External Validation of a Prediction Model Assessing Risk of Delivery in Fetuses with Growth Restriction after Diagnosis of Abnormal Umbilical Artery Doppler

Abstract

Objective We have previously described a model using maternal, antenatal, and ultrasonographic characteristics to assess the risk of delivery within 7 days following diagnosis of abnormal umbilical artery Doppler (UAD) in pregnancies affected by fetal growth restriction (FGR). Therefore, we sought to validate this model in an independent cohort.

Study Design Retrospective, single referral center study of liveborn singleton pregnancies from 2016 to 2019 complicated by FGR and abnormal UAD (systolic/diastolic ratio ≥95th percentile for gestational age [GA]). Prediction probabilities were calculated by applying the original model (Model 1) to the current cohort (Brigham and Women's Hospital [BWH] cohort). The variables of this model include GA at first abnormal UAD, severity of first abnormal UAD, oligohydramnios, preeclampsia, and prepregnancy body mass index. Model fit was assessed with area under the curve (AUC). Two alternative models (Models 2 and 3) were created to identify a model with better predictive characteristics than Model 1. The receiver operating characteristics curves were compared using the DeLong test.

Results A total of 306 patients were assessed for eligibility, 223 of whom were included in the BWH cohort. Median GA at eligibility was 31.3 weeks, and median interval from eligibility to delivery was 17 days (interquartile range: 3.5–33.5). Eighty-two (37%) patients delivered within 7 days of eligibility. Applying Model 1 to the BWH cohort resulted in an AUC of 0.865. Using the previously determined probability cutoff of 0.493, the model was 62% sensitive and 90% specific in predicting the primary outcome in this independent cohort. Models 2 and 3 did not perform better than Model 1 (p = 0.459).

Conclusion A previously described prediction model to predict risk of delivery in patients with FGR and abnormal UAD performed well in an independent cohort. With high specificity, this model could assist in identifying low-risk patients and improve antenatal corticosteroid timing.

Key Points

• Risk of delivery in 7 days can be predicted.

• Risk of delivery can inform corticosteroid timing.

• An externally validated clinical aid can be developed.

Keywords

fetal growth restriction - prediction model - abnormal umbilical artery Doppler - antenatal corticosteroids

^* Authors contributed equally to this work.

Publication History

Received: 08 March 2022

Accepted: 24 April 2023

Accepted Manuscript online:
26 April 2023

Article published online:
31 May 2023

• References

• 1 Swanson AM, David AL. Animal models of fetal growth restriction: considerations for translational medicine. Placenta 2015; 36 (06) 623-630
• 2 Bernstein IM, Horbar JD, Badger GJ, Ohlsson A, Golan A. The Vermont Oxford Network. Morbidity and mortality among very-low-birth-weight neonates with intrauterine growth restriction. Am J Obstet Gynecol 2000; 182 (1 Pt 1): 198-206
• 3 Unterscheider J, O'Donoghue K, Daly S. et al. Fetal growth restriction and the risk of perinatal mortality-case studies from the multicentre PORTO study. BMC Pregnancy Childbirth 2014; 14: 63
• 4 Ego A, Subtil D, Grange G. et al. Customized versus population-based birth weight standards for identifying growth restricted infants: a French multicenter study. Am J Obstet Gynecol 2006; 194 (04) 1042-1049
• 5 Getahun D, Ananth CV, Kinzler WL. Risk factors for antepartum and intrapartum stillbirth: a population-based study. Am J Obstet Gynecol 2007; 196 (06) 499-507
• 6 Bamfo JE, Odibo AO. Diagnosis and management of fetal growth restriction. J Pregnancy 2011; 2011: 640715
• 7 Resnik R. Intrauterine growth restriction. Obstet Gynecol 2002; 99 (03) 490-496
• 8 Martins JG, Biggio JR, Abuhamad A. Society for Maternal-Fetal Medicine (SMFM). SMFM. Society for Maternal-Fetal Medicine Consult Series# 52: diagnosis and management of fetal growth restriction: (replaces clinical guideline number 3, April 2012). Am J Obstet Gynecol 2020; 223 (04) B2-B17
• 9 Caradeux J, Martinez-Portilla RJ, Basuki TR, Kiserud T, Figueras F. Risk of fetal death in growth-restricted fetuses with umbilical and/or ductus venosus absent or reversed end-diastolic velocities before 34 weeks of gestation: a systematic review and meta-analysis. Am J Obstet Gynecol 2018; 218 (2S): S774-82.e21, 782.e21
• 10 Turan OM, Turan S, Gungor S. et al. Progression of Doppler abnormalities in intrauterine growth restriction. Ultrasound Obstet Gynecol 2008; 32 (02) 160-167
• 11 Committee on Obstetric Practice. Committee opinion no. 713: antenatal corticosteroid therapy for fetal maturation. Obstet Gynecol 2017; 130 (02) e102-e109
• 12 Vis JY, Wilms FF, Kuin RA. et al. Time to delivery after the first course of antenatal corticosteroids: a cohort study. Am J Perinatol 2011; 28 (09) 683-688
• 13 Yu HY, Has P, Danilack VA, Werner EF, Rouse DJ. Prediction model assessing risk of delivery after diagnosis of abnormal umbilical artery Doppler. Am J Perinatol 2021
• 14 American College of Obstetricians and Gynecologists. Committee opinion no 611: method for estimating due date. Obstet Gynecol 2014; 124 (04) 863-866
• 15 DeLong ER, DeLong DM, Clarke-Pearson DL. Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparametric approach. Biometrics 1988; 44 (03) 837-845
• 16 Ting JY, Kingdom JCP, Shah PS. Antenatal glucocorticoids, magnesium sulfate, and mode of birth in preterm fetal small for gestational age. Am J Obstet Gynecol 2018; 218 (2S): S818-S828