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.

The association between interdelivery interval and adverse perinatal outcomes in a diverse US population.

OBJECTIVE: The objective of this study was to investigate the association between interdelivery interval (IDI) and subsequent perinatal outcomes in a large population-based cohort. STUDY DESIGN: Retrospective cohort study of primiparous women with singleton gestations giving birth in the US in 2011 to 2012. IDI was defined as the time between last live birth and index live birth. IDI was categorized as 4 to 17 months, 18 to 36 months (referent), 37 to 60 months and >60 months. Statistical comparisons were made using chi-square tests and multivariable logistic regression models to control for confounding. Covariates included maternal age, prior preterm birth, prior cesarean and medical comorbidities. RESULTS: Of the 1 964 523 women meeting study criteria, 9.0% had an IDI of 4 to 17 months, 39.7% 18 to 36 months, 26.8% 37 to 60 months and 24.5% >60 months. Short IDI was associated with preterm delivery (<37 weeks; 13.8 vs 8.8%, (adjusted odds ratio (aOR) 1.51, 95% confidence interval (CI) 1.48 to 1.53)) and adverse perinatal outcomes including low 5-min Apgar, small for gestational age (SGA) status and neonatal intensive care unit (NICU) admission. Women with long IDI had a higher risk of induction of labor, cesarean delivery, chorioamnionitis, maternal ICU admission, preterm delivery and SGA status, 5-min Apgar score <4, and NICU admission. CONCLUSIONS: Compared with women with 18 to 36 month IDIs, women with either shorter or very long IDIs were at an increased risk of adverse maternal and neonatal outcomes.