Perinatal outcome in SGA births defined by customised versus population-based birthweight standards

Maternal perception of decreased fetal movements is independent of infant size

OBJECTIVE

Fetal movements are often used as a surrogate for fetal wellbeing. Previous research suggests a link between maternal perception of decreased fetal movements (DFM) and small-for-gestational-age (SGA) infants. The aim of this study was to investigate the association between maternal presentation with DFM and birth-weight centile categories at a large Australian perinatal center.

METHODS

This was a retrospective study of non-anomalous singleton infants born at ≥ 28 + 0 weeks' gestation between January 2016 and October 2020 at the Mater Mothers' Hospital in Brisbane, Australia. The primary outcome was the rate of DFM according to birth-weight centile category. Maternal demographic characteristics included age, body mass index, ethnicity, parity, medical conditions and previous stillbirth. The association between DFM and birth-weight centile was evaluated using adjusted multinomial regression models. Robust standard errors were used to account for clustering at the patient level. Wald tests and Akaike's and Bayesian information criteria were used to evaluate models.

RESULTS

Over the 5-year study period, 45 042 women met the inclusion criteria. Of these, 6690 (14.9%) women presented with DFM. Of the DFM cohort, 80.9% (5411/6690) had only one presentation with DFM, and 19.1% (1279/6690) had two or more presentations. The overall stillbirth rate was similar in women with DFM (0.1% (8/6690)) and those without DFM (0.1% (50/38 352)). There was no association between DFM (either single or multiple) and infant birth-weight centile.

CONCLUSIONS

This study suggests that presentation with DFM is not associated with infant size. Clinicians should consider additional risk factors and the overall clinical context when deciding appropriate management. DFM is not necessarily an indication for an immediate or urgent ultrasound scan to assess fetal size. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Relation of antepartum stillbirth to birthweight and gestational age: Prospective cohort study

OBJECTIVES

To investigate the incidence of antepartum stillbirth in relation to the distribution of neonatal/fetal weight for different gestational ages.

DESIGN

Prospective observational cohort study.

SETTING

Obstetric ultrasound departments in two UK maternity hospitals.

POPULATION

168 966 women with singleton pregnancies attending for routine antenatal care.

METHODS

We examined the incidence of antepartum stillbirths, within different birthweight and fetal weight percentile subgroups, conditioning for gestational age.

MAIN OUTCOME MEASURES

Incidence of antepartum stillbirth.

RESULTS

The risk of stillbirth progressively increased for lower birthweight. Considering the 25-75th percentile as the reference category, the relative risks for stillbirth at <37 weeks' gestation were 7.6 (95% confidence interval [CI] 5.7-10.2) <1st percentile, 2.6 (95% CI 1.8-3.7) 1 to 10th percentile, 1.4 (95% CI 0.9-2.1) 10 to 25th percentile, 0.8 (95% CI 0.4-1.5) 75 to 90th percentile, 0.8 (95% CI 0.4-1.7) 90 to 99th percentile, 0.9 (95% CI 0.3-2.5) >99th percentile. The respective values for births at ≥37 weeks' gestation were 5.0 (95% CI 2.9-8.9), 2.1 (95% CI 1.4-3.3), 1.4 (95% CI 0.9-2.1), 1.2 (95% CI 0.7-1.8), 1.0 (95% CI 0.6-1.8) and 4.0 (95% CI 1.8-9.3). The incidence of stillbirth in ongoing low-risk singleton pregnancies gradually increases for smaller fetuses at any gestational point. The higher incidence (5.56%) was evident for fetal weight <1st percentile between 24 and 28 weeks' gestation.

CONCLUSION

Fetal weight and the weight of the stillborn have a continuous association with the incidence of antepartum stillbirth which is affected by gestational age.

The influence of insulin-related genetic variants on fetal growth, fetal blood flow, and placental weight in a prospective pregnancy cohort

The fetal insulin hypothesis proposes that low birthweight and type 2 diabetes (T2D) in adulthood may be two phenotypes of the same genotype. In this study we aimed to explore this theory further by testing the effects of GWAS-identified genetic variants related to insulin release and sensitivity on fetal growth and blood flow from week 20 of gestation to birth and on placental weight at birth. We calculated genetic risk scores (GRS) of first phase insulin release (FPIR), fasting insulin (FI), combined insulin resistance and dyslipidaemia (IR + DLD) and insulin sensitivity (IS) in a study population of 665 genotyped newborns. Two-dimensional ultrasound measurements with estimation of fetal weight and blood flow were carried out at week 20, 25, and 32 of gestation in all 665 pregnancies. Birthweight and placental weight were registered at birth. Associations between the GRSs and fetal growth, blood flow and placental weight were investigated using linear mixed models. The FPIR GRS was directly associated with fetal growth from week 20 to birth, and both the FI GRS, IR + DLD GRS, and IS GRS were associated with placental weight at birth. Our findings indicate that insulin-related genetic variants might primarily affect fetal growth via the placenta.

Changes in preterm birth and birthweight during the SARS-CoV-2 pandemic: a nationwide study in South Korea

Birthweight is a strong determinant of a neonate’s health. The SARS-CoV-2 pandemic’s impact on birthweight has not been investigated in-depth, with inconsistent conclusions from initial studies. To assess changes in preterm birth and inappropriate birthweight between the SARS-CoV-2 pandemic and pre-pandemic periods. A nationwide birth micro-data consisted with exhaustive census of all births in 2011–2020 in South Korea was accessed to examine whether the mean birthweight and rates of under/overweight births changed significantly during the SARS-CoV-2 pandemic year (2020) compared to those of the pre-pandemic period (2011–2019). A total of 3,736,447 singleton births were analyzed. Preterm birth was defined as < 37 weeks of gestation. Low birthweight (LBW) and macrosomia were defined as birthweights < 2.5 kg and ≥ 4.0 kg, respectively. Small for gestational age (SGA) and large for gestational age (LGA) were defined as birthweights below the 10th and above 90th percentiles for sex and gestational age, respectively. Inappropriate birthweight was defined as one or more LBW, macrosomia, SGA, or LGA. Generalized linear models predicted birth outcomes and were adjusted for parental age and education level, marital status, parity, gestational age, and months from January 2011. There were 3,481,423 and 255,024 singleton births during the pre-pandemic and pandemic periods, respectively. Multivariable generalized linear models estimated negative associations between the pandemic and preterm birth (odds ratio [OR], 0.968; 95% confidence interval [CI] 0.958–0.978), LBW (OR: 0.967, 95% CI 0.956–0.979), macrosomia (OR: 0.899, 95% CI 0.886–0.912), SGA (OR: 0.974, 95% CI 0.964–0.983), LGA (OR: 0.952, 95% CI 0.945–0.959), and inappropriate birthweight (OR: 0.958, 95% CI 0.952–0.963), indicating a decline during the pandemic compared to pre-pandemic period. An 8.98 g decrease in birthweight (95% CI 7.98–9.99) was estimated during the pandemic. This is the largest and comprehensive nationwide study to date on the impact of the SARS-CoV-2 pandemic on preterm birth and inappropriate birthweight. Birth during the pandemic was associated with lower odds of being preterm, underweight, and overweight. Further studies are required to understand the dynamics underlying this phenomenon.

Stillbirths preceded by reduced fetal movements are more frequently associated with placental insufficiency: a retrospective cohort study

OBJECTIVES

Maternal report of reduced fetal movements (RFM) is a means of identifying fetal compromise in pregnancy. In live births RFM is associated with altered placental structure and function. Here, we explored associations between RFM, pregnancy characteristics, and the presence of placental abnormalities and fetal growth restriction (FGR) in cases of stillbirth.

METHODS

A retrospective cohort study was carried out in a single UK tertiary maternity unit. Cases were divided into three groups: 109 women reporting RFM, 33 women with absent fetal movements (AFM) and 159 who did not report RFM before the diagnosis of stillbirth. Univariate and multivariate logistic regression was used to determine associations between RFM/AFM, pregnancy characteristics, placental insufficiency and the classification of the stillbirth.

RESULTS

AFM or RFM were reported prior to diagnosis of stillbirth in 142 (47.2%) of cases. Pregnancies with RFM prior to diagnosis of stillbirth were independently associated with placental insufficiency (Odds Ratio (OR) 2.79, 95% Confidence Interval (CI) 1.84, 5.04) and were less frequently associated with maternal proteinuria (OR 0.16, 95% CI 0.07, 0.62) and previous pregnancy loss <24 weeks (OR 0.20, 95% CI 0.07, 0.70). When combined, AFM and RFM were less frequently reported in twin pregnancies ending in stillbirth and in intrapartum stillbirths.

CONCLUSIONS

The association between RFM and placental insufficiency was confirmed in cases of stillbirth. This provides further evidence that RFM is a symptom of placental insufficiency. Therefore, investigation after RFM should aim to identify placental dysfunction.

A retrospective autopsy study of 42 cases of stillbirth in Avicenna Research Institute

BACKGROUND

According to the World Health Organization about 2.6 million deaths were reported worldwide in 2015. More than 98% of stillbirths occur in developing countries. At present, the causes of many cases of stillbirth are unknown due to the lack of necessary data and autopsies in Iran. The aim of this study was to investigate the most plausible cause of stillbirth by evaluating clinical records and autopsies.

METHODS

A cross-sectional study of 42 stillbirth autopsies in Avicenna Research Institute from 2012 to 2019, was conducted. Data were extracted from a checklist prepared by the project researchers. The checklist contains maternal demographic information, medical history and maternal illness, pregnancy risk factors, placenta and stillbirth information. Collected data were reviewed and classified according to the ReCoDe (Relevant Condition at Death) system.

RESULTS

In the present study, based on ReCoDe classification, related causes of 95.2% of stillbirths were identified and 4.8% were in the unclassified group. The most common causes were: Fetal causes (64.3%), umbilical cord (14.3%), placenta (7.1%), amniotic fluid (4.8%), maternal medical conditions (2.4%). The causes of about 70% of stillbirth in Iran are unexplained, but in this study, using autopsy results and ReCoDe classification, only 4.8% of stillbirth causes remained unexplained.

CONCLUSIONS

In our study, unknown cases were rare after autopsy. But considering the limitations and costs of autopsy, we need to design the guideline to specify cases who need an autopsy. Fetal autopsy, placental examination and clinical information could reduce the proportion of stillbirths that remain unexplained.

Parity-Adjusted Term Neonatal Growth Chart Modifies Neonatal Morbidity and Mortality Risk Stratification

Objective: To investigate the impact of parity-customized versus population-based birth weight charts on the identification of neonatal risk for adverse outcomes in small (SGA) or large for gestational age (LGA) infants compared to appropriate for gestational age (AGA) infants. Study design: Observational, retrospective, cohort study based on electronic medical birth records at a single center between 2006 and 2017. Neonates were categorized by birth weight (BW) as SGA, LGA, or AGA, with the 10th and 90th centiles as boundaries for AGA in a standard population-based model adjusted for gestational age and gender only (POP) and a customized model adjusted for gestational age, gender, and parity (CUST). Neonates defined as SGA or LGA by one standard and not overlapping the other, are SGA/LGA CUST/POP ONLY. Analyses used a reference group of BW between the 25th and 75th centile for the population. Results: Overall 132,815 singleton, live, term neonates born to mothers with uncomplicated pregnancies were included. The customized model identified 53% more neonates as SGA-CUST ONLY who had significantly higher rates of morbidity and mortality compared to the reference group (OR = 1.33 95% CI [1.16−1.53]; p < 0.0001). Neonates defined as LGA by the customized model (LGA-CUST) and AGA by the population-based model LGA-CUST ONLY had a significantly higher risk for morbidity compared to the reference (OR = 1.36 95% CI [1.09−1.71]; p = 0.007) or the LGA POP group. Neonatal mortality only occurred in the SGA and AGA groups. Conclusions: The application of a parity-customized only birth weight chart in a population of singleton, term neonates is a simple platform to better identify birth weight related neonatal risk for morbidity and mortality.

Testing the assumptions of customized intrauterine growth charts using national birth studies

INTRODUCTION

Customized intrauterine growth charts are widely used for growth monitoring and research. They are based on three assumptions: (1) estimated fetal weight (EFW) has a normal distribution with a constant coefficient of variation at all gestational ages; (2) Hadlock's growth curve accurately describes the relation between EFW and gestational ages; (3) associations between EFW and the fetal and maternal characteristics included in the customization model (fetal sex, pre-pregnancy weight, height, parity) are proportional throughout pregnancy. The aim of this study was to test whether these underlying assumptions are verified.

MATERIAL AND METHODS

Data came from (1) the French Longitudinal Study of Children (ELFE) cohort, which recruited births after 32 weeks' gestation in 349 maternity hospitals in France in 2011, and (2) the National Perinatal Survey, which included births from all French maternity hospitals in 2016. The study population included, respectively, 6 920 and 8 969 singleton non-malformed term live births with data on customization characteristics and EFW. We computed the coefficient of variation by gestational age and then modeled the association of gestational age, maternal and fetal characteristics with EFW at the second and third trimester ultrasound and with birthweight using linear regression. To assess the proportionality of the impact of maternal and fetal characteristics, we computed the percent change in weight associated with these characteristics at these three time points.

RESULTS

The coefficient of variation was close to 12% at each gestational age, but EFW was not normally distributed, leading to small but systematic underestimation of fetuses under the 10th percentile. Weights representing the 50th and 10th percentiles based on Hadlock's growth trajectory were lower than observed or predicted weights. Most characteristics more strongly impacted weight at birth than during pregnancy. In the French Longitudinal study of Children (ELFE) cohort, boys were 1.8% (95% confidence interval [CI] 1.3-2.4) heavier than girls in the third trimester, whereas this percentage was 4.6% (95% CI 4.0-5.2) at birth. In the National Perinatal Survey, these percentages were 2.3% (95% CI 1.8-2.8) and 4.3% (95% CI 3.8-4.8).

CONCLUSIONS

These results from two independent sources revealed discrepancies between routine clinical EFW data used for growth monitoring and the customized growth model's assumptions.

Incidence, risk factors, and feto-maternal outcomes of inappropriate birth weight for gestational age among singleton live births in Qatar: A population-based study

BACKGROUND

Abnormal fetal growth can be associated with factors during pregnancy and at postpartum.

OBJECTIVE

In this study, we aimed to assess the incidence, risk factors, and feto-maternal outcomes associated with small-for-gestational age (SGA) and large-for-gestational age (LGA) infants.

METHODS

We performed a population-based retrospective study on 14,641 singleton live births registered in the PEARL-Peristat Study between April 2017 and March 2018 in Qatar. We estimated the incidence and examined the risk factors and outcomes using univariate and multivariate analysis.

RESULTS

SGA and LGA incidence rates were 6.0% and 15.6%, respectively. In-hospital mortality among SGA and LGA infants was 2.5% and 0.3%, respectively, while for NICU admission or death in labor room and operation theatre was 28.9% and 14.9% respectively. Preterm babies were more likely to be born SGA (aRR, 2.31; 95% CI, 1.45-3.57) but male infants (aRR, 0.57; 95% CI, 0.4-0.81), those born to parous (aRR 0.66; 95% CI, 0.45-0.93), or overweight (aRR, 0.64; 95% CI, 0.42-0.97) mothers were less likely to be born SGA. On the other hand, males (aRR, 1.82; 95% CI, 1.49-2.19), infants born to parous mothers (aRR 2.16; 95% CI, 1.63-2.82), or to mothers with gestational diabetes mellitus (aRR 1.36; 95% CI, 1.11-1.66), or pre-gestational diabetes mellitus (aRR 2.58; 95% CI, 1.8-3.47) were significantly more likely to be LGA. SGA infants were at high risk of in-hospital mortality (aRR, 226.56; 95% CI, 3.47-318.22), neonatal intensive care unit admission or death in labor room or operation theatre (aRR, 2.14 (1.36-3.22).

CONCLUSION

Monitoring should be coordinated to alleviate the risks of inappropriate fetal growth and the associated adverse consequences.

Increased Fibroblast Growth Factor 21 (FGF21) Concentration in Early Second Trimester Amniotic Fluid and Its Association with Fetal Growth

Altered fetal growth, either reduced or exacerbated, is associated with adverse perinatal outcomes. The underlying pathogenetic mechanisms of altered growth remain unclear. Fibroblast growth factor 21 (FGF21) and insulin are both considered to be major regulators of tissue growth and metabolism. The aim of our study was to investigate the association of second trimester amniotic fluid FGF21 and insulin concentrations with fetal growth. The amniotic fluid concentrations of FGF21 and insulin were determined in 80 cases of different fetal growth patterns (SGA—small for gestational age, LGA—large for gestational age, and AGA—appropriate for gestational age fetuses). Both peptides were found to be increased in cases of abnormal fetal growth, reduced growth velocity (SGA), or macrosomia (LGA). Specifically, FGF21 was significantly increased, as higher FGF21 levels were observed in the amniotic fluid of SGA and LGA fetuses compared with AGA fetuses (p < 0.05). Furthermore, the more severe the fetal smallness, the higher the FGF21 levels (p < 0.05). Similarly, higher insulin levels were noted in the amniotic fluid of SGA and LGA fetuses compared with those in AGA fetuses, though this was not statistically significant (p > 0.05). Again, the more severe the reduced fetal growth, the higher the insulin levels.

Reduced fetal growth velocity precedes antepartum fetal death

OBJECTIVES

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.

METHODS

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.

RESULTS

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 < 10^th 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.

CONCLUSIONS

Given that 74% of antepartum fetal death cases were not diagnosed as small-for-gestational age (EFW < 10^th 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.

Anti-epileptic drug exposure during pregnancy and neonatal birth weight outcomes: protocol for a systematic review and meta-analysis

BACKGROUND

The prevalence of epilepsy in pregnant women is estimated at 0.3-1%. Anti-epileptic drug (AED) exposure in-utero has been associated with various adverse health outcomes in neonates, including adverse birth weight outcomes.

OBJECTIVE

This review aims to summarize the published evidence on the association between AED exposure in pregnancy and adverse birth weight outcomes METHODS: Studies assessing AED exposure in pregnancy and neonatal birth weight outcomes, including small for gestational age (SGA), low birth weight (LBW), birth weight (BW), length, head circumference, and cephalization index will be identified in MEDLINE®, EMBASE, Cochrane Library, Scopus, Cumulative Index of Nursing and Allied Health Literature (CINAHL), International Pharmaceutical Abstracts (IPA), and Global Health. Open grey, Theses Canada, and ProQuest Dissertations will be used to locate gray literature. Eligible study designs will include both intervention and non-interventional studies. We will not impose any time limit in the review. We will use the Newcastle-Ottawa Scale to assess the methodological quality of observational studies and quasi-experimental studies included in the review. The risk of bias of experimental studies will be appraised using the Cochrane risk-of-bias tool for randomized trials (RoB 2). A meta-analysis will be conducted using a random-effects model.

DISCUSSION

The results from this review could improve clinicians' prescribing decisions by highlighting the safest AEDs for women who are pregnant or planning to conceive based on the evidence currently available.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020192713.

Accuracy of estimated fetal weight assessment in fetuses with abdominal wall defects

BACKGROUND

Gastroschisis and omphalocele are congenital abdominal wall defects in which the bowel and other abdominal contents extrude from the fetal abdominal cavity. Standard formulas for estimated fetal weight using ultrasound include fetal abdominal circumference measurement and have a range of error of approximately 10%. It is unknown whether the accuracy of estimated fetal weight assessment is compromised in fetuses with abdominal wall defects because of the extrusion of abdominal contents.

OBJECTIVE

This study aimed to assess the accuracy of standard estimated fetal weight assessment in fetuses with abdominal wall defects by comparing prenatal assessment of fetal weight with actual birthweight.

STUDY DESIGN

A retrospective cohort study of fetuses diagnosed with gastroschisis or omphalocele was performed at a single center from 2012 to 2018. Fetuses with additional anomalies or confirmed chromosome abnormalities were excluded. Estimated fetal weight was calculated using the Hadlock formula. Published estimates of fetal growth rate were used to establish a projected estimated fetal weight at birth from the final growth ultrasound, and the percent difference between projected estimated fetal weight at birth and actual birthweight was calculated. The Wilcoxon rank-sum test was used to examine the difference between projected estimated fetal weight and actual birthweight.

RESULTS

We had complete data for 112 fetuses with abdominal wall defects, including 85 with gastroschisis and 27 with omphalocele. The median (interquartile range) projected estimated fetal weight was similar to median birthweight, at 2283 g (interquartile range, 2000-2810) and 2306 g (interquartile range, 1991-264), respectively, which did not represent a statistically significant difference between projected estimated fetal weight and actual birthweight (P=.32). The median percent error was 6.8 (3.1-12.8). In addition, we did not find any statistical difference between projected estimated fetal weight and actual birthweight in patients with gastroschisis (P=.52) or omphalocele (P=.35) individually. Estimated fetal weight was underestimated in most cases (n=68 [60.7%]).

CONCLUSION

In fetuses with abdominal wall defects, standard measurement of fetal weight shows an accuracy that is at least comparable with previously established margins of error for ultrasound assessment of fetal weight. Standard estimated fetal weight assessment remains an appropriate method of estimating fetal weight in these fetuses.

Evaluation of Pregnancy Outcomes Among Women With Decreased Fetal Movements

IMPORTANCE

Stillbirth is a devastating pregnancy outcome with far-reaching economic and psychosocial consequences, but despite significant investment, a screening tool for identifying those fetuses at risk for stillbirth remains elusive. Maternal reporting of decreased fetal movements (DFM) has been found to be associated with stillbirth and other adverse perinatal outcomes.

OBJECTIVE

To examine pregnancy outcomes of women presenting with DFM in the third trimester at a tertiary Australian center with a clear clinical management algorithm.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data on all births meeting the inclusion criteria from 2009 through 2019 at Mater Mothers' Hospital in Brisbane, Australia. This is a tertiary center and Australia's largest maternity hospital. All singleton births without a known congenital anomaly after 28 weeks' gestation were included. Among 203 071 potential participants identified from the hospital database, 101 597 individuals met the eligibility criteria. Data analysis was performed from May through September 2020.

EXPOSURE

Presentation to hospital with DFM after 28 weeks gestation.

MAIN OUTCOMES AND MEASURES

The primary outcome of this study was the incidence of stillbirth. Multivariate analysis was undertaken to determine the association between DFM and stillbirth, obstetric intervention, and other adverse outcomes, including being born small for gestational age (SGA) and a composite adverse perinatal outcome (at least 1 of the following: neonatal intensive care unit admission, severe acidosis [ie, umbilical artery pH <7.0 or base excess -12.0 mmol/L or less], 5-minute Apgar score <4, or stillbirth or neonatal death). The hypothesis being tested was formulated prior to data collection.

RESULTS

Among 101 597 women with pregnancies that met the inclusion criteria, 8821 (8.7%) presented at least once with DFM and 92 776 women (91.3%) did not present with DFM (ie, the control population). Women presenting with DFM, compared with those presenting without DFM, were younger (mean [SD] age, 30.4 [5.4] years vs 31.5 [5.2] years; P < .001), more likely to be nulliparous (4845 women [54.9%] vs 42 210 women [45.5%]; P < .001) and have a previous stillbirth (189 women [2.1%] vs 1156 women [1.2%]; P < .001), and less likely to have a previous cesarean delivery (1199 women [13.6%] vs 17 444 women [18.8%]; P < .001). During the study period, the stillbirth rate was 2.0 per 1000 births after 28 weeks' gestation. Presenting with DFM was not associated with higher odds of stillbirth (9 women [0.1%] vs 185 women [0.2%]; adjusted odds ratio [aOR], 0.54; 95% CI, 0.23-1.26, P = .16). However, presenting with DFM was associated with higher odds of a fetus being born SGA (aOR, 1.14; 95% CI, 1.03-1.27; P = .01) and the composite adverse perinatal outcome (aOR, 1.14; 95% CI, 1.02-1.27; P = .02). Presenting with DFM was also associated with higher odds of planned early term birth (aOR, 1.26; 95% CI, 1.15-1.38; P < .001), induction of labor (aOR, 1.63; 95% CI, 1.53-1.74; P < .001), and emergency cesarean delivery (aOR, 1.18; 95% CI, 1.09-1.28; P < .001).

CONCLUSIONS AND RELEVANCE

The presence of DFM is a marker associated with increased risk for a fetus. This study's findings of a nonsignificantly lower rate of stillbirth among women with DFM may be reflective of increased community awareness of timely presentation to their obstetric care clinician when concerned about fetal movements and the benefits of tertiary level care guided by a clear clinical management protocol. However, DFM was associated with increased odds of an infant being born SGA, obstetric intervention, early term birth, and a composite of adverse perinatal outcomes.

Reduction of stillbirths in England from 2008 to 2017 according to uptake of the Growth Assessment Protocol: 10-year population-based cohort study

OBJECTIVE

Antenatal detection of small-for-gestational age (SGA) can reduce significantly the risk of stillbirth. The Growth Assessment Protocol (GAP) was developed to address the problem that most SGA fetuses are missed antenatally. We set out to analyze the effect that the GAP program has had on stillbirth rates in England.

METHODS

We analyzed data from 2008 (the year before roll-out of the GAP program) to 2017 (latest available Office for National Statistics (ONS) unit-based data). The program consists of five elements: training, evidence-based guidelines for risk assessment and surveillance of fetal growth, customized charts, recording of process and outcome indicators, and audit of missed SGA cases. All maternity units in England were categorized into one of three groups according to their GAP status in 2017: (1) not in the GAP program; (2) GAP implemented partially (incomplete adoption of protocol, no monitoring and audit); and (3) GAP implemented completely. A subset of the complete-implementation group comprised the 20 units with the highest SGA detection rates. Unit-level live-birth and stillbirth data were obtained from the ONS for each of these groups.

RESULTS

Stillbirth rates declined across all groups from 2008 to 2017, and significantly more in units in which GAP was implemented completely than in the non-GAP units (P < 0.05). The steepest decline in stillbirth rate was observed in the 20 units with the highest SGA detection rates, which had a 24% lower stillbirth rate compared with the units not using GAP (P < 0.01) in 2017. This difference remained significant after mixed-effects logistic regression analysis of potential confounding, including social deprivation (odds ratio, 0.76 (95% CI, 0.64-0.90)). Assessment of the nine Bradford Hill causality criteria and associated characteristics suggested that the association between implementation of the GAP program and reduction in stillbirth rate was causal.

CONCLUSIONS

There has been an overall reduction in stillbirth rates in England that is likely to be a result of increased awareness of the importance of antenatal detection of SGA as a key risk factor for stillbirth. The decline in stillbirth rates was significantly greater in maternity units that had fully implemented the GAP program, and was most pronounced in the units with the highest antenatal SGA detection rates. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Customized birth-weight centiles and placenta-related fetal growth restriction

OBJECTIVE

The value of using customized birth-weight centiles to improve the diagnostic accuracy for fetal growth restriction (FGR), in comparison with using population-based charts, remains a matter of debate. One potential explanation for the conflicting data is that most studies used measures of perinatal mortality and morbidity as proxies for placenta-mediated FGR, many of which are not specific and may be confounded by other factors such as prematurity. The aim of this study was to compare the diagnostic accuracy of small-for-gestational age (SGA) at birth, defined according to customized vs population-based charts, for associated abnormal placental pathology.

METHODS

This was a secondary analysis of data from a prospective cohort study on risk factors for placenta-mediated complications and abnormal placental pathology in low-risk nulliparous women. All placentae were sent for detailed histopathological examination by two perinatal pathologists. The primary exposure was SGA, defined as birth weight < 10^th centile for gestational age using either a customized (SGA_cust ) or a population-based (SGA_pop ) birth-weight reference. The outcomes of interest were one of three types of abnormal placental pathology associated with FGR: maternal vascular malperfusion (MVM), chronic villitis and fetal vascular malperfusion (FVM). Adjusted relative risks (aRR) with 95% CIs were estimated using modified Poisson regression analysis, with adjustment for smoking, body mass index and aspirin treatment.

RESULTS

A total of 857 nulliparous women met the study criteria. The proportions of infants identified as SGA based on the customized and population-based charts were 12.6% (108/857) and 11.4% (98/857), respectively. A diagnosis of SGA using either customized or population-based charts was associated with an increased risk of any placental pathology (aRR, 3.04 (95% CI, 2.29-4.04) and 1.60 (95% CI, 1.10-2.31), respectively) and MVM pathology (aRR, 12.33 (95% CI, 6.60-23.03) and 5.29 (95% CI, 2.87-9.76), respectively). SGA_cust , but not SGA_pop , was also associated with an increased risk for chronic villitis (aRR, 1.85 (95% CI, 1.07-3.18)) and FVM pathology (aRR, 2.48 (95% CI, 1.25-4.93)). SGA_cust had a higher detection rate for any placental pathology (30.3% vs 17.1%; P < 0.001), MVM pathology (63.2% vs 39.5%; P = 0.003) and chronic villitis (20.8% vs 8.3%; P = 0.007) than did SGA_pop , for a similar false-positive rate. This was mainly the result of a higher detection rate for abnormal pathology in the white and East-Asian subgroups and a lower false-positive rate for abnormal pathology in the South-Asian subgroup by SGA_cust than by SGA_pop . In addition, pregnancies in the SGA_cust group, but not those in the SGA_pop group, were more likely to be complicated by preterm birth and a low 5-min Apgar score than were the corresponding non-SGA group.

CONCLUSION

These findings suggest that customized birth-weight centiles may be superior to population-based birth-weight centiles in detecting FGR that is due to underlying placental disease. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Predictive Accuracy of Singleton Versus Customized Twin Growth Chart for Adverse Perinatal Outcome: A Cohort Study

Background: Fetal growth of twins differs from singletons. The objective was to assess the fetal growth in twin gestations in relation to singleton charts and customized twin charts, respectively, followed by a comparison of the frequency of neonatal complications in small-for-gestational-age (SGA) twins. Methods: We performed an analysis of twin pregnancies with established chorionicity with particular emphasis on postnatal adverse outcomes in newborns classified as SGA. Neonatal birth weight was comparatively assessed using both singleton and twin growth charts with following percentile estimation. Using a statistical model, we established the prediction strength of neonatal complications in SGA twins for both methods. Results: The dataset included 322 twin pairs (247 cases of dichorionic and 75 cases of monochorionic diamniotic gestations). Utilization of twin-specific normograms was less likely to label twins as SGA—nevertheless, this diagnosis strongly correlated with risk of observing adverse outcomes. Using a chart dedicated for twin pregnancies predicted newborn complications in the SGA group with higher sensitivity and had better positive predictive value regarding postnatal morbidity. Conclusions: Estimating twin growth with customized charts provides better prognosis of undesirable neonatal events in the SGA group comparing to singleton nomograms and consequently might determine neonatal intensive care prenatal approach.

Machine learning improves early prediction of small-for-gestational-age births and reveals nuchal fold thickness as unexpected predictor

OBJECTIVE

To investigate the performance of the machine learning (ML) model in predicting small-for-gestational-age (SGA) at birth, using second-trimester data.

METHODS

Retrospective data of 347 patients, consisting of maternal demographics and ultrasound parameters collected between the 20th and 25th gestational weeks, were studied. ML models were applied to different combinations of the parameters to predict SGA and severe SGA at birth (defined as 10th and third centile birth weight).

RESULTS

Using second-trimester measurements, ML models achieved an accuracy of 70% and 73% in predicting SGA and severe SGA whereas clinical guidelines had accuracies of 64% and 48%. Uterine PI (Ut PI) was found to be an important predictor, corroborating with existing literature, but surprisingly, so was nuchal fold thickness (NF). Logistic regression showed that Ut PI and NF were significant predictors and statistical comparisons showed that these parameters were significantly different in disease. Further, including NF was found to improve ML model performance, and vice versa.

CONCLUSION

ML could potentially improve the prediction of SGA at birth from second-trimester measurements, and demonstrated reduced NF to be an important predictor. Early prediction of SGA allows closer clinical monitoring, which provides an opportunity to discover any underlying diseases associated with SGA.

FIGO position paper on reference charts for fetal growth and size at birth: Which one to use?

Publication of the Intergrowth-21st and WHO growth charts raises the question of which growth data prenatal providers should use in clinical practice. Is it better to use a universal chart applied globally, or metrics based on local or regional growth patterns? And what about customized charts versus local charts? FIGO has reviewed the different growth charts and studies assessing their reproducibility and predictive values for small- and large-for-gestational age newborns and, where available, adverse fetal outcomes. It concludes that local or regional charts are likely to be best for identifying the 10th percentile of newborns at highest risk. However, international standards for growth may also be used when coupled with locally appropriate thresholds for risk interpretation.

Common maternal and fetal genetic variants show expected polygenic effects on risk of small- or large-for-gestational-age (SGA or LGA), except in the smallest 3% of babies

Babies born clinically Small- or Large-for-Gestational-Age (SGA or LGA; sex- and gestational age-adjusted birth weight (BW) <10th or >90th percentile, respectively), are at higher risks of complications. SGA and LGA include babies who have experienced environment-related growth-restriction or overgrowth, respectively, and babies who are heritably small or large. However, the relative proportions within each group are unclear. We assessed the extent to which common genetic variants underlying variation in birth weight influence the probability of being SGA or LGA. We calculated independent fetal and maternal genetic scores (GS) for BW in 11,951 babies and 5,182 mothers. These scores capture the direct fetal and indirect maternal (via intrauterine environment) genetic contributions to BW, respectively. We also calculated maternal fasting glucose (FG) and systolic blood pressure (SBP) GS. We tested associations between each GS and probability of SGA or LGA. For the BW GS, we used simulations to assess evidence of deviation from an expected polygenic model. Higher BW GS were strongly associated with lower odds of SGA and higher odds of LGA (ORfetal = 0.75 (0.71,0.80) and 1.32 (1.26,1.39); ORmaternal = 0.81 (0.75,0.88) and 1.17 (1.09,1.25), respectively per 1 decile higher GS). We found evidence that the smallest 3% of babies had a higher BW GS, on average, than expected from their observed birth weight (assuming an additive polygenic model: Pfetal = 0.014, Pmaternal = 0.062). Higher maternal SBP GS was associated with higher odds of SGA P = 0.005. We conclude that common genetic variants contribute to risk of SGA and LGA, but that additional factors become more important for risk of SGA in the smallest 3% of babies.

The Association between Delivery of Small-for-Gestational-Age Neonate and Their Risk for Long-Term Neurological Morbidity

Small-for-gestational-age (SGA) is defined as a birth weight below the 10th or below the 5th percentile for a specific gestational age and sex. Previous studies have demonstrated an association between SGA neonates and long-term pediatric morbidity. In this research, we aim to evaluate the possible association between small-for-gestational-age (SGA) and long-term pediatric neurological morbidity. A population-based retrospective cohort analysis was performed, comparing the risk of long-term neurological morbidities in SGA and non-SGA newborns delivered between the years 1991 to 2014 at a single regional medical center. The neurological morbidities included hospitalizations as recorded in hospital records. Neurological hospitalization rate was significantly higher in the SGA group (3.7% vs. 3.1%, OR = 1.2, 95% CI 1.1–1.3, p < 0.001). A significant association was noted between neonates born SGA and developmental disorders (0.2% vs. 0.1%, OR = 2.5, 95% CI 1.7–3.8, p < 0.001). The Kaplan-Meier survival curve demonstrated a significantly higher cumulative incidence of neurological morbidity in the SGA group (log-rank p < 0.001). In the Cox proportional hazards model, which controlled for various Confounders, SGA was found to be an independent risk factor for long-term neurological morbidity (adjusted hazard ratio( HR) = 1.18, 95% CI 1.07–1.31, p < 0. 001). In conclusion, we found that SGA newborns are at an increased risk for long-term pediatric neurological morbidity.

Intrauterine growth restriction and its associated factors in South Gondar zone hospitals, Northwest Ethiopia, 2019

Background

After prematurity, intrauterine growth restriction (IUGR) is the second leading cause of perinatal mortality. IUGR has significant consequences in fetal, neonatal, and adult life. Currently, Ethiopia lacks information on IUGR’s prevalence and its determinants. This study aimed to assess the proportion of IUGR at birth and its associated factors.

Methods

A cross-sectional study was carried out among women who give birth in four hospitals of south Gonder zone from November 2018 to February 2019. Multi-stage sampling was applied to select the required samples. IUGR was assessed using a standardized cutoff percentile/mean for each measurement. Data were collected by trained MSc clinical midwives. Bi-variable and multivariable logistic analyses were deployed to identify the association.

Results

A total of 803 maternity women were participating in this study with a response rate of 95%. The proportion of IUGR 23.5% (95% CI: 20.7–26.6), low birth weight 13.3%, small-for- gestational-age 19.7%,and preterm birth 23.16%. Women who was unable to read and write, (AOR; 2.46, 95% CI: 1.02–5.92), total family size ≥7 (AOR; 1.67, 95% CI: 1.04–2.66), maternal mid-upper arm circumference (MUAC) < 23 cm (AOR; 2.10, 95% CI: 1.39–3.01), body mass index (BMI) < 18.5 kg/m² (AOR; 2.57, 95% CI: 1.72–3.83), altitude > 3000 m (AOR; 1.89 95% CI: 1.19–3.01), small placental size (< 350 g) (AOR; 2.42, 95% CI: 1.67–3.54) and small-for-gestational-age (AOR; 1.94, 95% CI:1.86–4.52) were the most predictors of IUGR.

Conclusions

IUGR was a major public health concern in this study. Women who were unable to read and write, small-for-gestational-age, maternal BMI < 18.5 kg/m², family size ≥7, maternal MUAC < 23 cm, small placental size, and altitude > 3000 m were found the most predictor variables. Strengthen female education, nutritional intervention before and during pregnancy, and routine maternity care is critical. Further clinical follow-up research is essential which includes maternal, fetal, and placental gens.

Caveats in the monitoring of fetal growth using ultrasound estimated fetal weight

Introduction

Ultrasound estimated fetal weight is increasingly being used in the monitoring of fetal growth. Differences between estimated fetal weight formulae, curves and measurement methods could lead to significant differences in results. The aim of this study was to investigate the potential impact of these differences on estimated fetal weight and its use in monitoring fetal growth, both by modelling and by analysis of ultrasound scan data.

Methods

Four estimated fetal weight curves were compared in their original form and also normalised to term weight. Estimated fetal weight was calculated from 50th centiles of widely used charts of abdominal and head circumference and femur length and plotted on a widely used estimated fetal weight curve. Fetal measurement data were used to assess the impact of fetal proportions on estimated fetal weight error and on growth trajectory when different estimated fetal weight formulae are used.

Results

Estimated fetal weight curves differ significantly, but after normalisation there is closer agreement. Estimated fetal weight modelled using modern measurement methods differs from the widely used estimated fetal weight growth curve. Errors in estimated fetal weight are correlated with differences in fetal proportions and this can lead to significant changes in estimated fetal weight growth trajectory if different estimated fetal weight formulae are used.

Conclusions

Choice of measurement methods, estimated fetal weight formulae and growth curves have a significant effect on estimated fetal weight growth trajectories relative to normal ranges. It is important to understand these caveats when using estimated fetal weight to monitor fetal growth.

Sex- and growth-specific characteristics of small for gestational age infants: a prospective cohort study

Background

Asymmetric fetal growth and male sex are both associated with adverse neonatal outcome. However, less is known about the influence of asymmetric growth and fetal sex within SGA neonates, a group of infants already at increased risk for adverse neonatal outcomes. The aim of the present study was to provide insight into variance in risk factors for SGA in a fetal sex- and growth symmetry-specific way.

Methods

For this prospective, multicenter cohort study, data from the Screening for Pregnancy Endpoints (SCOPE) study were used with 5628 nulliparous participants, of which 633 (11.3%) pregnancies were complicated with SGA and 3376 (60.0%) women had uncomplicated pregnancies. Association between risk factors for SGA, SGA subgroups, and uncomplicated pregnancies were assessed with multivariable analyses.

Results

Prevalence of asymmetric growth varied from 45.8% of SGA infants to 5.5% of infants with a customized birthweight > 90th percentile (p < 0.001). Significantly more SGA males had asymmetric growth compared to SGA female infants (51.2% vs 40.4%, p = 0.009). Maternal pre-pregnancy diet and BMI < 20 and ≥ 30 were significantly associated with symmetric SGA but not with asymmetric SGA. Asymmetric SGA infants had not only lower customized birthweight percentile (4.4 (SD 2.8) vs 5.0 (SD 3.0), p < 0.001), but also lower rates of stillbirth (p = 0.041) and less often Apgar scores < 7 (p = 0.060).

Conclusions

Among SGA infants, low customized birthweight percentiles and male sex are associated with asymmetric growth. Only symmetric SGA is significantly associated with maternal risk factors in early pregnancy. There is a substantial variance in risk factors and neonatal outcomes for SGA based on growth symmetry, implying a different pathogenesis.

Trial registration

ACTRN12607000551493

UK stillbirth trends in over 11 million births provide no evidence to support effectiveness of Growth Assessment Protocol program

OBJECTIVE

Use of the Growth Assessment Protocol (GAP) has increased internationally under the assumption that it reduces the stillbirth rate. The evidence for this is limited and based largely on an ecological time-trend study. Discordance in the uptake of the GAP program between Scotland and England/Wales enabled us to assess the assertion that implementation of GAP leads to a reduced stillbirth rate.

METHODS

We analyzed data from the National Records for Scotland and the Office for National Statistics on the number of singleton maternities and stillbirths in Scotland and in England and Wales, respectively, from 1 January 2000 to 31 December 2015. National uptake of the GAP program over time in each of the regions was recorded. Stillbirth rate per 1000 maternities was calculated, according to year of delivery, and compared between Scotland and England/Wales.

RESULTS

During the study period, there were 870 632 singleton maternities in Scotland, of which 4243 were stillbirths, and there were 10 469 120 singleton maternities in England and Wales, of which 51 562 were stillbirths. There was a marked difference in uptake of the GAP program between the two regions, with substantially fewer maternity units in Scotland implementing the program. Stillbirth rates were static up to 2010, with a decline thereafter in both regions, to 3.75 (95% CI, 3.25-4.30) per 1000 maternities in Scotland and 4.30 (95% CI, 4.15-4.46) per 1000 maternities in England and Wales in 2015. From 2010 onwards, the decline in Scotland was faster, equating to 48 (95% CI, 47.9-48.1) fewer stillbirths per 100 000 maternities in Scotland than in England and Wales from 2010 to 2015 compared with 2000 to 2009.

CONCLUSIONS

We observed a decline in stillbirth rate in England and Wales, which coincided with implementation of the GAP program. However, a concurrent decline in stillbirth rate was observed in Scotland in the absence of increased implementation of GAP. The secular rates of change in stillbirth rate in England and Wales cannot be used to infer efficacy of the GAP program. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Reduced fetal movements at term in singleton low risk pregnancies-Is there an association with placental histopathological findings?

INTRODUCTION

Maternal perception of fetal movements has long been considered an indicator of fetal well-being. A sudden decrease in the number of fetal movements is suggestive of fetal compromise. We aimed to determine whether the maternal perception of reduced fetal movements (RFM) is associated with placental pathological lesions in a low-risk term population.

MATERIAL AND METHODS

Our study was a case-control study that was performed in a single university center. Placental histopathology, maternal demographics, labor characteristics, and neonatal outcomes of term, singleton pregnancies with maternal perception of RFM during the 2 weeks prior to delivery were collected. To isolate the effect of RFM on placental pathology, we excluded cases complicated by preterm birth, hypertensive disorders, diabetes mellitus, small-for-gestational-age and congenital/genetic anomalies. We compared pregnancy outcomes and placental pathology between the RFM group and a control group matched for gestational age and mode of delivery. Placental lesions were classified according to the "Amsterdam" criteria. Composite adverse neonatal outcome was defined as one or more of the following: sepsis, transfusion, hypoglycemia, phototherapy, respiratory morbidity, cerebral morbidity, necrotizing enterocolitis and fetal/neonatal death. Multivariable regression analysis was performed to identify independent associations with adverse neonatal outcome.

RESULTS

We included patients who gave birth from January 2008 until May 2019. The study group included 203 term pregnancies with RFM during the 2 weeks prior to delivery, which was matched with 203 controls. The RFM group was characterized by a higher rate of placental weight <10th percentile (22.6% vs. 3.9%, P < .001), a higher rate of maternal vascular malperfusion lesions (30.5% vs. 18.7%, P = .007) and lesions of maternal inflammatory response (43.3% vs. 29.5%, P = .005). At delivery, the RFM group had higher rates of cesarean delivery due to non-reassuring fetal heart rate monitoring (P = .01), 5-minute Apgar score ≤7 (P = .03), neonatal intensive care unit admissions (P < .001) and composite adverse neonatal outcomes (P = .007). Using multivariable analysis, RFM (adjusted odds ratio [aOR] 1.7, 95% confidence interval [CI] 1.1-4.8), and placental maternal vascular malperfusion lesions (aOR 1.2, 95% CI 1.0-2.9) were independently associated with adverse neonatal outcome.

CONCLUSIONS

After excluding important placental-related morbidities, RFM was associated with a higher rate of placental weight <10th percentile and placental maternal vascular malperfusion lesions vs. controls. This study suggests a placental involvement in the association between RFM at term and adverse pregnancy outcomes.

Prediction of adverse perinatal outcome by fetal biometry: comparison of customized and population-based standards

OBJECTIVE

To compare the predictive performance of estimated fetal weight (EFW) percentiles, according to eight growth standards, to detect fetuses at risk for adverse perinatal outcome.

METHODS

This was a retrospective cohort study of 3437 African-American women. Population-based (Hadlock, INTERGROWTH-21^st , World Health Organization (WHO), Fetal Medicine Foundation (FMF)), ethnicity-specific (Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)), customized (Gestation-Related Optimal Weight (GROW)) and African-American customized (Perinatology Research Branch (PRB)/NICHD) growth standards were used to calculate EFW percentiles from the last available scan prior to delivery. Prediction performance indices and relative risk (RR) were calculated for EFW < 10^th and > 90^th percentiles, according to each standard, for individual and composite adverse perinatal outcomes. Sensitivity at a fixed (10%) false-positive rate (FPR) and partial (FPR < 10%) and full areas under the receiver-operating-characteristics curves (AUC) were compared between the standards.

RESULTS

Ten percent (341/3437) of neonates were classified as small-for-gestational age (SGA) at birth, and of these 16.4% (56/341) had at least one adverse perinatal outcome. SGA neonates had a 1.5-fold increased risk of any adverse perinatal outcome (P < 0.05). The screen-positive rate of EFW < 10^th percentile varied from 6.8% (NICHD) to 24.4% (FMF). EFW < 10^th percentile, according to all standards, was associated with an increased risk for each of the adverse perinatal outcomes considered (P < 0.05 for all). The highest RRs associated with EFW < 10^th percentile for each adverse outcome were 5.1 (95% CI, 2.1-12.3) for perinatal mortality (WHO); 5.0 (95% CI, 3.2-7.8) for perinatal hypoglycemia (NICHD); 3.4 (95% CI, 2.4-4.7) for mechanical ventilation (NICHD); 2.9 (95% CI, 1.8-4.6) for 5-min Apgar score < 7 (GROW); 2.7 (95% CI, 2.0-3.6) for neonatal intensive care unit (NICU) admission (NICHD); and 2.5 (95% CI, 1.9-3.1) for composite adverse perinatal outcome (NICHD). Although the RR CIs overlapped among all standards for each individual outcome, the RR of composite adverse perinatal outcome in pregnancies with EFW < 10^th percentile was higher according to the NICHD (2.46; 95% CI, 1.9-3.1) than the FMF (1.47; 95% CI, 1.2-1.8) standard. The sensitivity for composite adverse perinatal outcome varied substantially between standards, ranging from 15% for NICHD to 32% for FMF, due mostly to differences in FPR; this variation subsided when the FPR was set to the same value (10%). Analysis of AUC revealed significantly better performance for the prediction of perinatal mortality by the PRB/NICHD standard (AUC = 0.70) compared with the Hadlock (AUC = 0.66) and FMF (AUC = 0.64) standards. Evaluation of partial AUC (FPR < 10%) demonstrated that the INTERGROWTH-21^st standard performed better than the Hadlock standard for the prediction of NICU admission and mechanical ventilation (P < 0.05 for both). Although fetuses with EFW > 90^th percentile were also at risk for any adverse perinatal outcome according to the INTERGROWTH-21^st (RR = 1.4; 95% CI, 1.0-1.9) and Hadlock (RR = 1.7; 95% CI, 1.1-2.6) standards, many times fewer cases (2-5-fold lower sensitivity) were detected by using EFW > 90^th percentile, rather than EFW < 10^th percentile, in screening by these standards.

CONCLUSIONS

Fetuses with EFW < 10^th percentile or EFW > 90^th percentile were at increased risk of adverse perinatal outcomes according to all or some of the eight growth standards, respectively. The RR of a composite adverse perinatal outcome in pregnancies with EFW < 10^th percentile was higher for the most-stringent (NICHD) compared with the least-stringent (FMF) standard. The results of the complementary analysis of AUC suggest slightly improved detection of adverse perinatal outcome by more recent population-based (INTERGROWTH-21^st ) and customized (PRB/NICHD) standards compared with the Hadlock and FMF standards. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

Does public reporting of the detection of fetal growth restriction improve clinical outcomes: a retrospective cohort study

OBJECTIVE

To assess the impact of publicly reporting a statewide fetal growth restriction (FGR) performance indicator.

DESIGN

Retrospective cohort study from 2000 to 2017.

SETTING

All maternity services in Victoria, Australia.

POPULATION

A total of 1 231 415 singleton births at ≥32 weeks of gestation.

METHODS

We performed an interrupted time-series analysis to assess the impact of publicly reporting an FGR performance indicator on the rate of detection for severe cases of small for gestational age (SGA). Rates of perinatal mortality and morbidity and obstetric intervention were assessed for severe SGA pregnancies and pregnancies delivered for suspected SGA.

MAIN OUTCOME MEASURES

Gestation at delivery, obstetric management and perinatal outcome.

RESULTS

The public reporting of a statewide FGR performance indicator was associated with a steeper reduction per quarter in the percentage of severe SGA undelivered by 40 weeks of gestation, from 0.13 to 0.51% (P = 0.001), and a decrease in the stillbirth rate by 3.3 per 1000 births among those babies (P = 0.01). Of babies delivered for suspected SGA, the percentage with birthweights ≥ 10th centile increased from 41.4% (n = 307) in 2000 to 53.3% (n = 1597) in 2017 (P < 0.001). Admissions to a neonatal intensive care unit for babies delivered for suspected SGA but with a birthweight ≥ 10th centile increased from 0.8 to 2.0% (P < 0.001).

CONCLUSIONS

The public reporting of an FGR performance indicator has been associated with the improved detection of severe SGA and a decrease in the rate of stillbirth among those babies, but with an increase in the rate of iatrogenic birth for babies with normal growth.

TWEETABLE ABSTRACT

The public reporting of hospital performance is associated with a reduction in stillbirth, but also with unintended interventions.

Birth weight charts for a Chinese population: an observational study of routine newborn weight data from Chongqing

Background

To construct birth weight charts for the Chongqing municipality, China and to identify whether differences in birth weight exist across urban/rural populations, thereby warranting separate charts.

Methods

Secondary analysis of routinely collected data from 338,454 live infants between 2014 and 2017 in Chongqing municipality. Sex-specific birth weight-for-gestational age centiles were constructed by the lambda-mu-sigma method via the GAMLSS R-based package. This method remodels the skewed birth weight distribution to estimate a normal distribution, allowing any birth weight centile to be generated. A separate set of centiles were created, accounting for urban/rural differences in birth weight.

Results

The centiles performed well across all gestational ages. For example, 2.37% (n = 4176) of males and 2.26% (n = 3656) of females were classified as below the 2nd centile (expected percentage = 2.28%), 49.75% of males (n = 87,756) and 50.73% of females (n = 82,203) were classified as below the 50th centile (expected proportion = 50%) and 97.52% of males (n = 172,021) and 97.48% of females (n = 157,967) were classified as below the 98th centile (expected proportion = 97.72%). The overall estimated centiles of birth weight for rural infants were higher than the centiles for urban infants at the earlier gestational ages (< 37 gestational weeks). However, this trend was reversed in infants born at term.

Conclusion

We have constructed a readily utilizable set of birth weight references from a large representative sample of births in Chongqing. The method used to construct the references allows for the calculation of the exact centile for any infant delivered between 28 and 42 completed weeks, which was not possible with previous charts.

Longitudinal study of individually adjusted fetal growth

OBJECTIVE

To construct individualized fetal growth curves estimated by ultrasound parameters adjusted for maternal and fetal characteristics.

METHODS

Data were retrospectively assessed from serial ultrasonographic examinations of singleton pregnancies at 12-42 gestational weeks among women without maternal or fetal conditions and full-term delivery at the University Hospital of University of São Paulo between July 1, 2014, and December 31, 2017. Measurements included biparietal diameter, head circumference, abdominal circumference, and femur length. Mixed linear regression was used to model the ultrasound biometric parameters as a function of gestational age, parity, maternal height, pre-pregnancy weight, and fetal sex.

RESULTS

In total, data were assessed from 1445 examinations of 434 pregnancies meeting the inclusion criteria. The estimated fetal weight model included gestational age, fetal sex, maternal height, and pre-pregnancy body mass index as covariates. The model enabled the construction of individual estimated fetal weight curves with respective percentiles covering 12-42 gestational weeks using maternal and fetal characteristics.

CONCLUSION

The growth curves, which are based on a sample of the Brazilian population with low risk of maternal or fetal morbidity and mortality, will make it possible to determine whether a fetus is achieving ideal growth potential according to maternal and fetal characteristics.

Deceleration of fetal growth rate as alternative predictor for childhood outcomes: a birth cohort study

BACKGROUND

Small for gestational age (SGA) is frequently used to define fetal growth restriction (FGR). However, FGR describes a slowdown in fetal growth and is not synonymous with SGA, which may introduce misclassification. We investigated the effect of both on delivery and childhood outcomes.

METHODS

From a prospective population-based cohort study we included 7959 live singleton births with data available on second trimester estimated fetal weight (EFW) and birth weight. We used a decrease in growth of > 40 percentiles between second trimester EFW and birthweight to define a deceleration in growth. SGA was defined as birthweight <p5.

RESULTS

Deceleration of growth occurred in 27,2% in SGA neonates and in 10,3% of neonates with an appropriate for gestational age (AGA) birthweight. Of all fetuses with decelerated growth, 90% was born AGA. SGA neonates were more often delivered by instrumental delivery or cesarean section and admitted to NICU. Both decelerated growth and SGA were associated with accelerated growth at 2 years, a smaller aortic diameter and lower left ventricular mass at 6 years.

CONCLUSIONS

Both decelerated growth and SGA are associated with unfavorable clinical outcomes in childhood. In addition to SGA, neonates with deceleration of growth should be considered a high-risk group.

Volume and vascularity: Using ultrasound to unlock the secrets of the first trimester placenta

Fetal growth restriction (FGR) is a major cause of perinatal morbidity and mortality. Identifying which pregnancies are at risk of FGR facilitates enhanced surveillance and early delivery before fetal demise can ensue. However, existing risk stratification strategies yield an unacceptably low detection rate. A robust and reliable first trimester screening test for FGR would not only enable high-risk women to be appropriately monitored but would facilitate future trials for possible interventions to enhance fetal growth. Both the volume and vascularity of the first trimester placenta has been demonstrated to be linked to adverse pregnancy outcomes including FGR and pre-eclampsia. The investigation of novel ultrasound markers for FGR are discussed along with the development of methods for fully automatic placental volume estimation which has the potential for use as part of a multi-variable population-based screening test.

Biochemical tests of placental function versus ultrasound assessment of fetal size for stillbirth and small-for-gestational-age infants

BACKGROUND

Stillbirth affects 2.6 million pregnancies worldwide each year. Whilst the majority of cases occur in low- and middle-income countries, stillbirth remains an important clinical issue for high-income countries (HICs) - with both the UK and the USA reporting rates above the mean for HICs. In HICs, the most frequently reported association with stillbirth is placental dysfunction. Placental dysfunction may be evident clinically as fetal growth restriction (FGR) and small-for-dates infants. It can be caused by placental abruption or hypertensive disorders of pregnancy and many other disorders and factorsPlacental abnormalities are noted in 11% to 65% of stillbirths. Identification of FGA is difficult in utero. Small-for-gestational age (SGA), as assessed after birth, is the most commonly used surrogate measure for this outcome. The degree of SGA is associated with the likelihood of FGR; 30% of infants with a birthweight < 10th centile are thought to be FGR, while 70% of infants with a birthweight < 3rd centile are thought to be FGR. Critically, SGA is the most significant antenatal risk factor for a stillborn infant. Correct identification of SGA infants is associated with a reduction in the perinatal mortality rate. However, currently used tests, such as measurement of symphysis-fundal height, have a low reported sensitivity and specificity for the identification of SGA infants.

OBJECTIVES

The primary objective was to assess and compare the diagnostic accuracy of ultrasound assessment of fetal growth by estimated fetal weight (EFW) and placental biomarkers alone and in any combination used after 24 weeks of pregnancy in the identification of placental dysfunction as evidenced by either stillbirth, or birth of a SGA infant. Secondary objectives were to investigate the effect of clinical and methodological factors on test performance.

SEARCH METHODS

We developed full search strategies with no language or date restrictions. The following sources were searched: MEDLINE, MEDLINE In Process and Embase via Ovid, Cochrane (Wiley) CENTRAL, Science Citation Index (Web of Science), CINAHL (EBSCO) with search strategies adapted for each database as required; ISRCTN Registry, UK Clinical Trials Gateway, WHO International Clinical Trials Portal and ClinicalTrials.gov for ongoing studies; specialist abstract and conference proceeding resources (British Library's ZETOC and Web of Science Conference Proceedings Citation Index). Search last conducted in Ocober 2016.

SELECTION CRITERIA

We included studies of pregnant women of any age with a gestation of at least 24 weeks if relevant outcomes of pregnancy (live birth/stillbirth; SGA infant) were assessed. Studies were included irrespective of whether pregnant women were deemed to be low or high risk for complications or were of mixed populations (low and high risk). Pregnancies complicated by fetal abnormalities and multi-fetal pregnancies were excluded as they have a higher risk of stillbirth from non-placental causes. With regard to biochemical tests, we included assays performed using any technique and at any threshold used to determine test positivity.

DATA COLLECTION AND ANALYSIS

We extracted the numbers of true positive, false positive, false negative, and true negative test results from each study. We assessed risk of bias and applicability using the QUADAS-2 tool. Meta-analyses were performed using the hierarchical summary ROC model to estimate and compare test accuracy.

MAIN RESULTS

We included 91 studies that evaluated seven tests - blood tests for human placental lactogen (hPL), oestriol, placental growth factor (PlGF) and uric acid, ultrasound EFW and placental grading and urinary oestriol - in a total of 175,426 pregnant women, in which 15,471 pregnancies ended in the birth of a small baby and 740 pregnancies which ended in stillbirth. The quality of included studies was variable with most domains at low risk of bias although 59% of studies were deemed to be of unclear risk of bias for the reference standard domain. Fifty-three per cent of studies were of high concern for applicability due to inclusion of only high- or low-risk women.Using all available data for SGA (86 studies; 159,490 pregnancies involving 15,471 SGA infants), there was evidence of a difference in accuracy (P < 0.0001) between the seven tests for detecting pregnancies that are SGA at birth. Ultrasound EFW was the most accurate test for detecting SGA at birth with a diagnostic odds ratio (DOR) of 21.3 (95% CI 13.1 to 34.6); hPL was the most accurate biochemical test with a DOR of 4.78 (95% CI 3.21 to 7.13). In a hypothetical cohort of 1000 pregnant women, at the median specificity of 0.88 and median prevalence of 19%, EFW, hPL, oestriol, urinary oestriol, uric acid, PlGF and placental grading will miss 50 (95% CI 32 to 68), 116 (97 to 133), 124 (108 to 137), 127 (95 to 152), 139 (118 to 154), 144 (118 to 161), and 144 (122 to 161) SGA infants, respectively. For the detection of pregnancies ending in stillbirth (21 studies; 100,687 pregnancies involving 740 stillbirths), in an indirect comparison of the four biochemical tests, PlGF was the most accurate test with a DOR of 49.2 (95% CI 12.7 to 191). In a hypothetical cohort of 1000 pregnant women, at the median specificity of 0.78 and median prevalence of 1.7%, PlGF, hPL, urinary oestriol and uric acid will miss 2 (95% CI 0 to 4), 4 (2 to 8), 6 (6 to 7) and 8 (3 to 13) stillbirths, respectively. No studies assessed the accuracy of ultrasound EFW for detection of pregnancy ending in stillbirth.

AUTHORS' CONCLUSIONS

Biochemical markers of placental dysfunction used alone have insufficient accuracy to identify pregnancies ending in SGA or stillbirth. Studies combining U and placental biomarkers are needed to determine whether this approach improves diagnostic accuracy over the use of ultrasound estimation of fetal size or biochemical markers of placental dysfunction used alone. Many of the studies included in this review were carried out between 1974 and 2016. Studies of placental substances were mostly carried out before 1991 and after 2013; earlier studies may not reflect developments in test technology.

The DESiGN trial (DEtection of Small for Gestational age Neonate), evaluating the effect of the Growth Assessment Protocol (GAP): study protocol for a randomised controlled trial

Background

Stillbirth rates in the United Kingdom (UK) are amongst the highest of all developed nations. The association between small-for-gestational-age (SGA) foetuses and stillbirth is well established, and observational studies suggest that improved antenatal detection of SGA babies may halve the stillbirth rate. The Growth Assessment Protocol (GAP) describes a complex intervention that includes risk assessment for SGA and screening using customised fundal-height growth charts. Increased detection of SGA from the use of GAP has been implicated in the reduction of stillbirth rates by 22%, in observational studies of UK regions where GAP uptake was high. This study will be the first randomised controlled trial examining the clinical efficacy, health economics and implementation of the GAP programme in the antenatal detection of SGA.

Methods/design

In this randomised controlled trial, clusters comprising a maternity unit (or National Health Service Trust) were randomised to either implementation of the GAP programme, or standard care. The primary outcome is the rate of antenatal ultrasound detection of SGA in infants found to be SGA at birth by both population and customised standards, as this is recognised as being the group with highest risk for perinatal morbidity and mortality. Secondary outcomes include antenatal detection of SGA by population centiles, antenatal detection of SGA by customised centiles, short-term maternal and neonatal outcomes, resource use and economic consequences, and a process evaluation of GAP implementation. Qualitative interviews will be performed to assess facilitators and barriers to implementation of GAP.

Discussion

This study will be the first to provide data and outcomes from a randomised controlled trial investigating the potential difference between the GAP programme compared to standard care for antenatal ultrasound detection of SGA infants. Accurate information on the performance and service provision requirements of the GAP protocol has the potential to inform national policy decisions on methods to reduce the rate of stillbirth.

Trial registration

Primary registry and trial identifying number: ISRCTN 67698474. Registered on 2 November 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3242-6) contains supplementary material, which is available to authorized users.

Reduced fetal growth velocities and the association with neonatal outcomes in appropriate-for-gestational-age neonates: a retrospective cohort study

Background

Fetal growth restriction is, despite advances in neonatal care and uptake of antenatal ultrasound scanning, still a major cause of perinatal morbidity. Neonates with birth weight > 10th percentile are assumed to be appropriate-for-gestational-age (AGA), although many are at increased risk of perinatal morbidity, because of undetected mild restriction of growth potential. We hypothesized that within AGA neonates, reduced fetal growth velocities are associated with adverse neonatal outcome.

Methods

A retrospective cohort study of singleton pregnancies, in the Maastricht University Medical Centre (MUMC) between 2010 and 2016. Women had two fetal biometry scans (18–22 weeks and 30–34 weeks of gestational age) and delivered a newborn with a birth weight between the 10th–80th percentile.

Differences in growth velocities of the abdominal circumference (AC), biparietal diameter (BPD), head circumference (HC) and femur length (FL) were compared between the suboptimal AGA (sAGA) (birth weight centiles 10–50) and optimal AGA (oAGA) (birth weight centiles 50–80) group. We assessed the association between velocities and neonatal outcomes.

Results

We included 934 singleton pregnancies. In the suboptimal AGA group, fetal growth velocities were lower (in mm/week): AC 10.72 ± 1.00 vs 11.23 ± 1.00 (p < .001), HC 10.50 ± 0.80 vs 10.68 ± 0.77 (p = 0.001), BPD 3.01 ± 0.28 vs 3.08 ± 0.27 (p < .0001) and FL 2.47 ± 0.21 vs 2.50 ± 0.22 (p = 0.014), compared to the optimal AGA group. Neonates with an adverse neonatal outcome had significantly lower growth velocities (in mm/week) of: AC 10.57 vs 10.94 (p = 0.034), HC 10.28 vs 10.59 (p = 0.003) and BPD 2.97 vs 3.04 (p = 0.043) compared to those with normal outcome. An inverse association was observed between the AC velocity and a composite adverse neonatal outcome (OR) = 0.667 (95%CI 0.507–0.879, p = 0.004), and between the AC velocity and neonates with NICU stay (OR) = 0.733 (95%CI 0.570–0.942, p = 0.015). Neonates with a birthweight lower than expected (based on the abdominal circumference at 20 weeks) had significantly more composite adverse neonatal outcomes 8.5% vs 5.0% (p = 0.047), NICU stays 9.6% vs 3.8% (p < .0001) and hospital stays 44.4% vs 35.6% (p = 0.006).

Conclusions

Appropriate-for-gestational-age neonates are a heterogeneous group with some showing suboptimal fetal growth. Abnormal fetal growth velocities, especially abdominal circumference velocity, are associated with adverse neonatal outcome and can potentially improve the detection of mild growth restriction when used in multivariate models.

Association between Brain-Derived Neurotrophic Factor (BDNF) Levels in 2nd Trimester Amniotic Fluid and Fetal Development

The development of the fetal nervous system mirrors general fetal development, comprising a combination of genetic resources and effects of the intrauterine environment. Our aim was to assess the 2^nd trimester amniotic fluid levels of brain-derived neurotrophic factor (BDNF) and to investigate its association with fetal growth. In accordance with our study design, samples of amniotic fluid were collected from women who had undergone amniocentesis early in the 2^nd trimester. All pregnancies were followed up until delivery and fetal growth patterns and birth weights were recorded, following which pregnancies were divided into three groups based on fetal weight: (1) AGA (appropriate for gestational age), (2) SGA (small for gestational age), and (3) LGA (large for gestational age). We focused on these three groups representing a reflection of the intrauterine growth spectrum. Our results revealed the presence of notably higher BDNF levels in the amniotic fluid of impaired growth fetuses by comparison with those of normal growth. Both SGA and macrosomic fetuses are characterized by notably higher amniotic fluid levels of BDNF (mean values of 36,300 pg/ml and 35,700 pg/ml, respectively) compared to normal-growth fetuses (mean value of 32,700 pg/ml). Though apparently small, this difference is, nevertheless, statistically significant (p value < 0.05) in SGA fetuses in the extremes of the distribution, i.e., below the 3rd centile. In conclusion, there is clear evidence that severe impairment of fetal growth induces the increased production of fetal brain growth factor as an adaptive mechanism in reaction to a hostile intrauterine environment, thereby accelerating fetal brain development and maturation.

Effect of maternal age, height, BMI and ethnicity on birth weight: an Italian multicenter study

AIM

To assess the effect of maternal age, height, early pregnancy body mass index (BMI) and ethnicity on birth weight.

SUBJECTS AND METHODS

A cross-sectional study was conducted on more than 42,000 newborns. Ethnicity was defined by maternal country of birth or, when missing (<0.6% of records), by citizenship. The effect of maternal characteristics on birth weight was evaluated with general linear models.

RESULTS

Maternal height and BMI, although not age, significantly affected birth weight. Among Italian babies, 4.7% of newborns were classified as appropriate-for-gestational age (AGA) (birth weight between the 10th and the 90th centile) according to the country-specific Italian Neonatal Study (INeS) charts and were re-classified as either large-(LGA) (birth weight >90th centile) or small-(SGA) (birth weight <10th centile) for gestational age (GA) after adjustment for maternal characteristics. On the contrary, 1.6% of Italian newborns were classified as SGA or LGA according to the INeS charts and re-classified as AGA after adjustment. Maternal ethnicity had a significant impact on birth weight. Specifically, babies born to Senegalese mothers were the lightest, whilst babies born to Chinese mothers were the heaviest.

CONCLUSIONS

Maternal height and early pregnancy BMI, should be considered in the evaluation of birth weight. The effect of ethnicity suggests the appropriateness of ethnic-specific charts. Further studies are necessary to determine if changes in birth weight classification, may translate into improved detection of subjects at risk of adverse outcomes.

Application of chromosomal microarray to investigate genetic causes of isolated fetal growth restriction

Background

Application of chromosomal microarray analysis (CMA) to investigate the genetic characteristics of fetal growth restriction (FGR) without ultrasonic structural anomalies at 18–32 weeks.

Methods

This study includes singleton fetuses with the estimated fetal weight (EFW) using the formula of Hadlock C below the 10th percentile for gestational age. FGRs without structural anomalies were selected, and the ones at high risk of noninvasive prenatal testing for trisomy 13, 18 and 21 would be excluded. The cases were divided into two groups: early-onset group (< 24^+ 0 weeks) and late-onset group (24–33 weeks). All patients were offered invasive prenatal testing with CMA and karyotype analysis.

Results

CMA detected 10 pathogenic copy number variants and 2 variant of uncertain significance case. CMA has a 5.5% (7/127) incremental yield of pathogenic chromosomal abnormalities over karyotyping. The positive detected rate was 9.6% (5/52) in early-onset group and 9.3% (7/75) in late-onset group respectively.

Conclusions

When FGR without structural anomaly is diagnosed before 33 weeks, an invasive prenatal procedure is strongly recommended. CMA can identify a 5.5% (7/127) incremental detection rate of pathogenic chromosomal abnormalities, which would impact clinical management for FGR.

Birth weight variants are associated with variable fetal intrauterine growth from 20 weeks of gestation

Fetal intrauterine growth is influenced by complex interactions between the maternal genes, environment and fetal genes. The aim of this study was to assess the effect of GWAS-identified genetic variants associated with birth weight on intrauterine fetal growth in 665 children. Fetal growth was estimated by two-dimensional ultrasound scans at 20, 25 and 32 weeks of gestation and growth trajectories were modeled using mixed linear regression. A genetic risk score (GRS) of birth weight-raising variants was associated with intrauterine growth showing an attenuating effect on the unconditional daily reduction in proportional weight gain of 8.92 × 10-6 percentage points/allele/day (p = 2.0 × 10-4), corresponding to a mean difference of 410 g at 40 weeks of gestation between a child with lowest and highest GRS. Eight variants were independently associated with intrauterine growth throughout the pregnancy, while four variants were associated with fetal growth in the periods 20-25 or 25-32 weeks of gestation, indicating that some variants may act in specific time windows during pregnancy. Four of the intrauterine growth variants were associated with type 2 diabetes, hypertension or BMI in the UK Biobank, which may provide basis for further understanding of the link between intrauterine growth and later risk of metabolic disease.

Fetal growth restriction in rural Bangladesh: a prospective study

BACKGROUND

Fetal growth restriction (FGR) and low birth weight(LBW) are serious public health problems. In developing countries, the incidence of low birth weight is predominantly the result of FGR, and both low birth weight and FGR are associated with neonatal death and later growth and development. Fetal growth charts are important for assessing the size of the fetus during pregnancy. The aims of this study were to describe the fetal growth pattern of a population in rural Bangladesh where maternal undernutrition is prevalent and to compare the timing of FGR in that population with WHO and INTERGROWTH- 21st international reference values.

METHODS

From November 2001 to October 2003, pregnant women were recruited in Matlab, a sub district of Bangladesh, and underwent three follow-up ultrasound examinations during pregnancy for measurement of the parameters of the fetal head, abdomen, and femur. The data were fitted to a linear-cubic model, and the derived values were compared with international reference values.

RESULTS

A total of 2678 singleton pregnancies were included in the analyses. The mean (SD) maternal age was 25.9 (5.8) years (range, 14-47 years). The mean (SD) early pregnancy BMI was 20.1 (2.6) kg/m2, and 27.6% of the women were underweight (BMI < 18.5 kg/m2). The growth of the biparietal diameter and abdominal circumference was significantly smaller throughout the pregnancy than the reference values (P ≤ 0.05). Moreover, a larger deviation in the growth of Bangladeshi fetuses was observed after 28 weeks of gestation when compared with the WHO and INTERGROWTH-21st reference fetal growth charts (P ≤ 0.05). After 28 weeks of gestation, the average Bangladesh estimated fetal weight gain per week of gestational age was significantly lower than the WHO estimated fetal weight by as much as 67.4 g (P ≤ 0.001).

CONCLUSIONS

The present population-based study showed that fetuses were smaller in the third trimester when compared with the reference charts. Growth faltering started in the second trimester for all the biometric parameters for the head, abdomen, and femur. This finding provides more challenges concerning nutritional interventions.

A new customized fetal growth standard for African American women: the PRB/NICHD Detroit study

BACKGROUND

The assessment of fetal growth disorders requires a standard. Current nomograms for the assessment of fetal growth in African American women have been derived either from neonatal (rather than fetal) biometry data or have not been customized for maternal ethnicity, weight, height, and parity and fetal sex.

OBJECTIVE

We sought to (1) develop a new customized fetal growth standard for African American mothers; and (2) compare such a standard to 3 existing standards for the classification of fetuses as small (SGA) or large (LGA) for gestational age.

STUDY DESIGN

A retrospective cohort study included 4183 women (4001 African American and 182 Caucasian) from the Detroit metropolitan area who underwent ultrasound examinations between 14-40 weeks of gestation (the median number of scans per pregnancy was 5, interquartile range 3-7) and for whom relevant covariate data were available. Longitudinal quantile regression was used to build models defining the "normal" estimated fetal weight (EFW) centiles for gestational age in African American women, adjusted for maternal height, weight, and parity and fetal sex, and excluding pathologic factors with a significant effect on fetal weight. The resulting Perinatology Research Branch/Eunice Kennedy Shriver National Institute of Child Health and Human Development (hereinafter, PRB/NICHD) growth standard was compared to 3 other existing standards--the customized gestation-related optimal weight (GROW) standard; the Eunice Kennedy Shriver National Institute of Child Health and Human Development (hereinafter, NICHD) African American standard; and the multinational World Health Organization (WHO) standard--utilized to screen fetuses for SGA (<10th centile) or LGA (>90th centile) based on the last available ultrasound examination for each pregnancy.

RESULTS

First, the mean birthweight at 40 weeks was 133 g higher for neonates born to Caucasian than to African American mothers and 150 g higher for male than female neonates; maternal weight, height, and parity had a positive effect on birthweight. Second, analysis of longitudinal EFW revealed the following features of fetal growth: (1) all weight centiles were about 2% higher for male than for female fetuses; (2) maternal height had a positive effect on EFW, with larger fetuses being affected more (2% increase in the 95th centile of weight for each 10-cm increase in height); and (3) maternal weight and parity had a positive effect on EFW that increased with gestation and varied among the weight centiles. Third, the screen-positive rate for SGA was 7.2% for the NICHD African American standard, 12.3% for the GROW standard, 13% for the WHO standard customized by fetal sex, and 14.4% for the PRB/NICHD customized standard. For all standards, the screen-positive rate for SGA was at least 2-fold higher among fetuses delivered preterm than at term. Fourth, the screen-positive rate for LGA was 8.7% for the GROW standard, 9.2% for the PRB/NICHD customized standard, 10.8% for the WHO standard customized by fetal sex, and 12.3% for the NICHD African American standard. Finally, the highest overall agreement among standards was between the GROW and PRB/NICHD customized standards (Cohen's interrater agreement, kappa = 0.85).

CONCLUSION

We developed a novel customized PRB/NICHD fetal growth standard from fetal data in an African American population without assuming proportionality of the effects of covariates, and without assuming that these effects are equal on all centiles of weight; we also provide an easy-to-use centile calculator. This standard classified more fetuses as being at risk for SGA compared to existing standards, especially among fetuses delivered preterm, but classified about the same number of LGA. The comparison among the 4 growth standards also revealed that the most important factor determining agreement among standards is whether they account for the same factors known to affect fetal growth.

Small for gestational age as an independent risk factor for long-term pediatric gastrointestinal morbidity of the offspring. J Matern Fetal Neonatal Med 2017;32:1407-1411. [PMID: 29157049 DOI: 10.1080/14767058.2017.1406473]

OBJECTIVE

The concept of neonatal programming has begun to emerge as an important component of adult health. Scarce data exist regarding perinatal risk factors for long-term gastrointestinal (GI) morbidity of the offspring. We aimed to evaluate the association between birthweight (BW) at term and long-term pediatric GI morbidity.

STUDY DESIGN

A population-based cohort analysis was performed, comparing the risk of long-term GI morbidity (up to the age of 18 years) in children delivered at term according to their BW. The study included all term deliveries occurring between 1991 and 2014 at a single regional tertiary medical center. Multiple gestations and fetuses with congenital malformations were excluded. BW was subdivided into: small for gestational age (small for gestational age (SGA) - BW ≤ 5th centile), appropriate for gestational age (AGA -5th centile < BW < 95th centile), and large for gestational age (LGA - BW ≥95th centile). Hospitalizations up to the age of 18 years involving GI morbidity were evaluated, using a predefined set of ICD-9 codes, as recorded in the hospital files. A Kaplan-Meier survival curve was used to compare cumulative GI morbidity incidence. A Cox proportional hazards model was constructed to control for confounders.

RESULTS

During the study period, 225,600 term singleton deliveries met the inclusion criteria. Of them, 4.6% (n = 10,415) were SGA and 4.3% (n = 9796) were LGA. During the 18-years follow-up period, 11,791 (5.2%) children were hospitalized with GI morbidity. Hospitalizations were significantly more common in the SGA group, as compared with the AGA and LGA groups (6.6 versus 5.2 versus 4.5%, respectively, p < .001) Specifically, inflammatory bowel disease, celiac, hernia, hepatitis, and cholecystitis, were more common in the SGA group. The Kaplan-Meier survival curve demonstrated a significantly higher cumulative incidence of gastrointestinal morbidity in the SGA group (log rank p < .001). In the Cox proportional hazards model, controlled for relevant clinical confounders, SGA BW was found to be an independent risk factor for long-term GI morbidity (adjusted HR = 1.23, 95%CI 1.14-1.33, p < .001).

CONCLUSIONS

SGA offspring are at an increased and independent risk for long-term pediatric GI morbidity.

3D fractional moving blood volume (3D-FMBV) demonstrates decreased first trimester placental vascularity in pre-eclampsia but not the term, small for gestation age baby

OBJECTIVE

To undertake an observational study to see whether first trimester placental vascularity, measured with a standardized power Doppler index: 3D-FMBV, is different in pregnancies which either develop pre-eclampsia or lead to term, normotensive small for gestational age (SGA) babies.

METHODS

Women were scanned between 11 and 13+6 weeks. The placental volume (sPlaV) was estimated using our previously validated semi-automated tool. Estimates of 3D-FMBV were generated from the raw power Doppler signal for the whole utero-placental interface, UPI (FMBV-UPI) and 5mm into the placenta (FMBV-IVS). Differences in the placental volume and FMBV for pregnancies developing pre-eclampsia and resulting in term, normotensive SGA babies were compared with term, normotensive, appropriate for gestational age (AGA), controls.

RESULTS

Results were available for 143 women. The placental volume (sPlaV) was reduced in both pre-eclampsia (p = 0.007) and term, normotensive SGA (p = 0.001) when compared with term normotensive AGA controls. 3D-FMBV estimates were significantly lower for pregnancies developing pre-eclampsia (FMBV-UPI, p = 0.03, FMBV-IVS, p = 0.01) but not for the normotensive SGA pregnancies (FMBV-UPI, p = 0.16, FMBV-IVS, p = 0.27).

CONCLUSION

Pregnancies destined to develop pre-eclampsia are more likely to have small placentas with significantly reduced vascularity at 11-13 weeks. Those pregnancies which were normotensive throughout but resulted in an SGA baby delivered at term, had significantly smaller placentas but with similar vascularity to normotensive AGA pregnancies.

[Does customized weight curves improve prenatal diagnosis of fetuses small for gestational age in a high-risk population?]

OBJECTIVES

To assess the accuracy of customized growth charts for the ultrasound antenatal diagnostic of fetus small for gestational age in a high-risk population of preterm.

METHODS

All premature infants born in a French university maternity center for a year and classified as small for gestational age at birth by using customized growth charts developed by Ego et al. were included in this retrospective study. At the ultrasound performed closest to the term, customized growth charts and population growth curves were compared for the antenatal diagnosis of a premature infants group classified small for gestational age in post-natal by customized growth charts and more at risk of perinatal complications.

RESULTS

Sixty-seven newborns were included in the study. Fifty-one (76.1%) were secondarily classified as small for gestational age although they were eutrophic on the basis of population growth curves and 16 (23.9%) were small for gestational age on both curves. The average time between the last ultrasound and birth was 2.2 weeks. On the threshold of the tenth percentile, the sensitivities of customized growth charts and curves in population were not significantly different (29.85% versus 41.79% P=0.05) for antenatal detection of fetus small for gestational age.

CONCLUSION

In our study, the use of customized growth charts does not improve the antenatal detection of most at-risk children.

The Impact of Kidney Development on the Life Course: A Consensus Document for Action

Hypertension and chronic kidney disease (CKD) have a significant impact on global morbidity and mortality. The Low Birth Weight and Nephron Number Working Group has prepared a consensus document aimed to address the relatively neglected issue for the developmental programming of hypertension and CKD. It emerged from a workshop held on April 2, 2016, including eminent internationally recognized experts in the field of obstetrics, neonatology, and nephrology. Through multidisciplinary engagement, the goal of the workshop was to highlight the association between fetal and childhood development and an increased risk of adult diseases, focusing on hypertension and CKD, and to suggest possible practical solutions for the future. The recommendations for action of the consensus workshop are the results of combined clinical experience, shared research expertise, and a review of the literature. They highlight the need to act early to prevent CKD and other related noncommunicable diseases later in life by reducing low birth weight, small for gestational age, prematurity, and low nephron numbers at birth through coordinated interventions. Meeting the current unmet needs would help to define the most cost-effective strategies and to optimize interventions to limit or interrupt the developmental programming cycle of CKD later in life, especially in the poorest part of the world.

2500-g Low Birth Weight Cutoff: History and Implications for Future Research and Policy

Purpose To research the origins of the 2500 g cutoff for low birth weight and the evolution of indicators to identify newborns at high mortality risk. Description Early research concluded "prematurity", measured mainly through birth weight, was responsible for increased health risks. The World Health Organization's original prematurity definition was birth weight ≤2500 g. 1960s research clarified the difference between gestational age and birth weight leading to questions of the causal role of birth weight for health outcomes. Focus turned to two etiologies of low birth weight, preterm births and intrauterine growth restriction, which were both causally associated with morbidity and mortality but through different pathways; a standard cutoff based on gestational age or customized cutoff was debated. Assessment While low birth weight can be due to preterm or intrauterine growth restriction (or both), the historic 2500 g cutoff remains the standard by which the majority of policy makers define low birth weight and use it to predict perinatal and infant adverse outcomes. Conclusion Current efforts to refocus research on preterm births and poor intrauterine growth are important to understanding the direct causes of mortality rather than low birth weight as a convenient surrogate. Such distinctions also allow researchers and practitioners to test and target interventions outcomes more effectively.

Prevalence and risk factors for inappropriate birth weight for gestational age

Background

Infants with an inappropriate birth weight for their gestational age are more likely to develop complications during pregnancy and postpartum, and have increased long-term health risks.

Objectives

To determine the prevalence and risk factors for infants with inappropriate birth weight for their gestational age.

Methods

We enrolled 820 women with uncomplicated, singleton pregnancies who gave birth to a live born infant at term. Prepregnancy baseline and obstetric information were extracted from medical records, including body mass index (BMI), gestational weight gain, and infant birth weight. Prevalence of small-for-gestational age (SGA) and large-for-gestational age (LGA) infants was determined. We compared variables between groups to identify associated factors.

Results

Prevalence of SGA was 2.6% and LGA was 10.5%. Prepregnancy BMI and gestational weight gain were significantly higher in the LGA than in the SGA group (P = 0.041 and < 0.001, respectively). The birth weight and gestational weight gain, but not the prepregnancy BMI, were significantly different (P < 0.001). Logistic regression analysis determined that inadequate gestational weight gain significantly increased the risk of SGA (adjusted OR 3.20, 95%CI 1.06 to 9.64, P = 0.039), and significantly reduced the risk of LGA (adjusted OR 0.43, 95% CI 0.20 to 0.91, P = 0.028). Excessive gestational weight gain significantly increased the risk of LGA (adjusted OR 2.00, 95% CI 1.21 to 3.30, P = 0.006). There was no significant association with prepregnancy BMI.

Conclusions

Controlling gestational weight gain may improve maternal and neonatal outcomes.