Intrauterine growth restriction: new standards for assessing adverse outcome

Pentaerythrityl tetranitrate improves the outcome of children born to mothers with compromised uterine perfusion-12-months follow-up and safety data of the double-blind randomized PETN trial

BACKGROUND

This is a follow-up study to the pentaerythrityl tetranitrate randomized controlled multicenter trial that reports neonatal outcome data of newborns admitted to neonatal intensive care units and outcome data of the offspring at 12 months of age.

OBJECTIVE

We present data on adverse events reported during the study to document the safety of pentaerythrityl tetranitrate treatment during pregnancy. To further evaluate the effects of pentaerythrityl tetranitrate on neonatal and long-term outcomes, we present follow up data from of 240 children at 12 months of age, including information on height, weight, head circumference, developmental milestones, and the presence of chronic disease and of 144 newborns admitted to the neonatal intensive care unit during the trial.

STUDY DESIGN

The pentaerythrityl tetranitrate trial was a randomized, double-blind, placebo-controlled study designed to assess the efficacy and safety of the nitric oxide-donor pentaerythrityl tetranitrate in the prevention of fetal growth restriction and perinatal death in pregnancies complicated by abnormal placental perfusion.

RESULTS

Results at 12 months demonstrated that significantly more children were age appropriately developed without impairments in the pentaerythrityl tetranitrate group (P=.018). In addition, the presence of chronic disease was lower in the pentaerythrityl tetranitrate group (P=.041). Outcome data of the 144 newborns admitted to the neonatal intensive care unit did not reveal differences between the treatment and placebo groups. There were no differences in the number or nature of reported adverse events between the study groups.

CONCLUSION

The analysis shows that study children born in the pentaerythrityl tetranitrate cohort have a clear advantage compared with the placebo group at the age of 12 months, as evidenced by the increased incidence of normal development without the presence of chronic disease. Although safety has been proven, further follow-up studies are necessary to justify pentaerythrityl tetranitrate treatment during pregnancies complicated by impaired uterine perfusion.

Abdominal circumference growth velocity as a predictor of adverse perinatal outcomes in small-for-gestational-age fetuses

OBJECTIVE

To assess the predictive value of abdominal circumference growth velocity (ACGV) between the second and third trimesters to predict adverse perinatal outcomes in a cohort of small-for-gestational-age fetuses without evidence of placental insufficiency (i.e. fetal growth restriction).

MATERIAL AND METHODS

This is a single-center retrospective cohort study of all singleton pregnancies with small-for-gestational-age fetuses diagnosed and delivered at a quaternary institution. Crude and adjusted odds ratios (ORs) and corresponding confidence intervals (CIs) were calculated via logistic regression models to assess the potential association between abnormal ACGV (i.e. ≤10th centile) and adverse perinatal outcomes defined as a composite outcome (i.e. umbilical artery pH <7.1, 5-min Apgar score <7, admission to the neonatal intensive care unit, hypoglycemia, intrapartum fetal distress requiring expedited delivery, and perinatal death). Furthermore, the area under the receiver-operating characteristic curve (AUC) of three logistic regression models based on estimated fetal weight and ACGV for predicting the composite outcome is also reported.

RESULTS

A total of 154 pregnancies were included for analysis. The median birthweight for the cohort was 2,437 g (interquartile range [IQR] 2280, 2635). Overall, the primary composite outcome was relatively common (29.2%). In addition, there was a significant association between abnormal ACGV and adverse perinatal outcomes (OR 3.37, 95% CI 1.60, 7.13; adjusted OR 4.30, 95% CI 1.77, 10.49). Likewise, the AUC for the ACGV was marginally higher (0.64) than the estimated fetal weight (0.54) and ACGV + estimated fetal weight (0.54). Still, no significant difference was detected between the curves (p = 0.297).

CONCLUSIONS

Our results suggest that an ACGV below the 10th centile is a risk factor for adverse perinatal outcomes among small-for-gestational-age fetuses.

Effect of pentaerythritol tetranitrate (PETN) on the development of fetal growth restriction in pregnancies with impaired uteroplacental perfusion at midgestation-a randomized trial

BACKGROUND

Fetal growth restriction is strongly associated with impaired placentation and abnormal uteroplacental blood flow. Nitric oxide donors such as pentaerythritol tetranitrate are strong vasodilators and protect the endothelium. Recently, we demonstrated in a randomized controlled pilot study a 38% relative risk reduction for the development of fetal growth restriction or perinatal death following administration of pentaerythritol tetranitrate to pregnant women at risk, identified by impaired uterine perfusion at midgestation. Results of this monocenter study prompted the hypothesis that pentaerythritol tetranitrate might have an effect in pregnancies with compromised placental function as a secondary prophylaxis.

OBJECTIVE

This study aimed to test the hypothesis that the nitric oxide donor pentaerythritol tetranitrate reduces fetal growth restriction and perinatal death in pregnant women with impaired placental perfusion at midgestation in a multicenter trial.

STUDY DESIGN

In this multicenter, randomized, double-blind, placebo-controlled trial, 2 parallel groups of pregnant women presenting with a mean uterine artery pulsatility index >95th percentile at 19+0 to 22+6 weeks of gestation were randomized to 50-mg Pentalong or placebo twice daily. Participants were assigned to high- or low-risk groups according to their medical history before randomization was performed block-wise with a fixed block length stratified by center and risk group. The primary efficacy endpoint was the composite outcome of perinatal death or development of fetal growth restriction. Secondary endpoints were neonatal and maternal outcome parameters.

RESULTS

Between August 2017 and March 2020, 317 participants were included in the study and 307 were analyzed. The cumulative incidence of the primary outcome was 41.1% in the pentaerythritol tetranitrate group and 45.5% in the placebo group (unadjusted relative risk, 0.90; 95% confidence interval, 0.69-1.17; adjusted relative risk, 0.90; 95% confidence interval, 0.69-1.17; P=.43). Secondary outcomes such as preterm birth (unadjusted relative risk, 0.73; 95% confidence interval, 0.56-0.94; adjusted relative risk, 0.73; 95% confidence interval, 0.56-0.94; P=.01) and pregnancy-induced hypertension (unadjusted relative risk, 0.65; 95% confidence interval, 0.46-0.93; adjusted relative risk, 0.65; 95% confidence interval, 0.46-0.92; P=0.01) were reduced.

CONCLUSION

Our study failed to show an impact of pentaerythritol tetranitrate on the development of fetal growth restriction and perinatal death in pregnant women with impaired uterine perfusion at midgestation. Pentaerythritol tetranitrate significantly reduced secondary outcome parameters such as the incidence of preterm birth and pregnancy-induced hypertension in these pregnancies.

Comparison of cardiac morphology and function in small for gestational age fetuses and fetuses with late-onset fetal growth retardation

OBJECTIVES

To compare cardiac structural and functional findings of fetuses with fetal growth restriction (FGR) and small for gestational age (SGA).

METHODS

In this prospective cohort study, patients were classified into three groups using Delphi procedure according to fetal weight, umbilical, uterine artery Doppler and cerebroplacental ratio. Fetal cardiac ultrasonographic morphology and Doppler examination was performed to all pregnant women at 36 weeks of gestation.

RESULTS

Seventy three patients were included in the study. There were one (6.7%) patient in the control group, 2 (13.3%) in the SGA group and 12 (80%) in the FGR group who needed neonatal intensive care unit (NICU) and NICU requirement was significantly higher in FGR fetuses (p<0.001). Left spherical index was found to be lower only among FGR fetuses (p=0.046). Left ventricular wall thickness was decreased and the right/left ventricular wall ratio was increased in FGR fetuses (p=0.006, p<0.001). Tricuspid/mitral valve ratio and mitral annular plane systolic excursion value was lower in FGR fetuses (p=0.034, p=0.024 respectively). Also, myocardial performance index was remarkably higher in FGR group (p=0.002).

CONCLUSIONS

We detected cardiac morphological changes in cases of both SGA and FGR-more pronounced in the FGR cases. Findings related to morphological changes on the left side in FGR cases were considered secondary to volume increase in FGR cases as an indicator of a brain-protective effect. In the FGR group, both systolic and diastolic dysfunctions were detected in the left heart.

Hippocampal mTOR Dysregulation and Morphological Changes in Male Rats after Fetal Growth Restriction

Fetal growth restriction (FGR) has been linked to long-term neurocognitive impairment, especially in males. To determine possible underlying mechanisms, we examined hippocampal cellular composition and mTOR signaling of male rat FGR offspring during main brain growth and development (postnatal days (PND) 1 and 12). FGR was either induced by a low-protein diet throughout pregnancy, experimental placental insufficiency by bilateral uterine vessel ligation or intrauterine stress by “sham” operation. Offspring after unimpaired gestation served as common controls. Low-protein diet led to a reduced cell density in the molecular dentate gyrus subregion, while intrauterine surgical stress was associated with increased cell density in the cellular CA2 subregion. Experimental placental insufficiency caused increased mTOR activation on PND 1, whereas intrauterine stress led to mTOR activation on PND 1 and 12. To determine long-term effects, we additionally examined mTOR signaling and Tau phosphorylation, which is altered in neurodegenerative diseases, on PND 180, but did not find any changes among the experimental groups. Our findings suggest that hippocampal cellular proliferation and mTOR signaling are dysregulated in different ways depending on the cause of FGR. While a low-protein diet induced a decreased cell density, prenatal surgical stress caused hyperproliferation, possibly via increased mTOR signaling.

Metabolic Consequences of Gestational Cannabinoid Exposure

Up to 20% of pregnant women ages 18-24 consume cannabis during pregnancy. Moreover, clinical studies indicate that cannabis consumption during pregnancy leads to fetal growth restriction (FGR), which is associated with an increased risk of obesity, type II diabetes (T2D), and cardiovascular disease in the offspring. This is of great concern considering that the concentration of Δ9- tetrahydrocannabinol (Δ9-THC), a major psychoactive component of cannabis, has doubled over the last decade and can readily cross the placenta and enter fetal circulation, with the potential to negatively impact fetal development via the endocannabinoid (eCB) system. Cannabis exposure in utero could also lead to FGR via placental insufficiency. In this review, we aim to examine current pre-clinical and clinical findings on the direct effects of exposure to cannabis and its constituents on fetal development as well as indirect effects, namely placental insufficiency, on postnatal metabolic diseases.

Evaluation of cardiac sphericity index among intrauterine growth restriction and normal fetuses

Foetal growth restriction (FGR) describes the pregnancy complications of pathological reduced foetal growth, leading to significant perinatal mortality and morbidity, and subsequent long-term cardiovascular outcomes. This prospective case-control study was performed on pregnant women referred to the hospitals of Tehran University of Medical Sciences in 2017-2019. All pregnant women underwent ultrasound scan and doppler sonography. FGR was defined as a sonographic estimation of foetal weight below the tenth percentile for a given gestational age. Cardiac sphericity index, including basal-apical length (BAL), transverse length (TL), global sphericity index (GSI), umbilical artery pulsatility index (PI), middle cerebral artery (MCA) PI and cerebroplacental ratio (CPR) were assessed. Mean gestational age in FGR and control groups were 233.90 ± 22.00 days and 229.00 ± 25.02 days, respectively. Foetal size index and estimated foetal weight in FGR foetuses were significantly lower than the control group (p < .05). BAL, TL and GSI were significantly affected by FGR (p = .0001, p = .018 and p = .0001, respectively). Abnormal GSI, MCA PI, umbilical artery PI and CPR were significantly more prevalent among FGR foetuses (p = .017, p = .0001, p = .0001 and p = .0001, respectively). Cardiac sphericity index, as well as uterine PI, MCA PI and CPR, were the determinants of FGR in foetuses with normal Doppler and abnormal GSI.IMPACT STATEMENTWhat is already known on this subject? Foetal growth restriction (FGR) describes the foetus that does not grow to its expected biological potential in utero, and is a relatively common complication of pregnancy. FGR is accosted with negative birth outcomes and long-term cardiovascular outcomes. One of the indicators of FGR is cardiac sphericity.What do the results of this study add? The findings of this study revealed that the cardiac sphericity index as well as umbilical PI, MCA PI and CPR ratio change in FGR foetuses.What are the implications of these findings for clinical practice and/or further research? It is recommended that more studies be performed to follow FGR foetuses longitudinally and evaluate the long-term cardiac abnormalities in infancy and childhood and compare it between FGR foetuses and normal foetuses.

Fetal Growth Restriction in Hypertensive vs. Heavy Smoking Women-Placental Pathology, Ultrasound Findings, and Pregnancy Outcomes

We compared placental pathology, ultrasonographic findings, and obstetric outcomes, in gestations complicated by fetal growth restriction (FGR) with either a background of hypertensive disorder or heavy tobacco cigarette smoking. The medical records and placental pathology reports of pregnancies complicated with FGR (birthweight < 10th percentile) between December 2008 and May 2018 from a single tertiary center were reviewed. Placental pathology, ultrasound findings, and pregnancy outcomes were compared between hypertensive patients (HTN) and heavy smokers (SMO). We included 213 pregnancies: 129 (60.6%) in the SMO group and 84 (39.4%) in the HTN group. The HTN group was characterized by a higher BMI (p = 0.01), higher rates of Cesarean deliveries (p = 0.006), and a lower gestational age at delivery (35.6 ± 3.8 vs. 37.5 ± 2.9 weeks, p < 0.001). The HTN group had higher rates of placental weights < 10th percentile (p = 0.04) and maternal vascular malperfusion lesions (p < 0.001), while the SMO group had higher rates of inflammatory lesions (p = 0.04). On ultrasound, the HTN group had a higher head/abdomen circumference ratio (p < 0.001) and more abnormal Doppler studies (< 0.001). Neonates in the HTN group had lower birthweights (p < 0.001) and higher rates of NICU admissions (p = 0.002) and adverse neonatal outcome (p = 0.006). On multivariable analysis, gestational age at delivery (aOR = 0.65, 95%CI 0.55-0.87), hypertensive disorders (aOR = 1.8, 95%CI = 1.21-4.81), placental MVM lesions (aOR = 1.23, 95%CI = 1.08-5.02), and the combination of HTN+MVM (aOR = 2.63, 95%CI 1.78-7.30) were independently associated with adverse neonatal outcome. Hypertension and smoking may lead to FGR in different pathways as the two groups significantly differed in maternal characteristics, placental pathology, ultrasound findings, and neonatal outcomes. A hypertensive disorder probably represents a more hostile maternal environment than smoking and these pregnancies would probably benefit from closes monitoring.

Preventing term stillbirth: benefits and limitations of using fetal growth reference charts

PURPOSE OF REVIEW

This review examines the variation in clinical practice with regards to ultrasound estimation of fetal weight, as well as calculation of fetal weight centiles.

RECENT FINDINGS

Placental dysfunction is associated with fetal smallness from intrauterine malnutrition as well as fetal disability and even stillbirth from hypoxemia. Although estimating fetal weight can be done accurately, the issue of which fetal weight centile chart should be used continues to be a contentious topic. The arguments against local fetal growth charts based on national borders and customization for variables known to be associated with disease are substantial. As for other human diseases such as hypertension and diabetes, there is a rationale for the use of an international fetal growth reference standard. Irrespective of the choice of fetal growth reference standard, a significant limitation of small for gestational age (SGA) detection programs to prevent stillbirth is that the majority of stillborn infants at term were not SGA at the time of demise.

SUMMARY

Placental dysfunction can present with SGA from malnutrition and/or stillbirth from hypoxemia depending on the gestational age of onset. Emerging data show that at term, fetal Doppler arterial redistribution is associated more strongly with perinatal death than fetal size. Properly conducted trials of the role for maternal characteristics, fetal size, placental biomarkers, and Doppler assessing fetal well-being are required urgently.

Fetal biometry assessment with Intergrowth 21st's and Salomon's equations in rural Burkina Faso

Background

Ultrasound scanning during the 2nd or the 3rd trimester of pregnancy for fetal size disturbances screening is heavily dependent of the choice of the reference chart. This study aimed to assess the agreement of Salomon and the Intergrowth 21st equations in evaluating fetal biometric measurements in a rural area of Burkina Faso, and to measure the effect of changing a reference chart.

Methods

Data collected in Nazoanga, Burkina Faso, between October 2010 and October 2012, during a clinical trial evaluating the safety and efficacy of several antimalarial treatments in pregnant women were analyzed. We included singleton pregnancies at 16–36 weeks gestation as determined by ultrasound measurements of fetal bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Expected mean and standard deviation at a given gestational age was computed using equations from Salomon references and using Intergrowth 21st standard. Then, z-scores were calculated and used subsequently to compare Salomon references with Intergrowth 21st standards.

Results

The analysis included 276 singleton pregnancies.

Agreement was poor except for HC: mean difference − 0.01, limits of agreement − 0.60 and 0.59. When AC was used as a surrogate of fetal size, switching from the reference of Salomon to the standards of Intergrowth 21st increased ten times the proportion of fetuses above the 90th percentile: 2.9 and 31.2%, respectively.

Mean differences were larger in the third trimester than in the second trimester. However, agreement remained good for HC in both trimesters.

Difference in the proportion of AC measurements above the 90th percentile using Salomon and Intergrowth 21st equations was greater in the second trimester (2.6 and 36.3%, respectively) than in the third trimester (3.5 and 19.8%, respectively). The greatest difference between the two charts was observed in the number of FL measurements classified as large in the second trimester (6.8 and 54.2%, using Salomon and Intergrowth 21st equations, respectively).

Conclusion

The agreement between Intergrowth 21st and Salomon equations is poor apart from HC. This would imply different clinical decision regarding the management of the pregnancy.

Maternal serum and cord blood leptin concentrations at delivery

Introduction

Studies have demonstrated leptin involvement in the physiology and pathophysiology of pregnancy and suggest that leptin may be a prognostic marker for some complications of pregnancy although the association remains unclear. To date no studies have reported leptin reference intervals established in normal pregnancy, which could be used for interpreting the differences in leptin levels found in normal and pathological pregnancies.

Objective

To determine leptin concentrations at delivery, in maternal serum in normal pregnancy and in cord blood and to establish reference intervals for leptin.

Material and methods

The study was performed in 194 pregnant women without any comorbid health conditions. Leptin concentrations in maternal serum and in cord blood were measured by ELISA and subsequently analyzed by gestational age (weeks), maternal Body Mass Index (BMI), mode of delivery and infant gender and birth weight. For comparative analyses of normally distributed variables, parametric tests such as the Student–t were used to test the assumption of homogeneity or non-homogeneity of variance and a One-Way ANOVA when more than two groups were compared. The Pearson correlation coefficient was calculated to assess the correlation between normally distributed variables (p<0.05). The reference intervals for leptin were obtained by referring to the central 95% of laboratory test values.

Results

In normal pregnant women, the mean serum leptin concentration at delivery was 37.17 ± 28.07 ng/mL and the established reference interval was 33.19–41.14 ng/mL. The mean leptin concentration in cord blood was 14.78 ± 15.97 ng/mL and the established reference interval was 12.32–17.67 ng/mL. There was a statistically significant positive correlation between maternal serum and cord blood leptin concentrations (r = 0.37; p = 0.00). Mean leptin concentrations in cord blood increased with gestational age (p = 0.00). No statistically significant differences in maternal serum and cord blood leptin concentrations were found in regard to mode of delivery and neonatal gender. A statistically significant correlation was found between maternal serum leptin and third-trimester BMI (r = 0.22; p = 0.00), but there was no association between maternal BMI and cord blood leptin concentration. There was a statistically significant positive correlation between cord blood leptin concentration and birth weight (r = 0.23; p = 0.00).

Conclusions

Reference intervals for leptin in maternal serum and in cord blood established in normal pregnancy could be used in clinical practice for interpreting the differences in leptin concentrations found in normal pregnancy and in complications of pregnancy. The results indicate a strong association between maternal serum leptin levels and obesity and between cord blood leptin levels and birth weight.

Does Pentaerytrithyltetranitrate reduce fetal growth restriction in pregnancies complicated by uterine mal-perfusion? Study protocol of the PETN-study: a randomized controlled multicenter-trial

BACKGROUND

Affecting approximately 10% of pregnancies, fetal growth restriction (FGR), is the most important cause of perinatal mortality and morbidity. Impaired placental function and consequent mal-perfusion of the placenta is the leading cause of FGR. Although, screening for placental insufficiency based on uterine artery Doppler measurement is well established, there is no treatment option for pregnancies threatened by FGR. The organic nitrate pentaerithrityl tetranitrate (PETN) is widely used for the treatment of cardiovascular disease and has been shown to have protective effects on human endothelial cells. In a randomized placebo controlled pilot-study our group could demonstrate a risk reduction of 39% for the development of FGR, and FGR or death, by administering PETN to patients with impaired uterine artery Doppler at mid gestation. To confirm these results a prospective randomized placebo controlled double-blinded multicentre trial was now initiated.

METHOD

The trial has been initiated in 14 centres in Germany. Inclusion criteria are abnormal uterine artery Doppler, defined by mean PI > 1.6, at 190 to 226 weeks of gestation in singleton pregnancies. Included patients will be monitored in 4-week intervals. Primary outcome measures are development of FGR (birth weight < 10th percentile), severe FGR (birth weight < 3rd centile) and perinatal death. Placental abruption, birth weight below the 3rd, 5th and 10th centile, development of FGR requiring delivery before 34 weeks` gestation, neonatal intensive care unit admission, and spontaneous preterm delivery < 34 weeks` and 37 weeks` gestation will be assessed as secondary endpoints. Patient enrolment was started in August 2017. Results are expected in 2020.

DISCUSSION

During the past decade therapeutic agents with possible perfusion optimizing potential have been evaluated in clinical trials to treat FGR. Meta-analysis and sub-analysis of trials targeting preeclampsia revealed ASS to have a potential in reducing FGR. Phosphodiesterase-type-5 inhibitors have recently been tested in a worldwide RCT for therapy of established FGR, failing to show an effect on neonatal outcome. The ongoing multicenter trial will, by confirming our previous results, finally provide a therapeutic option in cases at risk for FGR.

TRIAL REGISTRATION

DRKS00011374 registered at September 29th, 2017 and NCT03669185 , registered September 13th, 2018.

The Grown in Wales Study: Examining dietary patterns, custom birthweight centiles and the risk of delivering a small-for-gestational age (SGA) infant

Objectives

Maternal lifestyles, including diet, have been linked to infant birthweight. However, customised birthweight centiles (CBWC), which more accurately identify small babies that have increased fetal growth restriction and are at higher risk of newborn morbidity and later life health complications, are rarely considered when studying maternal diet. This study investigated maternal dietary patterns and their impact on infant CBWC within a cohort of women living in South Wales.

Methods

This study utilised cross-sectional data from the longitudinal Grown in Wales (GiW) cohort. Women 18–45 years old were recruited the morning prior to an elective caesarean section (ELCS). Women completed a food frequency questionnaire (FFQ). Additional data on pregnancy and birth outcomes was extracted from medical notes. Data from 303 participants was analysed.

Results

‘Western’ and ‘Health conscious dietary patterns were identified. The ‘Health Conscious’ dietary pattern was significantly associated with maternal BMI, age, education, income and exercise. Adjusted regression analyses indicated that greater adherence to a ‘Health Conscious’ dietary pattern was significantly associated with increased CBWC (AOR = 4.75 [95% CI: 1.17, 8.33] p = .010) and reduced risk of delivering a small-for-gestational age (SGA) infant (AOR = .51 [95% CI: .26, .99] p = .046).

Conclusion

A healthier diet was significantly associated with higher birthweight using CBWC and a reduced risk of delivering an SGA infant suggesting that birthweight will be improved in areas of Wales by focused support encouraging healthier dietary habits.

Retinoic acid signaling reduction recapitulates the effects of alcohol on embryo size

Intrauterine growth restriction (IUGR) is commonly observed in human pregnancies and can result in severe clinical outcomes. IUGR is observed in Fetal Alcohol Syndrome (FAS) fetuses as a result of alcohol (ethanol) exposure during pregnancy. To further understand FAS, the severe form of Fetal Alcohol Spectrum Disorder, we performed an extensive quantitative analysis of the effects of ethanol on embryo size utilizing our Xenopus model. Ethanol-treated embryos exhibited size reduction along the anterior-posterior axis. This effect was evident primarily from the hindbrain caudally, while rostral regions appeared refractive to ethanol-induced size changes, also known as asymmetric IUGR. Interestingly, some embryo batches in addition to shortening from the hindbrain caudally also exhibited an alcohol-dependent reduction of the anterior head domain, known as symmetric IUGR. To study the connection between ethanol exposure and reduced retinoic acid levels we treated embryos with the retinaldehyde dehydrogenase inhibitors, DEAB and citral. Inhibition of retinoic acid biosynthesis recapitulated the growth defects induced by ethanol affecting mainly axial elongation from the hindbrain caudally. To study the competition between ethanol clearance and retinoic acid biosynthesis we demonstrated that, co-exposure to alcohol reduces the teratogenic effects of treatment with retinol (vitamin A), the retinoic acid precursor. These results further support the role of retinoic acid in the regulation of axial elongation.

Pentaerythrityltetranitrate (PETN) improves utero- and feto-placental Doppler parameters in pregnancies with impaired utero-placental perfusion in mid-gestation - a secondary analysis of the PETN-pilot trial

AIM

In pregnancies complicated by impaired utero-placental perfusion, pentaeritrithyltetranitrate (PETN) has been shown to reduce the risk of severe fetal growth restriction (FGR) and perinatal death by 39%. The effect is most likely related to the vasodilatative influence of PETN. To assess its impact on utero-placental and fetal perfusion, we analyzed the Doppler parameters measured during the PETN pilot-trial.

METHODS

One hundred and eleven pregnancies presenting impaired utero-placental resistance at mid-gestation were included in the trial. Fifty-four women received PETN, while 57 received a placebo. Doppler velocimetry measurements were monitored biweekly. Statistical analysis was performed using a mixed linear model.

RESULTS

Within the first week of treatment, the mean pulsatility index (PI) of the uterine artery (UtA) dropped more prominently in the PETN group [-0.20, 95% confidence interval (CI): -0.34 to -0.05, P=0.007). The adjusted relative risk (RR) for abnormal cerebro-placental ratio (CPR) was significantly reduced by PETN [RR 0.412 (95% CI: 0.181-0.941)]. Kaplan-Meier analysis demonstrates the postponement of absent end-diastolic flow (AED), absent or reverse end-diastolic flow (ARED), brain sparing and abnormal cerebroplacental ratio (CPR) in the PETN group.

CONCLUSION

The demonstrated effect of PETN on utero-placental and feto-placental perfusion strengthens the evidence for a positive impact in pregnancies complicated by impaired placental perfusion and might explain the effect on neonatal outcome, as shown in the PETN-pilot trial.

Human leukocyte antigen DQ2/DQ8 positivity in women with history of stillbirth

PROBLEM

The aim of this study was to investigate the prevalence of human leukocyte antigens (HLA) DQ2 and DQ8 haplotypes, two common polymorphisms associate with celiac disease (CD), in women with previous stillbirth, but not affected by CD.

METHOD OF STUDY

Women with history of unexplained term stillbirth referred to our Center for High-Risk Pregnancies for a preconception counseling, and women with previous uncomplicated pregnancies, were enrolled as cases and controls. Celiac women were excluded from the study. Genetic tests for HLA DQ2/DQ8 were performed, and patients' data were compared.

RESULTS

The population included 56 women with a previous term stillbirth and 379 women with history of uncomplicated pregnancies. The prevalence of HLA-DQ2 or DQ8 positivity was significantly higher in cases than in controls (50% vs 29.5%) (P = 0.0031). Women with HLA DQ8 genotype have a significantly higher risk of stillbirth (OR: 2.84 CI: 1.1840-6.817) and in case of DQ2 genotype the OR for stillbirth was even higher (OR: 4.46 CI: 2.408-8.270). In the stillbirth group, SGA neonates were significantly more frequent in those with HLA-DQ2/DQ8 haplotypes than in those resulted negative to genetic testing (85.7% vs 42 .8%, P = 0.004).

CONCLUSION

In women with history of term stillbirth, a significantly higher prevalence of HLA DQ2/DQ8 haplotypes has been found compared to women with previous uneventful pregnancies. In addition, HLA DQ2/DQ8 positivity was significantly associated with suboptimal fetal growth in intrauterine fetal death cases, as shown by an increased prevalence of SGA babies.

Screening for fetal growth restriction using ultrasound and the sFLT1/PlGF ratio in nulliparous women: a prospective cohort study

BACKGROUND

Fetal growth restriction is a major determinant of perinatal morbidity and mortality. This condition has no gold standard definition, but a widely used proxy is delivery of a small for gestational age infant (<10th percentile) combined with an adverse pregnancy outcome. Effective screening for fetal growth restriction is an area of unmet clinical need. We aimed to determine the diagnostic effectiveness of a combination of ultrasonic fetal biometry and measurement of the ratio of soluble fms-like tyrosine kinase receptor 1 (sFLT1) to placental growth factor (PlGF) in predicting adverse pregnancy outcomes associated with delivery of a small for gestational age infant.

METHODS

In this prospective cohort study, using serial antenatal blood sampling and blinded ultrasound scans, we investigated the association between the combination of an elevated sFLT1/PlGF ratio (>85th percentile) and ultrasonically suspected small for gestational age (<10th percentile) at both 28 and 36 weeks of gestational age. The outcome following the 28 week measurement was preterm delivery of a small for gestational age infant. The outcome following the 36 week measurement was subsequent delivery of a small for gestational infant associated with maternal pre-eclampsia or perinatal morbidity or mortality. All definitions of exposure and outcome were predefined before we did our data analysis.

FINDINGS

Between Jan 14, 2008, and July 31, 2012, we recruited 4512 nulliparous women. 4098 women (91%) had a sFLT1/PlGF ratio measurement and estimated fetal weight at 28 or 36 weeks of gestational age, and outcome data available. 3981 women were analysed for 28 weeks of gestational age measurements and 3747 women were analysed for 36 weeks of gestational age measurements. At 28 weeks, 47 (1%) of 3981 women had the combination of ultrasonic small for gestational age and an elevated sFLT1/PlGF ratio. The positive likelihood ratio for preterm delivery of a small for gestational age infant associated with this combination was 41·1 (95% CI 23·0-73·6), the sensitivity was 38·5% (21·1-59·3), the specificity was 99·1% (98·7-99·3), and the positive predictive value was 21·3% (11·6-35·8). At 36 weeks, 102 (3%) of 3747 women had the combination of ultrasonic small for gestational age and an elevated sFLT1/PlGF ratio. The positive likelihood ratio for delivery of a small for gestational age infant associated with maternal pre-eclampsia or perinatal morbidity or mortality was 17·5 (95% CI 11·8-25·9), the sensitivity was 37·9% (26·1-51·4), the specificity was 97·8% (97·3-98·3), and the positive predictive value was 21·6% (14·5-30·8). The positive likelihood ratios at both gestational ages were higher than previously described definitions of suspected fetal growth restriction using purely ultrasonic assessment.

INTERPRETATION

The combination of ultrasonically suspected small for gestational age plus an elevated sFLT1/PlGF ratio in unselected nulliparous women identified a relatively small proportion of women who have high absolute risks of clinically important adverse outcomes. Screening and intervention based on this approach could result in net benefit and this could be an appropriate subject for a randomised controlled trial.

FUNDING

NIHR Cambridge Comprehensive Biomedical Research Centre, Medical Research Council, and Stillbirth and neonatal death society (Sands).

The effect of customization and use of a fetal growth standard on the association between birthweight percentile and adverse perinatal outcome

BACKGROUND

It has been proposed that correction of offspring weight percentiles (customization) might improve the prediction of adverse pregnancy outcome; however, the approach is not accepted universally. A complication in the interpretation of the data is that the main method for calculation of customized percentiles uses a fetal growth standard, and multiple analyses have compared the results with birthweight-based standards.

OBJECTIVES

First, we aimed to determine whether women who deliver small-for-gestational-age infants using a customized standard differed from other women. Second, we aimed to compare the association between birthweight percentile and adverse outcome using 3 different methods for percentile calculation: (1) a noncustomized actual birthweight standard, (2) a noncustomized fetal growth standard, and (3) a fully customized fetal growth standard.

STUDY DESIGN

We analyzed data from the Pregnancy Outcome Prediction study, a prospective cohort study of nulliparous women who delivered in Cambridge, UK, between 2008 and 2013. We used a composite adverse outcome, namely, perinatal morbidity or preeclampsia. Receiver operating characteristic curve analysis was used to compare the 3 methods of calculating birthweight percentiles in relation to the composite adverse outcome.

RESULTS

We confirmed previous observations that delivering an infant who was small for gestational age (<10th percentile) with the use of a fully customized fetal growth standard but who was appropriate for gestational age with the use of a noncustomized actual birthweight standard was associated with higher rates of adverse outcomes. However, we also observed that the mothers of these infants were 3-4 times more likely to be obese and to deliver preterm. When we compared the risk of adverse outcome from logistic regression models that were fitted to the birthweight percentiles that were derived by each of the 3 predefined methods, the areas under the receiver operating characteristic curves were similar for all 3 methods: 0.56 (95% confidence interval, 0.54-0.59) fully customized, 0.56 (95% confidence interval, 0.53-0.59) noncustomized fetal weight standard, and 0.55 (95% confidence interval, 0.53-0.58) noncustomized actual birthweight standard. When we classified the top 5% of predicted risk as high risk, the methods that used a fetal growth standard showed attenuation after adjustment for gestational age, whereas the birthweight standard did not. Further adjustment for the maternal characteristics, which included weight, attenuated the association with the customized standard, but not the other 2 methods. The associations after full adjustment were similar when we compared the 3 approaches.

CONCLUSION

The independent association between birthweight percentile and adverse outcome was similar when we compared actual birthweight standards and fetal growth standards and compared customized and noncustomized standards. Use of fetal weight standards and customized percentiles for maternal characteristics could lead to stronger associations with adverse outcome through confounding by preterm birth and maternal obesity.

A reference range of fetal abdominal circumference growth velocity between 20 and 36 weeks' gestation

OBJECTIVE

To create a single equation and reference range for abdominal circumference growth velocity (ACGV) between 20 and 36 weeks in singleton pregnancies.

METHOD

Observational study of pregnant women having routine scans for abdominal circumference (AC) at 20 and 36 weeks' gestation. Exclusion criteria were multiple pregnancy, abnormal karyotype, major fetal abnormalities, and absent data on first-trimester dating. Scan image quality and AC measurement reliability were assessed according to INTERGROWTH-21st criteria. Regression models for the AC mean and standard deviation were fitted separately at 20 and 36 weeks, and z scores were calculated. Abdominal circumference growth velocity was defined as the z score difference between 20 and 36 weeks divided by the interval in days and multiplied by 100.

RESULTS

The study population included 3334 fetuses. The equation for ACGV is (((AC₃₆  - 53.090 - 1.081*GA₃₆ )/(0.057638*GA₃₆  + 0.622741)) - ((AC₂₀  + 68.349 - 1.571*GA₂₀ )/(0.06265*GA₂₀  - 2.55361)))*100/(GA₃₆  - GA₂₀ ), where AC is expressed in millimeters and GA is gestational age in days. The 3rd, 5th, 10th, 50th, 90th, 95th, and 97th centiles are -1.8997, -1.6785, -1.3091, -0.0069, 1.3255, 1.7279, 1.9973, respectively.

CONCLUSION

We have defined ACGV between 20 and 36 weeks, and we have established its reference range. Further studies are needed to evaluate the clinical significance of growth patterns in the tail ends of this distribution.

The use of angiogenic biomarkers in maternal blood to identify which SGA fetuses will require a preterm delivery and mothers who will develop pre-eclampsia

OBJECTIVE

To determine (1) whether maternal plasma concentrations of angiogenic and anti-angiogenic factors can predict which mothers diagnosed with "suspected small for gestational age fetuses (sSGA)" will develop pre-eclampsia (PE) or require an indicated early preterm delivery (≤ 34 weeks of gestation); and (2) whether risk assessment performance is improved using these proteins in addition to clinical factors and Doppler parameters.

METHODS

This prospective cohort study included women with singleton pregnancies diagnosed with sSGA (estimated fetal weight <10th percentile) between 24 and 34 weeks of gestation (n = 314). Plasma concentrations of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), soluble endoglin (sEng) and placental growth factor (PlGF) were determined in maternal blood obtained at the time of diagnosis. Doppler velocimetry of the umbilical (Umb) and uterine (UT) arteries was performed. The outcomes were (1) subsequent development of PE; and (2) indicated preterm delivery at ≤ 34 weeks of gestation (excluding deliveries as a result of spontaneous preterm labor, preterm pre-labor rupture of membranes or chorioamnionitis).

RESULTS

(1) The prevalence of PE and indicated preterm delivery was 9.2% (n = 29/314) and 7.3% (n = 23/314), respectively; (2) the area under the receiver operating characteristic curve (AUC) for the identification of patients who developed PE and/or required indicated preterm delivery was greater than 80% for the UT artery pulsatility index (PI) z-score and each biochemical marker (including their ratios) except sVEGFR-1 MoM; (3) using cutoffs at a false positive rate of 15%, women with abnormal plasma concentrations of angiogenic/anti-angiogenic factors were 7-13 times more likely to develop PE, and 12-22 times more likely to require preterm delivery than those with normal plasma MoM concentrations of these factors; (4) sEng, PlGF, PIGF/sEng and PIGF/sVEGFR-1 ratios MoM, each contributed significant information about the risk of PE beyond that provided by clinical factors and/or Doppler parameters: women who had low MoM values for these biomarkers were at 5-9 times greater risk of developing PE than women who had normal values, adjusting for clinical factors and Doppler parameters (adjusted odds ratio for PlGF: 9.1, PlGF/sEng: 5.6); (5) the concentrations of sVEGFR-1 and PlGF/sVEGFR-1 ratio MoM, each contributed significant information about the risk of indicated preterm delivery beyond that provided by clinical factors and/or Doppler parameters: women who had abnormal values were at 8-9 times greater risk for indicated preterm delivery, adjusting for clinical factors and Doppler parameters; and (6) for a two-stage risk assessment (Umb artery Doppler followed by Ut artery Doppler plus biochemical markers), among women who had normal Umb artery Doppler velocimetry (n = 279), 21 (7.5%) developed PE and 11 (52%) of these women were identified by an abnormal UT artery Doppler mean PI z-score (>2SD): a combination of PlGF/sEng ratio MoM concentration and abnormal UT artery Doppler velocimetry increased the sensitivity of abnormal UT artery Doppler velocimetry to 76% (16/21) at a fixed false-positive rate of 10% (p = 0.06).

CONCLUSION

Angiogenic and anti-angiogenic factors measured in maternal blood between 24 and 34 weeks of gestation can identify the majority of mothers diagnosed with "suspected SGA" who subsequently developed PE or those who later required preterm delivery ≤ 34 weeks of gestation. Moreover, incorporation of these biochemical markers significantly improves risk assessment performance for these outcomes beyond that of clinical factors and uterine and umbilical artery Doppler velocimetry.

Intrauterine growth restriction: impact on cardiovascular development and function throughout infancy

Intrauterine growth restriction (IUGR) refers to the situation where a fetus does not grow according to its genetic growth potential. One of the main causes of IUGR is uteroplacental vascular insufficiency. Under these circumstances of chronic oxygen and nutrient deprivation, the growth-restricted fetus often displays typical circulatory changes, which in part represent adaptations to the suboptimal intrauterine environment. These fetal adaptations aim to preserve oxygen and nutrient supply to vital organs such as the brain, the heart, and the adrenals. These prenatal circulatory adaptations are thought to lead to an altered development of the cardiovascular system and "program" the fetus for life long cardiovascular morbidities. In this review, we discuss the alterations to cardiovascular structure, function, and control that have been observed in growth-restricted fetuses, neonates, and infants following uteroplacental vascular insufficiency. We also discuss the current knowledge on early life surveillance and interventions to prevent progression into chronic disease.

Early life nutrition and the opportunity to influence long-term health: an Australasian perspective

There are now significant data to support the hypothesis that early life nutrition in the fetus, infant and young child can have profound effects on long-term health. This review considers some of this evidence with specific reference to the current burden of disease in Australia and New Zealand. As the findings of further research become available, recommendations on optimizing early life nutrition should be formulated and made widely available as part of the preventative health policy agenda in both Australia and New Zealand.

When is birthweight at term (≥37 weeks' gestation) abnormally low? A systematic review and meta-analysis of the prognostic and predictive ability of current birthweight standards for childhood and adult outcomes

BACKGROUND

Health outcomes throughout the life course have been linked to fetal growth restriction and low birthweight. A variety of measures exist to define low birthweight, with a lack of consensus regarding which predict adverse outcome.

OBJECTIVES

To evaluate the relationship between birthweight standards and childhood and adult outcomes in term-born infants (≥37 weeks' gestation).

SEARCH STRATEGY

MEDLINE (1966-January 2011), EMBASE (1980-January 2011), and the Cochrane Library (2011:1) and MEDION were included.

SELECTION CRITERIA

Studies comprising live term-born infants (gestation ≥37 completed weeks), with weight or other anthropometric measurements recorded at birth along with childhood and adult outcomes.

DATA COLLECTION AND ANALYSIS

Data were extracted to populate 2 × 2 tables relating birthweight standard with outcome, and meta-analysis was performed where possible.

MAIN RESULTS

Fifty-nine articles (2 600 383 individuals) were selected. There was no significant relationship between birthweight <2.5 kg (odds ratio [OR] 0.98, 95% confidence intervals [CI] 0.87-1.10) and composite measure of childhood morbidity. Weight <10th centile on the population nomogram showed a small association (OR 1.49, 95% CI 1.02-2.19) for the same outcome. There was no significant association between either of the above measures and adult morbidity. The relationship between other measures and individual outcomes varied.

AUTHOR'S CONCLUSIONS

The association between low birthweight, by any definition, and childhood and adult morbidity was inconsistent. None of the current standards of low birthweight was a good predictor of adverse outcome.

Assessment of fetal growth by customized growth charts

Customized fetal growth charts take account of the individual variation in the fetal growth potential based on non-pathological maternal and fetal characteristics. Application of these customized weight charts might improve the distinction between pathological growth-restricted fetuses and fetuses that are small but have reached their growth potential. Current models for customized growth standards have been based on birth weight and fetal growth data. Variables used for customization are gestational age, maternal age, parity, ethnicity, height, weight and fetal sex. Thus far, it remains controversial whether these maternal and fetal characteristics used for customization are strong enough predictors for fetal growth on an individual level and are truly physiological characteristics. The currently available customized growth charts might be of benefit for use in epidemiological studies and clinical practice. Further studies are needed to validate these customized growth models and to examine whether and to what extend they improve identification of children that are at risk for morbidity in the perinatal period and later in life.

Care-related factors associated with antepartal diagnosis of intrauterine growth restriction: a case-control study

Background

Antenatal care is of core importance for maternal and child health and is therefore a central aspect of mother and child health care. One of the main goals of effective screening in antenatal care is the detection of suboptimal fetal growth. However, the sensitivity of antenatal diagnostic of suboptimal fetal growth (i.e. intrauterine growth restriction; IUGR) through clinical routine fetal ultrasonography has been observed to be low. A study conducted in Germany found that only 30% of IUGR cases and 40% of congenital malformations were diagnosed antenatally. Reasons for this low detection rate remain unclear.

Methods/Design

In the first of two study components, all mothers who delivered or will deliver a small for gestational age (SGA) newborn in one of three hospitals in Bremen (Germany) during recruitment phase are eligible for inclusion in a hospital based case–control study. Cases are defined as neonates with an IUGR that was not detected antenatally, while controls are defined as neonates whose IUGR was identified or at least suspected antenatally. Data collection instruments include a newborn documentation sheet, a standardized, computer-assisted personal interview with mothers, and a copy of pregnancy record books. The second component is a survey among all private practice-based gynecologists in the federal states of Bremen and Lower Saxony. The aim of this survey was to obtain detailed information e.g. on quality of ultrasonography equipment and examiner’s ultrasonography experience and qualification level.

Discussion

To our knowledge, this is one of the few German studies explicitly addressing care-related as well as maternal-related factors influencing the (non-) detection of IUGR by conducting comprehensive interviews with mothers and private practice-based gynecologists. Over the last 15 years there have been substantial technological advances in ultrasonography equipment in gynecological practices; hence there is the need to evaluate whether the detection rates of IUGR in Germany are still as low as previously reported in the late 1990ies. Our study results will contribute to a better understanding of core risk factors for low early detection rates of intrauterine growth restrictions and may support quality development in this important health care sector.

Ethnicity-specific growth distributions for prediction of newborn morbidity

OBJECTIVES

Birth weight distributions differ according to the ethnic origin of the mother. We aimed to determine whether using ethnicity-specific growth distributions would identify newborns at risk for adverse infant outcomes associated with small for gestational age (SGA) birth better than population-based distributions.

METHODS

We examined 2647 singletons born to healthy non-smoking mothers at British Columbia Women's Hospital at 37 to 41 completed weeks' gestation. We compared the ability of ethnicity-specific growth distributions and population-based distributions to predict which infants were at increased risk of adverse outcomes associated with SGA, as well as extended length of stay in hospital, using crude and adjusted odds ratios.

RESULTS

The ethnicity-specific growth distributions were associated with an increased risk of adverse infant outcomes while the population-based distributions were not (adjusted odds ratio [aOR] 1.49 [95% CI 0.82 to 2.70] vs. aOR 0.88 [95% CI 0.48 to 1.64]). While both distributions predicted extended length of stay in hospital, this likely reflects clinicians' use of the population-based distribution to identify SGA infants.

CONCLUSIONS

The use of ethnicity-specific growth distributions will likely improve our ability to differentiate between babies who are pathologically small and those who are constitutionally small, and prevent misclassification of constitutionally small but healthy newborns born to mothers of Chinese or South Asian descent as SGA.

Fetal MRI insular cortical morphometry and its association with neurobehavior in late-onset small-for-gestational-age fetuses

OBJECTIVE

To evaluate insular cortical morphometry assessed by magnetic resonance imaging (MRI) in late-onset small-for-gestational-age (SGA) fetuses compared with controls, and its association with neurobehavioral outcomes.

METHODS

MRI was performed in 65 late-onset SGA and 59 normally-grown fetuses at 37 weeks' gestation. T2-weighted half Fourier acquisition single-shot turbo spin echo (HASTE) anatomical and diffusion-weighted images were acquired. Insular cortical thickness, volume and fractional anisotropy values were assessed, and asymmetry indices were constructed. At 42 weeks of age, a Neonatal Behavioral Assessment Scale (NBAS) test was performed on the SGA neonates.

RESULTS

Late-onset SGA fetuses had significantly thinner insular cortical thickness and smaller insular cortical volume than did controls. SGA fetuses also presented a more pronounced left asymmetry in the posterior cortex and significantly lower fractional anisotropy values in the left insula. Insular measurements in the SGA group were significantly correlated with neurobehavior as assessed by NBAS scores.

CONCLUSIONS

Insular cortical morphometry was significantly different in late-onset SGA fetuses and correlated with poorer neurobehavioral performance. These data support the impact of growth restriction on brain development and the potential value of cortical assessment as a biomarker of neurodevelopment in at-risk fetuses.

Fetal response to maternal hunger and satiation - novel finding from a qualitative descriptive study of maternal perception of fetal movements

Background

Maternal perception of decreased fetal movements is a specific indicator of fetal compromise, notably in the context of poor fetal growth. There is currently no agreed numerical definition of decreased fetal movements, with the subjective perception of a decrease on the part of the mother being the most significant definition clinically. Both qualitative and quantitative aspects of fetal activity may be important in identifying the compromised fetus. Yet, how pregnant women perceive and describe fetal activity is under-investigated by qualitative means. The aim of this study was to explore normal fetal activity, through first-hand descriptive accounts by pregnant women.

Methods

Using qualitative descriptive methodology, interviews were conducted with 19 low-risk women experiencing their first pregnancy, at two timepoints in their third trimester. Interview transcripts were later analysed using qualitative content analysis and patterns of fetal activity identified were then considered along-side the characteristics of the women and their birth outcomes.

Results

This paper focuses on a novel finding; the description by pregnant women of fetal behaviour indicative of hunger and satiation. Full findings will be presented in later papers. Most participants (74% 14 of 19) indicated mealtimes were a time of increased fetal activity. Eight participants provided detailed descriptions of increased activity around meals, with seven (37% 7 of 19) of these specifying increased fetal activity prior to meals or in the context of their own hunger. These movements were interpreted as a fetal demand for food often prompting the mother to eat. Interestingly, the women who described increased fetal activity in the context of hunger subsequently gave birth to smaller infants (mean difference 364 gm) than those who did not describe a fetal response to hunger.

Conclusions

Food seeking behaviour may have a pre-birth origin. Maternal-fetal interaction around mealtimes could constitute an endocrine mediated communication, in the interests of maintaining optimal intrauterine conditions. Further research is warranted to explore this phenomenon and the potential influence of feeding on the temporal organisation of fetal activity in relation to growth.

Brainstem and cerebellar differences and their association with neurobehavior in term small-for-gestational-age fetuses assessed by fetal MRI

OBJECTIVE

We tested the hypothesis whether small-for-gestational-age (SGA) fetuses have different brain stem and cerebellar morphometry when compared with appropriate-for-gestational-age (AGA) fetuses and whether the differences in these structures were associated with their neonatal neurobehavior.

STUDY DESIGN

Magnetic resonance imaging was performed on 51 SGA fetuses and 47 AGA fetuses at 37 weeks' gestation. Pontine width, medullar width, vermian width and height, cerebellar primary fissure's depth, and cerebellar volume were measured and corrected by biparietal diameter and cerebellar volume by total intracranial volume. Ratios were compared between cases and control subjects. The association between morphometric differences and neurobehavioral outcome in SGAs was tested.

RESULTS

Brainstem and cerebellar ratios were significantly larger in SGA fetuses: pontine width, SGA 0.143 ± 0.01 vs AGA 0.135 ± 0.01 (P < .01); medullar width, SGA 0.088 ± 0.01 vs AGA 0.083 ± 0.01 (P = .03); vermian width, SGA 0.181 ± 0.03 vs AGA 0.162 ± 0.02 (P < .01); vermian height, SGA 0.235 ± 0.03 vs AGA 0.222 ± 0.01 (P < .01); cerebellar volume, SGA 0.042 ± 0.01 vs AGA 0.038 ± 0.00 (P = .04); with deeper cerebellar primary fissure in SGAs, SGA 0.041 ± 0.01 vs AGA 0.035 ± 0.01 (P = .01). Medullar, cerebellar biometries, and volumetry were significantly associated with different Neonatal Behavioral Assessment Scale cluster scores in SGA infants.

CONCLUSION

Brain stem and cerebellar morphometric measurements are significantly different in term SGA fetuses, which are associated significantly with their neurobehavioral outcome. This finding supports the existence of brain microstructural changes in SGA fetuses and lays the basis for potential image biomarkers to detect fetuses who are at risk.

When is birthweight at term abnormally low? A systematic review and meta-analysis of the association and predictive ability of current birthweight standards for neonatal outcomes

Background

Intrauterine growth restriction is a cause of neonatal morbidity and mortality. A variety of definitions of low birthweight are used in clinical practice, with a lack of consensus regarding which definitions best predict adverse outcomes.

Objectives

To evaluate the relationship between birthweight standards and neonatal outcome in term-born infants (at ≥ 37 weeks of gestation).

Search strategy

MEDLINE (1966–January 2011), EMBASE (1980–January 2011), and the Cochrane Library (2011:1) and MEDION were included in our search.

Selection criteria

Studies comprising live term-born infants (gestation ≥ 37 completed weeks), with weight or other anthropometric measurements recorded at birth along with neonatal outcomes.

Data collection and analysis

Data were extracted to populate 2 × 2 tables relating birthweight standard with outcome, and meta-analysis was performed where possible.

Main results

Twenty-nine studies including 21 034 114 neonates were selected. Absolute birthweight was strongly associated with mortality, with birthweight < 1.5 kg giving the largest association (OR 48.6, 95% CI 28.62–82.53). When using centile charts, regardless of threshold, the summary odds ratios were significant but closer to 1 than when using absolute birthweight. For all tests, summary predictive ability comprised high specificity and positive likelihood ratio for neonatal death, but low sensitivity and a negative likelihood ratio close to 1.

Author's conclusions

Absolute birthweight is a prognostic factor for neonatal mortality. The indirect evidence suggests that centile charts or other definitions of low birthweight are not as strongly associated with mortality as the absolute birthweight. Further research is required to improve predictive accuracy.

Changes in spectral power of fetal heart rate variability in small-for-gestational-age fetuses are associated with fetal sex

BACKGROUND

Little is known about the influences of fetal weight and sex on spectral analysis of fetal heart rate (FHR) variability.

AIM

The study aims to assess whether there are differences in spectral power of FHR variability according to fetal weight and sex during labor.

STUDY DESIGN

Case-control study. A total of 414 singleton term deliveries without fetal acidemia were divided into small-for-gestational-age (SGA) (n=29) and non-SGA (n=385) groups. Analyses were performed separately according to fetal sex.

SUBJECTS

FHR recordings obtained with cardiotocography during the last 2h of labor preceding delivery.

OUTCOME MEASURES

Our outcome measures include spectral power of FHR variability.

RESULTS

For the male group, SGA fetuses had significantly lower values for low, movement, high, and total frequencies of spectral power compared with non-SGA fetuses (all P<0.005). Normalized low frequency (LFn) was significantly higher, and normalized high frequency (HFn) was significantly lower in SGA fetuses compared with non-SGA fetuses (all P<0.005). In contrast, for the female group, there were no significant differences in any of the indices of spectral power between the SGA and non-SGA fetuses. In addition, SGA males had significantly higher LFn spectral power and lower HFn spectral power compared to SGA females (P=0.016, and 0.041, respectively).

CONCLUSIONS

SGA males have decreased spectral power of FHR variability compared with non-SGA males during labor. However, there are no differences between SGA and non-SGA female fetuses. It is important in the clinical setting to take fetal weight and sex into account during FHR monitoring using spectral analysis.

The effect of customized growth charts on the identification of large for gestational age newborns

OBJECTIVE

To determine the effect of using customized vs. standard population birthweight curves to define large for gestational age (LGA) infants.

METHODS

We analyzed data obtained from 2,097 singleton pregnancies using three different methods of classifying newborn birthweight: standard population curves, British or Spanish customized curves. We recorded maternal characteristics, proportion of LGA newborns when using each method, percentage of LGA according to one method but not for the others, and concordance between the different methods.

RESULTS

The proportion of LGA newborns according to Spanish customized curves was significantly lower than that calculated using either standard general population birthweight curves or British curves (p < 0.001). A third (33.9%) of the infants classified as LGA according to the general population method were adequate for gestational age (AGA) when the Spanish customized curves were used, and 18.5% of non-LGA were LGA according to customized curves (p < 0.001). Concordance between the different models high, but on excluding AGA the concordance coefficient was low (Cohen's κ <0.4).

CONCLUSIONS

The use of customized curves allows differentiation between constitutional LGA and cases of fetal overgrowth, leading to a decrease in the rate of both false-positives and negatives as well as the overall proportion of LGA babies.

Stillbirth and fetal growth restriction

OBJECTIVE

To confirm the role of fetal growth restriction (FGR) as a cause of stillbirth, and to compare diagnostic accuracy of customized fetal growth and population-based standards in identifying FGR within a pathological population of early and late stillbirths.

METHODS

Retrospective study on a cohort of 189 stillbirths occurred in single pregnancy between January 2006 and September 2011. Unexplained stillbirths, defined by Aberdeen-Wigglesworth and ReCoDe classifications, were evaluated on the basis of fetal birthweight with both Tuscany population and Gardosi customized standards. Unexplained stillbirths have been classified as early or late depending on the gestational age of occurrence.

RESULTS

Aberdeen-Wigglesworth classification, applied to the 189 cases of stillbirth, left 94 unexplained cases (49.7%), whereas the ReCoDe classification left only 40 (21%). By applying population standards to the 94 unexplained stillbirths we have identified 31 FGRs (33% of sample), while customized standards identified 54 FGRs (57%). Customised standards identified a larger number of FGRs with respect to population standards during the third trimester (i.e. 51% vs. 25% respectively) than in the second trimester (73% vs. 54% respectively) (p = 0.05).

CONCLUSIONS

Customized standards have a higher diagnostic accuracy in identifying FGRs especially during the third trimester.

Biological mechanisms for nutritional regulation of maternal health and fetal development

This review paper highlights mechanisms for nutritional regulation of maternal health and fetal development. Malnutrition (nutrient deficiencies or obesity) in pregnant women adversely affects their health by causing or exacerbating a plethora of problems, such as anaemia, maternal haemorrhage, insulin resistance, and hypertensive disorders (e.g. pre-eclampsia/eclampsia). Maternal malnutrition during gestation also impairs embryonic and fetal growth and development, resulting in deleterious outcomes, including intrauterine growth restriction (IUGR), low birthweight, preterm birth, and birth defects (e.g. neural tube defects and iodine deficiency disorders). IUGR and preterm birth contribute to high rates of neonatal morbidity and mortality. Major common mechanisms responsible for malnutrition-induced IUGR and preterm birth include: (i) abnormal growth and development of the placenta; (ii) impaired placental transfer of nutrients from mother to fetus; (iii) endocrine disorders; and (iv) disturbances in normal metabolic processes. Activation of a series of physiological responses leading to premature and sustained contraction of the uterine myometrium also results in preterm birth. Recent epidemiologic studies have suggested a link between IUGR and chronic metabolic disease in children and adults, and the effects of IUGR may be carried forward to subsequent generations through epigenetics. While advanced medical therapies, which are generally unavailable in low-income countries, are required to support preterm and IUGR infants, optimal nutrition during pregnancy may help ameliorate many of these problems. Future studies are necessary to develop effective nutritional interventions to enhance fetal growth and development and alleviate the burden of maternal morbidity and mortality in low- and middle-income countries.

Revisiting the risk of celiac disease in children born small for gestational age: a sibling design perspective

OBJECTIVE

An association between small for gestational age (SGA) and risk for celiac disease (CD) in childhood has previously been reported. However, this association may reflect residual confounding by genetic or environmental factors. For example, presence of subclinical CD in the mother might be a common cause of both SGA and CD in the offspring. We investigate whether SGA is causally associated with CD before age six years by applying both conventional population-based regression models and sibling analysis that investigates the association in siblings discordant for SGA.

MATERIAL AND METHODS

Using the Swedish Medical Birth Registry, we identified all singleton children born in Sweden during 1987-1993 (792,401). Of these we included 681,954 children in the study and identified 2641 cases of CD using the Swedish National In-Hospital Registry. We applied both conventional Cox regression analysis and a quasi-experimental sibling design that to some extent simulates a counterfactual situation of exposure, reducing possible confounding effects of genetic and shared environmental factors.

RESULTS

We identified an increased risk of CD in both boys (hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.25-2.32) and girls (HR 1.30, 95% CI 0.99-1.70) using conventional Cox regression models. Using sibling analysis, the association between SGA and CD was confirmed in boys (HR 4.23, 95% CI 1.19-15.04) but not in girls (HR 1.00, 95% CI 0.45-2.20).

CONCLUSIONS

Our results support a causal association between SGA and CD risk in boys but not in girls, although the mechanisms underlying this difference are still unclear.

Prediction of intrauterine fetal death in small-for-gestational-age fetuses: impact of including ultrasound biometry in customized models

OBJECTIVE

Customized growth charts derived from maternal demographic characteristics alone have been shown to improve the prediction of pregnancy complications compared to population growth curves. We sought to estimate the impact of adding ultrasound biometric parameters to the customized chart for the prediction of intrauterine fetal death (IUFD).

METHODS

A retrospective cohort study was undertaken using an ultrasound database including singleton pregnancies followed between 16 and 20 weeks' gestation. After exclusion of preterm births, congenital anomalies, multifetal pregnancies and stillbirths (excluded only from derivation samples), we identified 59 016 births, divided into derivation (34 832) and validation (24 184) samples. Coefficients for significant physiological and pathological variables affecting fetal growth were derived using backward stepwise multiple regression (Cust-chart). The same process was repeated including second-trimester biometric parameters: biparietal diameter, head circumference, femur length and abdominal circumference in the regression models (Cust-plus-USS-chart). The association between small-for-gestational age < 10(th) centile (SGA) pregnancies, defined using the two customized charts or our population-based growth chart (Pop-chart) and IUFD, were compared. Statistical analyses including OR, 95% CI and screening accuracy using each chart were performed.

RESULTS

The derived coefficients for fetal growth are comparable to those of previously published series. Of 24 184 pregnancies in the validation sample, IUFD was seen in 169 (0.7%). The pregnancies identified as SGA were: 2482 (10.26%), 2499 (10.33%) and 2634 (10.89%) using the Cust-chart, Cust-plus-USS-chart and Pop-chart, respectively. The OR (95% CI) for the association between SGA defined by the three charts and IUFD was: 7.0 (4.5-11), 6.5 (4.2-10.2) and 2.4 (1.6-3.6) according to the Cust-chart, Cust-plus-USS-chart and Pop-chart, respectively. Screening efficiency for IUFD using both customized charts was similar, with both demonstrating a higher sensitivity compared with the Pop-chart.

CONCLUSIONS

Customized charts are more efficient in identifying pregnancies at risk for IUFD compared with population-based charts. However, adding second-trimester ultrasound biometric parameters to the customized model does not improve the prediction of IUFD compared with using maternal characteristics only.

Intrauterine growth restriction: new concepts in antenatal surveillance, diagnosis, and management

Intrauterine growth restriction (IUGR) remains one of the main challenges in maternity care. Improvements have to start from a better definition of IUGR, applying the concept of the fetal growth potential. Customized standards for fetal growth and birthweight improve the detection of IUGR by better distinction between physiological and pathological smallness and have led to internationally applicable norms. Such developments have resulted in new insights in the assessment of risk and surveillance during pregnancy. Serial fundal height measurement plotted on customized charts is a useful screening tool, whereas fetal biometry and Doppler flow are the mainstay for investigation and diagnosis of IUGR. Appropriate protocols based on available evidence as well as individualized clinical assessment are essential to ensure good management and timely delivery.

Clinical strategies for improving the detection of fetal growth restriction

The single most important condition affecting the viable fetus is intrauterine growth retardation (IUGR). IUGR is a common condition, affecting about 10% to 15% of the general maternity population. Despite its importance and relatively high prevalence, IUGR detection is poor. This article will focus on how to improve on IUGR detection.

The customised growth potential: an international research tool to study the epidemiology of fetal growth

Customised centiles based on individual fetal growth potential enhance our ability to differentiate between physiological and pathological smallness. A series of studies in different maternity populations has found striking similarities in the way fetal growth varies with maternal and pregnancy related characteristics, and has established the clear advantages of this method over generic, population-based birthweight or fetal weight standards. The method opens up many new avenues for the retrospective study of risk factors and fetal growth. The findings quantify the strength of association between fetal growth restriction and perinatal outcome, and therefore also highlight the clinical imperative to improve antenatal detection of the at-risk fetus. Applied prospectively as customised charts, the concept improves the detection of fetal growth restriction and reduces the need for unnecessary investigations.