Definition Of Fetal Growth Restriction Research Articles

Placental pathology lesions: International Society for Ultrasound In Obstetrics And Gynecology vs. Society for Maternal-Fetal Medicine Fetal growth restriction definitions

Research on the definition of fetal growth restriction has focused on predicting adverse perinatal outcomes. A significant limitation of this approach is that the individual outcomes of interest could be related to the condition and the treatment. Evaluation of outcomes that reflect the pathophysiology of fetal growth restriction may overcome this limitation. To compare the diagnostic performance of the fetal growth restriction definitions established by the International Society for Ultrasound in Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine to predict placental histopathological findings associated with placental insufficiency and a composite adverse neonatal outcome. In this retrospective cohort study of singleton pregnancies, the International Society for Ultrasound in Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine guidelines were used to identify pregnancies with fetal growth restriction and a corresponding control group. The primary outcome was the prediction of placental histopathological findings associated with placental insufficiency, defined as lesions associated with maternal vascular malperfusion. A composite adverse neonatal outcome (i.e., umbilical artery pH≤7.1, Apgar score at 5 minutes ≤4, neonatal intensive care unit admission, hypoglycemia, respiratory distress syndrome requiring mechanical ventilation, intrapartum fetal distress requiring expedited delivery, and perinatal death) was investigated as a secondary outcome. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver-operating-characteristics curves were determined for each fetal growth restriction definition. Logistic regression models were used to assess the association between each definition and the studied outcomes. A subgroup analysis of the diagnostic performance of both definitions stratifying the population in early and late fetal growth restriction was also performed. Both societies' definitions showed a similar diagnostic performance as well as a significant association with the primary (International Society for Ultrasound in Obstetrics and Gynecology adjusted odds ratio 3.01 [95% confidence interval 2.42, 3.75]; Society for Maternal-Fetal Medicine adjusted odds ratio 2.85 [95% confidence interval 2.31, 3.51]) and secondary outcomes (International Society for Ultrasound in Obstetrics and Gynecology adjusted odds ratio 1.95 [95% confidence interval 1.56, 2.43]; Society for Maternal-Fetal Medicine adjusted odds ratio 2.12 [95% confidence interval 1.70, 2.65]). Furthermore, both fetal growth restriction definitions had a limited discriminatory capacity for placental histopathological findings of maternal vascular malperfusion and the composite adverse neonatal outcome (area under the receiver-operating-characteristics curve International Society for Ultrasound in Obstetrics and Gynecology 0.63 [95% confidence interval 0.61, 0.65], 0.59 [95% confidence interval 0.56, 0.61]; area under the receiver-operating-characteristics Society for Maternal-Fetal Medicine 0.63 [95% confidence interval 0.61, 0.66], 0.60 [95% confidence interval 0.57, 0.62]). The International Society for Ultrasound in Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine fetal growth restriction definitions have limited discriminatory capacity for placental histopathological findings associated with placental insufficiency and a composite adverse neonatal outcome.

Prenatal prediction of adverse outcome using different charts and definitions of fetal growth restriction.

Antenatal growth assessment using ultrasound aims to identify small fetuses that are at higher risk of perinatal morbidity and mortality. This study explored whether the association between suboptimal fetal growth and adverse perinatal outcome varies with different definitions of fetal growth restriction (FGR) and different weight charts/standards. This was a retrospective cohort study of 17 261 singleton non-anomalous pregnancies at ≥ 24 + 0 weeks' gestation that underwent routine ultrasound at a tertiary referral hospital. Estimated fetal weight (EFW) and Doppler indices were converted into percentiles using a reference standard (INTERGROWTH-21st (IG-21)) and various reference charts (Hadlock, Fetal Medicine Foundation (FMF) and Swedish). Test characteristics were assessed using the consensus definition, Society for Maternal-Fetal Medicine (SMFM) definition and Swedish criteria for FGR. Adverse perinatal outcome was defined as perinatal death, admission to the neonatal intensive care unit at term, 5-min Apgar score < 7 and therapeutic cooling for neonatal encephalopathy. The association between FGR according to each definition and adverse perinatal outcome was compared. Multivariate logistic regression analysis was used to test the strength of association between ultrasound parameters and adverse perinatal outcome. Ultrasound parameters were also tested for correlation. IG-21, Hadlock and FMF fetal size references classified as growth-restricted 1.5%, 3.6% and 4.6% of fetuses, respectively, using the consensus definition and 2.9%, 8.8% and 10.6% of fetuses, respectively, using the SMFM definition. The sensitivity of the definition/chart combinations for adverse perinatal outcome varied from 4.4% (consensus definition with IG-21 charts) to 13.2% (SMFM definition with FMF charts). Specificity varied from 89.4% (SMFM definition with FMF charts) to 98.6% (consensus definition with IG-21 charts). The consensus definition and Swedish criteria showed the highest specificity, positive predictive value and positive likelihood ratio in detecting adverse outcome, irrespective of the reference chart/standard used. Conversely, the SMFM definition had the highest sensitivity across all investigated growth charts. Low EFW, abnormal mean uterine artery pulsatility index (UtA-PI) and abnormal cerebroplacental ratio were significantly associated with adverse perinatal outcome and there was a positive correlation between the covariates. Multivariate logistic regression showed that UtA-PI > 95th percentile and EFW < 5th percentile were the only parameters consistently associated with adverse outcome, irrespective of the definitions or fetal growth chart/standard used. The apparent prevalence of FGR varies according to the definition and fetal size reference chart/standard used. Irrespective of the method of classification, the sensitivity for the identification of adverse perinatal outcome remains low. EFW, UtA-PI and fetal Doppler parameters are significant predictors of adverse perinatal outcome. As these indices are correlated with one other, a prediction algorithm is advocated to overcome the limitations of using these parameters in isolation. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

EP13.15: Assessing current definitions of fetal growth restriction in a low‐resource setting

EP13.15: Assessing current definitions of fetal growth restriction in a low‐resource setting

Sensitivity of Broadened Definition of Fetal Growth Restriction in Predicting Adverse Neonatal Outcomes [A342

INTRODUCTION: In 2020 the Society for Maternal-Fetal Medicine suggested broadening the fetal growth restriction (FGR) definition to include fetuses with isolated abdominal circumference (AC) less than 10th percentile. The purpose of this study was to determine if including these fetuses improves prediction of severe neonatal morbidity and mortality. METHODS: This is a retrospective analysis of births over the past 10 years within a hospital system affiliated with the University of Minnesota. A pregnancy was included if prenatal ultrasound data were available after 24 weeks gestation. Excluded were non-singletons and fetuses with diagnosis of structural or genetic abnormalities that could affect biometry measurements. Fetuses were categorized as FGR based on the prior definition (estimated fetal weight [EFW] less than 10th percentile) and on the proposed definition of EFW or AC less than 10th percentile. Institutional review board approval was obtained from the University of Minnesota (ID 00011238). RESULTS: A total of 26,526 births met inclusion criteria. The mean gestational age at birth was 39 weeks (SD 0.2). The rate of severe morbidity (e.g., severe acidosis, hypoxic ischemic encephalopathy, and sepsis) and mortality for those with EFW less than 10th percentile was 9.3% (odds ratio [OR] 3.6, P&lt;.001) and 2.8% (OR 26.1, P&lt;.001), respectively. For those with EFW or AC less than 10th percentile, rates were 6% (OR 2.3, P&lt;.001) and 1.5% (OR 15.0, P&lt;.001), respectively. CONCLUSION: Broadening the definition unsurprisingly increased the frequency of FGR, but frequency of adverse outcomes was lower. Thus, this analysis does not support the addition of isolated AC less than 10th percentile to the FGR definition.

Early-onset fetal growth restriction defined by only abdominal circumference is associated with perinatal mortality

SMFM recently expanded the definition of fetal growth restriction (FGR) to include abdominal circumference < 10th centile (%) as a diagnostic criterion in addition to the classic criterion of estimated fetal weight (EFW) < 10%. The broader definition is associated with improved detection of small for gestational age (SGA) neonates. Early-onset FGR diagnosed based on EFW alone prior to 32 estimated gestational age (EGA) is associated with increased risk of perinatal death. Among fetuses with normal EFW, we aimed to determine whether early-onset FGR diagnosed based on AC alone is associated with increased risks of adverse neonatal outcomes.

Reconsidering upstream approaches to improving population health

Racial and socioeconomic disparities in health outcomes have been well documented. 1 Blumenshine P Egerter S Barclay CJ Cubbin C Braveman PA Socioeconomic disparities in adverse birth outcomes: a systematic review. Am J Prev Med. 2010; 39: 263-272 Summary Full Text Full Text PDF PubMed Scopus (477) Google Scholar , 2 Matoba N Collins Jr, JW Racial disparity in infant mortality. Semin Perinatol. 2017; 41: 354-359 Crossref PubMed Scopus (43) Google Scholar Although overall global rates of poor birth outcomes have decreased, decades of research and interventions have not eliminated disparities. However, much intervention research has focused on individual-level risk factors and groups at high risk. In The Lancet, Jennifer Jardine and colleagues 3 Jardine J Walker K Gurol-Urganci I et al. Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort study. Lancet. 2021; (published online Nov 1.)https://doi.org/10.1016/S0140-6736(21)01595-6 Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar report on population attributable fractions, which indicate the proportion of a particular outcome that would be removed if a risk factor did not exist or was more similar to a reference population. The use of population attributable fractions is an important contribution because it demonstrates the excess risk of poor outcomes that can be attributed to population-level factors. The authors provide a potential roadmap for future interventions, emphasising the role of widespread health promotion in improving population-level health metrics over targeted, individual-level interventions that have less population impact. 4 Rose G Sick individuals and sick populations. Int J Epidemiol. 1985; 14: 32-38 Crossref PubMed Scopus (2188) Google Scholar This study 3 Jardine J Walker K Gurol-Urganci I et al. Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort study. Lancet. 2021; (published online Nov 1.)https://doi.org/10.1016/S0140-6736(21)01595-6 Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar included 1·16 million singleton births in England, which represented 94% of England's births obtained from administrative hospital data linked to the National Maternity and Perinatal Audit between 2015 and 2017. The authors report that 24% of stillbirths, 19% of preterm births, and 31% of fetal growth restriction could be attributed to socioeconomic inequality. The women included in the sample were 77·2% White, 11·9% south Asian, 4·9% Black, 1·8% mixed ethnicity, and 4·2% other ethnicity. Perhaps most striking were the authors’ findings on the intersection of race and socioeconomic disadvantage, describing that more than half of stillbirths, a third of preterm births, and nearly two-thirds of fetal growth restriction among south Asian and Black women could be eliminated if their risk factors were equal to the least socioeconomically deprived White women. The authors suggest that this finding supports a combination of population-based and risk-based approaches, but does not consider the inextricable link between ethnic background and socioeconomic deprivation. 5 Kane JB Miles G Yourkavitch J King K Neighborhood context and birth outcomes: going beyond neighborhood disadvantage, incorporating affluence. SSM Popul Health. 2017; 3: 699-712 Crossref PubMed Scopus (17) Google Scholar Additionally, the association between race or socioeconomic inequality and birth outcomes might vary because of factors like social support and experiences of racism and discrimination. In combination with the limitation of using an area-level index of deprivation, the authors acknowledge potential inaccuracies and bias in the population attributable fractions. 6 Mansournia MA Altman DG Population attributable fraction. BMJ. 2018; 360: k757 Crossref PubMed Scopus (114) Google Scholar They rightfully note that more detailed causal mediation analysis is a research priority. Moreover, because the definition of fetal growth restriction varies by the reference used, which itself varies by ethnic mix in the index population, 7 Grantz KL Fetal growth curves: is there a universal reference?. Obstet Gynecol Clin North Am. 2021; 48: 281-296 Summary Full Text Full Text PDF PubMed Scopus (2) Google Scholar interpretations of this outcome are unclear. Indeed, the authors may be capturing small-for-gestational age rather than fetal growth restriction, which may not indicate pathology. Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort studyOur results indicate that socioeconomic and ethnic inequalities were responsible for a substantial proportion of stillbirths, preterm births, and births with FGR in England. The largest inequalities were seen in Black and South Asian women in the most socioeconomically deprived quintile. Prevention should target the entire population as well as specific minority ethnic groups at high risk of adverse pregnancy outcomes, to address risk factors and wider determinants of health. Full-Text PDF

Effect of Maternal and Fetal Characteristics in Feto-Placental Doppler and Impact of Using Adjusted Standards in the Definition of Fetal Growth Restriction at Term

Introduction: This study aimed to determine the effect and clinical impact of physiological characteristics on the 95th/5th centile of the umbilical artery (UA) Doppler and the cerebroplacental ratio (CPR), at 36+ weeks. Methods: From the multicenter randomized trial “Ratio37,” we selected 4,505 low-risk pregnant women between June 2016 and January 2020. We registered physiological characteristics and the pulsatility indexes (PI) of the UA and middle cerebral artery (36–39 weeks). The 95th/5th centile of the UA PI and CPR was modeled by quantile regression. To evaluate the clinical impact of adjusting Doppler, we retrospectively applied gestational age (GA) and fully adjusted standards to 682 small for gestational age (SGA)-suspected fetuses (37 weeks) from a cohort of consecutive patients obtained between January 2010 and January 2020. Results: Several physiological characteristics significantly influenced the 95th/5th centile of the UA and CPR PI. The fully adjusted 95th centile of the UA was higher, and the 5th centile of the CPR was lower than GA-only-adjusted standards. Of the 682 SGA fetuses, 150 (22%) were classified as late fetal growth restricted only by GA and 112 (16.4%) when we adjusted Doppler. These 38 fetuses had similar perinatal outcome than the SGA group. Discussion: The 95th/5th centile of the UA and CPR PI is significantly influenced by physiological characteristics. Adjusting Doppler standards could differentiate better between FGR and SGA.

Impact of adding abdominal circumference to the definition of fetal growth restriction

Fetal growth restriction has traditionally been defined as fetuses with an estimated fetal weight <10th percentile for gestational age. In 2020, the Society for Maternal-Fetal Medicine recommended that the definition be expanded to include either an estimated fetal weight<10th percentile or a fetal abdominal circumference<10th percentile. We sought to determine the impact of adding the criterion abdominal circumference<10th percentile on the rate of diagnosis of fetal growth restriction vs using the criterion estimated fetal weight<10th percentile alone. In addition, we evaluated the definition proposed by Copel and Bahtiyar, estimated fetal weight<10th percentile or abdominal circumference<5th percentile. This was a retrospective, descriptive study from 3 consultative maternal-fetal medicine practices. Biometry was compiled from ultrasound examinations from January 2019 to July 2020. The inclusion criteria were singleton pregnancy, gestational age of ≥24 weeks, presence of fetal cardiac activity, and presence of 4 standard fetal biometry parameters (biparietal diameter, head circumference, abdominal circumference, and femur length). We tabulated the indications for the examinations and the number of examinations meeting several criteria for the diagnosis of fetal growth restriction: Traditional criterion (estimated fetal weight<10th percentile), Copel-Bahtiyar criteria (estimated fetal weight<10th percentile or abdominal circumference<5th percentile), and Society for Maternal-Fetal Medicine criteria (estimated fetal weight<10th percentile or abdominal circumference<10th percentile). During the study period, 20,633 ultrasound examinations met the inclusion criteria. In 62% of examinations, there was ≥1 factor for fetal growth restriction, and in 51% of examinations, there was ≥1 factor for large for gestational age. The rate of estimated fetal weight<10th percentile was 9.7%. The rate of abdominal circumference<5th percentile was 5.7%, and the rate of abdominal circumference<10th percentile was 9.2%. The rate of fetal growth restriction was 9.7% using the traditional definition (estimated fetal weight<10th percentile only). The rate of fetal growth restriction was 10.2% using the Copel-Bahtiyar definition (estimated fetal weight<10th percentile or abdominal circumference<5th percentile), significantly higher than using the traditional definition (P<.001). The rate of fetal growth restriction was 11.6% using the Society for Maternal-Fetal Medicine definition (estimated fetal weight<10th percentile or abdominal circumference<10th percentile), significantly higher than using either the traditional or Copel-Bahtiyar definition (P<.001 for both). Among examinations with an abdominal circumference<10th percentile, 79% also had an estimated fetal weight<10th percentile and was considered fetal growth restriction even without considering abdominal circumference. Adding the criterion abdominal circumference<5th percentile or abdominal circumference<10th percentile to the definition of fetal growth restriction resulted in a statistically significant increase in the rate of diagnosis of fetal growth restriction. However, the absolute increase in the rate was small and was not expected to place a large burden on practice resources.

Impact of Using Abdominal Circumference Independently in the Diagnosis of Fetal Growth Restriction.

Society for Maternal-Fetal Medicine guidelines for diagnosing fetal growth restriction (FGR) have broadened the definition to include abdominal circumference (AC) <10th percentile for gestational age (GA) regardless of estimated fetal weight (EFW). We aimed to compare the ability of three definitions of FGR to predict small for gestational age (SGA) neonates and adverse outcomes. We performed a secondary analysis of a prospective cohort of patients who underwent assessment of fetal growth between GA of 26 and 36 weeks. We compared three definitions of FGR: EFW <10th percentile; AC <10th percentile; either EFW or AC <10th percentile. The primary outcome was successful prediction of neonatal SGA. Secondary outcomes included a composite adverse neonatal outcome (CANO). We further compared these definitions of FGR using area under receiver operative curves (AUC) to measure their discriminatory abilities. About 1054 women met inclusion criteria. Ninety-one (8.6%) had EFW <10th percentile, 122 (11.6%) had AC <10th percentile, and 137 (12.9%) had either EFW or AC <10th percentile. SGA was seen in 139 (13.2%); CANO was seen in 139 (13.2%). Ability for detecting neonatal SGA was significantly better when the definition included both EFW or AC <10th percentile compared to either variable independently. The AUC were: 0.74, 0.73, 0.69; P= .0003. There was no statistical significance in ability for predicting CANO (AUC 0.51, 0.51, 0.50; P= .7447). Addition of AC as a criterion for diagnosing FGR improves our ability to predict neonatal SGA compared to using EFW alone. All three definitions were poorly predictive of neonates at risk for adverse outcomes.

725 Impact of using abdominal circumference independently in the diagnosis of fetal growth restriction

Recent updates to guidelines for diagnosing fetal growth restriction (FGR) have broadened the definition from estimated fetal weight (EFW)<10th percentile for gestational age to also include abdominal circumference (AC)<10th percentile for gestational age. The objective of this study is to compare these definitions of FGR to predict small for gestational age (SGA) neonates and adverse outcomes. We conducted a prospective cohort analysis of women presenting for fetal growth assessment between 26 and 36 weeks gestation (GA). We compared three definitions of FGR; EFW<10th percentile for GA by the Hadlock formula, abdominal circumference<10th percentile for GA, either EFW<10th percentile or AC<10th percentile. The primary outcome was prediction of neonatal SGA by the Alexander growth chart. Secondary outcomes included a neonatal outcome composite score. Of 1054 women meeting inclusion criteria, 91 (8.6%) were found to have EFW<10th percentile, 122 (11.6%) were found to have AC<10th percentile, and 137 (12.9%) were found to have either EFW or AC <10th percentile. SGA was seen in 139 (13.2%), and a composite adverse neonatal outcome was seen in 139 (13.2%). The overall ability for detecting neonatal SGA was significantly better when the definition included both EFW<10th percentile or AC<10th percentile compared to AC<10th percentile alone or EFW<10th percentile alone. The area under the curve and 95% confidence intervals were: 0.74, 0.70-0.78 vs 0.73, 0.68-0.77 vs 0.69, 0.65-0.73; respectively, p=0.0003. There was no statistical significance between the three definitions’ ability for predicting composite adverse neonatal outcomes (area under the curve 0.51, 95% confidence interval 0.48-0.54 vs 0.51 95% confidence interval 0.48-0.54 vs 0.50 95% confidence interval 0.47-0.53; p=0.7447). The new definition of FGR which now includes either AC or EFW <10th percentile improves our ability to detect neonatal SGA compared either parameter alone. All three definitions, however, were poor at detecting neonates who are at risk for neonatal adverse outcomes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

65 New SMFM definition of fetal growth restriction: Impact of adding AC < 10th percentile

65 New SMFM definition of fetal growth restriction: Impact of adding AC < 10th percentile

1123 Midtrimester fetal growth restriction as predictor of small for gestational age and adverse obstetrical outcomes

To assess whether fetal growth restriction (FGR), defined as estimated fetal weight (EFW) or abdominal circumference (AC) < 10th percentile, diagnosed on midtrimester anatomy scan is predictive of small for gestational age (SGA) and is associated with adverse obstetrical outcomes. This is a single center retrospective cohort study of women undergoing anatomy scan at 18-24 weeks gestation from 1/2017-12/2019. Women 18-45 years of age carrying non-anomalous singleton gestations with documented delivery outcomes were included. EFW percentile was calculated using Hadlock 85; AC percentile was calculated using Hadlock 84. Fetuses with FGR were matched with the next normal weight fetus (EFW and AC between the 10th and 90th percentiles) undergoing anatomy scan on the ultrasound schedule. The primary outcome was the rate of SGA. Secondary outcomes included the rates of abnormal genetic screening, gestational age at delivery, NICU admission, composite neonatal morbidity (hypoglycemia, hypothermia, respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, seizure, sepsis), and pregnancy related hypertensive disorders. 167 pregnancies were included in the final analysis. Fetuses with FGR were more likely to be SGA at delivery. This difference persisted across different definitions of FGR (Table 1). The sensitivity and specificity of midtrimester FGR for predicting SGA were 74.9% and 73.6%, respectively. Neonates in the FGR group were more likely to require NICU admission and to have an adverse neonatal composite outcome. Fetuses in the FGR group did not have higher rates of abnormal aneuploidy screening and were not delivered at an earlier gestational age (38.5 versus 39.0 weeks, p=0.21). Women in the FGR group were not at increased risk for pregnancy related hypertensive disorders (Table 2). Singleton fetuses with growth restriction on midtrimester anatomy scan are at increased risk of being SGA, requiring NICU admission, and experiencing adverse neonatal outcomes. However, over 48% of fetuses with midtrimester FGR achieve normal birth weight.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

782 Difference in ultrasound unit volume between birthweight and ultrasound derived definitions of fetal growth restriction

Recent guidelines recommend the use Hadlock rather than birth weight derived percentiles for diagnosis of fetal growth restriction (FGR). The objective of this study is to quantify the impact of changing from a birth weight (Williams et al.) to an ultrasound based (Hadlock et al.) percentile classification of FGR on ultrasound unit volume. We conducted a retrospective cohort study of all singleton pregnancies that presented for ultrasound ≥22 weeks’ gestation pre- and post an institutional change of FGR classification system from Williams et al. to Hadlock et al. between 2018-2020. Pregnancies with an estimated fetal weight <10% by either classification system were included in the analysis. The primary outcomes were the frequency of patient encounters, follow up examinations, biophysical profiles (BPP) ≥28 weeks, and umbilical artery (UA) Doppler assessments. Secondary outcomes were gestational age (GA) at delivery and rates of cesarean delivery, 5-minute Apgar <7, and fetal death between study years. 550 women met inclusion criteria over the study period. FGR diagnosis was discordant (FGR by Hadlock, but not Williams) in 77.6% of cases at diagnosis and in 46.9% at the last ultrasound before delivery. The median GA at FGR diagnosis was significantly earlier using Hadlock (31.9 vs 36.0 weeks; p<.001). Significant increases in the median number of encounters, BPP, UA Doppler, and total billed procedure codes were calculated between study years; Table 1. Fetal death was decreased (6.0% vs 2.1%; p=.043), but FGR diagnosis was discordant in only 4/15 cases that resulted in fetal death. No differences in GA at delivery, cesarean delivery and Apgar <7 at 5 minutes were identified between study years. Use of Hadlock results in increased rates of FGR and diagnosis at an earlier gestational age when compared to birth weight derived percentiles. This leads to a significant increase in overall ultrasound unit volume including use of UA Doppler surveillance.

Consensus Definition of Fetal Growth Restriction in Intrauterine Fetal Death: A Delphi Procedure.

Fetal growth restriction is a risk factor for intrauterine fetal death. Currently, definitions of fetal growth restriction in stillborns are heterogeneous. To develop a consensus definition for fetal growth restriction retrospectively diagnosed at fetal autopsy in intrauterine fetal death. A modified online Delphi survey in an international panel of experts in perinatal pathology, with feedback at group level and exclusion of nonresponders. The survey scoped all possible variables with an open question. Variables suggested by 2 or more experts were scored on a 5-point Likert scale. In subsequent rounds, inclusion of variables and thresholds were determined with a 70% level of agreement. In the final rounds, participants selected the consensus algorithm. Fifty-two experts participated in the first round; 88% (46 of 52) completed all rounds. The consensus definition included antenatal clinical diagnosis of fetal growth restriction OR a birth weight lower than third percentile OR at least 5 of 10 contributory variables (risk factors in the clinical antenatal history: birth weight lower than 10th percentile, body weight at time of autopsy lower than 10th percentile, brain weight lower than 10th percentile, foot length lower than 10th percentile, liver weight lower than 10th percentile, placental weight lower than 10th percentile, brain weight to liver weight ratio higher than 4, placental weight to birth weight ratio higher than 90th percentile, histologic or gross features of placental insufficiency/malperfusion). There was no consensus on some aspects, including how to correct for interval between fetal death and delivery. A consensus-based definition of fetal growth restriction in fetal death was determined with utility to improve management and outcomes of subsequent pregnancies.

Morphological and histopathological changes in placentas of pregnancies with intrauterine growth restriction.

Aim: The definition of fetal growth restriction (FGR) refers to the incapability of a fetus to achieve the appropriate estimated growth, with expected fetal weight below the 10th percentile calculated for its gestational age. Placental factors and hypoxemia are considered to be essential elements with influence on intrauterine growth restriction (IUGR) and fetal death. The purpose of the present study was to investigate the macroscopic and microscopic pathological findings regarding the placentas in pregnancies complicated by influence on IUGR. Patients, Materials and Methods: Our study included 42 third-trimester pregnant patients admitted to the Cuza Vodă Hospital of Obstetrics and Gynecology, Iaşi, Romania, in the last three years. Soon after delivery, the 42 placentas were collected and analyzed; 32 placentas came from cases previously diagnosed with influence on IUGR and were included in our study group. Ten other placentas included in the control group were selected from uncomplicated pregnancies. Standard Hematoxylin–Eosin (HE) staining method, as well as Periodic Acid–Schiff (PAS) staining, and immunohistochemical techniques for cluster of differentiation 31 (CD31) and collagen IV were used in order to highlight the morphological features of the studied placentas. Results: Our study revealed that reduced placental dimensions and eccentric umbilical cord insertion are correlated with the birthweight of the fetuses with IUGR (p<0.05). The most common histological finding in our study group was placental infarction later correlated with IUGR, but a certain causality could not be demonstrated, as this finding was also present in normal pregnancies. Other histopathological findings were also present in the influence on IUGR group, such as fibrin deposits, diffuse calcification, chronic villitis, avascular chronical villi, with no significant statistical correlations. CD31 was strongly immunoexpressed in the villous endothelial cells. Collagen IV presented a strong immunoreaction in the basement membrane and mesenchyme of the placental villi. Conclusions: Our study revealed a correlation between the dimensions of the diameters and volume of the maternal placenta and the presence of influence on IUGR. Moreover, it confirms the available data suggesting that the place of insertion of the umbilical cord is correlated with the weight of the fetus. Further studies with extended panel antibodies are needed in order to determine and complete the role of these morphological changes in the development of influence on IUGR.

Consensus Based Definition of Growth Restriction in the Newborn

To develop a consensus definition of growth restriction in the newborn that can be used clinically to identify newborn infants at risk and in research to harmonize reporting and definition in the current absence of a gold standard. An international panel of pediatric leaders in the field of neonatal growth were invited to participate in an electronic Delphi procedure using standardized methods and predefined consensus rules. Responses were fed back at group-level and the list of participants was provided. Nonresponders were excluded from subsequent rounds. In the first round, variables were scored on a 5-point Likert scale; in subsequent rounds, inclusion of variables and cut-offs were determined with a 70% level of agreement. In the final round participants selected the ultimate algorithm. In total, 57 experts participated in the first round; 79% completed the procedure. Consensus was reached on the following definition: birth weight less than the third percentile, or 3 out of the following: birth weight <10th percentile; head circumference <10th percentile; length <10th percentile; prenatal diagnosis of fetal growth restriction; and maternal pregnancy information. Consensus was reached on a definition for growth restriction in the newborn. This definition recognizes that infants with birth weights <10th percentile may not be growth restricted and that infants with birth weights >10th percentile can be growth restricted. This definition can be adopted in clinical practice and in clinical trials to better focus on newborns at risk, and is complementary to the previously determined definition of fetal growth restriction.

Individualized growth assessment: conceptual framework and practical implementation for the evaluation of fetal growth and neonatal growth outcome

Fetal growth abnormalities can pose significant consequences on perinatal morbidity and mortality of nonanomalous fetuses. The most widely accepted definition of fetal growth restriction is an estimated fetal weight less than the 10th percentile for gestational age according to population-based criteria. However, these criteria do not account for the growth potential of an individual fetus, nor do they effectively separate constitutionally small fetuses from ones that are malnourished. Furthermore, conventional approaches typically evaluate estimated fetal weight at a single time point, rather than using serial scans, to evaluate growth. This article provides a conceptual framework for the individualized growth assessment of a fetus/neonate based on measuring second-trimester growth velocity of fetal size parameters to estimate growth potential. These estimates specify size models that generate individualized third-trimester size trajectories and predict birth characteristics. Comparisons of measured and predicted values are used to separate normally growing fetuses from those with growth abnormalities. This can be accomplished with individual anatomical parameters or sets of parameters. A practical and freely available software (Individualized Growth Assessment Program) has been developed to allow implementation of this approach for clinical and research purposes.

What Do We Know about Risk Factors for Fetal Growth Restriction in Africa at the Time of Sustainable Development Goals? A Scoping Review.

The reduction in the under-5 year mortality rate to at least as low as 25 per 1000 livebirths by 2030 has been implemented as one of the new Sustainable Development Goals. Fetal growth restriction (FGR) is one of the most important determinants of infant mortality in developing countries. In this review, we assess the extent of the literature and summarize its findings on the main preventable factors of FGR in Africa. A scoping review was conducted using the Arksey and O'Malley framework. Five bibliographic databases and grey literature were used to identify studies assessing at least one risk factor for FGR. Aggregate risk estimates for the main factors associated with FGR were calculated. Forty-five of a total of 671 articles were selected for the review. The prevalence of FGR varied between 2.6 and 59.2% according to both the African region and the definition of FGR. The main preventable factors reported were a low maternal nutritional status (aggrerate odds ratio [OR]: 2.28, 95% confidence interval [CI] 1.59, 3.25), HIV infection (aOR 1.86, 95% CI 1.38, 2.50), malaria (aOR 1.95, 95% CI 1.04, 3.66), and gestational hypertension (aOR 2.61, 95% CI 2.42, 2.82). FGR is, to a large extent, preventable through existing efficacious interventions dedicated to malaria, HIV and nutrition. Further studies are still needed to assess the influence of risk factors most commonly documented in high-income countries. Improving research on FGR in Africa requires a consensual and standardized definition of FGR-for a higher comparability-between studies and settings.

Risk assessment of intrauterine growth restriction

Intrauterine growth restriction is a condition where the estimated fetal weight is less than the 10th percentile on ultrasound and the fetus has not attained its biologically determined growth potential because of a pathologic process. This review deals with the definitions of fetal growth restriction, the etiology associated with it, the types of fetal growth restriction and discusses how to differentiate between them. The various screening mechanisms available, the approach to a patient who is at risk for fetal growth restriction and whether they will benefit from any of the prophylactic measures available are also discussed.

Consensus definition of fetal growth restriction: a Delphi procedure.

To determine, by expert consensus, a definition for early and late fetal growth restriction (FGR) through a Delphi procedure. A Delphi survey was conducted among an international panel of experts on FGR. Panel members were provided with 18 literature-based parameters for defining FGR and were asked to rate the importance of these parameters for the diagnosis of both early and late FGR on a 5-point Likert scale. Parameters were described as solitary parameters (parameters that are sufficient to diagnose FGR, even if all other parameters are normal) and contributory parameters (parameters that require other abnormal parameter(s) to be present for the diagnosis of FGR). Consensus was sought to determine the cut-off values for accepted parameters. A total of 106 experts were approached, of whom 56 agreed to participate and entered the first round, and 45 (80%) completed all four rounds. For early FGR (< 32 weeks), three solitary parameters (abdominal circumference (AC) < 3(rd) centile, estimated fetal weight (EFW) < 3(rd) centile and absent end-diastolic flow in the umbilical artery (UA)) and four contributory parameters (AC or EFW < 10(th) centile combined with a pulsatility index (PI) > 95(th) centile in either the UA or uterine artery) were agreed upon. For late FGR (≥ 32 weeks), two solitary parameters (AC or EFW < 3(rd) centile) and four contributory parameters (EFW or AC < 10(th) centile, AC or EFW crossing centiles by > two quartiles on growth charts and cerebroplacental ratio < 5(th) centile or UA-PI > 95(th) centile) were defined. Consensus-based definitions for early and late FGR, as well as cut-off values for parameters involved, were agreed upon by a panel of experts. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.