A Uniform Management Approach to Optimize Outcome in Fetal Growth Restriction

Early postnatal transitional circulation in fetal growth restricted neonates

BACKGROUND

Fetal growth restriction (FGR) may impact early postnatal transitional circulation.

AIM

Echocardiographic assessment of left ventricular cardiac output, superior vena cava (SVC) and ductus venosus (DV) blood flow in FGR neonates first three days after birth.

STUDY DESIGN

Prospective observational study.

SUBJECTS

FGR and Non-FGR neonates.

OUTCOME MEASURES

Left ventricular cardiac output, SVC and DV blood flow day one, two, and three.

RESULTS

Adjusting for gestational age (GA), birth weight, sex, and twin/singleton, flow measurements were similar between Late-FGR (GA ≥ 32 weeks, n = 23) and Non-FGR (GA ≥ 32 weeks, n = 39). On day three, Late-FGR had significantly lower left ventricular stroke volume (Estimated Marginal Means (Standard Error) 0.99 (0.08) vs 1.22 (0.06) mL/kg, p = 0.027) and higher heart rate (134 (5) vs 119 (4) beats/min, p = 0.032). Left ventricular cardiac output and left ventricular stroke volume decreased significantly from day one to three in both groups; Late-FGR 170 (8) to 149 (8) mL/min/kg, p = 0.007, and 1.34 (0.07) to 1.17 (0.07) mL/kg, p = 0.015, and Non-FGR 161 (6) to 144 (6) mL/min/kg, p = 0.002, and 1.27 (0.06) to 1.16 (0.06) mL/kg, p = 0.021. SVC flow remained unchanged from day one to three in Late-FGR (92 (6) to 83 (6) mL/min/kg, p = 0.161) and decreased significantly in Non-FGR (83 (5) to 71 (5) mL/min/kg, p = 0.021). DV blood flow remained unchanged. No measurements differed between Early-FGR (GA 30+0-31+6 weeks) and Late-FGR.

CONCLUSIONS

Late-FGR had limited impact on left ventricular cardiac output, SVC and DV blood flow in early neonatal period. Most adaptive circulatory changes occurred early during transition.

Color Doppler ultrasound in high-low risk pregnancies and its relationship to fetal outcomes: a cross-sectional study

Objective

To calculate the multivessel color Doppler indices in high-risk and low-risk pregnancies and relate these to fetal outcomes.

Methods

The investigation involved 60 patients who were pregnant. The patients were separated into groups according to assessment of low and high risk. The patients underwent color Doppler ultrasonography to detect the maternal and fetal blood vessels, and the measured Doppler indices were then analyzed for any association with fetal outcomes.

Results

The gestational stages (in weeks) of the participants at the respective times of investigation and delivery were 32.06 ± 2.98 and 36.2 ± 1.78 in the low-risk group and 29.21 ± 1.95 and 29.83 ± 1.86 in the high-risk group. The pulsatility index (PI), resistive index (RI), and systolic/diastolic ratio (SD) decreased with gestation length in the low-risk group, whereas in the high-risk group, these values increased in the uterine and umbilical arteries. With increased gestational stage, MCA-PSV (peak systolic velocity) in the middle cerebral artery (MCA) increased, while PI decreased. Pulsatile and reversal flow of the uterine vein, the vein of Galen, and the umbilical vein were noted in high-risk pregnancies, and these negatively affected the fetal outcome. The fetal venous parameters were more specific and sensitive for predicting an unfavorable fetal outcome than the arterial factors, with a greater negative predictive value.

Conclusion

The results of our study indicate that abnormal Doppler indices of the blood vessels in high-risk pregnant patients will result in adverse clinical outcomes. Therefore, the patients can be monitored and managed accordingly using Doppler ultrasonography.

Pregnancy management and outcome after uterus transplantation

Uterus transplantation is a novel approach in women whose uterus is absent or severely abnormal. However, it is still an experimental procedure that poses risks to both mother and baby. To date, 32 live births after uterus transplantation have been reported in peer-reviewed journals, with several maternal, fetal and neonatal complications. The most common complications were preterm delivery, hypertensive disorders and placenta previa. Four patients experienced episodes of transplant rejection during pregnancy. The appropriate management of complicated and non-complicated pregnancies following uterus transplantation is still unresolved. In this review, obstetric outcomes after uterus transplantation and optimal management during pregnancy are discussed in light of the available data. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Maternal, obstetric, and fetal Doppler characteristics in a high-risk population: prediction of adverse perinatal outcomes and of cesarean section due to intrapartum fetal compromise

Objective

To evaluate the capacity of fetal Doppler, maternal, and obstetric characteristics for the prediction of cesarean section due to intrapartum fetal compromise (IFC), a 5-min Apgar score < 7, and an adverse perinatal outcome (APO), in a high-risk population.

Materials and Methods

This was a prospective cohort study involving 613 singleton pregnant women, admitted for labor induction or at the beginning of spontaneous labor, who underwent Doppler ultrasound within the last 72 h before delivery. The outcome measures were cesarean section due to IFC, a 5-min Apgar score < 7, and any APO.

Results

We found that maternal characteristics were neither associated with nor predictors of an APO. Abnormal umbilical artery (UA) resistance index (RI) and the need for intrauterine resuscitation were found to be significant risk factors for cesarean section due to IFC (p = 0.03 and p < 0.0001, respectively). A UA RI > the 95th percentile and a cerebroplacental ratio (CPR) < 0.98 were also found to be predictors of cesarean section due to IFC. Gestational age and a UA RI > 0.84 were found to be predictors of a 5-min Apgar score < 7 for newborns at < 29 and ≥ 29 weeks, respectively. The UA RI and CPR presented moderate accuracy in predicting an APO, with areas under the ROC curve of 0.76 and 0.72, respectively.

Conclusion

A high UA RI appears to be a significant predictor of an APO. The CPR seems to be predictive of cesarean section due to IFC and of an APO in late preterm and term newborns.

Defining poor growth and stillbirth risk in pregnancy for infants of mothers with overweight and obesity

BACKGROUND

Mothers who are obese carry heavier fetuses and have lower rates of small for gestational age (<10th birthweight centile) infants. However, their infants may be growth-restricted (with an increased risk of stillbirth) at a higher birthweight centile compared with infants from healthy-weight women.

OBJECTIVE

This study aimed to quantify the birthweight centile at which the risk of stillbirth in infants born to obese women equaled that of <10th-centile infants born to healthy-weight women, and clarify the relationship between maternal body mass index, infant size, and stillbirth.

STUDY DESIGN

We conducted a retrospective cohort study on all infants born in Victoria, Australia, from 2009 to 2019 (754,946 cases for analysis). We applied uncustomized birthweight centiles to all infants, and stratified the maternal cohort by body mass index (<20 kg/m2, 20-25 kg/m2, 25-30 kg/m2, 30-35 kg/m2, 35-40 kg/m2, ≥40 kg/m2). For each body mass index category, we assessed proportions of infants born <10th centile and <3rd centile, stillbirth rates among infants of all sizes, and small for gestational age infants. We calculated the stillbirth rate (per 1000) and relative risk (risk of stillbirth if born <10th centile vs >10th centile) for healthy-weight women (body mass index, 20-25 kg/m2). We then determined the birthweight centile for infants born to mothers within other body mass index categories that equaled that rate or risk.

RESULTS

Stillbirth rates increased with increasing maternal body mass index. Infants classified as small for gestational age (<10th centile) from mothers with high body mass index had a higher risk of stillbirth (relative risk, 3.15; 95% confidence interval, 2.22-4.47; for mothers with body mass index ≥40 kg/m2 vs healthy-weight mothers [body mass index, 20-25 kg/m2]). The stillbirth rate (stillborn infants per 1000 births) among <10th-centile infants born to healthy-weight mothers was 7.5 per 1000. The same stillbirth rate was observed at higher birthweight centiles for infants of women with higher body mass index (<18th centile for those with a body mass index of 25-30 kg/m2, <25th centile for body mass index of 30-35 kg/m2, <31st centile for body mass index of 35-40 kg/m2, <41st centile for body mass index of ≥40 kg/m2). The relative risk of stillbirth among small for gestational age infants of healthy-weight mothers was 5.46 (95% confidence interval, 4.65-6.40). The birthweight centile with a comparable relative risk of stillbirth increased with increasing body mass index (<16th centile for women with body mass index of 25-30 kg/m2, <19th centile for body mass index of 30-35 kg/m2, <28th centile for body mass index of 35-40 kg/m2, <30th centile for body mass index ≥40 kg/m2).

CONCLUSION

Obesity affects the relationship between infant size and perinatal mortality. The stillbirth risk observed in <10th-centile infants from healthy-weight mothers occurs at higher birthweight centiles with overweight or obese mothers. Clinicians should be aware that the same infant risk exists at a higher birthweight centile for women with higher body mass index.

The Association Between Serum Homocysteine Levels and Placenta-Mediated Complications: A Narrative Review

The most extremely unfavourable outcome of pregnancy is the death of the mother and newborn. Negative outcomes for mothers or babies can occur as a result of complications or issues during pregnancy, birth or the post-partum period. Early elevated maternal homocysteine (Hct) levels during pregnancy have been linked to altered placental development. There is evidence that suggests an elevated maternal blood Hct level is the new obstetrical risk factor, and the association between hyperhomocysteinemia (HHct) and numerous obstetrical problems was recently recognised. Hct is an essential amino acid, which contains sulphur and is formed from the metabolism of methionine. HHct has several known aetiologies, including genetic anomalies; a deficiency in folic acid, vitamin B6 and vitamin B12; hypothyroidism; old age; and renal illnesses. Vascular problems, coronary artery disease, atherosclerosis and embolic illnesses can all occur as a result of high blood levels of Hct. Hct levels are lower in normal pregnancies than it is in women who are not pregnant. Many pregnancy-related problems, including pre-eclampsia (PE), recurrent pregnancy loss (RPL), placental abruption, premature delivery and foetal growth restriction (FGR) have been connected to HHct in recent research. We looked for pertinent literature using a thorough and systematic search from PubMed, Medline, Embase, Cochrane Library, Google, etc., and articles that were published before August 2022 based on serum Hct levels and various placenta-mediated complications for this review. In this review, we described the synthesis and metabolism of Hct in humans, Hct levels at various phases of normal pregnancy and the association between Hct and placenta-mediated pregnancy complications. The outcomes discovered can help obstetricians increase the likelihood of a successful pregnancy in cases where placenta-mediated issues are present. Lowering Hct levels with a high dose of folic acid tablets during the subsequent pregnancy may be useful for women who experienced these difficulties in prior pregnancies as a result of HHct.

Adjusting growth standards for fetal sex improves correlation of small babies with stillbirth and adverse perinatal outcomes: A state-wide population study

OBJECTIVES

Sex impacts birthweight, with male babies heavier on average. Birthweight charts are thus sex specific, but ultrasound fetal weights are often reported by sex neutral standards. We aimed to identify what proportion of infants would be re-classified as SGA if sex-specific charts were used, and if this had a measurable impact on perinatal outcomes.

METHODS

Retrospective cohort study including all infants born in Victoria, Australia, from 2005-2015 (529,261 cases). We applied GROW centiles, either adjusted or not adjusted for fetal sex. We compared overall SGA populations, and the populations of males considered small by sex-specific charts only (SGAsex-only), and females considered small by sex-neutral charts only (SGAunadjust-only).

RESULTS

Of those <10th centile by sex-neutral charts, 39.6% were male and 60.5% female, but using sex-specific charts, 50.3% were male and 49.7% female. 19.2% of SGA females were reclassified as average for gestational age (AGA) using sex-specific charts. These female newborns were not at increased risk of stillbirth, combined perinatal mortality, NICU admissions, low Apgars or emergency CS compared with an AGA infant, but were at greater risk of being iatrogenically delivered on suspicion of growth restriction. 25.0% male infants were reclassified as SGA by sex-specific charts. These male newborns, compared to the AGAall infant, were at greater risk of stillbirth (RR 1.94, 95%CI 1.30-2.90), combined perinatal mortality (RR 1.80, 95%CI 1.26-2.57), NICU admissions (RR 1.38, 95%CI 1.12-1.71), Apgars <7 at 5 minutes (RR 1.40, 95%CI 1.25-1.56) and emergency CS (RR 1.12, 95%CI 1.06-1.18).

CONCLUSIONS

Use of growth centiles not adjusted for fetal sex disproportionately classifies female infants as SGA, increasing their risk of unnecessary intervention, and fails to identify a cohort of male infants at increased risk of adverse outcomes, including stillbirth. Sex-specific charts may help inform decisions and improve outcomes.

Fetal size classified using gestational days rather than gestational weeks improves correlation with stillbirth risk: A statewide population study

Objective

Many growth charts provide single centile cutoffs for each week of gestation, yet fetuses gain weight throughout the week. We aimed to assess whether using a single centile per week distorts the proportion of infants classified as small and their risk of stillbirth across the week.

Design

Retrospective cohort study.

Setting

Victoria, Australia.

Population

Singleton, non-anomalous infants born from 2005–2015 (529,261).

Methods

We applied growth charts to identify small-for-gestational-age (SGA) fetuses on week-based charts (single centile per gestational week) and day-based charts (centile per gestational day).

Main outcome measures

Proportions <10th centile by each chart, and stillbirth risk amongst SGA infants.

Results

Using week-based charts, 12.1% of infants born on the first day of a gestational week were SGA, but only 7.8% on the final day; ie. an infant born at the end of the week was 44% less likely to be classed as SGA (p<0.0001). The relative risk of stillbirth amongst SGA infants born on the final day of the week compared with the first was 1.47 (95%CI 1.09–2.00, p = 0.01). Using day charts, SGA proportions were similar and stillbirth risk equal between the beginning and end of the week (9.5% vs 9.9%).

Conclusions

Growth standards using a single cutoff for a gestational week overestimate the proportion of infants that are small at the beginning of the week and underestimate the proportion at the end. This distorts the risk of stillbirth amongst SGA infants based on when in the week an infant is born. Day-based charts should be used.

Ductus venosus Doppler assessment: do the results differ between the sagittal and the transverse approach?

OBJECTIVE

To compare the ductus venosus (DV) pulsatility index for veins (PIV) obtained in a mid-sagittal plane with that obtained in an oblique transverse plane of the fetal abdomen.

METHODS

Prospective observational study in singleton uncomplicated pregnancies undergoing an ultrasound examination between 24 and 34 weeks of gestation. Pregnancies complicated by fetal anomalies, fetal growth restriction, or oligohydramnios were excluded. Two consecutive recordings of DV Doppler waveform were obtained in each woman: one in a mid-sagittal plane, and the other in an oblique transverse plane of the fetal abdomen. The peak velocity during ventricular systole (S-wave) and diastole (D-wave), the velocity during atrial contraction (a-wave), and the time-averaged maximum velocity (TAmax) were measured, and the PIV was calculated. The paired t-test was used to compare results obtained with the two approaches. A change of the DV-PIV of 0.10 or more was considered clinically relevant.

RESULTS

The DV waveform was successfully obtained in 53 women (mean gestational age 28.5 weeks). The mean DV-PIV was 0.57 (±0.16 SD) in the sagittal plane and 0.54 (±0.16 SD) in the transverse plane. The mean difference (0.03) was statistically significant (p = .04), but not clinically relevant. The sagittal S-, D-, and a-wave velocities and TAmax were significantly higher in the sagittal plane compared to the transverse plane, with an increase of 12, 8, 8, and 10%, respectively (p < .05).

CONCLUSIONS

The difference in the DV-PIV obtained in a mid-sagittal plane compared to a transverse plane of the fetal abdomen is small and not clinically significant. The higher DV flow velocities observed in the sagittal plane are likely the result of a better alignment with the vessel obtained using this plane. These findings have implications for clinical practice and for research.

Magnetic resonance imaging of skull and brain parameters in fetuses with intrauterine growth restriction

Objective

To compare fetuses with intrauterine growth restriction (IUGR) and those with normal growth, in terms of skull and brain measurements obtained by magnetic resonance imaging (MRI).

Materials and Methods

This was a prospective cohort study including 26 single fetuses (13 with IUGR and 13 with normal growth), evaluated from 26 to 38 weeks of gestation. Using MRI, we measured skull and brain biparietal diameters (BPDs); skull and brain occipitofrontal diameters (OFDs); corpus callosum length and area; transverse cerebellar diameter; extracerebral cerebrospinal fluid (eCSF); and right and left interopercular distances (IODs).

Results

The following were significantly smaller in IUGR fetuses than in control fetuses: skull BPD (76.9 vs. 78.2 mm; p = 0.0029); brain BPD (67.8 vs. 71.6 mm; p = 0.0064); skull OFD (93.6 vs. 95 mm; p = 0.0010); eCSF (5.5 vs. 8.2 mm; p = 0.0003); right IOD (9.8 vs. 13.9 mm; p = 0.0023); and left IOD (11.8 vs. 16.3 mm; p = 0.0183). The skull BPD/eCSF, brain BPD/eCSF, skull OFD/eCSF, and brain OFD/eCSF ratios were also lower in IUGR fetuses.

Conclusion

IUGR fetuses had smaller OFD and BPD, both skull and brain, and less eCSF when compared to normal growth fetuses.

A Novel Review of Homocysteine and Pregnancy Complications

Homocysteine (Hct) is a substance produced in the metabolism of methionine. It is an essential type of amino acid gained from the daily diet. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is related to elevated total homocysteine (tHct) expressions, in particular, among women with low folate intake. Hyperhomocysteinemia (HHct) is caused by numerous factors, such as genetic defects, lack of folic acid, vitamin B₆ and B₁₂ deficiency, hypothyroidism, drugs, aging, and renal dysfunction. Increased Hct in peripheral blood may lead to vascular illnesses, coronary artery dysfunction, atherosclerotic changes, and embolic diseases. Compared to nonpregnant women, the Hct level is lower in normal pregnancies. Recent studies have reported that HHct was associated with numerous pregnancy complications, including recurrent pregnancy loss (RPL), preeclampsia (PE), preterm delivery, placental abruption, fetal growth restriction (FGR), and gestational diabetes mellitus (GDM). Besides, it was discovered that neonatal birth weight and maternal Hct levels were negatively correlated. However, a number of these findings lack consistency. In this review, we summarized the metabolic process of Hct in the human body, the levels of Hct in different stages of normal pregnancy reported in previous studies, and the relationship between Hct and pregnancy complications. The work done is helpful for obstetricians to improve the likelihood of a positive outcome during pregnancy complications. Reducing the Hct level with a high dosage of folic acid supplements during the next pregnancy could be helpful for females who have suffered pregnancy complications due to HHct.

Obstetric and pediatric growth charts for the detection of late-onset fetal growth restriction and neonatal adverse outcomes

OBJECTIVES

Late-onset fetal growth restriction (FGR) has heterogeneous prenatal and postnatal diagnostic criteria. We compared the prenatal and postnatal diagnosis of late-onset FGR and their ability to predict adverse perinatal outcomes.

METHODS

Retrospective cohort study of 5442 consecutive singleton pregnancies that delivered beyond 34 + 0 weeks. Prenatal diagnosis of FGR was based on customized fetal growth standards and fetal Doppler while postnatal diagnosis was based on a birthweight <3rd percentile according to newborn charts (Olsen's charts and Intergrowth 21st century programme). Perinatal outcomes were analyzed depending on whether the diagnosis was prenatal, postnatal or both.

RESULTS

A total of 94 out of 5442 (1.7%) were diagnosed as late-onset FGR prenatally. Olsen's chart and Intergrowth 21st chart detected that 125/5442 (2.3%) and 106/5442 (2.0%) of infants had a birthweight <3rd percentile, respectively. These charts identified 35/94 (37.2%) and 40/94 (42.6%) of the newborns with a prenatal diagnosis of late-onset FGR. Prenatally diagnosed late-onset FGR infants were at a higher risk for hypoglycemia, jaundice and polycythemia. Both prenatally and postnatally diagnosed as late-onset FGR had a higher risk for respiratory distress syndrome when compared to non-FGR. The higher risks for intensive care admission and composite adverse outcomes were observed in those with a prenatal diagnosis of late-onset FGR that was confirmed after birth.

CONCLUSIONS

Current definitions of pre- and postnatal late-onset FGR do not match in more than half of cases. Infants with a prenatal or postnatal diagnosis of this condition have an increased risk of neonatal morbidity even if these diagnoses are not coincident.

sFlt-1/PlGF ratio and timing of delivery in early-onset fetal growth restriction with antegrade umbilical artery flow

OBJECTIVE

To analyze the value of the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio in predicting the time to delivery in early-onset fetal growth restriction (FGR) with preserved antegrade umbilical artery (UA) flow at diagnosis.

METHODS

This was a prospective observational single-center cohort study of pregnancies with early-onset (< 32 + 0 weeks) FGR and antegrade UA flow, in which maternal serum sFlt-1/PlGF ratio was determined at diagnosis. FGR was defined as estimated fetal weight < 3^rd centile or < 10^th centile with UA pulsatility index > 95^th centile, fetal middle cerebral artery pulsatility index < 5^th centile or cerebroplacental ratio < 5^th centile. The previously described sFlt-1/PlGF ratio cut-off value of 85 for facilitating the diagnosis of pre-eclampsia was assessed in the prediction of the need to deliver in < 1 week and ≥ 4 weeks.

RESULTS

In total, 120 cases were included. There were 116 (96.7%) liveborn neonates and 108 (90.0%) perinatal survivors. Median (interquartile range (IQR)) gestational age at diagnosis of early-onset FGR was 27.1 (25.7-29.4) weeks. Median (IQR) sFlt-1/PlGF ratio at diagnosis was 196 (84-474). Ninety (75.0%) cases had a sFlt-1/PlGF ratio ≥ 85. Among pregnancies with a liveborn neonate, median (IQR) interval to delivery in the groups with sFlt-1/PlGF ratio < 85 and ≥ 85 was 41 (22-54) days and 11 (4-20) days, respectively (P < 0.01). The probability of having to deliver within 1 week after diagnosis was 0% and 35.6% in those with sFlt-1/PlGF ratio < 85 and ≥ 85, respectively (P = 0.03), and the probability of delaying delivery for ≥ 4 weeks was 72.4% and 19.5%, respectively (P < 0.01).

CONCLUSION

sFlt-1/PlGF ratio < 85 at diagnosis of early-onset FGR with antegrade UA flow identifies a group of pregnancies in which the need to deliver within 1 week is very low and the interval to delivery is expected to be prolonged for ≥ 4 weeks in > 70% of cases. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Two-dimensional Speckle tracking echocardiography in Fetal Growth Restriction: a systematic review

Background Fetal growth restriction (FGR), defined as an estimated fetal weight (EFW)<10th percentile, is associated with an increased risk for adverse fetal and neonatal outcome. Early antenatal diagnosis is important and remains challenging. Deformation changes in the fetal myocardium are early signs of myocardial dysfunction. These changes can be measured using two-dimensional speckle tracking echocardiography (2D-STE) to predict impaired placental function in the growth restricted fetus. Aim To review the literature on fetal heart deformation values measured with 2D-STE, in fetuses with an EFW< 10th centile and appropriate for gestational age (AGA) fetuses, and to compare the results in both groups. Methods The EMBASE, Medline, and Cochrane databases were searched from inception until April 2020. Observational studies on evaluating the cardiac deformation values longitudinal strain, strain rate, and/or global dyssynchrony of both ventricles in FGR, using 2D-STE, were included. Methodological quality was assessed using the Newcastle-Ottowa risk of bias scale. Results Four studies met the inclusion criteria. The mean gestational age (GA) varied from 30 to 38 weeks in the FGR group and 20 to 40 weeks in AGA fetuses. The number of included FGR fetuses (with or without Doppler abnormalities), varied from 30 to 50. Longitudinal strain in FGR fetuses was described as comparable (n = 2), increased (n = 1) and>95th percentile (n = 1) compared to AGA fetuses. Strain rate was measured in two studies. One reported an increased strain rate, another showed comparable strain rate. Two studies addressed global left ventricle (LV) and right ventricle (RV) dyssynchrony. Dyssynchrony was increased in FGR compared to AGA fetuses. Conclusion The currently published data is limited and heterogeneous concerning GA and Doppler profiles. The data presentation and the interpretation thereof make qualitative comparisons impossible. Large prospective longitudinal cohort studies looking at the value of deformation measurements of the fetal heart in FGR and AGA fetuses are needed to assess the clinical significance of deformation values measured with 2D-STE.

Fetal Doppler Assessment in Neonatal Care: Analysis of Fetal Doppler Abnormalities and Neonatal Outcomes

Fetal Doppler ultrasonography provides an effective and noninvasive approach to identify circulatory abnormalities in the maternal-fetal circulation. It is invaluable to assess the hemodynamic status of the fetus under a wide range of physiologic, infectious, and abnormal anatomic conditions. Findings from these studies are often used to make clinical decisions, including whether to proceed with urgent delivery of the fetus. In this review, we focus on key literature describing the main uses of Doppler ultrasonography in neonatal medicine, including how abnormal findings may be implicated in immediate and long-term outcomes. Our review highlights the importance of fetal Doppler examination as an effective intrauterine management strategy, and its full potential is more likely to be realized when considered in context with other available clinical information.

The impact of assisted reproductive technology on prenatally diagnosed fetal growth restriction in dichorionic twin pregnancies

OBJECTIVE

Whether the use of assisted reproductive technologies (ART) affects the outcome of twin pregnancies is still a matter of debate. Previous studies have evaluated the association between birth weight and ART, without a clear distinction between fetal growth restriction (FGR), a condition at higher risk of adverse outcome, and constitutionally small for gestational age (SGA) fetuses. The aim of this study was to determine whether dichorionic (DC) twin pregnancies obtained by ART have a greater risk of developing FGR, defined by accurate ultrasound criteria, than those spontaneously conceived (SC), and to compare the severity of ultrasound features in the growth restricted fetuses.

METHODS

A retrospective study was conducted on DC twin pregnancies delivered between 2010 to 2018 at a tertiary hospital. Twin pregnancies conceived spontaneously were compared with those obtained via in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), after exclusion of cases with major fetal or uterine malformations. The primary outcome was the incidence of FGR. Secondary outcome was the rate of SGA neonates, defined by a birth weight less than the 10th percentile. The ultrasound characteristics of the growth restricted fetuses in the two groups were also compared. The groups were compared using univariate and multivariate analyses.

RESULTS

Six hundred and seventy-eight DC twin pregnancies were identified. Of these, 367 (54.1%) conceived via IVF/ICSI and 311 (45.9%) conceived spontaneously. The incidence of FGR was not significantly different between the ART and the SC groups (7.9% vs 8.4% respectively, p = 0.76, adjusted OR 0.84, 95% CI 0.53-1.32). Growth restricted fetuses of the two groups showed similar occurrence of an estimated fetal weight less than the 3rd percentile, similar abnormalities in Doppler studies and similar gestational age at diagnosis. There was no difference in the incidence of delivery of an SGA neonate (p = 0.47) or in the rate of maternal complications and preterm delivery between the groups.

CONCLUSIONS

Twin pregnancies conceived by assisted reproductive technologies do not have a higher risk of ultrasound-diagnosed FGR than spontaneously conceived twin pregnancies, and fetuses diagnosed with growth restriction in the two groups show similar severity of the ultrasound findings.

Predictors of perinatal outcome in early-onset fetal growth restriction: A study from an emerging economy country

OBJECTIVE

To identify antenatal predictors of adverse perinatal outcomes in a population of preterm fetuses with early placental insufficiency diagnosed by Doppler abnormalities.

METHOD

In this cross-sectional study of a cohort of singleton pregnant women diagnosed with early placental insufficiency, relationships between perinatal variables (arterial and venous Doppler, gestational age, birth weight, oligohydramnios, estimated fetal weight, and fetal weight z-scores) and major neonatal complications were analyzed by logistic regression.

RESULTS

Two hundred sixty-five women were delivered, between 24 and 33 weeks gestation. The overall frequency of intact survival was 57.9% (n = 154). Gestational age thresholds for best prediction of survival was 27 + 6 weeks and for intact survival was 29 + 0 weeks gestation. Fetal weight and absent/reversed ductus venosus a-wave were the main predictors of survival in the regression model. When fetal weight was substituted for fetal weight z-score, ductus venosus abnormal Doppler predicted mortality and absent or reversed umbilical artery diastolic velocities predicted intact survival.

CONCLUSIONS

This study illustrates the impact of gestational age and fetal weight on perinatal outcomes in early placental insufficiency, with well-defined thresholds. Gestational age and fetal weight, or a combination of fetal weight z-scores and fetal Doppler parameters, were the best predictors of intact survival in our sample.

Obstetric and pediatric growth charts for the detection of fetal growth restriction and neonatal adverse outcomes in preterm newborns before 34 weeks of gestation

INTRODUCTION

Identification of fetal growth-restricted (FGR) infants depends on the fetal or newborn charts used to identify them. We aimed to compare the prenatal and postnatal diagnosis of FGR and their ability to predict adverse perinatal outcomes.

METHODS

Observational retrospective cohort study of 95 consecutive mother-infant pairs with preterm birth between 24 and 34 weeks (study period: January 2014 to December 2015). Prenatal sonographic diagnosis of FGR, based on customized fetal growth standards and fetal Doppler, was compared with the postnatal diagnosis of FGR based on a birthweight < 3rd percentile according to newborn charts (International Newborn size references for the Intergrowth twenty-first century program, and Olsen's charts). Neonatal mortality and adverse neonatal outcomes were compared among groups.

RESULTS

In 23/95 (24%) cases a prenatal diagnosis of early FGR was made. Postnatal FGR was confirmed in 11/23 (48%) cases using Olsen's charts and 8/23 (35%) using Intergrowth 21st charts. One postnatal FGR case was missed by prenatal ultrasound. Bronchopulmonary dysplasia, sepsis and hypoglycemia were more frequent in pre- and postnatal FGR versus non-FGR. After adjusting for gestational age and sex, only an increased relative risk of hypoglycemia (2.0, 95%CI 1.0-2.8) was observed in infants with pre- and postnatal FGR diagnosis. Nonsignificant differences on neonatal outcomes were identified between prenatal FGR cases with normal birthweight and the non-FGR group.

CONCLUSION

Only prenatal FGR cases in which a birthweight below the third percentile is confirmed by means of postnatal charts (Olsen or Intergrowth standard) are at higher risk of adverse postnatal outcome.

The Prediction of Gestational Hypertension, Preeclampsia and Fetal Growth Restriction via the First Trimester Screening of Plasma Exosomal C19MC microRNAs

The aim of the study was to verify if quantification of placental specific C19MC microRNAs in plasma exosomes would be able to differentiate during the early stages of gestation between patients subsequently developing pregnancy-related complications and women with the normal course of gestation and if this differentiation would lead to the improvement of the diagnostical potential. The retrospective study on singleton Caucasian pregnancies was performed within 6/2011-2/2019. The case control study, nested in a cohort, involved women that later developed GH (n = 57), PE (n = 43), FGR (n = 63), and 102 controls. Maternal plasma exosome profiling was performed with the selection of C19MC microRNAs with diagnostical potential only (miR-516b-5p, miR-517-5p, miR-518b, miR-520a-5p, miR-520h, and miR-525-5p) using real-time RT-PCR. The down-regulation of miR-517-5p, miR-520a-5p, and miR-525-5p was observed in patients with later occurrence of GH and PE. Maternal plasma exosomal profiling of selected C19MC microRNAs also revealed a novel down-regulated biomarker during the first trimester of gestation (miR-520a-5p) for women destinated to develop FGR. First trimester circulating plasma exosomes possess the identical C19MC microRNA expression profile as placental tissues derived from patients with GH, PE and FGR after labor. The predictive accuracy of first trimester C19MC microRNA screening (miR-517-5p, miR-520a-5p, and miR-525-5p) for the diagnosis of GH and PE was significantly higher in the case of expression profiling of maternal plasma exosomes compared to expression profiling of the whole maternal plasma samples.

Evaluation of fetal medicine foundation algorithm in predicting small-for-gestational-age neonates

OBJECTIVES

To examine the performance of the Fetal Medicine Foundation (FMF) 2012 predictive model and of isolated biophysical markers (uterine artery pulsatility index and mean arterial pressure) for small-for-gestational-age (SGA), in patients from Rio de Janeiro, Brazil.

METHODS

For this cross-sectional study, SGA was diagnosed when a newborn presented birth weight below the fifth percentile for gestational age. FMF2012 algorithm sensitivity and specificity, positive (PPV) and negative (NPV) predictive value, positive likelihood ratio (LR +) and area under the ROC curve (AUC) were calculated to predict total and preterm SGA (SGA < 37). The performance of isolated biophysical markers - mean arterial pressure (MAP) and mean uterine artery pulsatility index (UtAPI) were studied.

RESULTS

The final sample consisted of 1480 cases: 69 (4.6%) developed SGA, including 12 patients (0.8%) who were SGA < 37. The AUC showed that the performances of the FMF2012 combined model for SGA prediction was 0.687 and for preterm SGA was 0.824. With risk cutoff of 1:150, SGA screening yielded the following: sensitivity, 47%; specificity, 75%; LR +, 1.88; PPV, 8.66%; NPV, 96.72%. When screening for preterm SGA, we found sensitivity 66.6%, specificity 74.59%, LR +: 2.58, PPV 2%, and NPV 99.63%.

CONCLUSIONS

Performance of the FMF2012 algorithm in predicting SGA in our population was similar to that obtained in the reference population, according to sensitivity, but our false positive rate is significantly higher than the reference population.

Essential variables for reporting research studies on fetal growth restriction: a Delphi consensus

OBJECTIVE

To determine, by expert consensus using a Delphi procedure, a minimum reporting set of study variables for fetal growth restriction (FGR) research studies.

METHODS

A panel of experts, identified based on their publication record as lead or senior author of studies on FGR, was asked to select a set of essential reporting study parameters from a literature-based list of variables, utilizing the Delphi consensus methodology. Responses were collected in four consecutive rounds by online questionnaires presented to the panelists through a unique token-secured link for each round. The experts were asked to rate the importance of each parameter on a five-point Likert scale. Variables were selected in the three first rounds based on a 70% threshold for agreement on the Likert-scale scoring. In the final round, retained parameters were categorized as essential (to be reported in all FGR studies) or recommended (important but not mandatory).

RESULTS

Of the 100 invited experts, 87 agreed to participate and of these 62 (71%) completed all four rounds. Agreement was reached for 16 essential and 30 recommended parameters including maternal characteristics, prenatal investigations, prenatal management and pregnancy/neonatal outcomes. Essential parameters included hypertensive complication in the current pregnancy, smoking, parity, maternal age, fetal abdominal circumference, estimated fetal weight, umbilical artery Doppler (pulsatility index and end-diastolic flow), fetal middle cerebral artery Doppler, indications for intervention, pregnancy outcome (live birth, stillbirth or neonatal death), gestational age at delivery, birth weight, birth-weight centile, mode of delivery and 5-min Apgar score.

CONCLUSIONS

We present a list of essential and recommended parameters that characterize FGR independent of study hypotheses. Uniform reporting of these variables in prospective clinical research is expected to improve data quality, study consistency and ultimately our understanding of FGR. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Protocol for the prospective observational clinical study: estimation of fetal weight by MRI to PREdict neonatal MACROsomia (PREMACRO study) and small-for-gestational age neonates

INTRODUCTION

Macrosomia refers to growth beyond a specific threshold, regardless of gestational age. These fetuses are also frequently referred to as large for gestational age (LGA). Various cut-offs have been used but for research purposes, a cut-off above the 95th centile for birth weight is often preferred because it defines 90% of the population as normal weight. The use of centiles, rather than estimated weights, also accommodates preterm macrosomic infants, although most of the complications, maternal and fetal, arise during the delivery of large babies at term. This means that accurate identification of LGA fetuses (≥95th centile) may play an important role in guiding obstetric interventions, such as induction of labour or caesarean section. Traditionally, identification of fetuses suspected of macrosomia has been based on biometric measurements using two-dimensional (2D) ultrasound (US), yet this method is rather sub-optimal. We present a protocol (V.2.1, date 19 May 2016) for the estimation of fetal weight (EFW) by MRI to PREdict neonatal MACROsomia (PREMACRO study), which is a prospective observational clinical study designed to determine whether MRI at 36 + 0 to 36 + 6 weeks of gestation, as compared with 2D US, can improve the identification of LGA neonates ≥95th centile.

METHODS AND ANALYSIS

All eligible women attending the 36-week clinic will be invited to participate in the screening study for LGA fetuses ≥95th centile and will undergo US-EFW and MRI-EFW within minutes of each other. From these estimations, a centile will be derived which will be compared with the centile of birth weight used as the gold standard. Besides birth weight, other pregnancy and neonatal outcomes will be collected and analysed. The first enrolment for the study was in May 2016. As of September 2018, 2004 women have been screened and recruited to the study. The study is due to end in April 2019.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the International Conference on Harmonisation for good clinical practice and the appropriate regulatory requirement(s). A favourable ethical opinion was obtained from the Ethics Committee of the University Hospital Brugmann, reference number CE2016/44. Results will be published in peer-reviewed journals and disseminated at international conferences.

TRIAL REGISTRATION NUMBER

NCT02713568.

Managing fetal growth restriction: surveillance tests and their interpretation

The main challenges in pregnancies affected by fetal growth restriction consist in identifying signs of disease progression and determining the appropriate timing of delivery. The risk of continuing the pregnancy must be balanced with the risk of prematurity, which depends on gestational age. To allow appropriate monitoring of the growth-restricted fetus, several surveillance tests are available. These include ultrasound Doppler velocimetry of feto-placental vessels, cardiotocography, and amniotic fluid evaluation. It is well known that the combination of tests performs better than each test alone to predict fetal deterioration. The interpretation of test results depends on the gestational age and on the nature of the growth disorder (early- vs. late-onset disease). Appropriate knowledge on the surveillance tests interpretation and the frequency at which they need to be performed is crucial in managing fetal growth restriction, in order to produce better outcome and prevent stillbirth, and at the same time to avoid unnecessary interventions.

Analysis of the Performance of 11 Formulae for Fetal Weight Estimation in Preterm Fetuses with Abnormal Doppler Velocimetry - A Retrospective Multicenter Study

OBJECTIVE

 To assess 11 formulae commonly used to estimate fetal weight in a population of premature fetuses who had abnormal Doppler velocimetry due to early-onset placental insufficiency. The performance of each formula was evaluated in subgroups of fetuses with expected growth and intrauterine growth restriction.

METHODS

 Data were collected from fetuses and mothers who delivered at three Brazilian hospitals between November 2002 and December 2013. We used the following formulae: Campbell; Hadlock I, II, III, IV and V; Shepard; Warsof; Weiner I and II; and Woo III.

RESULTS

 We analyzed 194 fetuses. Of these, 116 (59.8%) were considered appropriate for gestational age (AGA), and 103 (53.1%) were male. The amniotic fluid volume was reduced in 87 (44.8%) fetuses, and the umbilical artery Doppler revealed absence or inversion of diastolic flow in 122 (62.9%) cases, and the analysis of the ductus venosus revealed abnormal flow in 60 (34.8%) fetuses. The Hadlock formulae using three or four fetal biometric parameters had low absolute percentage error in the estimated fetal weight among preterm fetuses with abnormal Doppler studies who were born within 5 days of the ultrasound evaluation. The results were not influenced by the clinical and ultrasound parameters often found in early-onset placental insufficiency.

CONCLUSION

 In this study, the formulae with the best performance for fetal weight estimation in the analyzed population were Hadlock I and IV, which use four and three fetal biometric parameters respectively to estimate the weight of preterm fetuses with abnormal Doppler studies.

Predictive accuracy of cerebroplacental ratio for adverse perinatal and neurodevelopmental outcomes in suspected fetal growth restriction: systematic review and meta-analysis

OBJECTIVE

The cerebroplacental ratio (CPR) has been proposed for the routine surveillance of pregnancies with suspected fetal growth restriction (FGR), but the predictive performance of this test is unclear. The aim of this study was to determine the accuracy of CPR for predicting adverse perinatal and neurodevelopmental outcomes in suspected FGR.

METHODS

PubMed, EMBASE, CINAHL and Lilacs were searched from inception to 31 July 2017 for cohort or cross-sectional studies reporting on the accuracy of CPR for predicting adverse perinatal and/or neurodevelopmental outcomes in singleton pregnancies with FGR suspected antenatally based on sonographic parameters. Summary receiver-operating characteristics (ROC) curves, pooled sensitivities and specificities, and summary likelihood ratios (LRs) were generated.

RESULTS

Twenty-two studies (including 4301 women) met the inclusion criteria. Summary ROC curves showed that the best predictive accuracy of CPR was for perinatal death and the worst was for neonatal acidosis, with areas under the summary ROC curves of 0.83 and 0.57, respectively. The predictive accuracy of CPR was moderate to high for perinatal death (pooled sensitivity and specificity of 93% and 76%, respectively, and summary positive and negative LRs of 3.9 and 0.09, respectively) and low for composite of adverse perinatal outcomes, Cesarean section for non-reassuring fetal status, 5-min Apgar score < 7, admission to the neonatal intensive care unit, neonatal acidosis and neonatal morbidity, with summary positive and negative LRs ranging from 1.1 to 2.5 and 0.3 to 0.9, respectively. An abnormal CPR result had moderate accuracy for predicting small-for-gestational age at birth (summary positive LR of 7.4). CPR had a higher predictive accuracy in pregnancies with suspected early-onset FGR. No study provided data for assessing the predictive accuracy of CPR for adverse neurodevelopmental outcome.

CONCLUSION

CPR appears to be useful in predicting perinatal death in pregnancies with suspected FGR. Nevertheless, before incorporating CPR into the routine clinical management of suspected FGR, randomized controlled trials should assess whether the use of CPR reduces perinatal death or other adverse perinatal outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Why we miss fetal growth restriction: Identification of risk factors for severely growth-restricted fetuses remaining undelivered by 40 weeks gestation

BACKGROUND

Severe fetal growth restriction (FGR) is a leading cause of adverse perinatal morbidity and mortality; however, in Victoria, 35% of severely growth-restricted infants are undelivered by 40 weeks gestation.

AIMS

We aimed to identify factors associated with failure to deliver severely growth-restricted fetuses by 40 weeks gestation.

METHODS

We conducted a retrospective case-control study of term singletons born <3rd centile for gestation at a single tertiary centre (2010-2017). Infants with a planned delivery for FGR between 37.0-39.6  weeks gestation ('planned birth' group; n = 187) were compared with those undelivered by 40.0  weeks ('undelivered' group; n = 233). Variables assessed included the presence of risk factors for FGR, model of care, symphyseal-fundal height measurements and third trimester ultrasounds.

RESULTS

An equivalent proportion of women were 'high-risk' for FGR on history (31.3% vs 38.0%, P = 0.187) in the planned and undelivered groups. Women booked under low-risk models (shared care and midwifery-led care) were significantly more likely to be in the undelivered group compared to those booked under traditional collaborative models (79.8% vs 37.4%, P < 0.001). Women in the undelivered group were less likely to have received a third trimester ultrasound (93.0% vs 40.3%, P < 0.001); however, they were more likely to have had a reassuring ultrasound with an estimation of fetal weight or abdominal circumference >10th centile (78.7% vs 16.1%, P < 0.001).

CONCLUSIONS

Failure to deliver the severely growth-restricted fetus before 40.0 weeks is more likely to occur in the following situations: (i) failure to receive an indicated third trimester ultrasound; (ii) the presence of falsely reassuring third trimester ultrasound scan; and (iii) booking under a low-risk rather than traditional collaborative models of care.

Progress in the understanding of the etiology and predictability of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of fetus to reach its growth potential for various reasons, leading to multiple perinatal complications and adult diseases of fetal origins. Shallow extravillous trophoblast (EVT) invasion-induced placental insufficiency and placental dysfunction are considered the main reasons for idiopathic FGR. In this review, first we discuss the major characteristics of anti-angiogenic state and the pro-inflammatory bias in FGR. We then elaborate major abnormalities in placental insufficiency at molecular levels, including the interaction between decidual leukocytes and EVT, alteration of miRNA expression and imprinted gene expression pattern in FGR. Finally, we review current animal models used in FGR, an experimental intervention based on animal models and the progress of predictive biomarker studies in FGR.Free Chinese abstract: A Chinese translation of this abstract is freely available at http://www.reproduction-online.org/content/153/6/R215/suppl/DC1.

Longitudinal changes of cardiotocographic parameters throughout pregnancy: a prospective cohort study comparing small-for-gestational-age and normal fetuses from 24 to 40 weeks

OBJECTIVE

To compare longitudinal trends of cardiotocographic (CTG) parameters between small-for-gestational-age (SGA) and normal fetuses, from 24 to 41 weeks of pregnancy.

METHODS

A prospective cohort study was carried out in singleton pregnancies without fetal malformations. At least one CTG was performed in each of the following intervals: 24-26 weeks+6 days, 27-29 weeks+6 days, 30-32 weeks+6 days, 33-35 weeks+6 days, 36-38 weeks+6 days and ≥39 weeks. Tracings were analyzed using the Omniview-SisPorto® 3.6 system. Cases with a normal pregnancy outcome, including a birthweight ≥10th percentile for gestational age, were compared with two groups of SGA fetuses: with birthweight <10th percentile (SGA<p10) and <3rd percentile (SGA<p3; a subgroup of the latter). Generalized linear mixed-effects models were used for analysis.

RESULTS

A total of 176 fetuses (31 SGA) and 1256 tracings (207 from SGA fetuses) were evaluated. All CTG parameters changed significantly throughout pregnancy in the three groups, with a decreasing baseline and probability of decelerations, and an increasing average long-term variability (LTV), average short-term variability (STV) and accelerations. Baseline showed a more pronounced decrease (steeper slope) in SGA fetuses, being higher in these cases at earlier gestational ages and lower later in pregnancy. Average LTV was significantly lower in SGA<p3 fetuses, but a parallel increase occurred in all groups. There was a considerable inter-fetal variability within each group.

CONCLUSION

A unique characterization of CTG trends throughout gestation in SGA fetuses was provided. A steeper descent of the baseline was reported for the first time. The findings raise the possibility of clinical application of computerized CTG analysis in screening and management of fetal growth restriction.

Late preterm and early term: when to induce a growth restricted fetus? A population-based study

PURPOSE

(1) Compare fetal and neonatal morbidity and mortality associated with induction of labor (IOL) versus expectant management (EM) in women with isolated fetal growth restriction (FGR) between 34^0/7 and 38^6/7 weeks; (2) Determine optimal gestational age for delivery of such fetuses.

MATERIALS AND METHODS

A retrospective population based cohort study of 2232 parturients with isolated FGR, including two groups: (1) IOL (n = 1428); 2) EM (n = 804).

RESULTS

IOL group had a lower stillbirth and neonatal death rates (p = .042, p < .001), higher 1 and 5 min Apgar scores and a higher vaginal delivery rate compared to the EM group. In the late preterm period, EM was associated with increased rate of low 1 and 5 min Apgar scores, nonreassuring fetal heart rate tracing (NRFHR), stillbirth and neonatal death rate (p = .001, p = .039). In the early term cohort, EM was associated with a higher rate of NRFHR and low 1 min Apgar scores (p = .003, p = .002). IOL at 37 weeks protected from stillbirth but not from adverse composite neonatal outcomes.

CONCLUSIONS

IOL of FGR fetuses at 37 weeks had a protective effect against stillbirth. In addition, at late preterm, it is associated with lower rates of stillbirth, neonatal death, and NRFHR.

Fetal growth restriction: current knowledge

BACKGROUND

Fetal growth restriction (FGR) is a condition that affects 5-10% of pregnancies and is the second most common cause of perinatal mortality. This review presents the most recent knowledge on FGR and focuses on the etiology, classification, prediction, diagnosis, and management of the condition, as well as on its neurological complications.

METHODS

The Pubmed, SCOPUS, and Embase databases were searched using the term "fetal growth restriction".

RESULTS

Fetal growth restriction (FGR) may be classified as early or late depending on the time of diagnosis. Early FGR (<32 weeks) is associated with substantial alterations in placental implantation with elevated hypoxia, which requires cardiovascular adaptation. Perinatal morbidity and mortality rates are high. Late FGR (≥32 weeks) presents with slight deficiencies in placentation, which leads to mild hypoxia and requires little cardiovascular adaptation. Perinatal morbidity and mortality rates are lower. The diagnosis of FGR may be clinical; however, an arterial and venous Doppler ultrasound examination is essential for diagnosis and follow-up. There are currently no treatments to control FGR; the time at which pregnancy is interrupted is of vital importance for protecting both the mother and fetus.

CONCLUSION

Early diagnosis of FGR is very important, because it enables the identification of the etiology of the condition and adequate monitoring of the fetal status, thereby minimizing risks of premature birth and intrauterine hypoxia.

Evaluation of the INTERGROWTH-21st project newborn standard for use in Canada

Objective

To evaluate the performance of the INTERGROWTH-21^st Project newborn standard vis-a-vis the current Canadian birth weight-for-gestational age reference.

Methods

All hospital-based singleton live births in Canada (excluding Quebec) between 2002 and 2012 with a gestational age between 33 and 42 weeks were included using information obtained from the Canadian Institute for Health Information. Small- and large-for gestational age centile categories of the INTERGROWTH standard and Canadian reference were contrasted in terms of frequency distributions and rates of composite neonatal morbidity/mortality.

Results

Among 2,753,817 singleton live births, 0.87% and 9.63% were <3^rd centile and >97^th centile, respectively, of the INTERGROWTH standard, while 2.27% and 3.55% were <3^rd centile and >97^th centile, respectively, of the Canadian reference. Infants <3^rd centile and >97^th centile had a composite neonatal morbidity/mortality rate of 46.4 and 12.9 per 1,000 live births, respectively, under the INTERGROWTH standard and 30.9 and 16.6 per 1,000 live births, respectively, under the Canadian reference. The INTERGROWTH standard <3^rd centile and >97^th centile categories had detection rates of 3.14% and 9.74%, respectively, for composite neonatal morbidity/ mortality compared with 5.48% and 4.60%, respectively for the Canadian reference. Similar patterns were evident in high- and low-risk subpopulations.

Conclusions

The centile distribution of the INTERGROWTH newborn standard is left shifted compared with the Canadian reference, and this shift alters the frequencies and neonatal morbidity/mortality rates associated with specific centile categories. Further outcome-based research is required for defining abnormal growth categories before the INTERGROWTH newborn standard can be used.

Cardiotocographic parameters in small-for-gestational-age fetuses: How do they vary from normal at different gestational ages? A study of 11687 fetuses from 25 to 40 weeks of pregnancy

AIM

The aim of this study was to assess how cardiotocographic (CTG) parameters differ between small-for-gestational-age (SGA) and normal fetuses at different gestational ages.

METHODS

This was a retrospective cross-sectional study using the first antepartum tracing of singleton pregnancies with no malformations. Fetuses with birthweight ≥10th percentile for gestational age and other normal pregnancy outcome criteria (term birth, normal umbilical artery pH and Apgar scores, no intensive care unit admission) were compared with fetuses with birthweight <10th and <3rd percentiles for gestational age (SGA < p10 and SGA < p3, a subgroup of the latter). Each CTG parameter was compared, by gestational age, using both statistical tests and percentile curves derived from normal outcome cases. Tracings were analyzed with the OmniviewSisPorto® 3.7 system.

RESULTS

A total of 11 687 tracings (from the same number of fetuses) were analyzed: 9701 normal, 1986 SGA < p10, and 543 SGA < p3. SGA fetuses had lower long- and short-term variability, and number of accelerations, with more pronounced differences between around 28 and 35 weeks. In contrast, baseline was lower in SGA fetuses from 34 weeks onwards. All differences were more pronounced for SGA < p3 fetuses. Similar trends throughout gestation occurred in all groups: decrease in baseline, and increase in long- and short-term variability, and accelerations.

CONCLUSIONS

This study represents an important step for accurate CTG interpretation in SGA fetuses and, consequently, management of fetal growth restriction (FGR), as it contributes to differentiate between maturational CTG changes that occur physiologically throughout pregnancy, and possible signs of fetal compromise in FGR.

Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology

Objective

To investigate the proportion of stillbirths at term associated with abnormal growth using customized birth weight percentiles and to compare histological placental findings both in underweight stillborn fetuses and in live births.

Methods

A retrospective case-control study of 150 singleton term stillbirths. The livebirth control groups included 586 cases of low-risk pregnancies and 153 late fetal growth restriction fetuses. Stillbirths and livebirths from low-risk pregnancies were classified using customized standards for fetal weight at birth, as adequate for gestational age (AGA; 10-90^th percentile), small (SGA; <10^th percentile) or large for gestational age (LGA; >90^th percentile). Placental characteristics in stillbirth were compared with those from livebirths using four categories: inflammation, disruptive, obstructive and adaptive lesions.

Results

There was a higher rate of SGA (26% vs 6%, p<0.001) and LGA fetuses (10.6% vs 5.6%, p<0.05) in the stillbirth group. Among stillbirth fetuses, almost half of the SGA were very low birthweight (≤3°percentile) (12% vs 0.3%, p<0.001). The disruptive (7.3% vs 0.17%;p<0.001), obstructive (54.6% vs 7.5%;p<0.001) and adaptive (46.6% vs 35.8%;p<0.001) findings were significantly more common in than in livebirth-low risk. Placental characteristics of AGA and SGA stillbirth were compared with those of AGA and FGR livebirth. In stillbirths-SGA we found a higher number of disruptive (12.8% vs 0%; p<0.001), obstructive (58.9% vs 23.5%;p<0.001) and adaptive lesions (56.4% vs 49%; p 0.47) than in livebirth-FGR.

Conclusion

The assessment of fetal weight with customized curves can identify fetuses which have not reached their genetically determined growth potential and are therefore at risk for adverse outcomes. Placental evaluation in stillbirths can reveal chronic histological signs that might be useful to clinical assessment, especially in underweight fetuses.

Fetal Hemodynamic Parameters in Low Risk Pregnancies: Doppler Velocimetry of Uterine, Umbilical, and Middle Cerebral Artery

Objective. To elaborate curves of longitudinal reference intervals of pulsatility index (PI) and systolic velocity (SV) for uterine (UtA), umbilical (UA), and middle cerebral arteries (MCA), in low risk pregnancies. Methods. Doppler velocimetric measurements of PI and SV from 63 low risk pregnant women between 16 and 41 weeks of gestational age. Means (±SD) for intervals of gestational age and percentiles 5, 50, and 95 were calculated for each parameter. The Intraclass Correlation Coefficients (ICC) were also estimated for assessing intra- and intervariability of measurements. Results. Mean PI of UtA showed decreasing values during pregnancy, but no regular pattern was identified for mean SV. For UA, PI decreased and SV increased along gestation. MCA presented PI increasing values until 32–35 weeks. SV showed higher levels with increasing gestation. High ICC values indicated good reproducibility. Conclusions. Reference intervals for the assessment of SV and PI of UtA, UA, and MCA were established. These reference intervals showed how a normal pregnancy is expected to progress regarding these Doppler velocimetric parameters and are useful to follow high risk pregnancies. The comparison between results using different curves may provide insights about the best patterns to be used.

Early onset fetal growth restriction

Fetal growth restriction remains a challenging entity with significant variations in clinical practice around the world. The different etiopathogenesis of early and late fetal growth restriction with their distinct progression of fetal severity and outcomes, compounded by doctors and patient anxiety adds to the quandary involving its management. This review summarises the literature around diagnosing and monitoring early onset fetal growth restriction (early onset FGR) with special emphasis on optimal timing of delivery as guided by recent research advances.

Ductus venosus Doppler in the assessment of fetal cardiovascular health: an updated practical approach

The ductus venosus has a central role in the distribution of highly oxygenated umbilical venous blood to the heart. Its waveform is related to the pressure-volume changes in the cardiac atria and it is therefore important in the monitoring of any fetal condition that may affect forward cardiac function. The cardiovascular parameters that can influence forward cardiac function include afterload, myocardial performance and preload. Decreased forward flow during atrial systole (a-wave) is the most sensitive and ubiquitous finding when any of these parameters is affected. In contrast, decreased forward velocities during end-systolic relaxation (v-wave) are more specifically related to myocardial performance. The ductus venosus pulsatility index alone does not accurately reflect cardiac function, and in cases of suspected fetal cardiac dysfunction, echocardiography is required to identify the underlying mechanism. The role of ductus venosus Doppler in the assessment of fetal growth restriction, supraventricular tachycardia, fetal hydrops, complicated monochorionic twins and congenital heart disease is discussed with these considerations in mind.