Middle cerebral artery blood flow velocities and pulsatility index and the cerebroplacental pulsatility ratio: longitudinal reference ranges and terms for serial measurements

Placental Sonomorphologic Appearance and Fetomaternal Outcome in Fontan Circulation

Objectives: Pregnancies in women with Fontan circulation are on the rise, and they are known to imply high maternal and fetal complication rates. The altered hemodynamic profile of univentricular circulation affects placental development and function. This study describes placental sonomorphologic appearance and Doppler examinations and correlates these to histopathologic findings and pregnancy outcomes in women with Fontan circulation. Methods: A single-center retrospective analysis of pregnancies in women with Fontan circulation was conducted between 2018 and 2023. Maternal characteristics and obstetric and neonatal outcomes were recorded. Serial ultrasound examinations including placental sonomorphologic appearance and Doppler studies were assessed. Macroscopic and histopathologic findings of the placentas were reviewed. Results: Six live births from six women with Fontan physiology were available for analysis. Prematurity occurred in 83% (5/6 cases) and fetal growth restriction and bleeding events in 66% (4/6 cases) each. All but one placenta showed similar sonomorphologic abnormalities starting during the late second trimester, such as thickened globular shape, inhomogeneous echotexture, and hypoechoic lakes, resulting in a jelly-like appearance. Uteroplacental blood flow indices were within normal range in all women. The corresponding histopathologic findings were non-specific and consisted of intervillous and subchorionic fibrin deposition, villous atrophy, hypoplasia, or fibrosis. Conclusions: Obstetric and perinatal complication rates in pregnancies of women with Fontan circulation are high. Thus, predictors are urgently needed. Our results suggest that serial ultrasound examinations with increased awareness of the placental appearance and its development, linked to the Doppler sonographic results of the uteroplacental and fetomaternal circulation, may be suitable for the early identification of cases prone to complications.

Elevated Middle Cerebral Artery Peak Systolic Velocity in Non-Anemic Fetuses: Providing a Better Understanding of Enigmatic Middle Cerebral Artery Peak Systolic Velocity

INTRODUCTION

Our aim was to investigate the incidence, comorbidities, and outcomes of fetuses with an elevated middle cerebral artery peak systolic velocity (MCA-PSV) >1.5 multiples of median (MoM), despite normal hemoglobin (Hgb) levels on fetal blood sampling (FBS).

METHODS

A single-center observational retrospective cohort study of all fetuses undergoing FBS and MCA-PSV >1.5 MoM. Only those fetuses with no or mild anemia were included. Indications for Doppler assessment, associated anomalies, and neonatal outcomes were collected.

RESULTS

Overall, 383 fetuses had an MCA-PSV >1.5 MoM and underwent FBS. Twenty-three (6%) fetuses met our inclusion criteria and had no or only mild anemia. Associations with elevated MCA-PSV were elucidated in 12 of the 23 cases (52.2%) and included mild anemia (n = 2), intracranial hemorrhage (n = 3), genetic disease (n = 1), idiopathic nonimmune hydrops (NIH, n = 1), hypoxic-ischemic encephalopathy (n = 1), maternal and or fetal acidosis (n = 3), and fetal growth restriction (n = 1). Favorable perinatal outcomes were observed in truly unexplained 11 cases with no additional anomalies (47.8%).

CONCLUSION

Elevated MCA-PSV >1.5 MoM with normal Hgb levels is seen in 6% of pregnancies undergoing FBS and is often associated with other significant maternal or fetal problems. Those with unexplained and isolated MCA-PSV elevation have normal outcomes.

Fetal circulatory physiology and brain development in complex congenital heart disease: A multi-modal imaging study

OBJECTIVE

Fetuses with complex congenital heart disease have altered physiology, contributing to abnormal neurodevelopment. The effects of altered physiology on brain development have not been well studied. We used multi-modal imaging to study fetal circulatory physiology and brain development in hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (TGA).

METHODS

This prospective, cross-sectional study investigated individuals with fetal congenital heart disease and controls undergoing fetal echocardiography and fetal brain MRI. MRI measured total brain volume and cerebral oxygenation by the MRI quantification method T2*. Indexed cardiac outputs (CCOi) and vascular impedances were calculated by fetal echocardiography. Descriptive statistics assessed MRI and echocardiogram measurement relationships by physiology.

RESULTS

Sixty-six participants enrolled (control = 20; HLHS = 25; TGA = 21), mean gestational age 33.8 weeks (95% CI: 33.3-34.2). Total brain volume and T2* were significantly lower in fetuses with cardiac disease. CCOi was lower in HLHS, correlating with total brain volume - for every 10% CCOi increase, volume increased 8 mm3 (95% CI: 1.78-14.1; p = 0.012). Echocardiography parameters and cerebral oxygenation showed no correlation. TGA showed no CCOi or aortic output correlation with MRI measures.

CONCLUSIONS

In HLHS, lower cardiac output is deleterious to brain development. Our findings provide insight into the role of fetal cardiovascular physiology in brain health.

Morphometric Analysis of Placenta and Fetal Doppler Indices in Normal and High-Risk Pregnancies

Background High-risk pregnancies, encompassing pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), preeclampsia toxemia (PET), and intrauterine growth restriction (IUGR), represent intricate medical challenges with potential repercussions for maternal and fetal health. This research undertakes a comprehensive comparative investigation into the variations of Doppler indices and placental parameters within the context of these high-risk conditions when juxtaposed against pregnancies characterized as normal. Methodology Employing a rigorous cross-sectional study design, a diverse cohort of pregnant individuals with gestational diabetes, IUGR, PIH, and preeclampsia was meticulously assembled. Additionally, a group of normal pregnant women served as the comparative reference. Doppler ultrasound assessments, viz, pulsatility index (PI), were carefully performed to estimate blood flow velocities within critical maternal and fetal vessels, while placental parameters were meticulously quantified, encompassing dimensions, vascular architecture, and morphological features. Results Except in the GDM group, all high-risk groups had reduced estimated placental weight and actual birth weight than normal pregnant women. All high-risk groups showed a highly significant elevation of the PI of the umbilical artery and PI of the middle cerebral artery (MCA) than normal but the PI of MCA was significantly reduced in the PET group than in normal individuals. The cerebro-placental ratio in the GDM and IUGR groups revealed markedly greater values, whereas PET showed lower values. IUGR and PIH groups showed a substantial reduction in the fetal birth weight. All high-risk groups (GDM, IUGR, PIH, and PET) showed a highly significant reduction in luminal area umbilical artery 1 than the normal pregnant women. In IUGR, marginal placental insertion was very high, followed by GDM and PET groups. Conclusions This study reveals that Doppler indices, placental parameters, newborn weight, and their related ratios may be utilized to anticipate gestation difficulties and gain insight into the pathophysiology of problematic conceptions.

Corpus Callosum Length and Cerebellar Vermian Height in Fetal Growth Restriction

INTRODUCTION

Growth-restricted fetuses may have changes in their neuroanatomical structures that can be detected in prenatal imaging. We aim to compare corpus callosal length (CCL) and cerebellar vermian height (CVH) measurements between fetal growth restriction (FGR) and control fetuses and to correlate them with cerebral Doppler velocimetry in growth-restricted fetuses.

METHODS

This was a prospective cohort of FGR after 20 weeks of gestation with ultrasound measurements of CCL and CVH. Control cohort was assembled from fetuses without FGR who had growth ultrasound after 20 weeks of gestation. We compared differences of CCL or CVH between FGR and controls. We also tested for the correlations of CCL and CVH with middle cerebral artery (MCA) pulsatility index (PI) and vertebral artery (VA) PI in the FGR group. CCL and CVH measurements were adjusted by head circumference (HC).

RESULTS

CCL and CVH were obtained in 68 and 55 fetuses, respectively. CCL/HC was smaller in FGR fetuses when compared to control fetuses (difference = 0.03, 95% CI: [0.02, 0.04], p < 0.001). CVH/HC was larger in FGR fetuses compared to NG fetuses (difference = 0.1, 95% CI: [-0.01, 0.02], p = < 0.001). VA PI multiples of the median were inversely correlated with CVH/HC (rho = -0.53, p = 0.007), while CCL/HC was not correlated with VA PI. Neither CCL/HC nor CVH/HC was correlated with MCA PI.

CONCLUSIONS

CCL/HC and CVH/HC measurements show differences in growth-restricted fetuses compared to a control cohort. We also found an inverse relationship between VA PI and CVH/HC. The potential use of neurosonography assessment in FGR assessment requires continued explorations.

Prediction of labour outcomes using prelabour computerised cardiotocogram and maternal and fetal Doppler indices: A prospective cohort study

OBJECTIVES

To investigate the association and the potential value of prelabour fetal heart rate short-term variability (STV) determined by computerised cardiotocography (cCTG) and maternal and fetal Doppler in predicting labour outcomes.

DESIGN

Prospective cohort study.

SETTING

The Prince of Wales Hospital, a tertiary maternity unit, in Hong Kong SAR.

POPULATION

Women with a term singleton pregnancy in latent phase of labour or before labour induction were recruited during May 2019-November 2021.

METHODS

Prelabour ultrasonographic assessment of fetal growth, Doppler velocimetry and prelabour cCTG monitoring including Dawes-Redman CTG analysis were registered shortly before induction of labour or during the latent phase of spontaneous labour.

MAIN OUTCOME MEASURES

Umbilical cord arterial pH, emergency delivery due to pathological CTG during labour and neonatal intensive care unit (NICU)/special care baby unit (SCBU) admission.

RESULTS

Of the 470 pregnant women invited to participate in the study, 440 women provided informed consent and a total of 400 participants were included for further analysis. Thirty-four (8.5%) participants underwent emergency delivery for pathological CTG during labour. A total of 6 (1.50%) and 148 (37.00%) newborns required NICU and SCBU admission, respectively. Middle cerebral artery pulsatility index (MCA-PI) and MCA-PI z-score were significantly lower in pregnancies that required emergency delivery for pathological CTG during labour compared with those that did not (1.23 [1.07-1.40] versus 1.40 [1.22-1.64], p = 0.002; and 0.55 ± 1.07 vs. 0.12 ± 1.06), p = 0.049]. This study demonstrated a weakly positive correlation between umbilical cord arterial pH and prelabour log10 STV (r = 0.107, p = 0.035) and the regression analyses revealed that the contributing factors for umbilical cord arterial pH were smoking (p = 0.006) and prelabour log10 STV (p = 0.025).

CONCLUSIONS

In pregnant women admitted in latent phase of labour or for induction of labour at term, prelabour cCTG STV had a weakly positive association with umbilical cord arterial pH but was not predictive of emergency delivery due to pathological CTG during labour.

Prediction by uterine artery Doppler screening of small-for-gestational-age neonates at 19-24 weeks' gestation

OBJECTIVE

Small-for-gestational-age (SGA) neonates are at increased risk of perinatal mortality and morbidity. We aimed to investigate the performance of uterine artery pulsatility index (UtA-PI) at 19-24 weeks' gestation to predict the delivery of a SGA neonate in a Chinese population.

METHODS

This was a retrospective cohort study using data obtained between January 2010 and June 2018. Doppler ultrasonography was performed at 19-24 weeks' gestation. SGA was defined as birth weight below the 10th centile according to the INTERGROWTH-21st fetal growth standards. The performance of UtA-PI to predict the delivery of a SGA neonate was assessed using receiver-operating-characteristics (ROC)-curve analysis.

RESULTS

We included 6964 singleton pregnancies, of which 748 (11%) delivered a SGA neonate, including 115 (15%) women with preterm delivery. Increased UtA-PI was associated with an elevated risk of SGA, both in neonates delivered at or after 37 weeks' gestation (term SGA) and those delivered before 37 weeks (preterm SGA). The areas under the ROC curve (AUCs) for UtA-PI were 64.4% (95% CI, 61.5-67.3%) and 75.8% (95% CI, 69.3-82.3%) for term and preterm SGA, respectively. The performance of combined screening by maternal demographic/clinical characteristics and estimated fetal weight in the detection of term and preterm SGA was improved significantly by the addition of UtA-PI, although the increase in AUC was modest (2.4% for term SGA and 4.9% for preterm SGA).

CONCLUSIONS

This is the first Chinese study to evaluate the role of UtA-PI at 19-24 weeks' gestation in the prediction of the delivery of a neonate with SGA. The addition of UtA-PI to traditional risk factors improved the screening performance for SGA, and this improvement was greater in predicting preterm SGA compared with term SGA. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Polystyrene micro- and nanoplastics cause placental dysfunction in mice†

Maternal exposure to microplastics and nanoplastics has been shown to result in fetal growth restriction in mice. In this study, we investigated the placental and fetal hemodynamic responses to plastics exposure in mice using high-frequency ultrasound. Healthy, pregnant CD-1 dams were given either 106 ng/L of 5 μm polystyrene microplastics or 106 ng/L of 50 nm polystyrene nanoplastics in drinking water throughout gestation and were compared with controls. Maternal exposure to both microplastics and nanoplastics resulted in evidence of placental dysfunction that was highly dependent on the particle size. The umbilical artery blood flow increased by 48% in the microplastic-exposed group and decreased by 25% in the nanoplastic-exposed group compared to controls (p < 0.05). The microplastic- and nanoplastic-exposed fetuses showed a significant decrease in the middle cerebral artery pulsatility index of 10% and 13%, respectively, compared to controls (p < 0.05), indicating vasodilation of the cerebral circulation, a fetal adaptation that is part of the brain sparing response to preserve oxygen delivery. Hemodynamic markers of placental dysfunction and fetal hypoxia were more pronounced in the group exposed to polystyrene nanoplastics, suggesting nanoplastic exposure during human pregnancy has the potential to disrupt fetal brain development, which in turn may cause suboptimal neurodevelopmental outcomes.

Placental size at gestational week 27 and 37: The associations with pulsatility index in the uterine and the fetal-placental arteries

INTRODUCTION

Fetal growth restriction is known to be related to decreased fetal and placental blood flow. It is not known, however, whether placental size is related to fetal and placental blood flow. We studied the correlations of intrauterine placental volume and placental-fetal-ratio with pulsatility index (PI) in the uterine arteries, fetal middle cerebral artery, and umbilical artery.

METHODS

We followed a convenience sample of 104 singleton pregnancies, and we measured placental and fetal volumes using magnetic resonance imaging (MRI) at gestational week 27 and 37 (n = 89). Pulsatility index (PI) was measured using Doppler ultrasound. We calculated cerebroplacental ratio as fetal middle cerebral artery PI/umbilical artery PI and placental-fetal-ratio as placental volume (cm3)/fetal volume (cm3).

RESULTS

At gestational week 27, placental volume was negatively correlated with uterine artery PI (r = -0.237, p = 0.015, Pearson's correlation coefficient), and positively correlated with fetal middle cerebral artery PI (r = 0.247, p = 0.012) and cerebroplacental ratio (r = 0.208, p = 0.035). Corresponding correlations for placental-fetal-ratio were -0.273 (p = 0.005), 0.233 (p = 0.018) and 0.183 (p = 0.064). Umbilical artery PI was not correlated with placental volume. At gestational week 37, we found weaker and no significant correlations between placental volume and the pulsatility indices.

CONCLUSIONS

Our results suggest that placental size is correlated with placental and fetal blood flow at gestational week 27.

Longitudinal change in cerebro-placental ratio (CPR) between 37 and 40 weeks of pregnancy is associated with non-reassuring fetal status and increased risk of cesarean section

OBJECTIVE

To evaluate in low-risk pregnancies if longitudinal change in cerebro-placental ratio (CPR) between 37 and 40 weeks of pregnancy is associated with cesarean section (CS) for non-reassuring fetal status (NRFS) during labor.

METHODS

This is a prospective observational study of women with singleton low-risk pregnancies who underwent an ultrasound scan at 36 + 0 to 37 + 6 and 39 + 0 to 41 + 6 weeks of pregnancy, when the CPR was calculated from the middle cerebral artery (MCA) and umbilical artery (UA) pulsatility indices. Managing professionals were kept blinded to the Doppler results. The association of the longitudinal change between both CPR (z-velocity) to CS for NRFS was evaluated by logistic regression.

RESULTS

A total of 401 pregnancies were included. The mean time interval between both CPR evaluations was 21 days (SD 7). A CS for fetal distress was performed in 7% of pregnancies. Independent of the CPR at 37 weeks, the likelihood of CS for fetal distress was significantly decreased by the longitudinal changes from 37 to 40 weeks (OR 0.61, 95%CI 0.4-0.92; p=.018). This association remained significant after further adjustment for potential confounders (nulliparity, maternal weight at booking and estimated fetal weight at 37): (OR 0.64, 95%CI 0.41-0.98; p=.044).

CONCLUSIONS

The longitudinal change of CPR between 37 and 40 weeks is associated with the need for CS for NRFS during labor.

Do differences in diagnostic criteria for late fetal growth restriction matter?

BACKGROUND

Criteria for diagnosis of fetal growth restriction differ widely according to national and international guidelines, and further heterogeneity arises from the use of different biometric and Doppler reference charts, making the diagnosis of fetal growth restriction highly variable.

OBJECTIVE

This study aimed to compare fetal growth restriction definitions between Delphi consensus and Society for Maternal-Fetal Medicine definitions, using different standards/charts for fetal biometry and different reference ranges for Doppler velocimetry parameters.

STUDY DESIGN

From the TRUFFLE 2 feasibility study (856 women with singleton pregnancy at 32+0 to 36+6 weeks of gestation and at risk of fetal growth restriction), we selected 564 women with available mid-pregnancy biometry. For the comparison, we used standards/charts for estimated fetal weight and abdominal circumference from Hadlock, INTERGROWTH-21st, and GROW and Chitty. Percentiles for umbilical artery pulsatility index and its ratios with middle cerebral artery pulsatility index were calculated using Arduini and Ebbing reference charts. Sensitivity and specificity for low birthweight and adverse perinatal outcome were evaluated.

RESULTS

Different combinations of definitions and reference charts identified substantially different proportions of fetuses within our population as having fetal growth restriction, varying from 38% (with Delphi consensus definition, INTERGROWTH-21st biometric standards, and Arduini Doppler reference ranges) to 93% (with Society for Maternal-Fetal Medicine definition and Hadlock biometric standards). None of the different combinations tested appeared effective, with relative risk for birthweight <10th percentile between 1.4 and 2.1. Birthweight <10th percentile was observed most frequently when selection was made with the GROW/Chitty charts, slightly less with the Hadlock standard, and least frequently with the INTERGROWTH-21st standard. Using the Ebbing Doppler reference ranges resulted in a far higher proportion identified as having fetal growth restriction compared with the Arduini Doppler reference ranges, whereas Delphi consensus definition with Ebbing Doppler reference ranges produced similar results to those of the Society for Maternal-Fetal Medicine definition. Application of Delphi consensus definition with Arduini Doppler reference ranges was significantly associated with adverse perinatal outcome, with any biometric standards/charts. The Society for Maternal-Fetal Medicine definition could not accurately detect adverse perinatal outcome irrespective of estimated fetal weight standard/chart used.

CONCLUSION

Different combinations of fetal growth restriction definitions, biometry standards/charts, and Doppler reference ranges identify different proportions of fetuses with fetal growth restriction. The difference in adverse perinatal outcome may be modest, but can have a significant impact in terms of rate of intervention.

Cerebroplacental hemodynamics in fetuses with transposition of the great arteries and usefulness in predicting neonatal condition

OBJECTIVES

Literature on cerebroplacental hemodynamics in fetuses with transposition of the great arteries (TGA) is scarce and provides conflicting results regarding the presence of a brain-sparing effect. The aims of this study were to examine Doppler parameters in the middle cerebral artery (MCA) and umbilical artery (UA) in a large cohort of fetuses with TGA, and to assess their possible utility in predicting the need for urgent balloon atrial septostomy (BAS) in the neonate.

METHODS

This was a retrospective observational study of fetuses diagnosed with TGA between 2008 and 2022 and an age-matched cohort of normal fetuses, conducted in a single tertiary fetal cardiology center. Medical records and echocardiographic examinations were reviewed to collect demographic, sonographic and follow-up data. Selected Doppler parameters were compared between fetuses with TGA and normal fetuses, as well as between TGA fetuses with and those without an associated ventricular septal defect (VSD), to assess the impact of this congenital heart defect on cerebroplacental circulation. Additionally, Doppler indices in patients with a restrictive foramen ovale (FO) were analyzed to identify potential predictors of the need for urgent BAS.

RESULTS

A total of 541 examinations of 159 fetuses with TGA performed between 19 and 40 weeks' gestation and 1300 examinations of 1215 age-matched normal fetuses were included in the study. MCA pulsatility index (PI) and UA-PI followed expected trends throughout pregnancy, with slightly higher values observed in TGA fetuses, albeit within the limits for the normal population. Cerebroplacental ratio (CPR) values were similar in normal and TGA fetuses. The presence of a small VSD did not have a clinically significant impact on Doppler parameters. Peak systolic velocity (PSV) in the MCA increased gradually after 35 weeks' gestation, especially in fetuses that did not develop restriction of the FO after birth. MCA-PSV values below 1.16 multiples of the median measured at 38 weeks or later predicted the need for urgent BAS with 81.4% sensitivity and 52.4% specificity.

CONCLUSIONS

MCA-PI, UA-PI and CPR values in fetuses with TGA usually fall within normal limits throughout pregnancy. The presence of a small VSD does not affect the Doppler parameters significantly. MCA-PSV increases in TGA fetuses after 35 weeks, and its value measured at the last prenatal examination (ideally after 37 weeks) may serve as an additional predictive factor for the need for urgent BAS. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Heart function by M-mode and tissue Doppler in the early neonatal period in neonates with fetal growth restriction

BACKGROUND

Fetal growth restricted (FGR) neonates have increased risk of circulatory compromise due to failure of normal transition of circulation after birth.

AIM

Echocardiographic assessment of heart function in FGR neonates first three days after birth.

STUDY DESIGN

Prospective observational study.

SUBJECTS

FGR- and non-FGR neonates.

OUTCOME MEASURES

M-mode excursions and pulsed-wave tissue Doppler velocities normalised for heart size and E/e' of the atrioventricular plane day one, two and three after birth.

RESULTS

Compared with controls (non-FGR of comparable gestational age, n = 41), late-FGR (gestational age ≥ 32 weeks, n = 21) exhibited higher septal excursion (15.9 (0.6) vs. 14.0 (0.4) %, p = 0.021) (mean (SEM)) and left E/e' (17.3 (1.9) vs.11.5 (1.3), p = 0.019). Relative to day three, indexes on day one were higher for left excursion (21 (6) % higher on day one, p = 0.002), right excursion (12 (5) %, p = 0.025), left e' (15 (7) %, p = 0.049), right a' (18 (6) %, p = 0.001), left E/e' (25 (10) %, p = 0.015) and right E/e' (17 (7) %, p = 0.013), whereas no index changed from day two to day three. Late-FGR had no impact on changes from day one and two to day three. No measurements differed between early-FGR (n = 7) and late-FGR.

CONCLUSIONS

FGR impacted neonatal heart function the early transitional days after birth. Late-FGR hearts had increased septal contraction and reduced left diastolic function compared with controls. The dynamic changes in heart function between first three days were most evident in lateral walls, with similar pattern in late-FGR and non-FGR. Early-FGR and late-FGR exhibited similar heart function.

Exploring the role of a time-efficient MRI assessment of the placenta and fetal brain in uncomplicated pregnancies and these complicated by placental insufficiency

INTRODUCTION

The development of placenta and fetal brain are intricately linked. Placental insufficiency is related to poor neonatal outcomes with impacts on neurodevelopment. This study sought to investigate whether simultaneous fast assessment of placental and fetal brain oxygenation using MRI T2* relaxometry can play a complementary role to US and Doppler US.

METHODS

This study is a retrospective case-control study with uncomplicated pregnancies (n = 99) and cases with placental insufficiency (PI) (n = 49). Participants underwent placental and fetal brain MRI and contemporaneous ultrasound imaging, resulting in quantitative assessment including a combined MRI score called Cerebro-placental-T2*-Ratio (CPTR). This was assessed in comparison with US-derived Cerebro-Placental-Ratio (CPR), placental histopathology, assessed using the Amsterdam criteria [1], and delivery details.

RESULTS

Pplacental and fetal brain T2* decreased with increasing gestational age in both low and high risk pregnancies and were corrected for gestational-age alsosignificantly decreased in PI. Both CPR and CPTR score were significantly correlated with gestational age at delivery for the entire cohort. CPTR was, however, also correlated independently with gestational age at delivery in the PI cohort. It furthermore showed a correlation to birth-weight-centile in healthy controls.

DISCUSSION

This study indicates that MR analysis of the placenta and brain may play a complementary role in the investigation of fetal development. The additional correlation to birth-weight-centile in controls may suggest a role in the determination of placental health even in healthy controls. To our knowledge, this is the first study assessing quantitatively both placental and fetal brain development over gestation in a large cohort of low and high risk pregnancies. Future larger prospective studies will include additional cohorts.

Management of late-onset fetal growth restriction: pragmatic approach

OBJECTIVES

There is limited prospective evidence to guide the management of late-onset fetal growth restriction (FGR) and its differentiation from small-for-gestational age. The aim of this study was to assess prospectively a novel protocol in which ultrasound criteria were used to classify women with suspected late FGR into two groups: those at low risk, who were managed expectantly until the anticipated date of delivery, and those at high risk, who were delivered soon after 37 weeks of gestation. We also compared the outcome of this prospective cohort with that of a historical cohort of women presenting similarly with suspected late FGR, in order to evaluate the impact of the new protocol.

METHODS

This was a prospective study of women with a non-anomalous singleton pregnancy at ≥ 32 weeks' gestation attending a tertiary hospital in London, UK, between February 2018 and September 2019, with estimated fetal weight (EFW) ≤ 10th centile, or EFW > 10th centile in addition to a decrease in fetal abdominal circumference of ≥ 50 centiles compared with a previous scan, umbilical artery Doppler pulsatility index > 95th centile or cerebroplacental ratio < 5th centile. Women were classified as low or high risk based on ultrasound and Doppler criteria. Women in the low-risk group were delivered by 41 weeks of gestation, unless they subsequently met high-risk criteria, whereas women in the high-risk group (EFW < 3rd centile, umbilical artery Doppler pulsatility index > 95th centile or EFW between 3rd and 10th centiles (inclusive) with abdominal circumference drop or abnormal Dopplers) were delivered at or soon after 37 weeks. The primary outcome was adverse neonatal outcome and included hypothermia, hypoglycemia, neonatal unit admission, jaundice requiring treatment, suspected infection, feeding difficulties, 1-min Apgar score < 7, hospital readmission and any severe adverse neonatal outcome (perinatal death, resuscitation using inotropes or mechanical ventilation, 5-min Apgar score < 7, metabolic acidosis, sepsis, and cerebral, cardiac or respiratory morbidity). Secondary outcomes were adverse maternal outcome (operative delivery for abnormal fetal heart rate) and severe adverse neonatal outcome. Women managed according to the new protocol were compared with a historical cohort of 323 women delivered prior to the implementation of the new protocol, for whom management was guided by individual clinician expertise.

RESULTS

Over 18 months, 321 women were recruited to the prospective cohort, of whom 156 were classified as low risk and 165 were high risk. Adverse neonatal outcome was significantly less common in the low-risk compared with the high-risk group (45% vs 58%; adjusted odds ratio (aOR), 0.6 (95% CI, 0.4-0.9); P = 0.022). There was no significant difference in the rate of adverse maternal outcome (18% vs 24%; aOR, 0.7 (95% CI, 0.4-1.2); P = 0.142) or severe adverse neonatal outcome (3.8% vs 8.5%; aOR, 0.5 (95% CI, 0.2-1.3); P = 0.153) between the low- and high-risk groups. Compared with women in the historical cohort classified retrospectively as low risk, low-risk women managed under the new protocol had a lower rate of adverse neonatal outcome (45% vs 58%; aOR, 0.6 (95% CI, 0.4-0.9); P = 0.026).

CONCLUSIONS

Appropriate risk stratification to guide management of late FGR was associated with a reduced rate of adverse neonatal outcome in low-risk pregnancies. In clinical practice, a policy of expectantly managing women with a low-risk late-onset FGR pregnancy at term could improve neonatal and long-term development. Randomized controlled trials are needed to assess the effect of an evidence-based conservative management protocol for late FGR on perinatal morbidity and mortality and long-term neurodevelopment. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Comparative Analysis of the Placental Microbiome in Pregnancies with Late Fetal Growth Restriction versus Physiological Pregnancies

A comparative analysis of the placental microbiome in pregnancies with late fetal growth restriction (FGR) was performed with normal pregnancies to assess the impact of bacteria on placental development and function. The presence of microorganisms in the placenta, amniotic fluid, fetal membranes and umbilical cord blood throughout pregnancy disproves the theory of the "sterile uterus". FGR occurs when the fetus is unable to follow a biophysically determined growth path. Bacterial infections have been linked to maternal overproduction of pro-inflammatory cytokines, as well as various short- and long-term problems. Proteomics and bioinformatics studies of placental biomass allowed the development of new diagnostic options. In this study, the microbiome of normal and FGR placentas was analyzed by LC-ESI-MS/MS mass spectrometry, and the bacteria present in both placentas were identified by analysis of a set of bacterial proteins. Thirty-six pregnant Caucasian women participated in the study, including 18 women with normal pregnancy and eutrophic fetuses (EFW > 10th percentile) and 18 women with late FGR diagnosed after 32 weeks of gestation. Based on the analysis of the proteinogram, 166 bacterial proteins were detected in the material taken from the placentas in the study group. Of these, 21 proteins had an exponentially modified protein abundance index (emPAI) value of 0 and were not included in further analysis. Of the remaining 145 proteins, 52 were also present in the material from the control group. The remaining 93 proteins were present only in the material collected from the study group. Based on the proteinogram analysis, 732 bacterial proteins were detected in the material taken from the control group. Of these, 104 proteins had an emPAI value of 0 and were not included in further analysis. Of the remaining 628 proteins, 52 were also present in the material from the study group. The remaining 576 proteins were present only in the material taken from the control group. In both groups, we considered the result of ns prot ≥ 60 as the cut-off value for the agreement of the detected protein with its theoretical counterpart. Our study found significantly higher emPAI values of proteins representative of the following bacteria: Actinopolyspora erythraea, Listeria costaricensis, E. coli, Methylobacterium, Acidobacteria bacterium, Bacteroidetes bacterium, Paenisporsarcina sp., Thiodiazotropha endol oripes and Clostridiales bacterium. On the other hand, in the control group statistically more frequently, based on proteomic data, the following were found: Flavobacterial bacterium, Aureimonas sp. and Bacillus cereus. Our study showed that placental dysbiosis may be an important factor in the etiology of FGR. The presence of numerous bacterial proteins present in the control material may indicate their protective role, while the presence of bacterial proteins detected only in the material taken from the placentas of the study group may indicate their potentially pathogenic nature. This phenomenon is probably important in the development of the immune system in early life, and the placental microbiota and its metabolites may have great potential in the screening, prevention, diagnosis and treatment of FGR.

Combination of Doppler measurements with amniotic fluid volume for the prediction of perinatal outcomes in fetal growth restriction

OBJECTIVES

We aimed to evaluate a new ratio of amniotic fluid volume (AFV) to Doppler measurements, and compare its association with adverse perinatal outcomes (APOs) in fetal growth restriction (FGR).

METHODS

This prospective study included pregnant women with singleton fetal growth-restricted fetuses. Each participant underwent a detailed ultrasonographic examination. Uterine artery pulsatility index, umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI), cerebroplacental ratio (CPR), and umbilical-to-cerebral ratio (UCR) were calculated, and the single deepest pocket (SDP) technique was used to estimate AFV. Amniotic-umbilical-to-cerebral ratio (AUCR) was calculated as the ratio of SDP to UCR: AUCR = SDP / (UA PI/MCA PI). APO was defined as umbilical venous cord blood pH <7.10, 5-minute APGAR score <7, and neonatal intensive care unit admission.

RESULTS

We compared the fetal ultrasonographic and demographic features between the APO and the non-APO groups. The mean UA PI and UCR were significantly higher in the APO group. The mean SDP, CPR, and AUCR were significantly lower in the APO group. Receiver operating characteristic curve analyses demonstrated the highest area under the curve value (0.882; P < 0.001) for AUCR to APOs.

CONCLUSION

The current study suggests that AUCR is the best predictor for APOs in FGR.

The effect of drip versus intermittent feeding on splanchnic oxygenation in preterm infants with intrauterine growth restriction: a prospective randomized trial

The main purpose of this study was to evaluate the impact of drip versus intermittent feeding on splanchnic oxygenation in preterm infants with intrauterine growth restriction. The second objective was to assess the relationship between fetal splanchnic circulation parameters and splanchnic oxygenation during the first week of life. A single-center, prospective, randomized study with 51 fetuses/infants was conducted. Fetal Doppler measurements including umbilical artery, middle cerebral artery, and superior mesenteric artery (SMA) were recorded in IUGR fetuses. After preterm delivery, the infants were randomly assigned to one of two feeding modalities: drip (3-h continuous) or intermittent (bolus in 10 min). Continuous regional splanchnic saturation (rSO₂S) monitoring was carried out during the first week of life, simultaneously with continuous oxygen arterial saturation (SaO₂) monitoring, and the infants' fractional oxygen extractions (FOE) were calculated. These parameters were evaluated as means on a daily basis for the first week of life, as well as pre-prandial and post-prandial measurements on the seventh day. Fetal Doppler flow velocimetry disturbances were present in 72.5% of the study cohort. The drip (26 infants) and intermittent (25 infants) groups were similar in demographic and clinical characteristics, as well as the prevalence of feeding intolerance and necrotizing enterocolitis. During the first week of life, there was no difference in daily mean rSO₂S and FOE values between the drip and intermittent groups, whereas unfed infants had mostly lower rSO₂S values. Pre-prandial and post-prandial rSO₂S values remained stable in both groups. Also, no association was detected between fetal splanchnic circulation parameters and neonatal splanchnic oxygenation. RSO₂S values were strongly correlated to gestational age and birth weight. During the whole week, except for the first 2 days, infants with umbilical catheters had significantly lower rSO₂S values than infants without.  Conclusion: Our data suggest that the key factor in splanchnic oxygenation is feeding, not the feeding modality. In addition, the umbilical vein catheter had a negative impact on splanchnic oxygenation.  Clinical Trial Registration: The Effect of Neonatal Feeding Modalities on Splanchnic Oxygenation, NCT05513495,  https://clinicaltrials.gov/ct2/results cond=&term=NCT05513495&cntry=TR&state=&city=&dist= . Retrospectively registered, date of registration: August 2022. What is Known: • It is known that preterm infants with IUGR are at increased risk of hypoxic-ischemic intestinal damage and impaired splanchnic oxygenation. What is New: • The key factor in splanchnic oxygenation of preterm infants with IUGR is feeding, not the feeding modality (drip or intermittent). • In addition, the umbilical vein catheter had a negative impact on splanchnic oxygenation.

Diagnostic Tests in the Prediction of Neonatal Outcome in Early Placental Fetal Growth Restriction

Background and Objectives: Monitoring pregnancies with fetal growth restriction (FGR) presents a challenge, especially concerning the time of delivery in cases of early preterm pregnancies below 32 weeks. The aim of our study was to compare different diagnostic parameters in growth-restricted preterm neonates with and without morbidity/mortality and to determine sensitivity and specificity of diagnostic parameters for monitoring preterm pregnancies with early preterm fetal growth restriction below 32 weeks. Materials and Methods: Our clinical study evaluated 120 cases of early preterm deliveries, with gestational age ≤ 32 + 0 weeks, with prenatally diagnosed placental FGR. All the patients were divided into three groups of 40 cases each based on neonatal condition,: I-Neonates with morbidity/mortality (NMM); II-Neonates without morbidity with acidosis/asphyxia (NAA); III-Neonates without neonatal morbidity/acidosis/asphyxia (NWMAA). Results: Amniotic fluid index (AFI) was lower in NMM, while NWMAA had higher biophysical profile scores (BPS). UA PI was lower in NWMAA. NWMAA had higher MCA PI and CPR and fewer cases with CPR <5th percentile. NMM had higher DV PI, and more often had ductus venosus (DV) PI > 95th‱ or absent/reversed A wave, and pulsatile blood flow in umbilical vein (UV). The incidence of pathological fetal heart rate monitoring (FHRM) was higher in NMM and NAA, although the difference was not statistically significant. ROC calculated by defining a bad outcome as NMM and a good outcome as NAA and NWMAA showed the best sensitivity in DV PIi. ROC calculated by defined bad outcome in NMM and NAA and good outcome in NWMAA showed the best sensitivity in MCA PI. Conclusions: In early fetal growth restriction normal cerebral blood flow strongly predicts good outcomes, while pathological venous blood flow is associated with bad outcomes. In fetal growth restriction before 32 weeks, individualized expectant management remains the best option for the optimal timing of delivery.

Developmental Ultrasound Characteristics in Guinea Pigs: Similarities with Human Pregnancy

BACKGROUND

Biometrical and blood flow examinations are fundamental for assessing fetoplacental development during pregnancy. Guinea pigs have been proposed as a good model to study fetal development and related gestational complications; however, longitudinal growth and blood flow changes in utero have not been properly described. This study aimed to describe fetal and placental growth and blood flow of the main intrauterine vascular beds across normal guinea pig pregnancy and to discuss the relevance of this data for human pregnancy.

METHODS

Pregnant guinea pigs were studied from day 25 of pregnancy until term (day ~70) by ultrasound and Doppler assessment. The results were compared to human data from the literature.

RESULTS

Measurements of biparietal diameter (BPD), cranial circumference (CC), abdominal circumference, and placental biometry, as well as pulsatility index determination of umbilical artery, middle cerebral artery (MCA), and cerebroplacental ratio (CPR), were feasible to determine across pregnancy, and they could be adjusted to linear or nonlinear functions. In addition, several of these parameters showed a high correlation coefficient and could be used to assess gestational age in guinea pigs. We further compared these data to ultrasound variables from human pregnancy with high similarities.

CONCLUSIONS

BPD and CC are the most reliable measurements to assess fetal growth in guinea pigs. Furthermore, this is the first report in which the MCA pulsatility index and CPR are described across guinea pig gestation. The guinea pig is a valuable model to assess fetal growth and blood flow distribution, variables that are comparable with human pregnancy.

Evaluación integrada del bienestar en un feto apropiado para la edad gestacional (AGA) e insuficiencia placentaria aguda debido a corioamnionitis histológica: Reporte de caso

Introducción. La insuficiencia vascular útero placentaria aguda es una causa de desenlace fetal adverso en fetos con crecimiento adecuado para la edad gestacional. Caso clínico. Paciente de 24 años, con 37 semanas de edad gestacional acude al Instituto Nacional Materno Perinatal de Lima, Perú, por referir escaso sangrado vía vaginal. En la evaluación clínica, se encontró una PA 90/60 mmHg, altura uterina 32 cm, latidos cardiacos fetales en 152. A la evaluación ecográfica, a 1 hora de la admisión se reportó feto de 2902 gramos (percentil 34 Hadlock), un Perfil Biofísico Fetal 6/8 por movimientos corporales disminuidos, Índice de líquido amniótico 11cm, placenta fúndica posterior grado III, IP Doppler de Arteria Cerebral Media 1.18, IP Doppler de la arteria umbilical 0.56, IP ductus venoso 0.26 e Istmo Aórtico con diástole ausente. La prueba estresante a las 3 horas de la admisión fue reportada en 5 puntos con movimientos fetales disminuidos, variabilidad disminuida y aceleraciones ausentes. Se indicó cesárea de emergencia obteniéndose recién nacido masculino de 2846 gr, talla 47.5 cm, Apgar 8 – 9. Se encontró líquido meconial de aspecto sanguinolento oscuro. Al corte de la placenta, se observó parénquima con infartos vellosos: recientes 10% y antiguos 5%. Vellosidades coriales hipoplásicas con espacios intervellosos amplios e infiltrado inflamatorio agudo en corion y amnios, correspondientes a Corioamnionitis aguda y funisitis aguda en el cordón umbilical. Conclusiones. La vigilancia integrada de fetos AEG permiten detectar a fetos en riesgo de desenlace adverso por una insuficiencia placentaria aguda secundaria a corioamnionitis histológica o subclínica.

Cardiac morphology in neonates with fetal growth restriction

OBJECTIVE

Assess effects of fetal growth restriction (FGR) on cardiac modelling in premature and term neonates.

STUDY DESIGN

Prospective echocardiographic study of a cohort of FGR neonates (n = 21) and controls (n = 41) with normal prenatal growth and circulation.

RESULTS

Unadjusted for gestational age, birth weight, sex, and twin/singleton, Late-FGR neonates had smaller hearts than controls, with globular left ventricles and symmetrical right ventricles. Adjusted estimates showed smaller left ventricles and similarly sized right ventricles, with symmetrical left and right ventricles. Early-FGR (compared with Late-FGR) had smaller hearts and globular left ventricles in unadjusted estimates, but after adjustment, sizes and shapes were similar.

CONCLUSION

FGR had significant impact on cardiac modelling, seen in both statistical models unadjusted and adjusted for gestational age, birth weight, sex, and twin/singleton. The adjustments, however, refined the results and revealed more specific effects of FGR, thus underscoring the importance of statistical adjustments in such studies.

Maternal Steroids on Fetal Doppler Indices, in Growth-Restricted Fetuses with Abnormal Umbilical Flow from Pregnancies Complicated with Early-Onset Severe Preeclampsia

Corticoids are largely used for fetal interest in expected preterm deliveries. This study went further, evaluating the effect of maternal administration of dexamethasone (Dex) on the umbilical artery (UA), middle cerebral artery (MCA), and ductus venous (DV) spectrum, in growth-restricted fetuses, with the absent end-diastolic flow (AEDF) in UA, from singleton early-onset severe preeclamptic pregnancies. Supplementary, the impact on both uterine arteries (UTAs) flow was also evaluated. In 68.7% of cases, the EDF was transiently restored (trAEDF group), in the rest of 31.2% remained persistent absent (prAEDF group). UA-PI significantly decreased in the first day after Dex (day 1/0; p < 0.05), reaching its minimum during day 2 (day 2/1; p > 0.05), revealing a significant recovery to day 4 (day 4/2; p < 0.05), in both groups. The MCA-PI decreased from day 1 until day 3 in both groups, but significantly only in the trAEDF group (p = 0.030 vs. p = 0.227. The DV-PI's decrease (during day 1) and the CPR's increase (between days 0 and 2) were not significant in both groups. UTAs-PIs did not vary. The prAEDF group had a significantly increased rate of antenatal worsening Doppler and a poorer perinatal outcome compared with the trAEDF group. In conclusion, Dex transiently restored the AEDF in UA in the majority of cases, a "positive" effect being a useful marker for better perinatal prognosis. UA-PI significantly decreased in all cases. The improvement in umbilical circulation probably was responsible for the short but not significant DV-PI reduction. MCA-PI decreased only in sensitive cases, probably due to an already cerebral "full" vasodilation in the prAEDF group. Furthermore, the CPR's nonsignificant improvement was the result of a stronger effect of Dex on UA-PI than on MCA-PI. Finally, despite the same etiology, it was only a weak correlation between the severity of the umbilical and uterine abnormal spectrum.

Umbilical Venous Volume Flow in Late-Onset Fetal Growth Restriction

OBJECTIVES

Umbilical vein flow (UVF) is reduced in fetal growth restriction (FGR). We compared absolute and size-adjusted UVF (estimated fetal weight [EFW] and abdominal circumference [AC]) and rates of abnormal UVF parameters (<10th percentile) among FGR fetuses meeting Delphi criteria (FGR-D) against small for gestational age (SGA) fetuses and appropriate for gestational age (AGA) controls.

METHODS

Absolute UVF, UVF/EFW, and UVF/AC were compared between 73 FGR pregnancies (35 FGR-D, 38 SGA) and 108 AGA controls. Rates of abnormal UVF were compared to abnormal umbilical artery pulsatility index (UAPI). Independent samples t-tests, Mann-Whitney U, odds ratio (OR), chi-squared, and Fisher's exact tests were used as appropriate.

RESULTS

Mean absolute UVF was significantly decreased in FGR-D compared to AGA (P = .0147), but not between SGA and AGA fetuses. The incidence of both abnormal absolute UVF and UVF/AC values (<10th centile) was higher among late-onset FGR fetuses versus AGA fetuses (UVF: OR 2.7, confidence interval [CI] 1.37-5.4; UVF/AC: OR 2.73, CI 1.37-5.4). UVF was more frequently abnormal than UAPI and in only two fetuses were both Doppler values abnormal.

CONCLUSION

Absolute UVF is altered in late-onset FGR, and most pronounced among FGR-D. UVF may provide additional insight into fetal compromise in those affected by growth restriction.

The importance of the cerebroplacental ratio for the prognosis of neonatal outcome in AGA fetuses

PURPOSE

As a Doppler sonographic parameter, the cerebroplacental ratio (CPR) provides information about fetal hemodynamics and the redistribution of fetal blood volume in response to a metabolic change. The present study was undertaken to determine the extent to which CPR can be used as a valid parameter in routine obstetric assessment. We investigated whether CPR can be used to assess the neonatal outcome in appropriate for gestational age (AGA) fetuses and its association with secondary cesarean section due to fetal distress.

METHODS

In this retrospective analysis 1739 pregnant women were admitted to the University Women's Clinic Magdeburg, Germany, between January 2016 and December 2017. Of them, 710 AGA fetuses were eligible for analysis. SGA fetuses with an estimated fetal weight < 10th percentile were excluded from the study. The AGA fetuses were divided in two groups based on the CPR: 669 fetuses showed a normal CPR ≥ 1.08; 41 fetuses showed a decreased CPR < 1.08.

RESULTS

In our study cohort decreased CPR in AGA fetuses was associated with threefold increased rate of cesarean sections due to fetal distress (p < 0.001). Our data suggested that low CPR is a reliable predictor of an impaired neonatal outcome in AGA fetuses in terms of a lower birth weight, transfer to neonatology, longer length of hospitalization, and the presence of severe morbidity.

CONCLUSION

Decreased CPR in AGA fetuses correlated with impaired neonatal outcome and secondary cesarean section due to fetal distress. The potential role of CPR for obstetric screening should be investigated in further studies.

Fetal Tibial Artery Doppler in Late IUGR Fetuses: A Longitudinal Study

INTRODUCTION

Late-onset intrauterine fetal growth restriction (IUGR) is a common pregnancy complication diagnosed in 5-10% of pregnant women worldwide. Under the impact of hypoxia, the fetus develops a protective mechanism of adaptive changes occurring in the cerebral circulation ("brain-sparing effect").

MATERIALS AND METHODS

We conducted detailed longitudinal Doppler examinations and the monitoring of the fetal condition in 53 IUGR fetuses. Doppler measurements of the pulsatility index in the fetal tibial (TA-PI), umbilical (UA-PI), and middle cerebral arteries (MCA-PI) were performed, and the cerebral placental ratio (CPR) was determined on a weekly basis from the 33rd week to the birth.

RESULTS

The longitudinal analysis showed a significant increase in the TA-PI. The UA showed a plateau, but no increase was detected near term. The MCA-PI and CPR showed a progressive decrease in values from inclusion to delivery. Our findings indicate that the increase in the TA-PI was the first sign of the aggravating state of the fetus with the changes registered from the 35th week. The parameters of the UA-PI did not show significant changes, while the MCA and CPR became abnormal later from the 37th week.

CONCLUSIONS

These observations can serve towards the development of guidelines for detecting the deteriorating signs and intervention timing in IUGR during late pregnancies.

Brain volumes and white matter microstructure in 8- to 10-year-old children born with fetal growth restriction

BACKGROUND

Fetal growth restriction caused by placental insufficiency is associated with increased risk of poor neurodevelopment, even in the absence of specific perinatal brain injury. Placental insufficiency leads to chronic hypoxaemia that may alter cerebral tissue organisation and maturation.

OBJECTIVE

The aim of this study was to assess the effects fetal growth restriction and fetal haemodynamic abnormalities have on brain volumes and white matter microstructure at early school age.

MATERIALS AND METHODS

This study examined 32 children born with fetal growth restriction at 24 to 40 gestational weeks, and 27 gestational age-matched children, who were appropriate for gestational age. All children underwent magnetic resonance imaging (MRI) at the age of 8-10 years. Cerebral volumes were analysed, and tract-based spatial statistics and atlas-based analysis of white matter were performed on 17 children born with fetal growth restriction and 14 children with birth weight appropriate for gestational age.

RESULTS

Children born with fetal growth restriction demonstrated smaller total intracranial volumes compared to children with normal fetal growth, whereas no significant differences in grey or white matter volumes were detected. On atlas-based analysis of white matter, children born with fetal growth restriction demonstrated higher mean and radial diffusivity values in large white matter tracts when compared to children with normal fetal growth.

CONCLUSION

Children ages 8-10 years old born with fetal growth restriction demonstrated significant changes in white matter microstructure compared to children who were appropriate for gestational age, even though no differences in grey and white matter volumes were detected. Poor fetal growth may impact white matter maturation and lead to neurodevelopmental impairment later in life.

The effect of middle cerebral artery peak systolic velocity on prognosis in early and late-onset fetal growth restriction

OBJECTIVES

We aim to investigate the utility of MCA PSV Doppler in determining the perinatal mortality and morbidity in serial Doppler measurements from the time of diagnosis to the delivery of complicated cases with fetal growth restriction (FGR).

METHODS

At 24-38 weeks of gestation, 65 pregnant women diagnosed with FGR were included in the study. The fetal biometry measurements, MCA PI, and MCA PSV Doppler evaluation of the cases formed at the diagnosis and the delivery were recorded. Gestational weeks, birth weights, APGAR scores, cord pH values, NICU (neonatal intensive care unit) admission, NICU duration of stay, and perinatal morbidity parameters such as RDS (respiratory distress syndrome), BPD (Bronchopulmonary dysplasia), NEC (necrotizing enterocolitis), sepsis and perinatal mortality were compared. The patients were divided into two groups: early and late-onset fetal growth restriction. Perinatal morbidity and mortality were accepted as adverse perinatal outcomes.

RESULTS

MCA PSV above the 95th percentile at the diagnosis and delivery time was seen at a significantly higher rate with adverse perinatal outcomes.

CONCLUSIONS

This study shows that evaluating MCA PSV with Doppler can be a helpful diagnostic method for early diagnosis of restriction and hypoxic fetuses. Also, it may be used in clinics as a noninvasive method to predict neonatal prognosis.

Effect of a standardized maternal meal on fetal middle cerebral artery Doppler indices: A single-blinded crossover study

Objective

Measures of Doppler blood flow velocity profiles are an integral part of monitoring fetal well-being during pregnancy. These examinations are performed at different times of the day and at different maternal meal states. In uncomplicated pregnancies, we assessed the effect of a standardized maternal meal on middle cerebral artery (MCA) and umbilical artery (UA) Doppler blood flow velocity pulsatility indices (PIs) and MCA peak systolic velocity (PSV).

Methods

In this prospective single-blinded crossover study 25 healthy women were examined at 36 weeks of pregnancy. The first examination was performed in the morning following overnight fast, and repeated after extended fast (state A), and after a standard breakfast meal (state B).

Results

Irrespective of maternal prandial status, the MCA-PI values were lower in the 2^nd compared to the 1^st examination (-0.187; p = 0.071, and -0.113; p = 0.099, state A and B, respectively). Compared to the values in the 1^st examination, the UA-PI values, were higher after extended fast (0.014; p = 0.436), and lower post-prandially (-0.036; p = 0.070). The difference (state B minus state A) between the meal states were not significant (0.074; p = 0.487 and -0.050; p = 0.058, for MCA-PI and UA-PI, respectively). Adjusting for the possible influence of fetal heart rate on MCA-PI and UA-PI, the differences between meal states remained non-significant (p = 0.179, p = 0.064, respectively). The MCA-PSV values increased after the meal (6.812; p = 0.035), whereas no increase was observed following extended fast (0.140; p = 0.951). The difference in MCA-PSV values between the two meal states was not significant (6.672; p = 0.055).

Conclusion

Our results demonstrate possible diurnal variations in MCA-PI and UA-PI, with and without adjustment for fetal heart rate, that seem to be unaffected by maternal meal intake in healthy pregnancies.

Computing Z-Score Equations for Clinical Use to Measure Fetal Umbilical Vein Size and Flow Using Six Independent Variables of Age and Size

INTRODUCTION

Measurements of the umbilical vein diameter (UVD) and blood flow (mL/min) (UVF) have been demonstrated to be decreased in fetuses with growth restriction (FGR) using gestational age (GA) as the independent variable. However, no previous studies have used the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), and the estimated fetal weight (EFW) to create equations to be used for z-score computations when evaluating fetuses at risk foran abnormal UVD and UVF.

METHODS

Two hundred and forty normal fetuses between 20 and 40 weeks of gestation were examined in which the UVD and time averaged maximal velocity (TAMX) were measured from which the UVF, UVF/HC, UVF/AC, and UVF/kg were computed. Fractional polynomial regression analysis was used to compute z-score equations using the above independent variables. Thirty-six fetuses with abnormal growth of the AC were examined to test the validity of the equations.

RESULTS

The UVD, TAMX, UVF, UVF/HC, and UVF/AC all increased with gestatonal age and fetal growth except for the UVF/kg, which decreased with age and growth. From the regression equations, two z-score calculators were created using an Excel spreadsheet that can be used in clinical practice. Abnormal measurements of the UVD, UVF, UVF/HC, UVF/AC, and UVF/kg were observed in the 36 study fetuses, 21 with an AC < 10^th centile and 15 with an AC > 90^th centile.

CONCLUSION

Using the equations generated from this study and the z-score calculators provides a clinical tool to measure the size and flow of the umbilical vein that may have clinical implications.

Patterns of Brain Sparing in a Fetal Growth Restriction Cohort

Objective: Our objective was to compare differences in Doppler blood flow in four fetal intracranial blood vessels in fetuses with late-onset fetal growth restriction (FGR) vs. those with small for gestational age (SGA). Methods: Fetuses with estimated fetal weight (EFW) <10th percentile were divided into SGA (n = 30) and FGR (n = 51) via Delphi criteria and had Doppler waveforms obtained from the middle cerebral artery (MCA), anterior cerebral artery (ACA), posterior cerebral artery (PCA), and vertebral artery (VA). A pulsatility index (PI) <5th centile was considered “abnormal”. Outcomes included birth metrics and neonatal intensive care unit (NICU) admission. Results: There were more abnormal cerebral vessel PIs in the FGR group versus the SGA group (36 vs. 4; p = 0.055). In FGR, ACA + MCA vessel abnormalities outnumbered PCA + VA abnormalities. All 8 fetuses with abnormal VA PIs had at least one other abnormal vessel. Fetuses with abnormal VA PIs had lower BW (1712 vs. 2500 g; p < 0.0001), delivered earlier (35.22 vs. 37.89 wks; p = 0.0052), and had more admissions to the NICU (71.43% vs. 24.44%; p = 0.023). Conclusions: There were more anterior vessels showing vasodilation than posterior vessels, but when the VA was abnormal, the fetuses were more severely affected clinically than those showing normal VA PIs.

3D Fractional Limb Volume Identifies Reduced Subcutaneous and Lean Mass in Fetal Growth Restriction

OBJECTIVES

Fetal 2D and 3D fractional limb volume (FLV) measurements by ultrasound can detect fetal lean and subcutaneous mass and possibly percent body fat. Our objectives were to 1) compare FLV measurements in fetuses with fetal growth restriction (FGR) versus small for gestational age (SGA) defined by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG)-supported international Delphi consensus and 2) correlate FLV findings with birth metrics. We hypothesize that FLV measurements will be significantly smaller in FGR versus SGA fetuses and will correlate closer with Ponderal index (PIx) in the neonate than abdominal circumference (AC).

METHODS

Patients were categorized as FGR or SGA as defined by ISUOG. Total thigh volume (TTV), volumes of lean mass (LMV), and fat mass volume (FMV) were calculated from 3D acquisitions. Measurements were compared between groups and correlated with birthweight (BW) and PIx (BW/crown-heal length).

RESULTS

The FGR group (n = 37) delivered earlier (37/2 versus 38/0; P = .0847), were lighter (2.2 kg versus 2.6 kg; P = .0003) and had lower PIx (0.023 versus 0.025; P = .0013) than SGAs (n = 22). FGRs had reduced TTV (40.6 versus 48.4 cm³ ; P = .0164), FMV (20.8 versus 25.3 cm³ ; P = .0413), and LMV (19.8 versus 23.1 cm³ ; P = .0387). AC had the highest area under the curve (0.69) for FGR. FMV was more strongly associated with PIx than the AC (P = .0032).

CONCLUSIONS

The AC and FLV measurements were significantly reduced in FGR fetuses compared to SGAs. While the AC outperformed FLV in predicting FGR, the FLV correlated best with PIx, which holds investigative promise.

The relationship of foetal superior mesenteric artery blood flow and the time to first meconium passage in newborns with late-onset foetal growth restriction

This study aimed to assess the relationship between the foetal superior mesenteric artery (SMA) Doppler and the time to first meconium passage (FMP) in foetuses with late-onset foetal growth restriction. This single-centre, prospective, observational, cohort study included 57 patients with late-onset FGR. The newborn infants were divided into two groups: preterm (36.8%) and term (63.2%). The time to FMP of the infants was compared to the foetal SMA parameters obtained within a week before delivery. The median time to FMP was similar between two groups (p = .31). The SMA pulsatility index (PI) was higher in the preterm group (p < .01). There was no correlation between foetal SMA PI or resistance index and time to FMP. In late-onset FGR infants, our study found no association between SMA Doppler measurements and time to FMP. However, a significant difference was detected in SMA PI between preterm and term infants. Impact StatementWhat is already known in this subject? Foetal growth restriction (FGR) can affect splanchnic circulation of the foetus and this alteration can be associated with some disorders including necrotising enterocolitis.What do the results of this study add? Superior mesenteric artery (SMA) Doppler indices are not associated with first meconium passage in neonates with late-onset foetal growth restriction. The pulsatility index of SMA is significantly higher in foetuses delivered before term.What are the implications of these findings for clinical practice and/or further research? Further research should be conducted to investigate the relationship between foetal SMA Doppler indices and neonatal gastrointestinal morbidities in foetuses with early onset FGR with Doppler anomalies. These studies can shed light from the prenatal to the postnatal period, allowing clinicians to predict potential problems and take precautions.

Effect of Vitamin D Supplementation on the Cerebral Placental Ratio in Pregnancy Complicated with Early Fetal Growth Restriction

Fetal growth restriction (FGR) is a complication of pregnancy connected with increased risk of intrauterine fetal demise. To increase the diagnostic accuracy, the cerebral placental ratio (CPR) is used. Vitamin D may play a role in the regulation of vascular flow in the fetus. The aim is to assess the relationship between CPR and vitamin D supplementation in fetuses with early FGR. It is a prospective cohort study. Pregnant females were divided into groups with 2000 IU and <500 IU of vitamin D. Both groups were observed for 14 days; USG was performed three times with one-week intervals. EFW and CPR were measured. Absolute CPR values were initially observed to differ significantly (p = 0.0032). Measurements on the seventh day of observation indicated that CPR was significantly higher (p = 0.0455) in fetuses of patients receiving vitamin D at a dose of 2000 IU 1.75 (IQR: 1.47; 2.06) vs. <500 IU group 1.55 (IQR: 1.04; 1.52). Similarly, on day 14: (p < 0.0001)—2.39 (IQR: 1.82; 2.69) vs. 1.21 (IQR: 0.98; 1.52). Supplementation with vitamin D at a dose of 2000 IU may have an influence on the increase in the CPR in fetuses with early FGR.

Modeling Pulsatility Index nomograms from different maternal and fetal vessels by quantile regression at 24-40 weeks of gestation: a prospective cross-sectional study

OBJECTIVE

Recent evidences highlight a considerable heterogeneity in the methodology of previously published studies reporting reference ranges for maternal and fetal Dopplers, which may have relevant implications in clinical practice. In view of these limitations, a standardized methodology to construct Doppler charts has been proposed. The aim of this study was to develop charts for pulsatility index (PI) of maternal and fetal Dopplers based upon the recently proposed standardized methodology and using quantile regression.

METHODS

Prospective cross-sectional study including 2516 low-risk singleton pregnancies between 24 and 40 weeks of gestation. The mean uterine, umbilical (UA), middle cerebral (MCA) and their ratio (cerebroplacental ratio, CPR) centile values were established by quantile regression in the considered gestational interval. Interclass correlation coefficient (ICC) of each maternal and fetal vessel was also computed to assess the intra- and inter-observer agreement of the results.

RESULTS

There was a good intra- and inter-observer agreement for each of the explored vessels (ICC >0.92 and >0.91 for a single and two observers, respectively). The 5th, 10th, 50th, 90th and 95th centiles of the reference range for gestation were constructed by quantile regression and compared to previously established reference charts. All the Doppler indices significantly changed with gestation. Second-degree polynomial regression models better described the changes with gestation in PCR and MCA PI values while a linear model better predicted the changes of other Doppler indices with advancing gestation. When compared to other studies reporting reference ranges for maternal and fetal Dopplers, the present charts showed similar median values but different distribution from the median.

CONCLUSIONS

We provided prospective charts of maternal and fetal Dopplers based upon a previously proposed standardized methodology and using quantile regression. When compared to previously published studies, these new charts showed similar median values but different deviations from the median which may help in better differentiating cases at higher risk of placental insufficiency and adverse perinatal outcome.

The impact of anti-hypertensive treatment on foetal growth and haemodynamics in pregnant women with pre-existing diabetes - An explorative study

OBJECTIVES

To explore the impact of anti-hypertensive treatment of pregnancy-induced hypertension on foetal growth and hemodynamics in women with pre-existing diabetes.

METHODS

A prospective cohort study of 247 consecutive pregnant women with pre-existing diabetes (152 type 1 diabetes; 95 type 2 diabetes), where tight anti-hypertensive treatment was initiated and intensified (mainly with methyldopa) when office blood pressure (BP) ≥135/85 mmHg and home BP ≥130/80 mmHg. Foetal growth was assessed by ultrasound at 27, 33 and 36 weeks and foetal hemodynamics were assessed by ultrasound Doppler before and 1-2 weeks after initiation of anti-hypertensive treatment.

RESULTS

In 215 initially normotensive women, anti-hypertensive treatment for pregnancy-induced hypertensive disorders was initiated in 42 (20%), whilst 173 were left untreated. Chronic hypertension was present in 32 (13%). Anti-hypertensive treatment for pregnancy-induced hypertensive disorders was not associated with foetal growth deviation (linear mixed model, p = 0.681). At 27 weeks, mainly before initiation of anti-hypertensive treatment, the prevalence of small foetuses with an estimated foetal weight <10th percentile was 12% in women initiating anti-hypertensive treatment compared with 4% in untreated women (p = 0.054). These numbers were close to the prevalence of birth weight ≤10th percentile (small for gestational age (SGA)) (17% vs. 4%, p = 0.003). Pulsatility index in the umbilical and middle cerebral artery remained stable after the onset of anti-hypertensive treatment in a representative subgroup (n = 12, p = 0.941 and p = 0.799, respectively).

CONCLUSION

There is no clear indication that antihypertensive treatment causes harm in this particular at-high-risk group of pregnant women with diabetes, such that a larger well-designed study to determine the value of tight antihypertensive control would be worthwhile.

Differences in body composition and growth persist postnatally in fetuses diagnosed with severe compared to mild fetal growth restriction

BACKGROUND

Fetal growth restriction (FGR) is most commonly diagnosed in pregnancy if the estimated fetal weight (EFW) is <  10th%. Those with abnormal Doppler velocimetry, indicating placental insufficiency and pathological FGR, demonstrate reduced fat and lean mass compared to both normally growing fetuses and FGR fetuses with normal Dopplers. The aim of this study was to determine how severity of FGR and abnormal Doppler velocimetry impacts neonatal body composition. Among a cohort of fetuses with an EFW <  10th%, we hypothesized that those with abnormal Dopplers and/or EFW <  3rd% would have persistent reductions in lean body mass and fat mass extending into the neonatal period compared to fetuses not meeting those criteria.

METHODS

A prospective cohort of FGR fetuses with an estimated fetal weight (EFW) <  10th% was categorized as severe (EFW <  3rd% and/or abnormal Dopplers; FGR-S) versus mild (EFW 3-10th% ; FGR-M). Air Displacement Plethysmography and anthropometrics were performed at birth and/or within the first 6-8 weeks of life.

RESULTS

FGR-S versus FGR-M were born one week earlier (P = 0.0024), were shorter (P = 0.0033), lighter (P = 0.0001) with smaller weight-for-age Z-scores (P = 0.0004), had smaller head circumference (P = 0.0004) and lower fat mass (P = 0.01) at birth. At approximately 6-8 weeks postmenstrual age, weight, head circumference, and fat mass were similar but FGR-S neonates were shorter (P = 0.0049) with lower lean mass (P = 0.0258).

CONCLUSION

Doppler velocimetry abnormalities in fetuses with an EFW <  10th% identified neonates who were smaller at birth and demonstrated catch-up growth by 6-8 weeks of life that favored fat mass accretion over lean mass and linear growth.

Right Ventricular Global Longitudinal Strain in Fetuses with Hypoplastic Left Heart Syndrome Does Not Differ Between Those With and Without Genetic Conditions

The presence of a genetic condition is a risk factor for increased mortality in hypoplastic left heart syndrome (HLHS). Speckle tracking strain analysis in interstage echocardiograms have shown promise in identifying patients with HLHS at increased risk of mortality. We hypothesized that fetuses with a genetic condition and HLHS have impaired right ventricular global longitudinal strain compared with fetuses with HLHS and no evident genetic condition. We performed a retrospective analysis of 60 patients diagnosed in fetal life with HLHS from 11/2015 to 11/2019. We evaluated presenting echocardiograms and calculated right ventricular global longitudinal strain (RV GLS) and fractional area of change (FAC) using post-processing software. We first compared RV GLS and FAC between those with genetic conditions to those without. We examined the secondary outcome of mortality among those with and without genetic conditions and among HLHS subgroups. Of the 60 patients with available genetic testing, 11 (18%) had an identified genetic condition. Neither RV GLS nor FAC was significantly different between patients with and without genetic conditions. There was no difference in RV GLS or FAC among HLHS phenotype or those who died or survived as infants. However, patients with a genetic syndrome had increased neonatal and overall mortality. In this cohort, RV GLS did not differ between those with and without a genetic diagnosis, among HLHS phenotypes, or between those surviving and dying as infants. Further analysis of strain throughout gestation and after birth could provide insight into the developing heart in fetuses with HLHS.

Cerebral Arterial Asymmetries in the Neonate: Insight into the Pathogenesis of Stroke

Neonatal and adult strokes are more common in the left than in the right cerebral hemisphere in the middle cerebral arterial territory, and adult extracranial and intracranial vessels are systematically left-dominant. The aim of the research reported here was to determine whether the asymmetric vascular ground plan found in adults was present in healthy term neonates (n = 97). A new transcranial Doppler ultrasonography dual-view scanning protocol, with concurrent B-flow and pulsed wave imaging, acquired multivariate data on the neonatal middle cerebral arterial structure and function. This study documents for the first-time systematic asymmetries in the middle cerebral artery origin and distal trunk of healthy term neonates and identifies commensurately asymmetric hemodynamic vulnerabilities. A systematic leftward arterial dominance was found in the arterial caliber and cortically directed blood flow. The endothelial wall shear stress was also asymmetric across the midline and varied according to vessels’ geometry. We conclude that the arterial structure and blood supply in the brain are laterally asymmetric in newborns. Unfavorable shearing forces, which are a by-product of the arterial asymmetries described here, might contribute to a greater risk of cerebrovascular pathology in the left hemisphere.

The utility of foetal splenic artery Doppler measurement in the diagnosis of late-onset foetal growth restriction

We aimed to examine the contribution of splenic artery (SA) Doppler parameters in the detection of foetuses with late-onset foetal growth restriction (LO-FGR) and to evaluate its power in predicting adverse perinatal outcomes. Within the study's scope, 52 cases in the LO-FGR group and 92 cases in the control group were evaluated. The criteria determined in the Delphi procedure by an international consensus were used to define the LO-FGR. Middle cerebral artery (MCA) pulsatility index (PI) and SA PI were significantly lower in the LO-FGR group (p: .002, p<.001, respectively). Likewise, cerebroplacental ratio (CPR) was significantly lower in the LO-FGR group (p<.001). Decreased CPR and decreased SA PI were significantly and positively associated with an increased likelihood of exhibiting adverse obstetric outcome (p<.001, p: .012, respectively). The receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off value for SA PI was 1.41 to predict LO-FGR with 70.7% sensitivity and 61.5% specificity (AUC = 0.684; 95% CI, 0.594-0.774).Impact StatementWhat is already known on this subject? The main clinical difficulty in late-onset foetal growth restriction (LO-FGR) is the detection of the disease.What do the results of this study add? The splenic artery (SA) pulsatility index (PI) may contribute to both diagnostic and the prediction of adverse perinatal outcomes in LO-FGR cases. Our results showed that the SA PI value, as well as cerebroplacental ratio (CPR), can be a useful parameter in predicting negative outcomes.What are the implications of these findings for clinical practice and/or further research? Various degrees of uteroplacental insufficiency in foetuses with LO-FGR may be associated with abnormalities in SA Doppler velocimetry. Splenic artery Doppler velocimetry can be used for the clinical management of LO-FGR.

Prenatal Diagnosis of Fetus With Transaldolase Deficiency Identifies Compound Heterozygous Variants: A Case Report

Transaldolase (TALDO) deficiency is a rare autosomal recessive disorder caused by variants in the TALDO1 gene that commonly results in multisystem dysfunction. Herein, we reported compound heterozygous variants in a Chinese prenatal case with TALDO deficiency using whole-exome sequencing (WES) for trios and Sanger sequencing. The heterozygous variants were located on the TALDO1 gene: NM_006755.2:c.574C > T(Chr11:g.763456C > T), a missense variant in exon 5 paternally inherited; NM_006755.2:c.462-2A > G(Chr11:g.763342A > G), a splicing aberration in intron 4 maternally inherited. The qualitative analysis of urinary polyols in neonatal urine indicated that xylitol + arabitol and ribitol in the proband’s urine were significantly increased. These findings expand the variation spectrum of the TALDO1 gene, provide solid evidence for the counseling of the family in regard to future pregnancies, strongly support the application of WES in prenatal diagnosis, and further prove that effective postpartum treatments could improve prognosis.

Altered erythropoiesis in newborns with congenital heart disease

BACKGROUND

Fetal hypoxia has been implicated in fetal growth restriction in congenital heart disease (CHD) and leads to stress erythropoiesis in utero. The objective is to assess erythropoiesis and its association with growth in newborns with CHD.

METHODS

Fetuses with prenatally diagnosed CHD from 2013 to 2018 were retrospectively reviewed. Pregnancies with multiple gestation, genetic abnormalities, major extra-cardiac anomalies, and placental abruption were excluded. Complete blood count tests at birth were compared to published normative values. Spearman correlation assessed associations of red blood cell (RBC) indices with birth anthropometrics and prenatal Doppler measures.

RESULTS

A total of 160 newborns were included. Median gestational age was 38.3 (37.3, 39.0) weeks. Infants ≥37 weeks gestation had lower hemoglobin (Hgb), hematocrit, and elevated nucleated RBC (nRBC), mean corpuscular volume, and mean corpuscular hemoglobin compared to reference. No differences in RBC indices were observed in infants <34 and 34-37 weeks gestation. There was no difference in Hgb and nRBC between CHD subgroups. Neither Hgb nor nRBC were associated with birth anthropometrics or Doppler patterns.

CONCLUSIONS

Term infants with CHD demonstrated multiple alterations in erythrocyte indices suggesting ineffective stress erythropoiesis in late gestation resulting in lower Hgb at birth. Altered erythropoiesis was not correlated to growth or Doppler patterns.

IMPACT

Newborns with congenital heart disease (CHD) born at term gestation demonstrated altered erythropoiesis. Term newborns with CHD have decreased hemoglobin levels despite having red blood cell indices consistent with stress erythropoiesis, suggesting an incomplete compensatory response to in utero physiologic disturbances associated with CHD. The etiology is unknown; however, it may be influenced by multiple risk factors during pregnancy in the maternal-fetal dyad. Alterations in red blood cell indices were not associated with outcomes of fetal growth.

A review study of fetal circulatory models to develop a digital twin of a fetus in a perinatal life support system

BACKGROUND

Preterm birth is the main cause of neonatal deaths with increasing mortality and morbidity rates with decreasing GA at time of birth. Currently, premature infants are treated in neonatal intensive care units to support further development. However, the organs of, especially, extremely premature infants (born before 28 weeks of GA) are not mature enough to function optimally outside the womb. This is seen as the main cause of the high morbidity and mortality rates in this group. A liquid-filled incubator, a so-called PLS system, could potentially improve these numbers for extremely premature infants, since this system is designed to mimic the environment of the natural womb. To support the development and implementation of such a complex system and to interpret vital signals of the fetus during a PLS system operation, a digital twin is proposed. This mathematical model is connected with a manikin representing the digital and physical twin of the real-life PLS system. Before developing a digital twin of a fetus in a PLS system, its functional and technical requirements are defined and existing mathematical models are evaluated.

METHOD AND RESULTS

This review summarizes existing 0D and 1D fetal circulatory models that potentially could be (partly) adopted for integration in a digital twin of a fetus in a PLS system based on predefined requirements. The 0D models typically describe hemodynamics and/or oxygen transport during specific events, such as the transition from fetus to neonate. Furthermore, these models can be used to find hemodynamic differences between healthy and pathological physiological states. Rather than giving a global description of an entire cardiovascular system, some studies focus on specific organs or vessels. In order to analyze pressure and flow wave profiles in the cardiovascular system, transmission line or 1D models are used. As for now, these models do not include oxygen transport.

CONCLUSION

This study shows that none of the models identified in literature meet all the requirements relevant for a digital twin of a fetus in a PLS system. Nevertheless, it does show the potential to develop this digital twin by integrating (parts) of models into a single model.

Cerebroplacental ratio for prediction of adverse intrapartum and neonatal outcomes in a term uncomplicated pregnancy

Background

Fetal hypoxia is one of the major causes of high perinatal morbidity and mortality rates. Doppler ultrasound tests such as cerebroplacental ratio (CPR) evaluation are commonly used to assess blood flow disturbances in placento-umbilical and feto-cerebral circulations. A low cerebroplacental ratio has been shown to be associated with an increased risk of stillbirth regardless of the gestation or fetal weight. We conducted this study to assess the fetal cerebroplacental ratio in prediction of adverse intrapartum and neonatal outcomes in a term, uncomplicated pregnancy to reduce fetal and neonatal morbidity and mortality.

Results

It was found that neonates with CPR ≤1.1 had significantly higher frequencies of cesarean delivery (CS) for intrapartum fetal compromise compared to those with CPR >1.1 (p=0.043). Neonates with CPR ≤1.1 had significantly lower Apgar score at 1 min and 5 min than those with CPR >1.1 (p=0.004) and (p=0.003), respectively. Neonates with CPR ≤1.1 had significantly higher rates of NICU admission than those with CPR <1.1 (p=0.004).

Conclusion

The cerebroplacental ratio shows the highest sensitivity in the prediction of fetal heart rate abnormalities and adverse neonatal outcome in uncomplicated pregnancies at term. The cerebroplacental ratio index is useful in clinical practice in antenatal monitoring of these women in order to select those at high risk of intra- and postpartum complications.

A survey of current practice in reporting third trimester fetal biometry and Doppler in Australia and New Zealand

Introduction

Inconsistent reporting practices in third trimester ultrasound, the choice of reference charts in particular, have the potential to misdiagnose abnormal fetal growth. But this may lead to unnecessary anxiety and confusion amongst patients and clinicians and ultimately influence clinical management. Therefore, we sought to determine the extent of variability in choice of fetal biometry and Doppler reference charts and reporting practices in Australia and New Zealand.

Methods

Clinicians performing and/or reporting obstetric ultrasound were invited to answer questions about fetal biometry and Doppler charts in a web-based survey.

Results

At least four population-based charts are in current use. The majority of respondents (78%) report the percentile for known gestational age (GA) alongside measurements and 63% using a cut-off of estimated fetal weight (EFW) < 10^th percentile when reporting small for gestational age (SGA) and/or fetal growth restriction (FGR). The thresholds for the use of fetal and maternal Doppler in third trimester ultrasound varied in terms of the GA, EFW cut-off, and how measures were reported. The majority of respondents were not sure of which Doppler charts were used in their practice.

Conclusion

This survey revealed inconsistencies in choice of reference chart and reporting practices. The potential for misdiagnosis of abnormal fetal growth remains a significant issue.

Third-trimester growth diversity in small fetuses classified as appropriate-for-gestational age or small-for-gestational age at birth

OBJECTIVE

We have shown previously that third-trimester growth in small fetuses (estimated fetal weight (EFW) < 10^th percentile) with birth weight (BW) < 10^th percentile is heterogeneous using individualized growth assessment (IGA). We aimed to test our hypothesis that individual growth patterns in small fetuses with BW > 10^th percentile are also variable but in different ways.

METHODS

This was a study of 191 cases with EFW < 10^th percentile and BW > 10^th percentile (appropriate-for-gestational-age (AGA) cohort), derived from the PORTO study. Composite size parameters were used to quantify growth pathology at individual third-trimester timepoints (individual composite prenatal growth assessment score (-icPGAS)). The fetal growth pathology score 1 (-FGPS1), calculated cumulatively from serial -icPGAS values, was used to characterize third-trimester growth patterns. Vascular-system evaluation included umbilical artery (UA) and middle cerebral artery (MCA) Doppler velocimetry. Outcome variables were birth age (preterm/term delivery) and BW (expressed as growth potential realization index for weight (GPRI_WT ) and percentile). The findings from the AGA cohort were compared with those from small fetuses (EFW < 10^th percentile) with BW < 10^th percentile (small-for-gestational-age (SGA) cohort).

RESULTS

The AGA cohort was found to have 134 fetuses (70%) with normal growth pattern and 57 (30%) with growth restriction based on IGA criteria. Seven growth-restriction -FGPS1 patterns were observed, including the previously defined progressive, late, adaptive and recovering types. The recovering type was the most common growth pattern in the AGA cohort (50.9%). About one-third of fetuses without any evidence of growth restriction had significant unexplained abnormalities in the UA (34%) and MCA (31%) and elevated mean GPRI_WT values (113 ± 12.5%). Comparison of the AGA and SGA cohorts indicated a significant difference in the distribution of -FGPS1 growth patterns (P = 0.0001). Compared with the SGA cohort, the AGA cohort had more fetuses with a normal growth pattern (70% vs 38%) and fewer cases with growth restriction (30% vs 62%). While the recovering type was the most common growth-restriction pattern in the AGA cohort (51%), the progressive type was the primary growth-restriction pattern in the SGA cohort (44%). No difference in the incidence of MCA or UA abnormality was found between the SGA and AGA cohorts when comparing subgroups of more than 10 fetuses.

CONCLUSIONS

Both normal-growth and growth-restriction patterns were observed in the AGA cohort using IGA, as seen previously in the SGA cohort. The seven types of growth restriction defined in the SGA cohort were also identified in AGA cases, but their distribution was significantly different. In one-third of cases without evidence of growth pathology in the AGA cohort, Doppler abnormalities in the UA and MCA were seen. This heterogeneity underscores the difficulty of accurate classification of fetal and neonatal growth status using conventional population-based methods. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Reference values for fetal Doppler-based cardiocirculatory indices in monochorionic-diamniotic twin pregnancy

Background

Placental anastomoses in monochorionic diamniotic (MCDA) twin pregnancy have a major impact on fetal circulation. This study was designed to define reference ranges of cardiac and vascular Doppler indices in MCDA twin pregnancies.

Methods

This cross-sectional study included 442 uncomplicated MCDA twin fetuses undergoing Doppler ultrasonography at 18–35 weeks of gestation. Left and right myocardial performance index (LV-MPI, RV-MPI), E/A ratio of atrioventricular valves, pulsatility indices of umbilical artery, middle cerebral artery (MCA), and ductus venosus (DV), cerebroplacental ratio, peak systolic velocity of MCA, S/a ratio of DV, and early diastolic filling time of ductus venosus (DV-E) were evaluated under standardized settings. The equation models between Doppler indices and gestational age (GA) were fitted. After adjustment for GA, the correlations between MPI and fetal heart rate (FHR), and between MPI and DV indices were analyzed.

Results

Estimated centiles of Doppler indices were derived as a function of GA, being distinct in values from those of singletons. There was no correlation between GA-adjusted MPI and FHR. DV-E was inversely related to LV-MPI.

Conclusions

MCDA twins showed significant changes in some Doppler indices throughout gestation with quantitative differences from singletons, emphasizing the importance of MC twin-specific reference values for clinical application. Further adjustment of MPI for FHR was unnecessary. DV-E is a vascular index indirectly representing fetal diastolic function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04255-w.

An integrated approach based on advanced CTG parameters and Doppler measurements for late growth restriction management

Background

The clinical diagnosis of late Fetal Growth Restriction (FGR) involves the integration of Doppler ultrasound data and Fetal Heart Rate (FHR) monitoring through computer assisted computerized cardiotocography (cCTG). The aim of the study was to evaluate the diagnostic power of combined Doppler and cCTG parameters by contrasting late FGR –and healthy controls.

Methods

The study was conducted from January 2018 to May 2020. Only pregnant women who had the last Doppler measurement obtained within 1 week before delivery and cCTG performed within 24 h before delivery were included in the study. Two hundred forty-nine pregnant women fulfilling the inclusion criteria were enrolled in the study; 95 were confirmed as late FGR and 154 were included in the control group.

Results

Among the extracted cCTG parameters, Delta Index, Short Term Variability (STV), Long Term Variability (LTV), Acceleration and Deceleration Phase Rectified Slope (APRS, DPRS) values were lower in the late FGR participants compared to the control group. In the FGR cohort, Delta, STV, APRS, and DPRS were found different when stratifying by MCA_PI (MCA_PI <5th centile or > 5th centile). STV and DPRS were the only parameters to be found different when stratifying by (UA_PI >95th centile or UA_PI <95th centile). Additionally, we measured the predictive power of cCTG parameters toward the identification of associated Doppler measures using figures of merit extracted from ROC curves.

The AUC of ROC curves were accurate for STV (0,70), Delta (0,68), APRS (0,65) and DPRS (0,71) when UA_PI values were > 95th centile while, the accuracy attributable to the prediction of MCA_PI was 0.76, 0.77, 0.73, and 0.76 for STV, Delta, APRS, and DPRS, respectively.

An association of UA_PI>95th centile and MCA_PI<5th centile with higher risk for NICU admission, was observed, while CPR < 5th centile resulted not associated with any perinatal outcome. Values of STV, Delta, APRS, DPRS were significantly lower for FGR neonates admitted to NICU, compared with the uncomplicated FGR cohort.

Conclusions

The results of this study show the contribution of advanced cCTG parameters and fetal Doppler to the identification of late FGR and the association of those parameters with the risk for NICU admission.

Trial registration

Retrospectively registered.

Fetal cerebral blood-flow redistribution: analysis of Doppler reference charts and association of different thresholds with adverse perinatal outcome

OBJECTIVES

First, to compare published Doppler reference charts of the ratios of flow in the fetal middle cerebral and umbilical arteries (i.e. the cerebroplacental ratio (CPR) and umbilicocerebral ratio (UCR)). Second, to assess the association of thresholds of CPR and UCR based on these charts with short-term composite adverse perinatal outcome in a cohort of pregnancies considered to be at risk of late preterm fetal growth restriction.

METHODS

Studies presenting reference charts for CPR or UCR were searched for in PubMed. Formulae for plotting the median and the 10^th percentile (for CPR) or the 90^th percentile (for UCR) against gestational age were extracted from the publication or calculated from the published tables. Data from a prospective European multicenter observational cohort study of singleton pregnancies at risk of fetal growth restriction at 32 + 0 to 36 + 6 weeks' gestation, in which fetal arterial Doppler measurements were collected longitudinally, were used to compare the different charts. Specifically, the association of UCR and CPR thresholds (CPR < 10^th percentile or UCR ≥ 90^th percentile and multiples of the median (MoM) values) with composite adverse perinatal outcome was analyzed. The association was also compared between chart-based thresholds and absolute thresholds. Composite adverse perinatal outcome comprised both abnormal condition at birth and major neonatal morbidity.

RESULTS

Ten studies presenting reference charts for CPR or UCR were retrieved. There were large differences between the charts in the 10^th and 90^th percentile values of CPR and UCR, respectively, while median values were more similar. In the gestational-age range of 28-36 weeks, there was no relationship between UCR or CPR and gestational age. From the prospective observational study, 856 pregnancies at risk of late-onset preterm fetal growth restriction were included in the analysis. The association of abnormal UCR or CPR with composite adverse perinatal outcome was similar for percentile thresholds or MoM values, as calculated from the charts, and for absolute thresholds, both on univariable analysis and after adjustment for gestational age at measurement, estimated fetal weight MoM and pre-eclampsia. The adjusted odds ratio for composite adverse perinatal outcome was 3.3 (95% CI, 1.7-6.4) for an absolute UCR threshold of ≥ 0.9 or an absolute CPR threshold of < 1.11 (corresponding to ≥ 1.75 MoM), and 1.6 (95% CI, 0.9-2.9) for an absolute UCR threshold of ≥ 0.7 to < 0.9 or an absolute CPR threshold of ≥ 1.11 to < 1.43 (corresponding to ≥ 1.25 to < 1.75 MoM).

CONCLUSIONS

In the gestational-age range of 32 to 36 weeks, adjustment of CPR or UCR for gestational age is not necessary when assessing the risk of adverse outcome in pregnancies at risk of fetal growth restriction. The adoption of absolute CPR or UCR thresholds, independent of reference charts, is feasible and makes clinical assessment simpler than if using percentiles or other gestational-age normalized units. The high variability in percentile threshold values among the commonly used UCR and CPR reference charts hinders reliable diagnosis and clinical management of late preterm fetal growth restriction. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.