rates >90% have been reported. Early prenatal diagnosis and increased survival enforce the need for valid data for long-term outcome in the pre- and postnatal counseling of parents with a child with gastroschisis.

METHODS

Long-term follow-up on all newborns with gastroschisis at Odense University Hospital (OUH) from January 1 1997-December 31 2009. Follow-up included neonatal chart review for neonatal background factors, including whether a GORE^®DUALMESH was used for staged closure, electronic questionnaires, interview and laboratory investigations. Cases were divided into complex and simple cases according to the definition by Molik et al. (2001). Survival status was determined by the national personal identification number registry. Because of the consistency of the registration, survival status was obtained from all children participating in the study.

RESULTS

A total of 71 infants (7 complex and 64 simple) were included. Overall seven out of the 71 children (9.9%, median age: 52days (25-75% percentile 0-978days) had died at the time of follow-up. Three died during the neonatal period and four died after the neonatal period. Parenteral nutrition (PN) induced liver failure and suspected adhesive small bowel obstruction were the causes of deaths after the neonatal period. Overall mortality was high in the "complex" group compared to the simple group (3/7 (42.9%) vs 4/64 (6.3%), p = 0.04). Forty (62.5%) of the surviving children consented to participate in the follow-up. A total of 12 children had had suspected adhesive small bowel obstruction. Prevalence of small bowel obstruction was not related to the number of operations needed for neonatal closure of the defect. Staged closure was done in 5/12 (41.7%) who developed small bowel obstruction vs 11/35 (31.43%) without small bowel obstruction, p=0.518. A GORE^®DUALMESH was used in 16 children (22.5%). Of these 2 were complex and 14 were simple cases. Prevalence of recurrent abdominal pain was 22.5% (9/40) among children with gastroschisis compared to 12% in a study on Danish school children, p=0.068. Gastrointestinal symptoms had led to hospital admission after primary discharge in significantly more children with gastroschisis 16 (40.0%) than children younger than 16years old in the general Danish population 129.419/1.081.542 (12.0%), p=0.000. Fecal calprotectin level was above the reference level (>50mg/kg) in 6/16 (37.5%) children >8years old with gastroschisis compared to 1/7 (14.3%) healthy children. (Fisher's exact=0.366). Only 8/38 (21.1%) children with gastroschisis reported to have an umbilicus.

CONCLUSION

Mortality among children with gastroschisis is still significant with the highest risk among complicated cases. The majority of the deaths is potentially preventable as PN-related causes and suspected adhesive small bowel obstruction counted for five of seven deaths. Neither categorization upon method of abdominal wall closure nor categorization into simple and complex cases can predict the risk of adhesive small bowel obstruction. With improved administration of PN and timely information and attention to the risk of the small bowel obstruction there is good possibility that the associated mortality could decrease. Type of study and level of evidence: Prognosis study, level II.

Gastroschisis: A Review of Management and Outcomes

We performed an evidence-based review of the obstetrical management of gastroschisis. Gastroschisis is an abdominal wall defect, which has increased in frequency in recent decades. There is variation of prevalence by ethnicity and several known maternal risk factors. Herniated intestinal loops lacking a covering membrane can be identified with prenatal ultrasonography, and maternal serum α-fetoprotein level is commonly elevated. Because of the increased risk for growth restriction, amniotic fluid abnormalities, and fetal demise, antenatal testing is generally recommended. While many studies have aimed to identify antenatal predictors of neonatal outcome, accurate prognosis remains challenging. Delivery by 37 weeks appears reasonable, with cesarean delivery reserved for obstetric indications. Postnatal surgical management includes primary surgical closure, staged reduction with silo, or sutureless umbilical closure. Overall prognosis is good with low long-term morbidity in the majority of cases, but approximately 15% of cases are very complex with complicated hospital course, extensive intestinal loss, and early childhood death.

Sonographic Detection and Clinical Importance of Growth Restriction in Pregnancies With Gastroschisis

OBJECTIVES

The purpose of this study was to estimate the utility of sonography to detect small-for-gestational-age (SGA) neonates in pregnancies with gastroschisis and to evaluate neonatal outcomes according to birth weight percentile.

METHODS

We conducted a retrospective cohort study of singleton pregnancies with fetal gastroschisis delivered at our hospital between August 1997 and December 2012. Diagnosis of growth restriction was based on estimated fetal weight below the 10th percentile using the nomogram of Hadlock et al (Am J Obstet Gynecol 1985; 151:333-337), evaluated at 4-week intervals throughout gestation and compared with subsequent birth weight, to evaluate the accuracy of sonography to detect and exclude SGA neonates. Pregnancy and neonatal outcomes were evaluated according to birth weight percentile.

RESULTS

There were 111 births with gastroschisis (6 per 10,000), and one-third (n = 37) had birth weight below the 10th percentile. The sensitivity and negative predictive value of sonography for an SGA neonate both approached 90% by 32 weeks and were approximately 95% thereafter. Detection increased with advancing gestational age (P = .02). The birth weight percentile was not associated with preterm birth, infection, bowel complications requiring surgery, duration of hospitalization, or perinatal mortality. Delayed closure of the gastroschisis defect was more frequent with birth weights at or below the 3rd percentile (P = .03).

CONCLUSIONS

Sonography reliably identified SGA neonates with gastroschisis in our series, and its utility improved with advancing gestation. Apart from delayed closure of the defect, a low birth weight percentile was not associated with an increased risk of morbidity or mortality in the immediate neonatal period.

Fetal Growth Pattern and Prediction of Low Birth Weight in Gastroschisis

OBJECTIVES

To examine growth patterns and predictions of low birth weight in gastroschisis fetuses.

METHODS

This is a retrospective study of isolated fetal gastroschisis before week 24. Ultrasound fetal biometric parameters - head circumference (HC), abdominal circumference (AC), femur length, HC/AC ratio and estimated fetal weight (EFW)--were plotted against normal growth charts. The percentage difference in mean values between normal and gastroschisis fetuses was determined. The growth deficit for each ultrasound parameter was calculated for the fetuses with 1 examination in each designated period (period I: weeks 20-25(+6); period II: weeks 26-31(+6); period III: from week 32 until term). For low birth weight prediction, measurements below the 10th percentile in periods I and II were tested.

RESULTS

Seventy pregnancies were examined. For all fetal parameters, the mean measurements were lower in fetuses with gastroschisis (p < 0.005). The EFW revealed an increased growth deficit between the periods (p = 0.030). HC was predictive of low birth weight in period II (OR = 6.07; sensitivity = 70.8%; specificity = 71.4%).

CONCLUSIONS

Fetuses with gastroschisis present a reduced growth pattern, and it appears that no growth recovery occurs after the growth restriction has been established. Between week 26 and week 31(+6), an HC measurement below the 10th percentile is associated with an increased risk of low birth weight.

Gastroschisis--what should be told to parents?

Gastroschisis is a common congenital abdominal wall defect. It is almost always diagnosed prenatally thanks to routine maternal serum screening and ultrasound screening programs. In the majority of cases, the condition is isolated (i.e. not associated with chromosomal or other anatomical anomalies). Prenatal diagnosis allows for planning the timing, mode and location of delivery. Controversies persist concerning the optimal antenatal monitoring strategy. Compelling evidence supports elective delivery at 37  weeks' gestation in a tertiary pediatric center. Cesarean section should be reserved for routine obstetrical indications. Prognosis of infants with gastroschisis is primarily determined by the degree of bowel injury, which is difficult to assess antenatally. Prenatal counseling usually addresses gastroschisis issues. However, parental concerns are mainly focused on long-term postnatal outcomes including gastrointestinal function and neurodevelopment. Although infants born with gastroschisis often endure a difficult neonatal course, they experience few long-term complications. This manuscript, which is structured around common parental questions and concerns, reviews the evidence pertaining to the antenatal, neonatal and long-term implications of a fetal gastroschisis diagnosis and is aimed at helping healthcare professionals counsel expecting parents.

Fetal abdominal wall defects

The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management.