Consensus definition of fetal growth restriction: a Delphi procedure

Can measurement of the foetal renal parenchymal thickness with ultrasound be used as an indirect measure of nephron number?

Chronic kidney disease continues to be under recognised and is associated with a significant global health burden and costs. An adverse intrauterine environment may result in a depleted nephron number and an increased risk of chronic kidney disease. Antenatal ultrasound was used to measure the foetal renal parenchymal thickness (RPT), as a novel method to estimate nephron number. Foetal renal artery blood flow was also assessed. This prospective, longitudinal study evaluated the foetal kidneys of 102 appropriately grown and 30 foetal growth-restricted foetuses between 20 and 37 weeks gestational age (GA) to provide vital knowledge on the influences foetal growth restriction has on the developing kidneys. The foetal RPT and renal artery blood flow were measured at least every 4 weeks using ultrasound. The RPT was found to be significantly thinner in growth-restricted foetuses compared to appropriately grown foetuses [likelihood ratio (LR) = 21.06, P ≤ 0.0001] and the difference increases with GA. In foetuses with the same head circumference, a growth-restricted foetus was more likely to have a thinner parenchyma than an appropriately grown foetus (LR = 8.9, P = 0.0028), supporting the principle that growth-restricted foetuses preferentially shunt blood towards the brain. No significant difference was seen in the renal arteries between appropriately grown and growth-restricted foetuses. Measurement of the RPT appears to be a more sensitive measure than current methods. It has the potential to identify infants with a possible reduced nephron endowment allowing for monitoring and interventions to be focused on individuals at a higher risk of developing future hypertension and chronic kidney disease.

Maternal plasma endocan levels in intrauterine growth restriction

Objectives: Intrauterine growth restriction (IUGR) is diagnosed when the estimated fetal weight remains below the 10th percentile of gestational age based on pathological restriction of growth and/or accompanying Doppler abnormalities. Endothelial dysfunction is a common pathogenetic pathway underlying IUGR etiology. Endocan (ESM-1) is a novel marker of endothelial dysfunction and inflammation found in the maternal circulation. This study was designed to compare plasma endocan levels between pregnancies complicated with IUGR and a control group.Study design: Forty-four pregnancies complicated with IUGR and 47 healthy pregnancies were included. Maternal plasma endocan levels were detected by ELISA. Parametric data was studied by Student's t-test. Mann-Whitney U-test was used in analyzing non-parametric data. Categorical variables underwent chi-square test. ROC analysis was performed to define the cutoff value of endocan in detecting IUGR. Spearman correlation test was performed.Results: Maternal plasma endocan level varied significantly between IUGR and healthy pregnancies and was 1.8 fold higher in the IUGR group (793.0 (IQR:544.4-1896.0) ng/L vs. 441.8 (IQR: 408.3-512.4) ng/L, p < .001). There was a weak negative correlation between endocan level and 5th and 10th minute APGAR Scores (r =  -0.256; p = .015 and r =  -0.215; p = .042, respectively), a weak positive correlation with umbilical artery pulsatility index, and a moderate negative correlation with cerebroplacental ratio (r  =  0.394; p < .001 and r =  -0.459; p < .001, respectively).Conclusions: There was a significant difference between endocan levels of IUGR and healthy pregnancies. Further studies might be designed to investigate the performance of endocan in predicting neonatal outcomes for pregnancies complicated with IUGR.

The ability of late pregnancy maternal tests to predict adverse pregnancy outcomes associated with placental dysfunction (specifically fetal growth restriction and pre-eclampsia): a protocol for a systematic review and meta-analysis of prognostic accuracy studies

BACKGROUND

Pre-eclampsia and being born small for gestational age are associated with significant maternal and neonatal morbidity and mortality. Placental dysfunction is a key pathological process underpinning these conditions; thus, markers of placental function have the potential to identify pregnancies ending in pre-eclampsia, fetal growth restriction, and the birth of a small for gestational age infant.

PRIMARY OBJECTIVE

To assess the predictive ability of late pregnancy (after 24 weeks' gestation) tests in isolation or in combination for adverse pregnancy outcomes associated with placental dysfunction, including pre-eclampsia, fetal growth restriction, delivery of a SGA infant (more specifically neonatal growth restriction), and stillbirth.

METHODS

Studies assessing the ability of biochemical tests of placental function and/or ultrasound parameters in pregnant women beyond 24 weeks' gestation to predict outcomes including pre-eclampsia, stillbirth, delivery of a SGA infant (including neonatal growth restriction), and/or fetal growth restriction will be identified by searching the following databases: EMBASE, MEDLINE, Cochrane CENTRAL, Web of Science, CINAHL, ISRCTN registry, UK Clinical Trials Gateway, and WHO International Clinical Trials Portal. Any study design in which the biomarker and ultrasound scan potential predictors have been assessed after 24 weeks' gestation but before diagnosis of outcomes (pre-eclampsia, fetal growth restriction, SGA (including neonatal growth restriction), and stillbirth) will be eligible (this would include randomized control trials and nested prospective case-control and cohort studies), and there will be no restriction on the background risk of the population. All eligible studies will be assessed for risk of bias using the modified QUADAS-2 tool. Meta-analyses will be undertaken using the ROC models to estimate and compare test discrimination and reclassification indices to test calibration. Validation will be explored by comparing consistency across studies.

DISCUSSION

This review will assess whether current published data reporting either a single or combination of tests in late pregnancy can accurately predict adverse pregnancy outcome(s) associated with placental dysfunction. Accurate prediction could allow targeted management and possible intervention for high-risk pregnancies, ultimately avoiding adverse outcomes associated with placental disease.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018107049.

Maternal and Perinatal Outcomes Associated With Extremely High Values for the sFlt-1 (Soluble fms-Like Tyrosine Kinase 1)/PlGF (Placental Growth Factor) Ratio

Background There is little knowledge about the significance of extremely high values (>655) for the ratio of sFlt-1 (soluble fms-like tyrosine kinase 1) to PlGF (placental growth factor). We aim to describe the time-to-delivery interval and maternal and perinatal outcomes when such values are demonstrated while assessing suspected or confirmed placental dysfunction based on clinical or sonographic criteria. Methods and Results A multicenter retrospective cohort study was performed on 237 singleton gestations between 20+0 and 37+0 weeks included at the time of first demonstrating a sFlt-1/PlGF ratio >655. Clinicians were aware of this result, but standard protocols were followed for delivery indication. Main outcomes were compared for women with and without preeclampsia at inclusion. In those with preeclampsia (n=185, of whom 77.3% had fetal growth restriction), severe preeclampsia features and fetal growth restriction in stages III or IV were present in 49.2% and 13.5% cases, respectively, at inclusion and in 77.3% and 28.6% cases, respectively, at delivery. In the group without preeclampsia (n=52, 82.7% had fetal growth restriction), these figures were 0% and 30.8%, respectively, at inclusion and 21.2% and 50%, respectively, at delivery. Interestingly, 28% of women without initial preeclampsia developed it later. The median time to delivery was 4 days (interquartile range: 1-6 days) and 7 days (interquartile range: 3-12 days), respectively (P<0.01). Overall, perinatal mortality was 62.1% before 24 weeks; severe morbidity surpassed 50% before 29 weeks but became absent from 34 weeks. Maternal serious morbidity was high at any gestational age. Conclusions An sFlt-1/PlGF ratio >655 is almost invariably associated with preeclampsia or fetal growth restriction that progresses rapidly. In our tertiary care settings, we observed that maternal adverse outcomes were high throughout gestation, whereas perinatal adverse outcomes diminished as pregnancy advanced.

Can fetal fractions in the cell-free DNA test predict the onset of fetal growth restriction?

Objective To investigate the possible predictive value of fetal fraction in the cell-free DNA (cfDNA) test in pregnancies with early- and late-onset fetal growth restriction (FGR). Methods This retrospective study comprised 247 women who were screened using the cfDNA test for aneuploidies during the first or second trimester and had deliveries at our institution from January 2016 to December 2019. The fetal fractions of women with early- (n = 14) and late-onset (n = 83) FGR and those with uncomplicated pregnancies (n = 150) were compared. Results The median fetal fractions for the early-onset FGR, late-onset FGR, and control groups were 5.7 [interquartile range (IQR) 2.65], 7 (IQR 5), and 7.35 (IQR 3.65), respectively. The fetal fractions were significantly lower in the early-onset FGR group than in the late-onset FGR and control groups (P = 0.047 and P = 0.037, respectively). There was no difference in fetal fractions between the late-onset FGR and control groups (P = 1.00). Conclusion As a placenta-related disease, early-onset FGR had lower fetal fractions in the cfDNA test than uncomplicated pregnancies. For clinical use, lower fetal fractions can contribute as a biomarker for screening asymptomatic women for possible placenta-related diseases, such as early-onset FGR. However, more studies are needed to define the "lower" limit.

Effects of intrauterine insulin-like growth factor-1 therapy for fetal growth restriction on adult metabolism and body composition are sex specific

Fetal growth restriction (FGR) is associated with compromised growth and metabolic function throughout life. Intrauterine therapy of FGR with intra-amniotic insulin-like growth factor-1 (IGF1) enhances fetal growth and alters perinatal metabolism and growth in a sex-specific manner, but the adult effects are unknown. We investigated the effects of intra-amniotic IGF1 treatment of FGR on adult growth and body composition, adrenergic sensitivity, and glucose-insulin axis regulation. Placental embolization-induced FGR was treated with four weekly doses of 360 µg intra-amniotic IGF1 (FGRI) or saline (FGRS). Offspring were raised to adulthood (18 mo: FGRI, n = 12 females, 12 males; FGRS, n = 13 females, 10 males) alongside offspring from unembolized and untreated sheep (CON; n = 12 females, 21 males). FGRI females had increased relative lean mass compared with CON but not FGRS (P < 0.05; 70.6 ± 8.2% vs. 61.4 ± 8.2% vs. 67.6 ± 8.2%), decreased abdominal adipose compared with CON and FGRS (P < 0.05; 43.7 ± 1.2% vs. 49.3 ± 0.9% vs. 48.5 ± 1.0%), increased glucose utilization compared with FGRS but not CON (P < 0.05; 9.6 ± 1.0 vs. 6.0 ± 0.9 vs. 7.6 ± 0.9 mg·kg^-1·min^-1), and increased β-hydroxybutyric acid:nonesterified fatty acid ratio in response to adrenaline compared with CON and FGRS (P < 0.05; 3.9 ± 1.4 vs. 1.1 ± 1.4 vs. 1.8 ± 1.4). FGRS males were smaller and lighter compared with CON but not FGRI (P < 0.05; 86.8 ± 6.3 vs. 93.5 ± 6.1 vs. 90.7 ± 6.3 kg), with increased peak glucose concentration (10%) in response to a glucose load but few other differences. These effects of intra-amniotic IGF1 therapy on adult body composition, glucose-insulin axis function, and adrenergic sensitivity could indicate improved metabolic regulation during young adulthood in female FGR sheep.

The associations of particulate matters with fetal growth in utero and birth weight: A birth cohort study in Beijing, China

BACKGROUND

Previous studies examined the associations of particulate matters (PM) with fetal growth in utero or birth weight with inconsistent results, and few studies investigated that whether the associations of PM with fetal growth in utero also present at birth. We aimed to investigate the associations of PM with both fetal growth in utero and birth weight.

METHODS

We established a birth cohort (2014-2017) with 18,863 singleton pregnancies in Tongzhou Maternal and Child Hospital of Beijing, China. Maternal exposure to PM with aerodynamic diameters ≤2.5 μm and ≤ 10 μm (PM_2.5/PM₁₀) during pregnancy was estimated using the inverse distance weighting method. Estimated birth weight (EFW) was assessed by ultrasound measurements and birth weight was measured at birth, which were both standardized as gestational-age- and gender-adjusted Z-score. EFW undergrowth, low birth weight (LBW) and small-for-gestational-age were defined as the categorized outcomes. Generalized estimating equations and generalized linear regression were used to examine the associations of PM with quantitative and categorized outcomes, controlling for temperature, greenspace and individual covariates.

RESULTS

A 10 μg/m³ increase in PM_2.5 and PM₁₀ were associated with lower EFW Z-score [-0.031, 95% confident interval (CI): -0.047, -0.016 and -0.030, 95% CI: -0.043, -0.017]. A 10 μg/m³ increase in PM_2.5 was associated with lower birth weight Z-score (-0.035, 95% CI: -0.061, -0.010) and higher risk of LBW (OR = 1.240, 95% CI: 1.019, 1.508). These results remained robust in co-pollutant models and sensitivity analyses. We didn't find significant results in other analyses.

CONCLUSIONS

The study identified an inverse association between PM and fetal growth in utero. The association between PM_2.5 and fetal growth persisted from pregnancy to birth. This study supported that further actions towards controlling air pollution are strongly recommended for promoting early-life health.

Cytokine profiles in maternal serum are candidates for predicting an optimal timing for the delivery in early-onset fetal growth restriction

OBJECTIVE

We examined whether maternal serum cytokine profiles of mothers with early-onset fetal growth restriction (FGR) were associated with delivery within 2 weeks after sampling during the third trimester.

STUDY DESIGN

This exploratory prospective cross-sectional study included a total of 20 singleton fetuses with early-onset FGR and 31 healthy controls. Maternal serum samples during the early third trimester were analyzed for 23 cytokines.

RESULTS

Of 20 fetuses with early-onset FGR, 14 had delivery within 2 weeks after sampling. Multivariate analysis revealed that maternal serum concentrations of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble CD40 ligand (sCD40L) were independently associated with delivery within 2 weeks in early-onset FGR. Among cases of early-onset FGR, concentrations of almost all maternal serum cytokines were similar. Maternal serum sVEGFR-1 concentrations were high when delivery occurred within 2 weeks. Maternal serum sCD40L concentrations were elicited only in cases in which delivery within 2 weeks occurred due to fetal deterioration.

CONCLUSION

We identified two biomarkers, one specific for FGR and the other dependent on severity, that were significant components of angiogenic activities and inflammation factors. Imbalances in serum protein expression may have a substantial effect on the pathogenesis of FGR.

Pregnancy-associated venous insufficiency course with placental and systemic oxidative stress

The development of lower extremity venous insufficiency (VI) during pregnancy has been associated with placental damage. VI is associated with increased oxidative stress in venous wall. We have investigated potential disturbance/dysregulation of the production of reactive oxygen species (ROS) in placenta and its eventual systemic effects through the measurement of malondialdehyde (MDA) plasma levels in women with VI. A total of 62 women with VI and 52 healthy controls (HCs) were studied. Levels of nicotinamide adenine dinucleotide phosphate-oxidase 1 (NOX1), 2 (NOX2), inducible nitric oxide synthase (iNOS), endothelial (eNOS), poly(ADP-ribose) polymerase PARP (PARP) and ERK were measured in placental tissue with immunohistochemistry and RT-qPCR. Plasma and placental levels of MDA were determined by colorimetry at the two study times of 32 weeks of gestation and post-partum. Protein and gene expression levels of NOX1, NOX2, iNOS, PARP and ERK were significantly increased in placentas of VI. eNOS activity was low in both study groups, and there were no significant differences in gene or protein expression levels. Women with VI showed a significant elevation of plasma MDA levels at 32 weeks of gestation, and these levels remained elevated at 32 weeks post-partum. The MDA levels were significantly higher in placentas of women with VI. Placental damage that was found in the women with VI was characterized by overexpression of oxidative stress markers NOX1, NOX2, and iNOS, as well as PARP and ERK. Pregnant women with VI showed systemic increases in oxidative stress markers such as plasma MDA levels. The foetuses of women with VI had a significant decrease in their venous pH as compared to those from HC women. The situation of oxidative stress and cellular damage created in the placenta is in coexpression with the production of a pH acidification.

Etiology and perinatal outcome of periviable fetal growth restriction associated with structural or genetic anomaly

OBJECTIVE

To investigate the etiology and perinatal outcome of periviable fetal growth restriction (FGR) associated with a structural defect or genetic anomaly.

METHODS

This was a retrospective study of singleton pregnancies seen at a referral fetal medicine unit between 2005 and 2018, in which FGR (defined as fetal abdominal circumference ≤ 3^rd percentile for gestational age) was diagnosed between 22 + 0 and 25 + 6 weeks of gestation. The study group included pregnancies with periviable FGR associated with a genetic or structural anomaly (anomalous FGR), while the control group consisted of structurally and genetically normal pregnancies with periviable FGR (non-anomalous FGR). Results of genetic testing, TORCH screen and postmortem examination, as well as perinatal outcome, were investigated.

RESULTS

Of 255 pregnancies complicated by periviable FGR, 188 were eligible; of which 52 (28%) had anomalous FGR and 136 (72%) had non-anomalous FGR. A confirmed genetic abnormality accounted for 17/52 cases (33%) of anomalous FGR, with trisomy 18 constituting over 50% (9/17; 53%). The most common structural defects associated with FGR were central nervous system abnormalities (13/35; 37%). Overall, 12 (23%) cases of anomalous FGR survived the neonatal period. No differences were found in terms of perinatal survival between pregnancies with anomalous and those with non-anomalous FGR.

CONCLUSIONS

Most pregnancies complicated by anomalous FGR were associated with a structural defect. The presence of an associated genetic defect was invariably lethal, while those with a structural defect, in the absence of a confirmed genetic abnormality, survived into infancy in over 90% of cases, with an overall one in three chance of perinatal survival. These data can be used for counseling prospective parents. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Oxygen and Glucose Consumption in Human Pregnancy Complicated by Fetal Growth Restriction

In healthy pregnancy, glucose and oxygen availability are essential for fetal growth and well being. However, how substrate delivery and fetal uptake are affected in human pregnancy complicated by fetal growth restriction (FGR) is still unknown. Here, we show that the human FGR fetus has a strikingly reduced umbilical uptake of both oxygen and glucose. In 30 healthy term and 32 FGR human pregnancies, umbilical volume flow (Qumb) and parallel umbilical vein (uv) and artery (ua) blood samples were obtained at elective Cesarean section to calculate fetal glucose and oxygen uptake as Qumb · Δ (uv-ua) differences. Umbilical blood flow was significantly lower in FGR pregnancy (-63%; P<0.001) but not when normalized for fetal body weight. FGR pregnancy had significantly lower umbilical oxygen delivery and uptake, both as absolute values (delivery: -78%; uptake: -78%) and normalized (delivery: -50%; uptake: -48%) for fetal body weight (all P<0.001). Umbilical glucose absolute delivery and uptake were significantly reduced (delivery: -68%; uptake: -72%) but only glucose uptake was decreased when normalized for fetal body weight (-30%; P<0.05). The glucose/oxygen quotient was significantly increased (+100%; P<0.05) while glucose clearance was significantly decreased (71%; P<0.001) in FGR pregnancy (both P<0.05). The human fetus in FGR pregnancy triggers compensatory mechanisms to reduce its metabolic rate, matching the proportion of substrate consumption relative to oxygen delivery as a survival strategy during complicated pregnancy.

Chained Risk Assessment for Life-Long Disease Burden of Early Exposures - Demonstration of Concept Using Prenatal Maternal Smoking

Traditional risk factors and environmental exposures only explain less than half of the disease burden. The developmental origin of the health and disease (DOHaD) concept proposes that prenatal and early postnatal exposures increase disease susceptibility throughout life. The aim of this work is to demonstrate the application of the DOHaD concept in a chained risk assessment and to provide an estimate of later in life burden of disease related to maternal smoking. We conducted three systematic literature searches for meta-analysis and reviewed the literature reporting meta-analyses of long-term health outcomes associated with maternal smoking and intermediate risk factors (preterm birth, low birth weight, childhood overweight). In the chained model the three selected risk factors explained an additional 2% (34,000 DALY) of the total non-communicable disease burden (1.4 million DALY) in 2017. Being overweight in childhood was the most important risk factor (28,000 DALY). Maternal smoking was directly associated with 170 DALY and indirectly via the three intermediate risk factors 1000 DALY (1200 DALY in total). The results confirm the potential to explain a previously unattributed part of the non-communicable diseases by the DOHAD concept. It is likely that relevant outcomes are missing, resulting in an underestimation of disease burden.

First-trimester maternal serum alpha-fetoprotein is not a good predictor for adverse pregnancy outcomes: a retrospective study of 3325 cases

Background

It is well known that second-trimester maternal serum alpha-fetoprotein (MS-AFP) is a predictor for adverse pregnancy outcomes (APOs), such as preterm birth, stillbirth, preeclampsia and small for gestational age (SGA). However, it is unknown whether first-trimester MS-AFP is also predictive of APOs.

Methods

We retrospectively reviewed the data on the first-trimester MS-AFP levels and pregnancy outcomes of 3325 singleton pregnant women. The cutoff value of 2.5 multiple of the median (MoM) was used to evaluate the risks of APOs regarding MS-AFP. The receiver operating characteristic (ROC) curves were used to evaluate the predictive efficiencies of MS-AFP to these disorders.

Results

A total of 181 pregnancies resulted in preterm birth, 32 in stillbirth, 81 in preeclampsia, and 362 in SGA. Compared to women with MS-AFP < 2.5MoM, those with MS-AFP ≥ 2.5MoM had increased risks (odds ratio, 95% confidence interval) of preterm birth (2.53, 1.65~3.88), preeclampsia (3.05, 1.71~5.43) and SGA (1.90, 1.34~2.69), and had an earlier distribution of gestational weeks at delivery (P = 0.004) and a lower distribution of neonatal birth weights (P = 0.000), but the actual between-group differences were minuscule. The areas under ROC curves were 0.572 (P = 0.001), 0.579 (P = 0.015) and 0.565 (P = 0.000) for preterm birth, preeclampsia and SGA, respectively. Subdivisions for the disorders did not obviously improve the performances of MS-AFP.

Conclusions

Elevated first-trimester MS-AFP is associated with increased risk of preterm birth, preeclampsia and SGA. However, the predictive efficiencies were low and it is not a good predictor for these APOs.

Are maternal hemodynamic indices markers of fetal growth restriction in pregnancies with a small-for-gestational-age fetus?

OBJECTIVE

Pregnancies complicated by fetal growth restriction (FGR) have a worse outcome than those with a small-for-gestational-age (SGA) fetus. There is increasing evidence of a maternal cardiovascular role in the pathophysiology of FGR. We aimed to compare maternal hemodynamic indices between pregnancies complicated by FGR and those delivering a SGA neonate, using a non-invasive device.

METHODS

This was a prospective study of normotensive pregnancies complicated by FGR (defined as estimated fetal weight (EFW) < 3^rd centile or Doppler evidence of impaired placental-fetal blood flow), those with a SGA fetus (defined as EFW < 10^th centile) and control pregnancies with an appropriately grown fetus. Assessment of maternal hemodynamics (heart rate (HR), cardiac output (CO), mean arterial pressure (MAP), systemic vascular resistance (SVR) and stroke volume) was performed using a non-invasive device (USCOM-1A®). Uterine artery (UtA) pulsatility index (PI) was measured using transabdominal ultrasound. Hemodynamic variables that are affected by gestational age and maternal characteristics were corrected for using device-specific reference ranges. Comparison between groups was performed using the chi-square test or the Mann-Whitney U-test, as appropriate.

RESULTS

A total of 102 FGR, 64 SGA and 401 control pregnancies, with a median gestational age of 36 weeks, were included in the analysis. Women with a pregnancy complicated by FGR and those with a SGA fetus were shorter and weighed less than did controls. Compared with controls, the FGR group had significantly lower median maternal HR (80 beats per min (bpm) vs 85 bpm; P = 0.001) and CO multiples of the median (MoM; 0.91 vs 0.98; P = 0.003), and higher median maternal MAP (90 mmHg vs 87 mmHg; P = 0.040), SVR MoM (1.2 vs 1.0; P < 0.001) and UtA-PI MoM (1.1 vs 0.96; P < 0.001), but there was no significant difference in stroke volume MoM (1.0 vs 0.98; P = 0.647). Compared with the SGA group, the FGR group had a significantly lower median HR (80 bpm vs 87 bpm; P = 0.022), and higher median maternal MAP (90 mmHg vs 85 mmHg; P = 0.025), SVR MoM (1.2 vs 1.0; P = 0.002) and UtA-PI MoM (1.1 vs 0.98; P = 0.005), but there was no significant difference in CO MoM (0.91 vs 0.96; P = 0.092) or stroke volume MoM (1.0 vs 1.0; P = 0.806). There were no significant differences in adjusted maternal hemodynamic indices between the SGA group and controls.

CONCLUSION

Pregnancies complicated by FGR presented with impaired maternal hemodynamic function, as evidenced by lower HR and CO, as well as higher MAP, SVR and UtA resistance. Pregnancies delivering a SGA neonate, without evidence of FGR, had normal maternal hemodynamic function. Maternal hemodynamic indices may therefore be of value in distinguishing FGR from SGA pregnancies. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Lipid profiling in maternal and fetal circulations in preeclampsia and fetal growth restriction-a prospective case control observational study

Background

While many risk factors for preeclampsia, such as increased body mass index, advanced maternal age, chronic hypertension, diabetes, are now established in clinical practice, maternal lipid profile has not been included in the risk assessment for preeclampsia. We aim to characterize the serum levels of Total Cholesterol (TC), High density lipoprotein (HDL), Low density lipoprotein (LDL), Triglycerides (TG), Apolipoprotein A1, Apolipoprotein B and their ratios TC/HDL and ApoB/ApoA1 in the maternal and fetal circulations of normal pregnancy, preeclampsia (PE), fetal growth restriction (FGR) and PE + FGR.

Methods

A prospective cross-sectional case control study was conducted measuring maternal and fetal lipid levels by enzymatic analysis and immune-turbidimetric enzymatic assays. FGR was defined by elevated umbilical artery Doppler resistance in association with estimated fetal weight < 10%. Kruskal Wallis non-parametric analysis of variance was used to test for homogeneity across the clinical groups for each of the variables, Mann-Whitney tests for pairwise comparisons and Spearman rank correlation were used to quantify gestational age-related changes.

Results

(1) TG levels were elevated in maternal PE and cord blood PE + FGR groups compared to normal pregnancies. (2) A statistically significant elevation of fetal ApoB levels was observed in PE, FGR and PE + FGR compared to normal pregnancies. Apolipoprotein levels A1 and B were not different between maternal groups. (3) TC, HDL, LDL and TC/HDL levels did not show any significant gestational variation or between clinical groups in the maternal or fetal circulation.

Conclusions

Elevation in maternal TG levels may have a role in the pathogenesis of PE. The implications of elevated maternal and fetal TG levels and elevated fetal Apolipoprotein B levels deserves further exploration of their role in long term cardiovascular risk in the mother as well as the offspring.

Intra-placental arterial Doppler: A marker of fetoplacental vascularity in late-onset placental disease?

INTRODUCTION

Late-gestation adverse pregnancy outcome is associated with reduced placental villous vascularity but rarely with a frankly abnormal umbilical artery Doppler waveform. The clinical utility of umbilical artery Doppler velocimetry in late gestation is limited by poor understanding of what aspect(s) of placental structure and function the impedance reflects. We hypothesized that placental arterial circulation impedance reflects placental vascularity and arterial function.

MATERIAL AND METHODS

This was a secondary analysis of data from the FEMINA2 study, a study of pregnancy outcome after reduced fetal movement. Forty-three pregnancies that delivered within 7 days of ultrasound assessment were examined. Impedance was quantified by pulsatility index (PI) from umbilical, chorionic plate arteries, and intra-placental arteries. Site-specific PI was compared with villous vascularity (CD31 immunostaining) and placental arterial function (wire myography) by regression analysis (P < .01) where factor analysis suggested potential co-variance (Eigen value > 2).

RESULTS

Pulsatility index decreased with proximity to the placental microvasculature (P < .0001). Intra-placental artery PI correlated significantly with vessel number (R²  = 0.40, P = .0007). No significant relations between umbilical or chorionic plate artery PI and villous vascularity were found (P ≥ .11 and P ≥ .042). No significant co-variance was suggested between PI at any Doppler sampling site and ex vivo placental arterial function indices. Measurement reliability (intraclass correlation coefficient) was highest in the umbilical artery (PI 0.75 and 0.50 for intra- and interoperator reliability, respectively) and lowest in the intra-placental arteries (PI 0.55 and 0.41, respectively). Systematic bias in umbilical artery PI was observed between observers, but not at other Doppler sampling sites.

CONCLUSIONS

More vascular placentas ex vivo are associated with reduced intra-placental artery Doppler impedance in utero. Although umbilical (but not intra-placental) artery Doppler PI is associated with adverse outcome after reduced fetal movement, this predictive ability does not appear to be through assessment of placental vascularity or chorionic plate arterial function. The inferior reliability of intra-placental artery Doppler, although similar to previously published reliability of umbilical artery Doppler, impairs its ability to detect subtle differences in placental vascularity, and must be significantly improved before it could be considered a clinically useful test.

Conflicting Effects of Fetal Growth Restriction on Blood Pressure Between Human and Rat Offspring: A Meta-Analysis

Low birth weight is associated with hypertension. Low birth weight can result from fetal growth restriction (FGR) or prematurity. FGR is postulated to impact blood pressure (BP) by developmental programming. This systematic review and meta-analysis studies BP in human and animal offspring following FGR. Pubmed and Web of Science were searched for studies reporting on BP after placental insufficiency induced FGR compared with normal growth controls. Primary outcome was mean absolute BP difference (ΔBP mm Hg [95% CI]). Meta-analysis was performed using random-effects models. Subgroup analyses were executed on species, sex, age, pregnancy duration, and stress during BP readings. Due to large interspecies heterogeneity, analyses were performed separately for human (n=41) and animal (n=31) studies, the latter restricted to rats (n=27). Human studies showed a ΔBP between FGR and controls of -0.6 mm Hg ([95% CI, -1.7 to 0.6]; I²=91%). Mean ΔBP was -2.6 mm Hg (95% CI, -5.7 to 0.4) in women versus -0.5 mm Hg (95% CI, -3.7 to 2.7) in men. Subgroup analyses did not indicate age, gestational age, and stress during measurements as sources of heterogeneity. In rats, mean BP was 12.0 mm Hg ([95% CI, 8.8-15.2]; I²=81%) higher in FGR offspring. This difference was more pronounced in FGR males (13.6 mm Hg [95% CI, 10.3-17.0] versus 9.1 mm Hg [95% CI, 5.3-12.8]). Subgroup analyses on age showed no statistical interaction. BP readings under restrained conditions resulted in larger BP differences between FGR and control rats (15.3 mm Hg [95% CI, 11.6-18.9] versus 5.7 mm Hg [95% CI, 1.1-10.3]). Rat studies confirm the relation between FGR and offspring BP, while observational studies in humans do not show such differences. This may be due to the observational nature of human studies, methodological limitations, or an absence of this phenomenon in humans. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: CRD42018091819.

Expression of placental glucose transporter proteins in pregnancies complicated by fetal growth disorders

During pregnancy fetal growth disorders, including fetal macrosomia and fetal growth restriction (FGR) are associated with numerous maternal-fetal complications, as well as due to the adverse effect of the intrauterine environment lead to an increased morbidity in adult life. Accumulating evidence suggests that occurrence of fetal macrosomia or FGR, may be associated with alterations in the transfer of nutrients across the placenta, in particular of glucose. The placental expression and activity of specific GLUT transporters are the main regulatory factors in the process of maternal-fetal glucose exchange. This review article summarizes the results of previous studies on the expression of GLUT transporters in the placenta, concentrating on human pregnancies complicated by intrauterine fetal growth disorders. Characteristics of each transporter protein found in the placenta is presented, alterations in the location and expression of GLUT isoforms observed in individual placental compartments are described, and the factors regulating the expression of selected GLUT proteins are examined. Based on the above data, the potential function of each GLUT isoform in the maternal-fetal glucose transfer is determined. Further on, a detailed analysis of changes in the expression of glucose transporters in pregnancies complicated by fetal growth disorders is given, and significance of these modifications for the pathogenesis of fetal macrosomia and FGR is discussed. In the final part novel interventional approaches that might reduce the risk associated with abnormalities of intrauterine fetal growth through modifications of placental GLUT-mediated glucose transfer are explored.

Identification of miR-210-5p in human placentae from pregnancies complicated by preeclampsia and intrauterine growth restriction, and its potential role in the pregnancy complications

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are pregnancy complications resulting from abnormal placental development. As epigenetic regulators, microRNAs can regulate placental development and contribute to the disease pathophysiology by influencing the expression of genes involved in placental development or disease. Our previous study revealed an increase in miR-210-5p expression in placentae from patients with early-onset pregnancy complications and identified candidate gene targets for miR-210-5p. The purpose of this study was to: (i) validate candidate gene targets predicted for miR-210-5p from microRNA-RNA expression data, and (ii) overexpress miR-210-5p in a trophoblast cell line (HTR-8/SVneo) to assess impact on trophoblast cell functions. Integration of the miRNA and RNA sequencing expression data revealed 8 candidate gene targets for miR-210-5p in patients with PE only or PE + IUGR. Luciferase reporter assays identified two gene targets for miR-210-5p, CSF1 and ITGAM. Real-time PCR confirmed the decreased expression of CSF1 and ITGAM in patients with PE + IUGR. Immunohistochemistry of placentae from late second trimester identified CSF1 and ITGAM in intermediate trophoblast cells in the decidua. Expression levels of CSF1 and ITGAM were reduced in HTR-8/SVneo cells following increased miR-210-5p expression. Concomitantly, HTR-8/SVneo cells demonstrate an average 45% reduction in cell migration. These findings suggest that miR-210-5p may contribute to dysfunction of intermediate trophoblasts and potentially contribute to the disease process of these pregnancy complications.

Genetic syndromes associated with isolated fetal growth restriction

Early onset fetal growth restriction (FGR) may be due to impaired placentation, environmental or toxic exposure, congenital infections or genetic abnormalities. Remarkable research, mainly based on retrospective series, has been published on the diverse genetic causes. Those have become more and more relevant with the improvement in the accuracy of the analysis techniques and the rising of breakthrough genomewide methods such as the whole genome sequencing. However, no publication has presented an integrated view of management of those fetuses with an early and severe affection. In this review, we explored to which extent genetic syndromes can cause FGR fetuses without structural defects. The most common chromosomal abnormalities (Triploidies and Trisomy 18), submicroscopic chromosomal anomalies (22q11.2 microduplication syndrome) and single gene disorders (often associated with mild ultrasound findings) related to early and severe FGR had been analysed. Finally, we addressed the impact of epigenetic marks on fetal growth, a matter of growing importance. At the end of this review, we should be able to provide an adequate counseling to parents in terms of diagnosis, prognosis and management of those pregnancies.

Placental MRI and its application to fetal intervention

OBJECTIVE

Magnetic resonance imaging (MRI) of placental invasion has been part of clinical practice for many years. The possibility of being better able to assess placental vascularization and function using MRI has multiple potential applications. This review summarises up-to-date research on placental function using different MRI modalities.

METHOD

We discuss how combinations of these MRI techniques have much to contribute to fetal conditions amenable for therapy such as singletons at high risk for fetal growth restriction (FGR) and monochorionic twin pregnancies for planning surgery and counselling for selective growth restriction and transfusion conditions.

RESULTS

The whole placenta can easily be visualized on MRI, with a clear boundary against the amniotic fluid, and a less clear placental-uterine boundary. Contrasts such as diffusion weighted imaging, relaxometry, blood oxygenation level dependent MRI and flow and metabolite measurement by dynamic contrast enhanced MRI, arterial spin labeling, or spectroscopic techniques are contributing to our wider understanding of placental function.

CONCLUSION

The future of placental MRI is exciting, with the increasing availability of multiple contrasts and new models that will boost the capability of MRI to measure oxygen saturation and placental exchange, enabling examination of placental function in complicated pregnancies.

Neonatal Outcome After Preeclampsia and HELLP Syndrome: A Population-Based Cohort Study in Germany

Aim: To analyze short term outcomes of very low birth weight infants (VLBWI) born preterm after maternal preeclampsia and HELLP syndrome within the German Neonatal Network. Methods: The German Neonatal Network is a large population-based cohort study enrolling VLBWI since 2009. Two thousand six hundred and fifty two infants below 32 weeks of gestation born after maternal preeclampsia or HELLP syndrome and 13,383 infants born prematurely for other causes between 2009 and 2018 were included in our analysis. Descriptive statistics and multinomial regression models including preeclampsia and HELLP syndrome were performed for short-term outcome measures such as intracerebral hemorrhage, necrotizing enterocolitis requiring surgery, bronchopulmonary dysplasia, retinopathy of prematurity, periventricular leukomalacia, persistent ductus arteriosus requiring surgery, blood culture positive sepsis and death. Results: After adjustment for confounding variables, preterm birth due to preeclampsia or HELLP syndrome was associated with a reduced risk for intracerebral hemorrhage (OR 0.73, 95% CI 0.60-0.89), necrotizing enterocolitis requiring surgery (OR 0.35 95% CI 0.15-0.82), periventricular leukomalacia (OR 0.61 95% CI 0.40-0.92), and death (OR 0.72 95% CI 0.55-0.96) as compared to other causes of preterm birth. Conclusions: The indication for preterm birth has an impact on neonatal outcome in preterm infants born below 32 weeks. This notion should be included when counseling the families.

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.

Networks for studies on reproductive and perinatal health: Searching for a consensus

OBJECTIVE

To address the essential characteristics of a network and aspects related to network sustainability.

METHOD

A descriptive study based on a two-round Delphi survey was conducted from 2016 to 2018. Researchers participating in maternal and perinatal health networks were identified by searching PubMed for network-based publications and invited to complete a two-round Delphi questionnaire by email.

RESULTS

Among 529 eligible researchers identified, 54 (10.2%) and 46 (8.7%) responses were received in the first and second rounds, respectively. A consensus on 13 of 21 [OK] questions, and 5 of 10 questions was achieved in the first and second rounds, respectively. The results indicated that a responsible leader is required, and both coordinators and members have a role in decision-making within the network. Good communication and periodic face-to-face meetings are key factors in sustainability and motivation. Rules for secure access to the network database and definition of authorship of scientific papers are essential. Mentioning the name of the network in publications is important for strengthening its activities and the obtainment of funds.

CONCLUSION

Although operational characteristics of the network may differ according to setting and collaborators, homogeneous and essential network characteristics were identified.

Fetal heart rate variability responsiveness to maternal stress, non-invasively detected from maternal transabdominal ECG

PURPOSE

Prenatal stress (PS) during pregnancy affects in utero- and postnatal child brain-development. Key systems affected are the hypothalamic-pituitary-adrenal axis and the autonomic nervous system (ANS). Maternal- and fetal ANS activity can be gauged non-invasively from transabdominal electrocardiogram (taECG). We propose a novel approach to assess couplings between maternal (mHR) and fetal heart rate (fHR) as a new biomarker for PS based on bivariate phase-rectified signal averaging (BPRSA). We hypothesized that PS exerts lasting impact on fHR.

METHODS

Prospective case-control study matched for maternal age, parity, and gestational age during the third trimester using the Cohen Perceived Stress Scale (PSS-10) questionnaire with PSS-10 over or equal 19 classified as stress group (SG). Women with PSS-10 < 19 served as control group (CG). Fetal electrocardiograms were recorded by a taECG. Coupling between mHR and fHR was analyzed by BPRSA resulting in fetal stress index (FSI). Maternal hair cortisol, a memory of chronic stress exposure for 2-3 months, was measured at birth.

RESULTS

538/1500 pregnant women returned the questionnaire, 55/538 (10.2%) mother-child pairs formed SG and were matched with 55/449 (12.2%) consecutive patients as CG. Maternal hair cortisol was 86.6 (48.0-169.2) versus 53.0 (34.4-105.9) pg/mg (p = 0.029). At 36 + 5 weeks, FSI was significantly higher in fetuses of stressed mothers when compared to controls [0.43 (0.18-0.85) versus 0.00 (- 0.49-0.18), p < 0.001].

CONCLUSION

Prenatal maternal stress affects the coupling between maternal and fetal heart rate detectable non-invasively a month prior to birth. Lasting effects on neurodevelopment of affected offspring should be studied.

TRIAL REGISTRATION

Clinical trial registration: NCT03389178.

Role of sFlt-1 and PlGF in the screening of small-for-gestational age neonates during pregnancy: A systematic review

Background

Fetal growth restriction, i.e. the restriction of genetically predetermined growth potential due to placental dysfunction, is a major cause of neonatal morbidity and mortality. The consequences of inadequate fetal growth can be life-long, but the risks can be reduced substantially if the condition is identified prenatally. Currently, screening strategies are based on ultrasound detection of a small-for-gestational age fetus and do not take into account the underlying vascular pathology in the placenta. Measurement of maternal circulating angiogenic biomarkers placental growth factor, sFlt-1 (soluble FMS-like tyrosine kinase-1) are increasingly used in studies on fetal growth restriction as they reflect the pathophysiological process in the placenta. However, interpretation of the role of angiogenic biomarkers in prediction of fetal growth restriction is hampered by the varying design, population, timing, assay technique and cut-off values used in these studies.

Methods

We conducted a systematic-review in PubMed (MEDLINE), EMBASE (Ovid) and Cochrane to explore the predictive performance of maternal concentrations of placental growth factor, sFlt-1 and their ratio for fetal growth restriction and small-for-gestational age, at different gestational ages, and describe the longitudinal changes in biomarker concentrations and optimal discriminatory cut-off values.

Results

We included 26 studies with 2514 cases with small-for-gestational age, 27 cases of fetal growth restriction, 582 cases mixed small-for-gestational age/fetal growth restriction and 29,374 reference. The largest mean differences for the two biomarkers and their ratio were found after 26 weeks of gestational age and not in the first trimester. The ROC-AUC varied between 0.60 and 0.89 with sensitivity and specificity matching the different cut-off values or a preset false-positive rate of 10%.

Conclusions

Most of the studies did not make a distinction between small-for-gestational age and fetal growth restriction, and therefore the small-for-gestational age group consists of fetuses with growth restriction and fetuses that are constitutionally normal. The biomarkers can be a valuable screening tool for small-for-gestational age pregnancies, but unfortunately, there is not yet a clear cut-off value to use for screening. More research is needed to see if these biomarkers are sufficiently able to differentiate growth restriction on their own and how these biomarkers in combination with other relevant clinical and ultrasound parameters can be used in clinical routine diagnostics.

Evaluating the accuracy and precision of sonographic fetal weight estimation models in extremely early-onset fetal growth restriction

INTRODUCTION

Birthweight is a critical predictor of survival in extremely early-onset fetal growth restriction (diagnosed pre-28 weeks' gestation, with abnormal umbilical/uterine artery Doppler waveforms), therefore accurate fetal weight estimation is a crucial component of antenatal management. Currently available sonographic fetal weight estimation models were predominantly developed in populations of mixed gestational age and varying fetal weights, but not specifically tested within the context of extremely early-onset fetal growth restriction. This study aimed to determine the accuracy and precision of fetal weight estimation in this population and investigate whether model performance is affected by other factors.

MATERIAL AND METHODS

Cases where a growth scan was performed within 48 hours of delivery (n = 65) were identified from a cohort of extremely early-onset fetal growth-restricted pregnancies at a single tertiary maternity center (n = 159). Fetal biometry measurements were used to calculate estimated fetal weight using 21 previously published models. Systematic and random errors were calculated for each model and used to identify the best performing model, which in turn was used to explore the relationship between error and gestation, estimated fetal weight, fetal presentation, fetal asymmetry and amniotic fluid volume.

RESULTS

Both systematic (median 8.2%; range -44.1 to 49.5%) and random error (median 11.6%; range 9.7-23.8%) varied widely across models. The best performing model was Hadlock head circumference-abdominal circumference-femur length (HC-AC-FL), regardless of gestational age, fetal size, fetal presentation or asymmetry, with an overall systematic error of 1.5% and random error of 9.7%. Despite this, it only calculated the estimated fetal weight within 10% of birthweight in 64.6% of cases. There was a weak negative relation between mean percentage error with Hadlock HC-AC-FL and amniotic fluid volume, suggesting fetal weight is overestimated at lower liquor volumes and underestimated at higher liquor volumes (P = 0.002, adjusted R²  = 0.08).

CONCLUSIONS

Hadlock HC-AC-FL is the most accurate model currently available to estimate fetal weight in extremely early-onset fetal growth restriction independent of gestation or fetal size, asymmetry or presentation. However, for 35.4% of cases in this study, estimated fetal weight calculated using this model deviates by more than 10% from birthweight, highlighting a need for an improved model.

Role of sFlt-1/PlGF ratio and feto-maternal Doppler for the prediction of adverse perinatal outcome in late-onset pre-eclampsia

PURPOSE

The sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio and uterine artery Doppler have shown to be helpful in the diagnosis of pre-eclampsia (PE). The predictive value of the cerebroplacental ratio (CPR) regarding adverse perinatal outcome (APO) in low-risk pregnancies is intensively discussed. We evaluated the extent to which sFlt-1/PlGF ratio and feto-maternal Doppler may be useful in predicting APO in singleton pregnancies complicated by late-onset PE and/or HELLP syndrome.

METHODS

This is a retrospective study from 2010 to 2018 consisting of singleton pregnancies with confirmed diagnosis of late-onset (lo ≥ 34 weeks) PE/HELLP syndrome in which sFlt-1/PlGF ratio and feto-maternal Doppler (mUtA-PI: mean uterine artery pulsatility index and CPR) were determined. The ability of sFlt-1/PlGF ratio, mUtA-PI, CPR and their combination to predict APO or SGA was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

67 patients were included in the final analysis. Of these, sFlt-1/PlGF was > 110 (defining angiogenic lo PE) in 40.3% (27/67), mUtA-PI was above the 95th centile in 34.3% (23/67) patients and CPR was lower than the 5th centile in 10.4% (7/67). Abnormal sFlt-1/PlGF and mUtA-PI as well as CPR were associated with a lower birth weight (BW). Late-preterm birth (< 37 weeks) as well as postnatal diagnosis of small for gestational age (SGA: BW < 3rd centile) was significantly more often in angiogenic lo PE cases. Neither sFlt-1/PIGF nor CPR or mUtA-PI were APO predictors. Only for sFlt-1/PlGF, ROC analysis revealed a significant predictive value for postnatal SGA (AUC = 0.856, p = 0.001, 95% CI 0.75-0.97). There was no statistical added value of combined SGA predictors as compared to sFlt-1/PlGF alone.

CONCLUSIONS

In patients with lo PE, adding sFlt-1/PlGF ratio to routine antepartum fetal surveillance may be useful to identify cases of postnatal SGA. However, further prospective studies are warranted to define the role of feto-maternal Doppler and sFlt-1/PlGF ratio as outcome predictors.

Perinatal outcome of appropriate-weight fetuses with decelerating growth

INTRODUCTION

To assess the perinatal outcome of fetuses dropping by ≥50 estimated fetal weight (EFW) centiles between the second and third trimester.

METHODS

Singleton pregnancies progressing after 32 + 0 weeks, who had their second- and third-trimester scans at our institutions were enrolled in the study. The perinatal outcome of AGA fetuses crossing more than 50 centiles was compared to that of fetuses with FGR, small for gestational age (SGA) and nondecelerating appropriate for gestational age (AGA). The primary perinatal outcomes were perinatal death, neonatal intensive care (NICU) admission and emergency cesarean section (CS). The rates of these outcomes were compared between the four groups and regression analysis was performed to account for maternal and fetal confounders.

RESULTS

Our analysis included 4394 cases. Compared to nondecelerating SGA, fetuses crossing ≥50 centiles had higher rates of NICU admission (odds ratio [OR] 1.8, 95% confidence interval [CI] CI 1.1-3.1) and perinatal death (OR 3.8, 95%CI 1.3-11.4). Regression analysis showed that significant independent predictors for NICU admission included maternal age, gestational age at birth and FGR (area under the curve [AUC] 0.851), whereas significant predictors for perinatal death included maternal age, gestational age at birth, decelerating growth ≥50 centiles, conception through ART and third-trimester CPR centile (AUC 0.801).

CONCLUSION

AGA fetuses that cross >50 EFW centiles between the second and third trimester are at increased risk of adverse perinatal outcome and it seems advisable that they are followed up as typical FGR cases.

Ultrasound in labor admission to predict need for emergency cesarean section: a prospective, blinded cohort study

OBJECTIVE

To assess whether assessment with ultrasound could improve the detection of emergency cesarean section (ECS) in laboring women.

METHODS

Women who presented with symptoms of active labor or women in need of labor induction were invited to participate in the study. Women included in the study were evaluated with ultrasonography for fetal biometry and vaginal examinations for Bishop score assessment. The main aim in this study was determining factors associated with ECS due to fetal distress and obstructed labor.

RESULTS

No fetal biometry variable was associated with ECS due to any indication (fetal distress and obstructed labor combined) in the univariate analysis. In multivariate analyses, biometry variables were adjusted for Bishop score at admission and only abdominal circumference percentile showed a significant association with the odds of ECS due to any indication (OR:1.02, 95% CI: 1.01-1.03). Biparietal diameter and abdominal circumference variables were associated with the odds of ECS due to obstructed labor in both univariate and multivariate analyses (p < .05 for all). However, the predictive accuracy of biparietal diameter percentile (area under the curve (AUC): 0.55, 95% CI: 0.46-0.63) and abdominal circumference percentile (AUC: 0.56, 95% CI: 0.48-0.64) without adjunct variables were poor. Moreover, the addition of fetal biometry parameters to Bishop score did not improve the predictive accuracy of Bishop score.

CONCLUSION

Ultrasound assessment at admission, in addition to Bishop score assessment, did not significantly improve the prediction of ECS. Also, the fetal biometry alone had poor predictive capability for ECS. Routine ultrasound assessment at labor admission appears to be ineffective for predicting ECS.PrecisFetal biparietal diameter and abdominal circumference showed an association with emergency cesarean due to obstructed labor but the predictive accuracy of fetal biometry was low. Routine ultrasound examination at admission, in addition to Bishop score assessment, may not useful for assessing the risk of emergency section in unselected populations.

Study protocol for a prospective cohort study to investigate Hemodynamic Adaptation to Pregnancy and Placenta-related Outcome: the HAPPO study

INTRODUCTION

The importance of cardiovascular health in relation to pregnancy outcome is increasingly acknowledged. Women who develop certain pregnancy complications, in particular preeclampsia, are at higher risk for future cardiovascular disease. Independent of its outcome, pregnancy requires a substantial adaptive response of the maternal cardiovascular system. In the Hemodynamic Adaptation to Pregnancy and Placenta-related Outcome (HAPPO) study, we aim to examine longitudinal maternal haemodynamic adaptation to pregnancy from the preconception period onwards. We hypothesise that women who will develop adverse pregnancy outcomes have impaired cardiovascular health before conception, leading to haemodynamic maladaptation to pregnancy and diminished uteroplacental vascular development.

METHODS AND ANALYSIS

In this prospective cohort study embedded in the Rotterdam periconception cohort, 200 women with a history of placenta-related pregnancy complications (high-risk group) and 100 women with an uncomplicated obstetric history (low-risk group) will be included. At five moments (preconception, first, second and third trimester and postdelivery), women will undergo an extensive examination of the macrocirculatory and microcirculatory system and uteroplacental vascular development. The main outcome measures are differences in maternal haemodynamic adaptation to pregnancy between women with and without placenta-related pregnancy complications. In a multivariate linear mixed model, the relationship between maternal haemodynamic adaptive parameters, (utero)placental vascularisation indices and clinical outcomes (occurrence of pregnancy complications, embryonic and fetal growth trajectories, miscarriage rate, gestational age at delivery, birth weight) will be studied. Subgroup analysis will be performed to study baseline and trajectory differences between high-risk and low-risk women, independent of subsequent pregnancy outcome.

ETHICS AND DISSEMINATION

This study protocol was approved by the Medical Ethics Committee of the Erasmus MC, Rotterdam, the Netherlands (MEC 2018-150). Results will be disseminated to the medical community by publications in peer-reviewed journals and presentations at scientific congresses. Also, patient associations will be informed and the public will be informed by dissemination through (social) media.

TRIAL REGISTRATION NUMBER

NL7394 (www.trialregister.nl).

Assessment of ventricular contractility in fetuses with an estimated fetal weight less than the tenth centile

OBJECTIVE

To determine whether abnormal global, transverse, and longitudinal ventricular contractility of the heart in fetuses with an estimated fetal weight <10th centile is present, irrespective of Doppler studies of the umbilical artery and cerebroplacental ratio.

STUDY DESIGN

This was a retrospective study of 50 fetuses with an estimated fetal weight <10th centile that were classified based on Doppler results from the pulsatility indices of the umbilical artery and middle cerebral artery, and the calculated cerebroplacental ratio (pulsatility indices of the umbilical artery/middle cerebral artery). Right and left ventricular measurements were categorized into 3 groups: (1) global ventricular contractility (fractional area change), (2) transverse ventricular contractility (24-segment transverse fractional shortening), and (3) basal-apical longitudinal contractility (longitudinal strain, longitudinal displacement fractional shortening, and basal lateral and septal wall annular plane systolic excursion). Z scores for the above measurements were computed for fetuses with an estimated fetal weight <10th centile using the mean and standard deviation derived from normal controls. Ventricular contractility measurements were considered abnormal if their Z score values were <5th centile (z score <-1.65) or >95th centile (Z score >1.65), depending on the specific ventricular measurement.

RESULTS

The average gestational age at the time of the examination was 32 weeks 4 days (standard deviation 3 weeks 4 days). None of the 50 study fetuses demonstrated absent or reverse flow of the umbilical artery Doppler waveform. Eighty-eight percent (44/50) of fetuses had one or more abnormal measurements of cardiac contractility of 1 or both ventricles. Analysis of right ventricular contractility demonstrated 78% (39/50) to have 1 or more abnormal measurements, which were grouped as follows: global contractility 38% (19/50), transverse contractility 66% (33/50); and longitudinal contractility 48% (24/50). Analysis of left ventricular contractility demonstrated 1 or more abnormal measurements in 58% (29/50) that were grouped as follows: global contractility 38% (19/50); transverse contractility 40% (20/50); and longitudinal contractility 40% (20/50). Of the 50 study fetuses, 25 had normal pulsatility index of the umbilical artery and cerebroplacental ratios, 80% of whom had 1 or more abnormalities of right ventricular contractility and 56% of whom had 1 or more abnormalities of left ventricular contractility. Abnormal ventricular contractility for these fetuses was present in all 3 groups of measurements; global, transverse, and longitudinal. Those with an isolated abnormal pulsatility index of the umbilical artery (n=11) had abnormalities of transverse contractility of the right ventricular and global contractility in the left ventricle. When an isolated cerebroplacental ratio abnormality was present, the right ventricle demonstrated abnormal global, transverse, and longitudinal contractility, with the left ventricle only demonstrating abnormalities in transverse contractility. When both the pulsatility index of the umbilical artery and cerebroplacental ratio were abnormal (3/50), transverse and longitudinal contractility measurements were abnormal for both ventricles, as well as abnormal global contractility of the left ventricle.

CONCLUSIONS

High rates of abnormal ventricular contractility were present in fetuses with an estimated fetal weight <10th centile, irrespective of the Doppler findings of the pulsatility index of the umbilical artery, and/or cerebroplacental ratio. Abnormalities of ventricular contractility were more prevalent in transverse measurements than global or longitudinal measurements. Abnormal transverse contractility was more common in the right than the left ventricle. Fetuses with estimated fetal weight less than the 10th centile may be considered to undergo assessment of ventricular contractility, even when Doppler measurements of the pulsatility index of the umbilical artery, and cerebroplacental ratio are normal.

Size and shape of the four-chamber view of the fetal heart in fetuses with an estimated fetal weight less than the tenth centile

BACKGROUND

Fetuses with an estimated fetal weight below the 10^th centile have an increased risk of adverse perinatal and long-term outcomes as well as increased rates of cardiac dysfunction, which often alters cardiac size and shape of the 4-chamber view and the individual ventricles. As a result, a simple method has emerged to screen for potential cardiac dysfunction in fetuses with estimated fetal weights <10^th centile by measuring the size and shape of the 4-chamber view and the size of the ventricles.

OBJECTIVE

To determine the number of fetuses with an abnormal size and shape of the 4-chamber view and size of the ventricles in fetuses with an estimated fetal weight <10^th centile.

MATERIALS AND METHODS

This was a retrospective study of 50 fetuses between 25 and 37 weeks of gestation with an estimated fetal weight <10^th centile. Data from their last examination were analyzed. From an end-diastolic image of the 4-chamber view, the largest basal-apical length and transverse width were measured from their corresponding epicardial borders. This allowed the 4-chamber view area and global sphericity index (4-chamber view length/4-chamber view width) to be computed. In addition, tracing along the endocardial borders with speckle tracking software enabled measurements of the right and left ventricular chamber areas and the right ventricle/left ventricle area ratios to be computed. Doppler waveform pulsatility indices from the umbilical (umbilical artery pulsatility index) and middle cerebral arteries (middle cerebral artery pulsatility index) were analyzed, and the cerebroplacental ratio (middle cerebral artery pulsatility index/umbilical artery pulsatility index) computed. Umbilical artery pulsatility indices >90^th and cerebroplacental ratios <10^th centile were considered abnormal. Using data from the control fetuses, the centile for each of the cardiac measurements was categorized by whether it was <10^th or >90^th centile, depending upon the measurement.

RESULTS

Of the 50 fetuses with estimated fetal weight <10^th centile, 50% (n = 25) had a normal umbilical artery pulsatility index and cerebroplacental ratio. These fetuses had significantly more (P < 0.02 to <0.0001) abnormalities of the size and shape of the 4-chamber view than controls. In all, 44% had a 4-chamber view area >90^th centile, 32% had a 4-chamber view global sphericity index <10^th centile, 56% had a 4-chamber view width >90^th centile, and 80% had 1 or more abnormalities of size and/or shape. The remaining 50% of fetuses (n = 25) had abnormalities of 1 or both for the umbilical artery pulsatility index and/or cerebroplacental ratio. These fetuses had significantly higher rates of abnormalities (P <0.05 to <0.0001) than controls for the following 4-chamber view measurements: 36% had a 4-chamber view area >90^th centile; 28% had a 4-chamber view global sphericity index <10^th centile; and 68% had a 4-chamber view width >90^th centile. Only those fetuses with an abnormal umbilical artery pulsatility index had significant changes in ventricular size; 56% had a left ventricular area <10^th centile; 28% had a right ventricular area <10^th centile; 36% had right ventricular/left ventricular area ratio >90^th centile. One or more of the above abnormal measurements were present in 92% of the fetuses.

CONCLUSION

Higher rates of abnormalities of cardiac size and shape of the 4-chamber view were found in fetuses with an estimated fetal weight <10^th centile, regardless of their umbilical artery pulsatility index and cerebroplacental ratio measurements. Those with a normal umbilical artery pulsatility index and an abnormal cerebroplacental ratio had larger and wider measurements of the 4-chamber view. In addition, the shape of the 4-chamber view was more globular or round than in controls. These fetuses may have an increased risk of perinatal complications and childhood and/or adult cardiovascular disease. Screening tools derived from the 4-chamber view, acting as surrogates for ventricular dysfunction, may identify fetuses who could benefit from further comprehensive testing and future preventive interventions.

Influence of maternal characteristics and gestational age on hemodynamic indices: NICOM device-specific reference ranges

OBJECTIVES

To construct reference ranges for stroke volume, cardiac output and systemic vascular resistance (SVR) in normal pregnancy for the NICOM® device, and to explore associations between maternal characteristics and these hemodynamic variables.

METHODS

This was a prospective cohort study of healthy singleton pregnancies between 10 and 40 weeks' gestation attending a tertiary referral hospital between September 2012 and May 2018. Measurements of stroke volume, cardiac output and SVR were obtained throughout pregnancy using NICOM, a non-invasive device based on bioreactance technology. NICOM device-specific reference ranges were created with respect to gestational age and maternal characteristics. Once the distribution of the data had been determined with respect to the gestational age, patient characteristics were added to the model to test whether they provided a significant improvement in prediction of the median value. The effect was assessed of maternal weight, height, smoking status, conception using assisted reproductive technology, nulliparity and ethnicity.

RESULTS

We included 411 women in this study. The relationships between cardiac variables and gestational age observed in the NICOM-specific reference ranges are consistent with previous findings, with increasing cardiac output values until around 35 weeks and a decrease thereafter until term, and decreasing SVR until around 36 weeks, followed by an increase towards 40 weeks. Stroke volume showed a small linear increase across gestation with lower variability in observations close to term. Maternal weight, height and age were associated with cardiac output (all P < 0.05) and SVR (all P < 0.01), whilst maternal weight and height were associated with stroke volume (both P < 0.001). Ethnicity was significantly associated with stroke volume (P = 0.001) but not with cardiac output or SVR.

CONCLUSIONS

This study presents device-specific reference ranges for stroke volume, cardiac output and SVR for the NICOM device in healthy pregnancy and describes the maternal characteristics that are associated with the values of these hemodynamic measurements. Studies using NICOM in pregnancy can use these ranges in order to evaluate observations relative to those expected in uncomplicated pregnancy conditional on maternal characteristics. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Inter- and intra-observer variability in fetal ductus venosus blood flow measurements in high-risk fetuses at 26-32 weeks

OBJECTIVES

Early preterm fetal growth restriction is a significant contributor to perinatal morbidity and mortality. The ductus venosus pulsatility index for veins (DV PIV) is proposed as a monitoring tool because it appears to improve perinatal outcomes. The test characteristics and robustness of DV PIV have been inadequately described. The aim of this study was to investigate inter- and intra-observer variability of DV PIV.

STUDY DESIGN

Nineteen women with a gestational age between 26 and 32 completed weeks were included in this study. Doppler sonographic fetal assessment was performed by two independent maternal-fetal medicine specialists. Each sonographer alternately performed three flow tracings for each participant, in the absence of the other sonographer (six tracings in total per patient). DV PIV was calculated automatically from stored tracings by a third researcher. Inter- and intra-observer variability of DV PIV and limits of agreement were assessed using the Bland-Altman method. Comparison of the distribution was performed with Kendall's related samples test, and the intraclass correlation coefficient (ICC) was calculated.

RESULTS

In total, 114 DV measurements were taken from 19 participants with a median age of 31 years [interquartile range (IQR) 26-34 years] at a median gestational age of 28 weeks (IQR 27-29 weeks). The proportional limits of agreement for intra-observer variation were -0.48 to 0.48 and -0.39 to 0.62 for the two observers. ICCs were 0.66 [95% confidence interval (CI) 0.42-0.84] and 0.68 (95% CI 0.45-0.85). The proportional limits of agreement for inter-observer variation were -0.29 to 0.19 with an ICC of 0.89 (95% CI 0.73-0.96).

CONCLUSION

Inter-observer variation was far less than intra-observer variation, probably due to mitigation of biological variation by averaging three measurements. DV PIV has acceptable test characteristics for use in a clinical setting when the average of at least three consecutive measurements is used.

Effectiveness of routine third trimester ultrasonography to reduce adverse perinatal outcomes in low risk pregnancy (the IRIS study): nationwide, pragmatic, multicentre, stepped wedge cluster randomised trial

OBJECTIVES

To investigate the effectiveness of routine ultrasonography in the third trimester in reducing adverse perinatal outcomes in low risk pregnancies compared with usual care and the effect of this policy on maternal outcomes and obstetric interventions.

DESIGN

Pragmatic, multicentre, stepped wedge cluster randomised trial.

SETTING

60 midwifery practices in the Netherlands.

PARTICIPANTS

13 046 women aged 16 years or older with a low risk singleton pregnancy.

INTERVENTIONS

60 midwifery practices offered usual care (serial fundal height measurements with clinically indicated ultrasonography). After 3, 7, and 10 months, a third of the practices were randomised to the intervention strategy. As well as receiving usual care, women in the intervention strategy were offered two routine biometry scans at 28-30 and 34-36 weeks' gestation. The same multidisciplinary protocol for detecting and managing fetal growth restriction was used in both strategies.

MAIN OUTCOME MEASURES

The primary outcome measure was a composite of severe adverse perinatal outcomes: perinatal death, Apgar score <4, impaired consciousness, asphyxia, seizures, assisted ventilation, septicaemia, meningitis, bronchopulmonary dysplasia, intraventricular haemorrhage, periventricular leucomalacia, or necrotising enterocolitis. Secondary outcomes were two composite measures of severe maternal morbidity, and spontaneous labour and birth.

RESULTS

Between 1 February 2015 and 29 February 2016, 60 midwifery practices enrolled 13 520 women in mid-pregnancy (mean 22.8 (SD 2.4) weeks' gestation). 13 046 women (intervention n=7067, usual care n=5979) with data based on the national Dutch perinatal registry or hospital records were included in the analyses. Small for gestational age at birth was significantly more often detected in the intervention group than in the usual care group (179 of 556 (32%) v 78 of 407 (19%), P<0.001). The incidence of severe adverse perinatal outcomes was 1.7% (n=118) for the intervention strategy and 1.8% (n=106) for usual care. After adjustment for confounders, the difference between the groups was not significant (odds ratio 0.88, 95% confidence interval 0.70 to 1.20). The intervention strategy showed a higher incidence of induction of labour (1.16, 1.04 to 1.30) and a lower incidence of augmentation of labour (0.78, 0.71 to 0.85). Maternal outcomes and other obstetric interventions did not differ between the strategies.

CONCLUSION

In low risk pregnancies, routine ultrasonography in the third trimester along with clinically indicated ultrasonography was associated with higher antenatal detection of small for gestational age fetuses but not with a reduced incidence of severe adverse perinatal outcomes compared with usual care alone. The findings do not support routine ultrasonography in the third trimester for low risk pregnancies.

TRIAL REGISTRATION

Netherlands Trial Register NTR4367.

A Core Outcome Set for the prevention and treatment of fetal GROwth restriction: deVeloping Endpoints: the COSGROVE study

BACKGROUND

Fetal growth restriction refers to a fetus that does not reach its genetically predetermined growth potential. It is well-recognized that growth-restricted fetuses are at increased risk of both short- and long-term adverse outcomes. Systematic evaluation of the evidence from clinical trials of fetal growth restriction is often difficult because of variation in the outcomes that are measured and reported. The development of core outcome sets for fetal growth restriction studies would enable future trials to measure similar meaningful outcomes.

OBJECTIVE

The purpose of this study was to develop core outcome sets for trials of prevention or treatment of fetal growth restriction.

STUDY DESIGN

This was a Delphi consensus study. A comprehensive literature review was conducted to identify outcomes that were reported in studies of prevention or treatment of fetal growth restriction. All outcomes were presented for prioritization to key stakeholders (135 healthcare providers, 68 researchers/academics, and 35 members of the public) in 3 rounds of online Delphi surveys. A priori consensus criteria were used to reach agreement on the final outcomes for inclusion in the core outcome set at a face-to-face meeting with 5 healthcare providers, 5 researchers/academics, and 6 maternity service users.

RESULTS

In total, 22 outcomes were included in the final core outcome set. These outcomes were grouped under 4 domains: maternal (n=4), fetal (n=1), neonatal (n=12), and childhood (n=5).

CONCLUSION

The Core Outcome Set for the prevention and treatment of fetal GROwth restriction: deVeloping Endpoints study identified a large number of potentially relevant outcomes and then reached consensus on those factors that, as a minimum, should be measured and reported in all future trials of prevention or treatment of fetal growth restriction. This will enable future trials to measure similar meaningful outcomes and to ensure that findings from different studies can be compared and combined.

Fetal growth restriction: From Polyvagal theory to developmental impairments?

BACKGROUND

The Polyvagal theory argues that behavioral modulation is a fundamental neurodevelopmental process that depends on autonomic regulation.

OBJECTIVE

The present study aimed to assess sleep architecture in newborns with fetal growth restriction (FGR) using polysomnography as an indicator of Polyvagal theory.

METHODS

We studied polysomnography recordings from 68 preterm infants, 34 with FGR and 34 born with appropriate growth for gestational age (AGA), who were matched according to the corrected age for prematurity (CA). Total sleep time, arousals, the percentage of quiet sleep, active sleep, indeterminate sleep, and heart rate were compared between the groups. Linear multiple regression analyses were used to evaluate polysomnography data for the FGR and AGA groups.

RESULTS

Average heart rate was significantly lower in most FGR groups compared with AGA groups, and small to large effect sizes were observed in several sleep responses when comparing these groups. In the lineal regression model the CA explains significantly the differences in heart rate, controlled by FGR (p = .012). Additionally, there was evidence that sleeping states show similar trends, that is, increases in quiet and indeterminate sleep, as well as decreases in active sleep when CA was controlled by FGR.

CONCLUSION

FGR probably intensifies the unfavorable effect of preterm birth in the responses evaluated by polysomnography. It seems that FGR is associated with alteration in sleep regulation and with differences in heart rate modulation, which may serve as a strategy to preserve energy and such differences likely underlie neurodevelopmental impairments in affected newborns.

Longitudinal change in cerebroplacental ratio in small-for-gestational-age fetuses and risk of stillbirth

OBJECTIVE

To investigate whether assessment of longitudinal change in Doppler variables in small-for-gestational-age (SGA) fetuses improves the prediction of those at risk of stillbirth.

METHODS

This was a longitudinal study of two cohorts of singleton pregnancies, which included SGA and appropriate-for-gestational-age (AGA) fetuses, respectively. The inclusion criteria for the SGA cohort were singleton pregnancy at ≥ 20 weeks' gestation, classified as SGA (estimated fetal weight < 10^th centile). The AGA cohort consisted of singleton pregnancies deemed at high risk of being SGA, which were followed up longitudinally but remained AGA. Fetal middle cerebral artery (MCA) pulsatility index (PI) and umbilical artery (UA)-PI were measured longitudinally and cerebroplacental ratio (CPR) was calculated, and values were converted to multiples of the median. The last two measurements prior to delivery were included in the analysis. Longitudinal models for Doppler variables were developed using linear-mixed models and their accuracy in the prediction of stillbirth was tested using generalized linear models. A Bayesian framework was employed to compare the accuracy of longitudinal and standard (last-scan measurement) models.

RESULTS

In total, 1549 AGA and 941 SGA pregnancies were included in the analysis. There were 30 (3.2%) and no stillbirth cases in the SGA and AGA groups, respectively. Change in MCA-PI, UA-PI and CPR with advancing gestation was significantly different between liveborn AGA and SGA fetuses, with a less pronounced difference with advancing gestation. Using the last measurement, the best models for the prediction of stillbirth in SGA pregnancies were those based on CPR (accuracy, 75.0%; 95% CI, 72.6-77.2%) and UA-PI (accuracy, 71.0%; 95% CI, 68.6-73.4%). The posterior probability of the standard CPR model having a higher accuracy compared with the UA-PI model was 97.2% (magnitude of change (MC), 3.9%; 95% credible interval (CrI), 0.5-7.3%). The accuracies of the standard, compared with the longitudinal, models for UA-PI (71.0% vs 72.8%), MCA-PI (64.6% vs 63.8%) and CPR (75.0% vs 74.9%) in the prediction of stillbirth were not significantly different. The posterior probabilities for improvement in accuracy using longitudinal, compared with standard, assessment were 50.1% (MC, < 0.1%; 95% CrI, -3.3 to 3.3%), 35.2% (MC, -0.1%; 95% CrI, -4.5 to 2.8%) and 82.2% (MC, 1.9%; 95% CrI, -1.5 to 5.3%) for CPR, MCA-PI and UA-PI models, respectively. Therefore, change in Doppler parameters did not improve the accuracy of the prediction of stillbirth, compared with that of the last-scan measurement.

CONCLUSION

Longitudinal assessment of Doppler parameters was not useful in improving the detection of stillbirth in SGA pregnancies, as compared with a single-point assessment. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Growth Restriction

Fetal growth restriction (FGR) is a failure of fetus to reach its expected biological growth, based on its genetically predetermined potential. Whenever effective fetal weight is less than, 10th percentile or 2 standard deviation of population-specific growth curve, it is considered small for gestational age (SGA). The FGR is associated with poor somatic growth with concomitant changes in placental and cerebral blood flow and/or biochemical markers along with EBW < 3rd percentile. It is an important cause of perinatal mortalities and morbidities. Ultrasound plays a definitive role in diagnosis and its management. This article is aimed to mini review the published guidelines on FGR and SGA and summarize the areas of consensus.

The Role of Early Pregnancy Maternal Selenium Levels on the Risk for Small-for-Gestational Age Newborns

It has not yet been established, whether or not the maternal serum selenium (Se) in early pregnancy may be a risk marker of small-for-gestational age (SGA) birth weight. Selenium is important for human health and is involved in oxidative balance, a key element in the development of the placenta and fetus. This innovative study was nested in a prospective cohort of 750 women recruited in the 10–14th week of a single pregnancy, all of whom were healthy during recruitment. We examined mothers delivering SGA infants (with birth weight <10th percentile) (n = 48) and matched mothers delivering appropriate-for-gestational age (AGA) infants (between 10–90th percentile) (n = 192). We measured the maternal microelement concentrations in the serum from the 10–14th gestational week, using the inductively coupled plasma mass spectrometry (ICP-MS). The odds ratios of SGA (and 95% confidence intervals) were assessed in logistic regression. The mean maternal Se concentrations were lower in mothers in the SGA group compared to the AGA group (59.60 vs. 62.54 µg/L; p = 0.020). Women in the lowest Q₁ quartile of Se (≤56.60 µg/L) have about three times higher risk of SGA compared to women in the higher quartiles (Q₂ or Q₄); the odds ratio of SGA was OR = 3.02 (p = 0.019) for Q₁ vs. Q₂ quartile. The risk profile graph confirms the results. We found that excessive pre-pregnancy BMI (body mass index) affected the estimated SGA odds ratios. Early pregnancy maternal serum selenium status can be a risk marker of SGA newborns and more research is needed in larger groups.

Hemodynamic factors associated with fetal cardiac remodeling in late fetal growth restriction: a prospective study

Background Altered cardiac geometry affects a proportion of fetuses with growth restriction (FGR). The aim of this study was to explore the hemodynamic factors associated with cardiac remodeling in late FGR. Methods This was a prospective study of singleton pregnancies complicated by late-onset FGR undergoing assessment of left (LV) and right (RV) ventricular sphericity-index (SI). The study population was divided in two groups according to the presence of cardiac remodelling, defined as LVSI <5th centile. The following outcomes were explored: gestational age at birth, birthweight, caesarean section (CS) for fetal distress, umbilical artery (UA) pH and neonatal admission to special care unit. The differences between the 2 groups in UA pulsatility index (PI), middle cerebral artery (MCA) PI, uterine artery PI, cerebroplacental ratio (CPR) and umbilical vein (UV) flow corrected for fetal abdominal circumference (UVBF/AC) were tested. Results In total, 212 pregnancies with late FGR were enrolled in the study. An abnormal LV SI was detected in 119 fetuses (56.1%). Late FGR fetuses with cardiac remodeling had a lower birthweight (2390 g vs. 2490; P = 0.04) and umbilical artery pH (7.21 vs. 7.24; P = 0.04) and were more likely to have emergency CS (42.8% vs. 26.9%; P = 0.023) and admission to special care unit (13.4% vs. 4.3%; P = 0.03) compared to those with normal LVSI. No difference in either UA PI (p = 0.904), MCA PI (P = 0.575), CPR (P = 0.607) and mean uterine artery PI (P = 0.756) were present between fetuses with or without an abnormal LV SI. Conversely, UVBF/AC z-score was lower (-1.84 vs. -0.99; P ≤ 0.001) in fetuses with cardiac remodeling and correlated with LV (P ≤ 0.01) and RV SI (P ≤ 0.02). Conclusion Fetal cardiac remodelling occurs in a significant proportion of pregnancies complicated by late FGR and is affected by a high burden of short-term perinatal compromise. The occurrence of LV SI is independent from fetal arterial Dopplers while it is positively associated with umbilical vein blood flow.

Pathologic placental lesions in early and late fetal growth restriction

INTRODUCTION

The purpose of the study was to evaluate the differences in individual histopathologic placental lesions in pregnancies complicated by early-onset (<32 weeks at diagnosis) and late-onset (≥32 weeks at diagnosis) fetal growth restriction (FGR).

MATERIAL AND METHODS

A cohort study of 440 singleton pregnancies complicated by FGR, diagnosed according to standard ultrasonographic criteria, followed up and delivered at the same institution between 2010 and 2016. Placental lesions were classified according to the Amsterdam Placental Workshop Consensus Criteria. Pathologic examination of placentas from 113 healthy singleton term pregnancies served as controls. Binary and multinomial logistic regression models were used to evaluate the independent association of placental lesions with the type of FGR.

RESULTS

In our cohort the prevalences of early and late FGR were 37.3% (164/440) and 62.7% (276/440), respectively. The overall rates of preeclampsia (69/164 vs 59/276, P < 0.01) and absent/reversed umbilical artery pulsatility indices (61/164 vs 14/276, P < 0.001) were higher among early FGR than late FGR. Placental characteristics from early and late FGR pregnancies differed mainly in regard to maternal vascular malperfusion scores rather than fetal scores, with preeclampsia found to be a cofactor modulating the rates and severity of associated lesions. In the binary logistic analysis, recent infarcts (OR 2.44, 95% CI 1.2-5), distal villous hypoplasia (OR 1.8, 95% CI 1.0-3.2), atherosis (OR 2.71, 95% CI 1.35-5.47), persistent endovascular trophoblasts (OR 1.67, 95% CI 1.03-2.7), and a reduced fetal/placental weight score (OR 0.27, 95% CI 0.2-0.38) were independently associated with an increased likelihood of early FGR compared with late FGR. The sensitivity, specificity, and area under the curve of the model were 60% (95% CI 51.2-66.2), 89.1% (95% CI 84.9-92.3), and 0.81 (95% CI 0.77-0.85), respectively, suggesting a fair to good predictive value.

CONCLUSIONS

Individual placental lesions suggestive of increased rates of ischemia, defective remodeling of spiral arteries, peripheral hypoxia interfering with villus development, and reduced placental efficiency were significantly more common in early FGR than late FGR.

The impact of placental massive perivillous fibrin deposition on neonatal outcome in pregnancies complicated by fetal growth restriction

INTRODUCTION

Massive perivillous fibrin deposition (MPDD) is an uncommon placental lesion which has been associated with an increased risk of adverse pregnancy outcome in retrospective series. The purpose of the study was to evaluate the frequency and consequences of MPFD in pregnancies complicated by fetal growth restriction (FGR).

MATERIALS AND METHODS

A cohort study of 355 pregnancies complicated by FGR diagnosed according to standard ultrasonographic criteria, enrolled, followed and delivered at a single obstetric unit. Pathological placental lesions were classified according to the Amsterdam Placental Workshop Consensus. Penalized logistic regression models were used to evaluate the association of MPFD with maternal risk factors, other pathological lesions and neonatal outcome.

RESULTS

The rates of moderate (25-50% of villi) and severe (>50% of villi) MPFD were 8.7% (31/355) and 3.1% (11/355), respectively. Compared to other FGR cases, MPFD pregnancies were characterized by higher placental volume (450 ± 144.5 SD as compared to 412.2 ± 151 cm³,p < 0.001) and lower birthweight/placental weight ratio (5.32 ± 1.53 compared to 6.1 ± 1.52,p < 0.001). The rates of abnormal Doppler ultrasound studies of umbilical and middle cerebral artery were similar in MPFD subjects and controls. After correction for gestational age and birthweight, MPFD was associated with an increased risk of neonatal intraventricular hemorrhage (>grade II) (OR = 5.66,95% CI = 1.69-18.97), sepsis (OR = 5.9, 95% CI = 1.27-27.12), proven necrotizing enterocolitis (OR = 9.84,95% CI = 2.49-38.8) and overall severe adverse neonatal outcome (OR = 5.71,95% CI = 2.05-15.87).

CONCLUSIONS

Moderate-to-severe MPFD was relatively common among FGR pregnancies and was associated with morphometric modifications of placenta and with an increased risk of severe adverse neonatal outcome.

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.

Early-onset fetal growth restriction: A systematic review on mortality and morbidity

INTRODUCTION

Severe early-onset fetal growth restriction is an obstetric condition with significant risks of perinatal mortality, major and minor neonatal morbidity, and long-term health sequelae. The prognosis of a fetus is influenced by the extent of prematurity and fetal weight. Clinical care is individually adjusted. In literature, survival rates vary and studies often only include live-born neonates with missing rates of antenatal death. This systematic review aims to summarize the literature on mortality and morbidity.

MATERIAL AND METHODS

A broad literature search was conducted in OVID MEDLINE from 2000 to 26 April 2019 to identify studies on fetal growth restriction and perinatal death. Studies were excluded when all included children were born before 2000 because (neonatal) health care has considerably improved since this period. Studies were included that described fetal growth restriction diagnosed before 32 weeks of gestation and antenatal mortality and neonatal mortality and/or morbidity as outcome. Quality of evidence was rated with the GRADE instrument.

RESULTS

Of the 2604 publications identified, 25 studies, reporting 2895 pregnancies, were included in the systematic review. Overall risk of bias in most studies was judged as low. The quality of evidence was generally rated as very low to moderate, except for 3 large well-designed randomized controlled trials. When combining all data on mortality, in 355 of 2895 pregnancies (12%) the fetus died antenatally, 192 died in the neonatal period (8% of live-born neonates) and 2347 (81% of all pregnancies) children survived. Of the neonatal morbidities recorded, respiratory distress syndrome (34% of the live-born neonates), retinopathy of prematurity (13%) and sepsis (30%) were most common. Of 476 children that underwent neurodevelopmental assessment, 58 (12% of surviving children, 9% of all pregnancies) suffered from cognitive impairment and/or cerebral palsy.

CONCLUSIONS

When combining the data of 25 included studies, survival in fetal growth restriction pregnancies, diagnosed before 32 weeks of gestation, was 81%. Neurodevelopmental impairment was assessed in a minority of surviving children. Individual prognostic counseling on the basis of these results is hampered by differences in patient and pregnancy characteristics within the included patient groups.

Ultrasound diagnosis of microcephaly: a comparison of three reference curves and postnatal diagnosis

PURPOSE

To evaluate which reference curve (RC)-Snijders, Intergrowth 21st (IG21) and World Health Organization (WHO)-is more accurate for microcephaly diagnosis.

METHODS

Retrospective cohort study with more than 30,000 exams in more than 11,000 women. Microcephaly was confirmed by a neonatologist at birth and positive predictive values (PPVs) and misdiagnosis were assessed.

RESULTS

A total of 71 cases were confirmed as microcephaly at birth. IG21 and Snijders PPVs showed to be more significant over WHO's (p < 0.001), without difference between them (p = 0.39). All RC were superimposed and did not show significant difference. When evaluated in different fragments, three trends were observed (until 30 weeks, between 30 and 36 and after 36 weeks of gestational age), with the latter interval showing a significant difference between IG21 and WHO (p = 0.0079). Conversely, WHO exhibited only one misdiagnosis, a much lower rate than Snijders, who missed eight cases and IG21, nine.

CONCLUSION

WHO's RC appears to misdiagnose fewer cases, which could be useful for a population screening, while IG21's RC presented a more significant PPV, being more useful for a more precise final diagnosis in reference centers.