Neonatal Outcomes among Fetuses with an Abdominal Circumference <3rd %ile and Estimated Fetal Weight 3rd to 9th %ile Compared to Fetuses with an EFW <3rd %ile

Abstract

Objective Fetal growth restriction (FGR) is defined as an estimated fetal weight (EFW) or abdominal circumference (AC) <10th percentile (%ile) for gestational age (GA). An EFW <3rd %ile for GA is considered severe FGR (sFGR). It remains unknown if fetuses with isolated AC <3rd %ile should be considered sFGR. Our primary objective was to assess composite neonatal outcomes in fetuses with an AC <3^rd %ile and overall EFW 3rd to 9th %ile compared with those with an EFW <3rd %ile.

Study Design This retrospective cohort study was undertaken at a tertiary academic center from January 2016 to December 2021. Inclusion criteria were singleton fetuses with an EFW <3rd %ile (Group 1) or AC <3rd %ile with EFW 3rd to 9th %ile (Group 2) at 28 weeks' gestation or greater. Exclusion criteria were multiple gestations, presence of a major fetal anomaly, resolution of FGR, genetic syndrome, or infection. Composite neonatal outcome was defined by any of the following: neonatal intensive care unit admission >48 hours, necrotizing enterocolitis, sepsis, respiratory distress syndrome, mechanical ventilation, retinopathy of prematurity, seizures, intraventricular hemorrhage, stillbirth, or death before discharge. Small for gestational age (SGA) was defined as birth weight <10th %ile for GA.

Results A total of 743 patients fulfilled our study criteria, with 489 in Group 1 and 254 in Group 2. The composite neonatal outcome occurred in 281 (57.5%) neonates in Group 1 and 53 (20.9%) in Group 2 (p < 0.01). The rates of SGA at birth were 94.9 and 75.6% for Group 1 and Group 2, respectively (OR 5.99, 95% confidence interval 3.65–9.82).

Conclusion Although AC <3rd %ile with EFW 3rd to 9th %ile is associated with a lower frequency of SGA and neonatal morbidity than EFW <3 %ile, fetuses with AC <3 %ile still exhibited moderate rates of these adverse perinatal outcomes. Consideration should be given to inclusion of an AC <3rd %ile with EFW 3rd to 9th %ile as a criterion for sFGR. However, prospective studies comparing delivery at 37 versus 38 to 39 weeks' gestation are needed to ensure improved outcomes before widespread adaptation in clinical practice.

Key Points

• The composite neonatal outcome occurred in 57.5% of fetuses with an overall EFW <3rd %ile and 20.9% of fetuses with an AC <3rd %ile but EFW 3rd to 9th %ile.

• Both groups demonstrated a high positive predictive value for SGA birth weight.

• Consideration should be given to inclusion of an AC <3rd %ile as a criterion for sFGR.

Keywords

fetal growth restriction - small for gestational age - abdominal circumference - neonatal outcome

Publication History

Received: 30 November 2023

Accepted: 30 January 2024

Accepted Manuscript online:
01 February 2024

Article published online:
07 March 2024

• 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, Daly S, Geary MP. et al. Predictable progressive Doppler deterioration in IUGR: does it really exist?. Am J Obstet Gynecol 2013; 209 (06) 539.e1-539.e7
• 4 Martins JG, Biggio JR, Abuhamad A. Society for Maternal-Fetal Medicine (SMFM). Electronic address: [e-mail]. 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
• 5 McCowan LM, Figueras F, Anderson NH. Evidence-based national guidelines for the management of suspected fetal growth restriction: comparison, consensus, and controversy. Am J Obstet Gynecol 2018; 218 (2S): S855-S868
• 6 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
• 7 Fadigas C, Saiid Y, Gonzalez R, Poon LC, Nicolaides KH. Prediction of small-for-gestational-age neonates: screening by fetal biometry at 35-37 weeks. Ultrasound Obstet Gynecol 2015; 45 (05) 559-565
• 8 Blue NR, Yordan JMP, Holbrook BD, Nirgudkar PA, Mozurkewich EL. Abdominal circumference alone versus estimated fetal weight after 24 weeks to predict small or large for gestational age at birth: a meta-analysis. Am J Perinatol 2017; 34 (11) 1115-1124
• 9 David C, Tagliavini G, Pilu G, Rudenholz A, Bovicelli L. Receiver-operator characteristic curves for the ultrasonographic prediction of small-for-gestational-age fetuses in low-risk pregnancies. Am J Obstet Gynecol 1996; 174 (03) 1037-1042
• 10 Caradeux J, Martinez-Portilla RJ, Peguero A, Sotiriadis A, Figueras F. Diagnostic performance of third-trimester ultrasound for the prediction of late-onset fetal growth restriction: a systematic review and meta-analysis. Am J Obstet Gynecol 2019; 220 (05) 449-459.e19
• 11 Monier I, Blondel B, Ego A, Kaminiski M, Goffinet F, Zeitlin J. Poor effectiveness of antenatal detection of fetal growth restriction and consequences for obstetric management and neonatal outcomes: a French national study. BJOG 2015; 122 (04) 518-527
• 12 Pressman K, Odibo L, Duncan JR, Odibo AO. Impact of using abdominal circumference independently in the diagnosis of fetal growth restriction. J Ultrasound Med 2022; 41 (01) 157-162
• 13 American College of Obstetricians and Gynecologists' Committee on Practice Bulletins—Obstetrics and the Society for Maternal-Fetal Medicine. ACOG Practice Bulletin No. 204: Fetal Growth Restriction. Obstet Gynecol 2019; 133 (02) e97-e109
• 14 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
• 15 Pilliod RA, Cheng YW, Snowden JM, Doss AE, Caughey AB. The risk of intrauterine fetal death in the small-for-gestational-age fetus. Am J Obstet Gynecol 2012; 207 (04) 318.e1-318.e6
• 16 Lees C, Marlow N, Arabin B. et al; TRUFFLE Group. Perinatal morbidity and mortality in early-onset fetal growth restriction: cohort outcomes of the trial of randomized umbilical and fetal flow in Europe (TRUFFLE). Ultrasound Obstet Gynecol 2013; 42 (04) 400-408