Estimated Fetal Weight Percentile Research Articles

Predictive ability of fetal growth charts in identifying kindergarten-age developmental challenges: a cohort study

BackgroundThe Society for Maternal-Fetal Medicine recommends defining fetal growth restriction as an estimated fetal weight or abdominal circumference below the 10th percentile of a population-based reference. However, as multiple references are available, an understanding of their ability to identify infants at increased risk due to fetal growth restriction is critical. Previous studies have focus on the ability of different population references to identify short-term outcomes, but fetal growth restriction also has longer-term consequences for child development. ObjectivesTo estimate the association between estimated fetal weight (EFW) percentiles on the INTERGROWTH-21st and WHO fetal growth charts and kindergarten-age childhood development, and establish the charts’ discriminatory ability in predicting kindergarten-age developmental challenges. Study DesignWe conducted a retrospective cohort study linking obstetrical ultrasound scans conducted at BC Women's Hospital, Vancouver, Canada, with population-based standardized kindergarten test results.The cohort was limited to non-anomalous, singleton fetuses scanned ≥ 28 weeks’ gestation, 2000-2011, with follow-up to 2017.We classified EFWs into percentiles using the INTERGROWTH-21st and WHO charts. We used generalized additive modelling to link EFW percentile with routine province-wide kindergarten readiness test results. We calculated the area under the receiver-operating characteristic curve (AUC), as well as other measures of diagnostic accuracy with 95% confidence intervals (CI) at select percentile cut-points of the charts. We repeated analyses using the Hadlock chart to help contextualize findings.The main outcome measure was the total Early Development Instrument (EDI) score (/50). Secondary outcomes were EDI sub-domain scores for language and cognitive development, and for communication skills and general knowledge; designation of ‘developmentally vulnerable’ or ‘special needs’. ResultsAmong 3418 eligible fetuses, those with lower EFW percentiles had systematically lower EDI scores and increased risks of developmental vulnerability. However, the clinical significance of differences was modest in magnitude: e.g., total EDI score -2.8 [95% CI: -5.1, -0.5] in children with an EFW 3-9th percentile of INTERGROWTH chart (vs. reference of 31-90th). The charts’ predictive abilities for adverse child development were limited (e.g., AUC<0.53 for all 3 charts). ConclusionsLower EFW percentiles on the INTERGROWTH-21st and WHO charts indicate increased risks of adverse kindergarten-age child development at the population level, but are not accurate individual-level predictors of adverse child development.

Intrauterine Growth Restriction-Prediction and Peripartum Data on Hospital Care.

Background and Objectives: We aimed to prospectively obtain data on pregnancies complicated with intrauterine growth restriction (IUGR) in the Prenatal Diagnosis Unit of the Emergency County Hospital of Craiova. We collected the demographic data of mothers, the prenatal ultrasound (US) features, the intrapartum data, and the immediate postnatal data of newborns. We aimed to assess the detection rates of IUGR fetuses (the performance of the US in estimating the actual neonatal birth weight), to describe the prenatal care pattern in our unit, and to establish predictors for the number of total hospitalization days needed postnatally. Materials and Methods: Data were collected from cases diagnosed with IUGR undergoing prenatal care in our hospital. We compared the percentile of estimated fetal weight (EFW) using the Hadlock 4 technique with the percentile of weight at birth. We retrospectively performed a regression analysis to correlate the variables predicting the number of hospitalization days. Results: Data on 111 women were processed during the period of 1 September 2019-1 September 2022. We confirmed the significant differences in US features between early- (Eo) and late-onset (Lo) IUGR cases. The detection rates were higher if the EFW was lower, and Eo-IUGR was associated with a higher number of US scans. We obtained a mathematical formula for estimating the total number of hospitalization days needed postnatally. Conclusion: Early- and late-onset IUGR have different US features prenatally and different postnatal outcomes. If the US EFW percentile is lower, a prenatal diagnosis is more likely to be made, and a closer follow-up is offered in our hospital. The total number of hospitalization days may be predicted using intrapartum and immediate postnatal data in both groups, having the potential to optimize the final financial costs and to organize the neonatal department efficiently.

Impact of fetal biparietal diameter greater than 10 centimeters on mode of delivery

To evaluate the relationship between fetal biparietal diameter (BPD) greater than 10 cm on prenatal ultrasound and likelihood of successful vaginal delivery. This was a secondary analysis of a retrospective cohort of pregnancies resulting in delivery of live singleton fetuses at a single tertiary-care hospital 2007-2019, from which mode of delivery and biometry measurements from ultrasounds performed at 28-42 weeks’ gestation were available. Delivery outcomes of patients with fetal BPD >10cm in the third trimester were compared to those with BPD < 10cm. Generalized linear models were used to evaluate risk of vaginal delivery, adjusting for estimated fetal weight (EFW) percentile and gestational age at the time of ultrasound assessment. 17,402 pregnancies met inclusion criteria, of which 155 (0.89%) had a BPD >10.0 cm on ultrasound at 28-42 weeks and a known mode of delivery. Vaginal delivery occurred less often (33.93%) in pregnancies with a BPD >10.0 cm compared to those with BPD measurements < 10.0 cm (67.52%, p = < 0.01). However, after controlling for gestational age at ultrasound assessment and calculated EFW percentile, the relationship between vaginal delivery and BPD >10.0 cm was no longer statistically significant (RR 0.71 [95% CI 0.50-1.01], p=0.059). After adjusting for gestational age at ultrasound assessment and EFW percentile, Pregnancies with an increased fetal BPD >10 cm on third trimester ultrasound were as likely to achieve vaginal birth as those with a BPD < 10cm. This suggests that pregnancies with elevated fetal biparietal diameters should not be discouraged from attempting vaginal birth in absence of other contraindications to a trial of labor.

Routine Ultrasound at 30th–33rd weeks versus 30th–33rd and 35th–37th weeks in Low-Risk Pregnancies: A Randomized Trial

Introduction: The aim of this study was to evaluate the accuracy of 35–37 weeks’ ultrasound for fetal growth restriction (FGR) detection and the impact of 30th–33rd weeks versus 30th–33rd and 35th–37th weeks’ ultrasound on perinatal outcomes. Methods: This was a randomized controlled trial that enrolled 1,061 low-risk pregnant women: 513 in the control group (routine ultrasound performed at 30th–33rd weeks) and 548 in the study group (with an additional ultrasound at 35th–37th weeks). FGR was defined as a fetus with an estimated fetal weight (EFW) below the 10th percentile. p values < 0.05 were considered statistically significant. Results: The ultrasound at 35–37 weeks had an overall accuracy of FGR screening of 94%. Spearman’s correlation coefficient between EFW and birthweight centile was higher for at 35–37 weeks’ ultrasound (ρ = 0.75) compared with 30–33 weeks’ ultrasound (ρ = 0.44). The study group had a lower rate of operative vaginal deliveries (24.4% vs. 39.3%, p = 0.005) and cesarean deliveries for nonreassuring fetal status (16.8% vs. 38.8%, p < 0.001). Discussion/Conclusion: A later ultrasound (35–37 weeks) had a high accuracy for detection of FGR and had a higher correlation between EFW and birthweight centiles. Furthermore, it was also associated with lower adverse perinatal outcomes compared to an earlier ultrasound.

Usefulness of angiogenic factors in prenatal counseling of late-onset fetal growth-restricted and small-for-gestational-age gestations: a prospective observational study.

To create a predictive model including biomarkers and evaluate its ability to predict adverse perinatal outcomes in late-onset small fetuses, ultimately helping to provide individualized counseling at the time of diagnosis. This was a prospective observational study, including singleton pregnancies with an estimated fetal weight (EFW) below the 10th percentile, at a gestational age between 32 + 0 and 36 + 6weeks of gestation (WG). Variables recorded at diagnosis to predict adverse pregnancy outcomes were: soluble fms-like tyrosine-kinase-1 to placental growth factor ratio (sFlt-1/PlGF), fetal Doppler (umbilical artery and middle cerebral artery), uterine artery pulsatility index (UtAPI), EFW percentile, gestational age, and the presence of maternal risk factors for placental insufficiency. Logistic regression models were developed for the prediction of three co-primary outcomes: composite adverse perinatal outcomes (APO), and the need for elective delivery before 35 or 37 WG. Sixty (52.2%) fetal growth restricted (FGR) and 55 (47.8%) small for gestational age (SGA) were enrolled. Thirteen (11.3%) women needed elective delivery before 35 WG and 27 (23.5%) women before 37 WG. At least one APO occurred in 43 (37.4%) pregnancies. The best marker in univariate analyses was the sFlt-1/PlGF ratio [AUC = 0.932 (95% CI, 0.864-0.999)]. The multivariate model including sFlt-1/PlGF showed a better predictive performance for APO than the multivariate model without sFlt-1/PlGF (P < 0.024). sFlt-1/PlGF is a good predictor of APO at the time of late-onset FGR/SGA diagnosis. Our predictive models may be useful to provide early individualized prenatal counseling in this group of women. Further studies are needed to validate these preliminary findings in a larger cohort.

Impact of chemotherapy during pregnancy on fetal growth

Background Chemotherapy crosses the placenta, however, it remains unclear to what extent it affects fetal growth. The current literature suggests up to 21% of the offspring of women receiving chemotherapy are small for gestational age (SGA, birth weight <10th percentile). Limiting research to birth weights only might misjudge fetal growth restriction (FGR) in this high-risk population with multiple risk factors for impaired fetal growth. Moreover, the role of the duration of chemotherapy and gestational age at initiation of chemotherapy in fetal growth is yet poorly understood. Objective This retrospective cohort study evaluates fetal growth and neonatal birthweights in pregnant women receiving chemotherapy. Study design All pregnant patients, registered by the International Network of Cancer, Infertility and Pregnancy (INCIP), treated with chemotherapy with at least two ultrasounds reporting on fetal growth, were eligible for this study. Duration and gestational age at initiation of chemotherapy were our major determinants, followed by cancer type and stage, maternal characteristics (parity, BMI, ethnicity hypertension, and diabetes) and individual cytotoxic agents (anthracycline, taxanes, and platinum). Fetal growth outcomes were described using the following mutually exclusive groups (1) FGR, based on a Delphi consensus (2016); (2) “low risk SGA” (birth weight below the 10th percentile), but an estimated growth above the 10th percentile; (3) “fetal growth disturbance”, which did not meet all FGR criteria; (4) “non-FGR”. Obstetric and oncological characteristics were compared between the growth impaired groups and non-FGR group. We calculated estimated fetal weight (EFW) according to Hadlock’s formula (1991) and birth weight percentile according to Nicolaides (2018). We used univariable and multivariable regression, and linear mixed effect models to investigate the effect of duration and gestational age at initiation of chemotherapy on birth weight, and fetal growth, respectively. Results We included 201 patients, diagnosed with cancer between March 2000 and March 2020. Most patients were diagnosed with breast cancer (n = 132, 66%). Regimens included anthracyclines (n = 121, 60%), (anthracyclines and) taxanes (n = 45, 22%) and platinum (n = 35, 17%). Fetal growth abnormalities were detected in 75 pregnancies: 43 (21%) FGR, 10 (5%) low risk SGA and 22 (8.5%) fetal growth disturbance. Chemotherapy prior to 20 weeks of gestation (47% vs. 25%, p = .04) and poor maternal gestational weight gain (median percentile 15 (range 0–97) vs. 8 (0–84), p = .03) were more frequent in the FGR group compared to the non-FGR group, whereas no difference was seen for specific chemotherapy or cancer types. Univariable regression identified gestational weight gain, hypertension, systemic disease, parity, neonatal sex and maternal BMI as confounders for birth weight percentiles. Multivariable regression revealed that each additional week of chemotherapy was associated with lower birth weight percentiles (–1.06; 95%CI −2.01; −0.04; p = .04), and that later initiation of chemotherapy was associated with an increase in birth weight percentile (1.10 per week; 95%CI 0.26; 1.95; p = .01). Each additional week of chemotherapy was associated with lower EFW and abdominal circumference (AC) percentiles (–1.77; 95%CI −2.21; −1.34, p < .001; −1.64; 95%CI −1.96; –1.32, p < .001, respectively). Conclusions This study demonstrates that FGR is common after chemotherapy in pregnancy, and that the duration of chemotherapy has a negative impact. Sonographic follow-up of fetal growth and well-being is recommended.

Prediction of Neonatal Growth Restriction in Fetuses With Gastroschisis by Early Third Trimester Ultrasonography Utilizing Contemporary Birth Weight Percentiles.

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. 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. 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. 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.

Detection of small- and large-for-gestational age using different combinations of prenatal and postnatal charts.

To determine the extent to which the detection rate of small-for-gestational age (SGA) and large-for-gestational age (LGA) at birth is influenced by the use of different combinations of estimated-fetal-weight (EFW) and birth-weight (BW) charts. This was a cohort study of all pregnant women with a singleton term birth receiving care in a university hospital during a 3-year period. All participants underwent a universal 36-week ultrasound scan for EFW measurement and had BW recorded at delivery. Five different reference charts were used for EFW and BW centile calculation. Two-by-two contingency tables were constructed using EFW as the screening test variable and BW as the outcome variable in order to calculate sensitivity, specificity, positive predictive value (PPV) and negative predictive value for all possible chart combinations. The cohort included 17 678 pregnancies. The sensitivity of EFW < 10th centile for the detection of BW < 10th centile ranged from 10.8% to 66.8% and the sensitivity of EFW < 3rd centile for the detection of BW < 3rd centile ranged from 4.1% to 66.8%, depending on the charts used. The sensitivity of EFW > 90th centile for BW > 90th centile ranged between 22.9% and 68.3%. When locally derived charts for EFW and BW were used, the sensitivity of detection of BW < 10th centile using EFW < 10th centile was 43.7% (PPV, 45.5%); for the detection of BW < 3rd centile using EFW < 3rd centile, the sensitivity was 25.6% (PPV, 26.7%) and, for the detection of BW > 90th centile using EFW > 90th centile, it was 49.6% (PPV, 49.0%). Different combinations of EFW and BW charts can yield vastly different detection rates (sensitivity) in the same population cohort and time period. If SGA and LGA detection rates are to be used as a meaningful performance indicator, healthcare systems should follow a clear and predefined methodology that includes explicit definitions of common reference standards. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Greater estimated fetal weight and birth weight in IVF/ICSI pregnancy after frozen-thawed vs fresh blastocyst transfer: prospective cohort study with novel unified modeling methodology.

To compare, using a unified approach, standardized estimated fetal weight (EFW) trajectories from the second trimester to birth and birth-weight (BW) measurements in in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancies obtained after frozen-thawed vs fresh blastocyst transfer (BT). This was a secondary analysis of a prospective longitudinal cohort study performed at the Fetal Medicine and Obstetric Departments of San Raffaele Hospital in Milan, Italy, from January 2016 to December 2020. Eligible for inclusion were singleton viable gestations conceived by autologous IVF/ICSI conception after fresh or frozen-thawed BT that underwent standard fetal biometry assessment at 19-41 weeks and had BW measurements available. All ultrasound assessments were performed by operators blinded to the employment of cryopreservation. Patients with twin gestation, significant pregestational disease, miscarriage, major fetal abnormalities and use of other types of medically assisted reproduction techniques were excluded. EFW and BW Z-scores and their trajectories were analyzed using general linear models (GLM) and logistic regression with a unified modeling methodology based on the Fetal Medicine Foundation fetal and neonatal population weight charts, adjusting for major confounders. Differences between prenatal EFW and postnatal BW centiles in the two groups were assessed and compared using contingency tables, χ2 test and conversion of prenatal to postnatal centiles. A total of 631 IVF/ICSI pregnancies were considered, comprising 263 conceived following fresh BT and 368 after frozen-thawed BT. A total of 1795 EFW observations were available (n = 715 in fresh BT group and n = 1080 in frozen-thawed BT group; median of three observations per patient). EFW and BW < 10th centile were significantly more frequent in the fresh than in the frozen-thawed BT group (P = 0.003 and P < 0.001, respectively). EFW and BW > 90th centile were significantly more frequent in the frozen-thawed vs fresh BT group (P = 0.034 and P = 0.002, respectively). GLM showed significantly decreasing EFW Z-scores with advancing gestational age (GA) in both groups. The effect of GA was assumed to be equal in the two study groups, as no significant interaction effect was found. Smoothed mean EFW Z-scores from 19 weeks of gestation to term and smoothed mean BW Z-scores were both significantly higher in the frozen-thawed compared with the fresh BT group (EFW Z-score, 0.70 ± 1.29 vs 0.28 ± 1.43; P < 0.001; BW Z-score, 0.04 ± 1.08 vs -0.31 ± 1.28; P < 0.001). Mean smoothed EFW Z-score values in the frozen-thawed vs fresh BT groups were 1.01 ± 0.12 vs 0.60 ± 0.08 at 19-27 weeks, 0.36 ± 0.07 vs -0.06 ± 0.04 at 28-35 weeks and -0.66 ± 0.01 vs -0.88 ± 0.02 at 36-41 weeks. Mean smoothed BW Z-score values in the frozen-thawed vs fresh BT groups were -0.80 ± 0.14 vs -1.20 ± 0.10 at 28-35 weeks and 0.22 ± 0.16 vs -0.24 ± 0.14 at 36-41 weeks. Assessment of EFW and BW concordance showed a significantly greater rate of postnatal confirmation of prenatally predicted small-for-gestational age (SGA) < 10th centile in the fresh compared with the frozen-thawed BT group (P < 0.001), whereas the rate of postnatal confirmation of large-for-gestational age (LGA) > 90th centile was significantly higher in the frozen-thawed vs the fresh BT group (P < 0.001). Logistic regression analysis showed that the smoothed rate of EFW < 3rd centile was about 6-fold higher in the fresh vs frozen-thawed BT group (P < 0.001), whereas the smoothed rates of EFW 90th -97th centile and > 97th centile were nearly double in the frozen-thawed compared with the fresh BT group (P < 0.05 and P < 0.001, respectively). Robust novel unified prenatal-postnatal modeling in IVF/ICSI pregnancies after frozen-thawed or fresh BT from 19 weeks of gestation to birth showed non-divergent growth trajectories, with higher EFW and BW Z-scores in the frozen-thawed vs fresh BT group. The mean EFW Z-scores in both IVF/ICSI groups were greater than those expected for natural conceptions, being highest in the midtrimester and decreasing with advancing gestation in both groups, becoming negative after 32 weeks in the fresh and after 35 weeks in the frozen-thawed BT group. Mean BW Z-scores were negative in both groups, with lower values in preterm fetuses, and increased with advancing gestation, becoming positive at term in the frozen-thawed BT group. IVF/ICSI conceptions from frozen-thawed as compared to fresh BT presented increased rate of LGA and reduced rate of SGA both prenatally and postnatally. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Cerebroplacental Ratio Prediction of Intrapartum Fetal Compromise according to the Interval to Delivery

Introduction: A controversy exists about the accuracy of the cerebroplacental ratio (CPR) for the prediction of cesarean section for intrapartum fetal compromise (CS-IFC). Our aim was to evaluate whether the interval to delivery modifies the accuracy of CPR either as a single marker or combined with estimated fetal weight centile (EFWc), type of labor onset (TLO), and other clinical variables. Methods: This was a multicenter retrospective study of 5,193 women with singleton pregnancies who underwent an ultrasound scan at 35⁺⁰–41⁺⁰ weeks and gave birth within 1 month of examination, at any of the participating hospitals in Spain, UK, and Italy. CS-IFC was diagnosed in case of an abnormal intrapartum fetal heart rate or intrapartum fetal scalp pH <7.20, requiring urgent cesarean section. The diagnostic ability of CPR in multiples of the median (CPR MoM) was evaluated at different intervals to delivery, alone and combined with EFWc, TLO, and other pregnancy data such as maternal age, maternal body mass index, parity, and fetal sex, for the prediction of CS-IFC by means of ROC curves and logistic regression analysis. Results: The predictive ability of CPR MoM for CS-IFC worsened with the interval to delivery. In general, the best prediction was obtained prior to labor and by adding information related to EFWc and TLO (AUC 0.71 [95% CI: 0.64–0.79], 0.73 [95% CI: 0.66–0.80], and 0.75 [95% CI: 0.69–0.81]; p < 0.0001). Addition of more clinical data did not improve prediction. In addition, results did not vary when only cases with spontaneous onset of labor were studied. Conclusion: CPR MoM prediction of CS-IFC at the end of pregnancy worsens with the interval to delivery. Accordingly, it should be done in the short term and considering EFWc and TLO.

Ultrasound prediction of adverse perinatal outcome at diagnosis of late-onset fetal growth restriction.

ABSTRACTObjectiveTo evaluate the relationship between Doppler and biometric ultrasound parameters measured at diagnosis and perinatal adverse outcome in a cohort of late‐onset growth‐restricted (FGR) fetuses.MethodsThis was a multicenter retrospective study of data obtained between 2014 and 2019 including non‐anomalous singleton pregnancies complicated by late‐onset FGR (≥ 32 weeks), which was defined either as abdominal circumference (AC) or estimated fetal weight (EFW) < 10th percentile for gestational age or as reduction of the longitudinal growth of AC by over 50 percentiles compared to ultrasound scan performed between 18 and 32 weeks of gestation. We evaluated the association between sonographic findings at diagnosis of FGR and composite adverse perinatal outcome (CAPO), defined as stillbirth or at least two of the following: obstetric intervention due to intrapartum fetal distress, neonatal acidemia, birth weight < 3rd percentile and transfer to the neonatal intensive care unit (NICU).ResultsOverall, 468 cases with complete biometric and umbilical, fetal middle cerebral and uterine artery (UtA) Doppler data were included, of which 53 (11.3%) had CAPO. On logistic regression analysis, only EFW percentile was associated independently with CAPO (P = 0.01) and NICU admission (P < 0.01), while the mean UtA pulsatility index (PI) multiples of the median (MoM) > 95th percentile at diagnosis was associated independently with obstetric intervention due to intrapartum fetal distress (P = 0.01). The model including baseline pregnancy characteristics and the EFW percentile was associated with an area under the receiver‐operating‐characteristics curve of 0.889 (95% CI, 0.813–0.966) for CAPO (P < 0.001). A cut‐off value for EFW corresponding to the 3.95th percentile was found to discriminate between cases with and those without CAPO, yielding a sensitivity of 58.5% (95% CI, 44.1–71.9%), specificity of 69.6% (95% CI, 65.0–74.0%), positive predictive value of 19.8% (95% CI, 13.8–26.8%) and negative predictive value of 92.9% (95% CI, 89.5–95.5%).ConclusionsRetrospective data from a large cohort of late‐onset FGR fetuses showed that EFW at diagnosis is the only sonographic parameter associated independently with the occurrence of CAPO, while mean UtA‐PI MoM > 95th percentile at diagnosis is associated independently with intrapartum distress leading to obstetric intervention. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Prediction of SGA at anatomy ultrasound: EFW percentiles and estimated due date difference

Fetal growth restriction (FGR) is defined as estimated fetal weight (EFW) < 10th percentile. However, the clinical significance of EFW < 10th percentile at anatomy ultrasound is unclear. Our goal is to describe two different methods to diagnose early FGR at the anatomy ultrasound, by EFW percentile or by day difference between established Estimated Due Date (EDD) and EDD by anatomy ultrasound.

Does percentile decline of estimated fetal weight, within the normal range, affect pregnancy outcome?

Intrauterine growth restriction is related to adverse pregnancy outcome. However, there are sparse data regarding the decline in estimated fetal weight (EFW) percentile throughout the pregnancy, while remaining within the normal range. Our purpose was to evaluate whether decrease of EFW percentiles within the normal range of the 10th to the 90th percentile, influences obstetric or neonatal outcomes.

Third trimester Sonographic estimated fetal weight - What factors affect its’ accuracy

Third trimester estimated fetal weight (EFW) is part of fetal wellbeing evaluating. This study aimed to evaluate factors which influence the accuracy of EFW percentile measured in the third trimester compared to the actual delivery weight (ADW) percentile.

Impact of Selection of Growth Chart in the Diagnosis of Suboptimal Fetal Growth and Neonatal Birthweight and Correlation with Adverse Neonatal Outcomes in a Third Trimester South Indian Antenatal Cohort; A Prospective Cross-Sectional Study

AbstractObjectives: To compare fetal and neonatal growth charts pertaining to different models (population-specific, universal reference, universal standard and fully customised) in detecting suboptimal fetal growth in the third trimester. Methods: This was a prospective observational study conducted at two fetal medicine centers. After applying the inclusion criteria [singleton pregnancies between 28 and 40 weeks, verified dates and estimated fetal weight (EFW) ≤ 25th centile as per the Hadlock chart], 292 women were consecutively recruited. Four fetal growth charts (Hadlock, Intergrowth, fully customised GROW, Sonocare) and three neonatal charts (Fenton, Intergrowth and fully customised GROW) were used in the study. The EFW and birthweight centiles were categorized into three groups: &lt; 3.0, 3.1–10th and &gt; 10th centiles. The charts were evaluated by their ability to detect pregnancies with uteroplacental insufficiency and/or development of adverse neonatal outcomes in the third trimester. Results: Significant difference was noted between the fetuses/neonates assigned as &lt; 3rd centile (Hadlock-9.3%, Sonocare-4.8%, Intergrowth- 6.8% and the fully customised GROW- 6.5%) and the neonatal charts (Fenton-18.5%, Intergrowth- 20.2% and fully customised GROW- 13.4%). At a cut-off of 3rd centile, the GROW chart had the highest sensitivity (84.2%) followed by Intergrowth (78.9%), Hadlock (70.37%) and Sonocare (64.29%). Similarly, for a cut-off of &lt; 10th, the sensitivity was GROW 70.27%, Sonocare 64%, Intergrowth 60.8% and Hadlock 50%. Amongst the neonatal charts, fully customised GROW chart had the greatest detection rate (&lt; 3rd = 74.36%, &lt; 10th = 70.27%). However, there was no significant difference between the charts in the detection of pregnancies with suboptimal fetal growth associated with uteroplacental insufficiency and/or adverse neonatal outcomes. Conclusion: Despite substantial discrepancy between the growth charts in diagnosing fetal smallness, adding multivessel Doppler negates significant differences between them in diagnosing suboptimal fetal growth associated with uteroplacental insufficiency and adverse neonatal outcomes.

Reduced fetal growth velocity precedes antepartum fetal death.

To determine whether decreased fetal growth velocity precedes antepartum fetal death and to evaluate whether fetal growth velocity is a better predictor of antepartum fetal death compared to a single fetal biometric measurement at the last available ultrasound scan prior to diagnosis of demise. This was a retrospective, longitudinal study of 4285 singleton pregnancies in African-American women who underwent at least two fetal ultrasound examinations between 14 and 32 weeks of gestation and delivered a liveborn neonate (controls; n = 4262) or experienced antepartum fetal death (cases; n = 23). Fetal death was defined as death diagnosed at ≥ 20 weeks of gestation and confirmed by ultrasound examination. Exclusion criteria included congenital anomaly, birth at < 20 weeks of gestation, multiple gestation and intrapartum fetal death. The ultrasound examination performed at the time of fetal demise was not included in the analysis. Percentiles for estimated fetal weight (EFW) and individual biometric parameters were determined according to the Hadlock and Perinatology Research Branch/Eunice Kennedy Shriver National Institute of Child Health and Human Development (PRB/NICHD) fetal growth standards. Fetal growth velocity was defined as the slope of the regression line of the measurement percentiles as a function of gestational age based on two or more measurements in each pregnancy. Cases had significantly lower growth velocities of EFW (P < 0.001) and of fetal head circumference, biparietal diameter, abdominal circumference and femur length (all P < 0.05) compared to controls, according to the PRB/NICHD and Hadlock growth standards. Fetuses with EFW growth velocity < 10th percentile of the controls had a 9.4-fold and an 11.2-fold increased risk of antepartum death, based on the Hadlock and customized PRB/NICHD standards, respectively. At a 10% false-positive rate, the sensitivity of EFW growth velocity for predicting antepartum fetal death was 56.5%, compared to 26.1% for a single EFW percentile evaluation at the last available ultrasound examination, according to the customized PRB/NICHD standard. Given that 74% of antepartum fetal death cases were not diagnosed as small-for-gestational age (EFW < 10th percentile) at the last ultrasound examination when the fetuses were alive, alternative approaches are needed to improve detection of fetuses at risk of fetal death. Longitudinal sonographic evaluation to determine growth velocity doubles the sensitivity for prediction of antepartum fetal death compared to a single EFW measurement at the last available ultrasound examination, yet the performance is still suboptimal. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Third trimester ultrasound estimated fetal weight for increasing prenatal prediction of small-for-gestational age newborns in low-risk pregnant women

Aim The early detection of small-for-gestational age (SGA) fetuses and newborns is pivotal in the prevention of perinatal mortality. Objectives To compare the predictive capability of performing ultrasound-based estimated fetal weight (EFW) at 32 versus 36 weeks’ gestation on the detection rate of SGA fetuses and SGA newborns at delivery, and to find a better cutoff level to consider a fetus at risk of being born small. Material and methods Nine hundred fifteen low-risk pregnant women were assessed at both 32 and 36 weeks’ gestation. EFW centile was calculated in both occasions. The rate of SGA fetuses was compared. SGA fetuses were considered when both abdominal circumference (AC) and EFW were below the 10th centile from a total of 488 delivered at our Hospital. Paired comparisons between ultrasound at 32 and 36 weeks’ gestation were done to predict SGA at delivery. Percentages of SGA fetuses were compared by chi-squared test. ANOVA test was used for comparing centiles among groups. Receiver operating characteristic (ROC) curve was used to find the best cutoff ultrasound centile to predict SGA at delivery. Statistical significance was previously set at 95% level (p < .05). Results Ultrasound-based EFW at 32 weeks showed 23 cases of SGA (2.5%) while at 36 weeks this rate increased up to 4% (37/915) (p < .000001). When comparing both outcomes, 2.8% of those catalogued as adequate-for-gestational age (AGA) at 32 weeks were cases of SGA at 36 weeks. In addition, 47.8% of those diagnosed as SGA were not confirmed at 36 weeks. Only 12.3% of SGA neonates were identified at 32 weeks’ gestation ultrasound, while using the 36 weeks’ gestation approach this rate increased up to 30.9%. So, only a low proportion of SGA neonates were SGA fetuses at any of these two gestational ages. However, the area under the curve (AUC) at 36 weeks was as high as 0.86. Being a matter of cutoff rather than a matter of choosing the correct variable, ROC analysis showed that the best cutoff for prediction having the best sensitivity (0.80) with the best specificity (0.77) was 28th centile of EFW. This represents 24.9% of the studied women (228/915). Conclusions In general, ultrasound at 36 weeks has better performance detecting SGA fetuses than ultrasound at 32 weeks and we suggest to definitively change from 32 to 36 weeks in order to increase the detection rate of SGA fetuses. Moreover, in order to detect those fetuses who will grow below the lower level of the normal range in the last month of pregnancy, we suggest that those with EFW below the 28th centile at 36 weeks should be rescanned later in pregnancy to identify prenatally as many cases as we can of SGA newborns.

Early Onset Acceleration of Fetal Growth in Gestational Diabetes Mellitus: Deciding About When and Whom to Screen for Preventing Fetal Macrosomia

The precise time into pregnancy at which women are screened for gestational diabetes mellitus (GDM) is crucial for determining the benefits of diagnosis. However, this issue remains a source of intense debate among guidance authorities and there is no consensus about when and whom to screen. Since 2010, the IADPSG recommends universal screening with 75g OGTT at 24–28 weeks’ gestation (WG), due to evidence of a positive linear correlation between maternal blood glucose levels around 28 WG and risk of fetal macrosomia. Nonetheless, emerging evidence indicates that initial acceleration of fetal growth (FG) related to GDM, predicting fetal macrosomia, is already underway at 20 WG, thereby suggesting that screening strategies for GDM earlier than the recommended 24–28 WG should be reconsidered (1). By exploiting the routine 19–21 WG obstetrical assessment of FG (anomaly scan), along with the risk stratification system endorsed by the Italian NHS, which offers, in addition to the usual GDM screening test at 24–28 WG, an early 75g OGTT at 16–18 WG to women who are classified as at high risk (HR) for GDM (i.e. previous GDM, pre-gravid obesity, or FPG at first prenatal visit between 5.6–6.9 mmol/L), we aimed to verify whether an early onset acceleration of FG related to GDM would be observed in our pregnant population, and if reversion could occur with current screening recommendations. For this, 769 consecutive women in singleton pregnancies, subjected to both anomaly scan and GDM screening, were retrospectively enrolled at our Institution between Jan 2018-Feb 2020. At a mean time of 20.8 WG, the percentiles of estimated fetal weight (EFW) and abdominal circumference (AC) were significantly higher in women who tested positive for GDM at late screening than in women with normal glucose tolerance (NGT). However, while no differences in the birthweight (BW) percentiles of neonates born to non-HR women diagnosed with GDM at 24–28 WG, with respect to NGT women were observed (p=0.416), neonates born to HR women diagnosed with GDM at 24–28 WG (due to refusal to comply with early screening advices) were significantly heavier (p<0.001). In contrast, both the EFW and AC percentiles, as well as the BW percentiles, were significantly lower in infants born to HR women diagnosed with GDM at 16–18 WG with respect to their late diagnosis counterparts (EFW p=0.001, AC p=0.002, BW p=0.048), and not dissimilar to those of NGT women (EFW p=0.824, AC p=0.873, BW p=0.242). These results were confirmed by regression analysis, while adjusting for maternal confounders. Although an initial acceleration of FG related to GDM can be detected at anomaly scan in non-HR women, reversion occurs with current screening recommendations. Earlier screening strategies should be reserved to HR women, as the acceleration of FG related to GDM in these cases is less responsive to treatment delays. (1) Ref: Li et al. Lancet Diabetes Endocrinol. 2020;8(4):292–300.

929 Predictive performance of race/ethnicity based growth velocities in pregnancies complicated by diabetes

Recently, the NICHD published a race/ethnicity-based fetal growth velocity percentile calculator derived from a cohort of low-risk pregnancies. Fetal growth velocity is accelerated in pregnancies affected by diabetes. However, use of growth velocity percentiles are untested in this population. We sought to determine the test performance of growth velocity percentiles in pregnancies with diabetes. Retrospective cohort study of all women with pregestational and gestational diabetes with ultrasound data at two third trimester time points (28w0d-31w6d and 32w0d-35w6d) between 2009-2019 at a single academic institution. Self-reported race/ethnicity and fetal biometry were used to calculate abdominal circumference (AC) and estimated fetal weight (EFW) velocities between time points. Traditional AC and EFW percentiles were recorded for the second ultrasound for comparison. ROC curves and areas under the curve (AUC) were compared between parameters for prediction of composite neonatal outcome and LGA. Test statistics were calculated and compared at optimal cut points identified by the Youden J statistic. There were 1,093 pregnancies included in the analysis with 599 (54.8%) and 297 (27%) complicated by adverse composite outcome or LGA birthweight. No differences in AUCs for neonatal composite outcome were found (p=.234; Figure 1). Traditional EFW and AC biometric percentiles were significantly better predictors of LGA birthweight than either velocity parameter (Figure 2). The optimal cut point for EFW velocity (51%) had poor overall performance with a sensitivity 65.7% (CI 60.0%-71.0%) and positive predictive value (PPV) of 35.6% (CI 31.6-39.8%) for LGA. Results were similar for AC velocity (cut point 57%) with a sensitivity of 57.6% (CI 51.7%-63.3%) and PPV of 36.9% (CI 32.5%-41.4%). Neither traditional ultrasound biometry nor race/ethnicity-based growth velocity accurately predicted adverse neonatal outcomes in pregnancies complicated by diabetes. However, traditional ultrasound biometry was superior to both EFW and AC growth velocities for prediction of LGA birth weight.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

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)