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

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.

Examining the Relationship Between Gastroschisis and Placental Fetal Vascular Malperfusion

INTRODUCTION

Gastroschisis is a congenital malformation characterized by intestinal herniation through an abdominal wall defect. Despite its unknown pathogenesis, known risk factors include maternal smoking, alcohol use, and young maternal age. Previous work has shown that gastroschisis is associated with placental delayed villous maturation, and the goal of this study was to assess for additional associated placental pathologies that may help clarify the pathogenesis of gastroschisis.

METHODS

We conducted a retrospective slide review of 29 placentas of neonates with gastroschisis. Additionally, we reviewed pathology reports from one control group of 30 placentas with other congenital malformations. Gross and histological data were collected based on a standardized rubric.

RESULTS

Gastroschisis was associated with increased placental fetal vascular malperfusion (FVM) in 62% of cases (versus 0% of controls, p < 0.0001). It was also associated with increased placental villous maldevelopment in 76% of cases (versus 3% of controls, p < 0.0001).

CONCLUSION

Our study demonstrates an association between gastroschisis and FVM. While FVM could be the consequence of vascular disruption due to the ventral location of gastroschisis, it could also reflect estrogen-induced thrombosis in early pregnancy. Further research is needed to separate these possibilities and determine the cause of the placental FVM observed in gastroschisis.

Usefulness of ultrasound fetal anthropometry in primary and secondary screening to identify small for gestational age: A meta-analysis

PURPOSE

This study was performed to evaluate the usefulness of ultrasound fetal anthropometry in primary and secondary screening to identify small for gestational age (SGA).

METHODS

Ten databases, for example, PubMed (MEDLINE), were searched to include all English-language studies published since 2015 that provided true-positive and false-positive and true-negative and false-negative results of SGA identification. A bivariate diagnostic meta-analysis was performed to summarize the sensitivity and specificity as well as positive and negative likelihood ratios (PLR and NLR, respectively) of ultrasound fetal anthropometry for identification of SGA.

RESULTS

Sensitivity and NLR are important in primary screening. Both femur length and anthropometric formulas showed low sensitivity, although abdominal circumference showed moderate sensitivity. Abdominal circumference, femur length, and anthropometric formulas did not have sufficiently low NLR. However, specificity and PLR are important in secondary screening. Abdominal circumference, femur length, and anthropometric formulas all showed high specificity. Neither abdominal circumference nor femur length had sufficiently high PLR, but anthropometric formulas showed sufficiently high PNL.

CONCLUSIONS

Abdominal circumference, femur length, and anthropometric formulas are unsuitable in primary screening to identify SGA. However, anthropometric formulas, but not abdominal circumference and femur length, are useful in secondary screening to identify SGA.