Doppler assessment of the fetus with intrauterine growth restriction

Comparing outcomes of fetal growth restriction defined by estimated fetal weight versus isolated abdominal circumference

PURPOSE

The objective of this study was to compare maternal and neonatal outcomes when the diagnosis of FGR was based on isolated abdominal circumference < 10th percentile for gestational age (GA) (iAC group) versus overall estimated fetal weight < 10th percentile (EFW group).

METHODS

This was a retrospective cohort study of singleton gestations who underwent growth ultrasounds and delivered at a single health system from 1/1/19-9/4/20. The study group was comprised of patients with AC < 10th percentile and EFW ≥ than the 10th percentile (iAC group). The control group included patients with overall EFW < 10th percentile (EFW group). Outcomes evaluated included GA at delivery, mode of delivery, fetal and neonatal outcomes. Data was analyzed using Mann Whitney U, X2, and Fisher exact tests with significance defined as p < 0.05.

RESULTS

635 women met the inclusion criteria, 259 women in the iAC group and 376 women in the EFW group. The iAC group was noted to have a later GA at diagnosis and delivery. iAC was associated with lower rates of preterm birth (PTB), NICU admission, SGA at delivery and umbilical artery cord gas < 7.0.

CONCLUSION

Using iAC as a definition of FGR increased the number of FGR cases by 1.69-fold over EFW criteria alone. However, obstetrical and neonatal outcomes for the iAC group appear to be significantly better than those in the EFW group, with low rates of PTB, NICU admission, and umbilical artery cord gas < 7.0.

Cardiac structural and functional remodeling in the fetuses associated with maternal hypothyroidism during pregnancy

OBJECTIVES

We sought to investigate the effect of maternal hypothyroidism during pregnancy on fetal cardiac structural and functional remodeling using fetal echocardiography.

METHODS

A total of 59 pregnant women with history of hypothyroidism were prospectively enrolled as the study group, and 74 normal fetuses as the control group. Fetal echocardiography was performed on each subject. Demographic, clinical, and fetal echocardiographic variables were measured, including left ventricular (LV) and right ventricular (RV) free wall and ventricular septal thickness, fractional shortening (FS), stroke volume (SV), cardiac output (CO), combined cardiac output (CCO), cardiac index (CI), combined cardiac index (CCI), aortic and pulmonary artery velocity, ductus venosus (DV) and pulmonary vein (PV) spectral Doppler, and Tei index.

RESULTS

The incidence of echogenic intracardiac foci (EIF) was higher in the study group than that in the control group (18.6% vs. 6.8%, p = .036). The thickness of LV free wall and interventricular septum was reduced, the pulmonary velocities and CCI, RV FS, CO, and CI were lower, the S, D, S/A, and pulsatility index (PI) of DV were higher, and LV Tei index was higher in the study group compared with the control group. There was no significant difference in other variables between the two groups.

CONCLUSIONS

There is cardiac remodeling, and systolic, diastolic functional alterations in fetuses with maternal hypothyroidism. Further investigation is warranted to develop strategies to optimize the outcome of these fetuses.

Evaluation of the Caval aortic index in fetal growth restriction: A case-control study in a tertiary center

OBJECTIVE

To examine the inferior vena cava (IVC) diameter, aortic diameter, and caval aortic index in fetuses with growth restriction and to compare the findings with fetuses from uncomplicated pregnancies at similar gestational weeks.

METHODS

This prospective study was conducted with a total of 176 pregnant women. According to the diagnostic criteria, 84 pregnancies diagnosed with fetal growth restriction (FGR) were compared with a control group of 92 uncomplicated pregnancies at similar gestational weeks.

RESULTS

The aortic and IVC diameter values were significantly lower in the FGR group (P < 0.001), whereas the caval aortic index was similar between the two groups. The examination of the ultrasound parameters of the cases with FGR according to the neonatal intensive care requirement revealed similar aortic diameter and caval aortic index values but a significantly smaller IVC diameter in the cases requiring neonatal intensive care (P = 0.022).

CONCLUSION

We determined that the aortic and IVC diameter values were smaller in the fetuses with growth restriction, but the caval aortic index was similar in the two groups. The measurement of the IVC diameter in FGR may be useful in predicting the neonatal intensive care requirements of these fetuses.

Sonographic evaluation of maternal uterine artery from 11 - 30 weeks 6 days of gestational age in a Nigerian population: A predictive index for pre-eclampsia and intrauterine growth restriction

INTRODUCTION

Uterine artery (UtA) Doppler sonography is a potential screening tool for pregnancy complications in placental insufficiency. Evaluation of the maternal and fetal vessels in pregnancy ensures accurate identification and prediction of pregnancy complications, such as preeclampsia (PE) and intrauterine growth restrictions (IUGR). The study aims to establish local reference values for UtA in a Nigerian population.

METHODS

This prospective longitudinal study was conducted among 230 pregnant women. All participants had their left (Lt) and right (RT) UtAs evaluated with a Doppler ultrasound from 11 to 30 weeks 6 days of gestational age. Peak systolic velocity (PSV), End diastolic Velocity (EDV), Systolic/Diastolic ratio (S/D), Pulsatility Index (PI), and Resistivity Index (RI) were measured and documented.

RESULTS

The mean values of UtA at 11-30 weeks 6 days of GA ranged as follows: 0.79-0.53 (RI), 1.83-0.79 (PI), 5.16-2.23 (S/D), 96.37-98.00 (PSV) & 26.07-44.14 (EDV). While the mean values of the Rt. & Lt. UtA 's ranged as follows: 0.79-0.50 (RI. Rt), 0.78-0.56 (RI. Lt), 2.05-0.80 (PI. Rt), 1.61-0.78 (PI. Lt), 6.03-2.13 (S/D. Rt), 4.29-2.33 (S/D. Lt), 89.79-99.23 (PSV. Rt), 102.76-96.71 (PSV. Lt) & 23.31-45.25 (EDV. Rt), 28.83-43.02 (EDV. Lt) respectively.

CONCLUSION

UtA Doppler reference range was established in the study population. These reference ranges will be of clinical value in daily obstetric practice.

IMPLICATION FOR PRACTICE

Obstetricians and sonographers will apply these values for early prediction of pregnancies at risk of complications in the locality.

Persistent Reverse End Diastolic Flow in Fetal Middle Cerebral Artery: A Rare Finding with Poor Outcomes

Doppler findings of persistent reverse end-diastolic flow (PREDF) in a fetal middle cerebral artery (MCA) are a very rare sonographic finding and are a marker of poor fetal condition. This finding often leads to intrauterine fetal death or early neonatal death. Reverse end-diastolic flow in the middle cerebral artery is an advanced hemodynamic event. Fetal cerebral circulation normally has a high impedance; in the event of fetal hypoxemia, impedance decreases, resulting in the central redistribution of blood flow to vital organs, which maintains the oxygen delivery to the brain. Reverse flow in the middle cerebral arteries describes the loss of this autoregulatory process. PREDF is a sequence that occurs due to increased extracranial or intracranial pressure. Previous case reports mentioned intracranial hemorrhage, fetal growth restriction, fetal anemia, and fetal hepatic abnormalities as problems leading to PREDF. This condition presumably arises due to cerebral edema associated with severe hypoxemia. We reported Doppler findings of PREDF MCA in a 33-year-old female patient at 30 weeks gestation who was referred to the hospital with severe preeclampsia accompanied by fetal growth restriction and oligohydramnios. A cesarean section was performed due to severe preeclampsia and a low bishop score. Hypotheses on various etiologies and their association with intrauterine/neonatal death as well as the best management still require further investigation.

Processing Ultrasound Scans of the Inferior Vena Cava: Techniques and Applications

The inferior vena cava (IVC) is the largest vein in the body. It returns deoxygenated blood to the heart from the tissues placed under the diaphragm. The size and dynamics of the IVC depend on the blood volume and right atrial pressure, which are important indicators of a patient's hydration and reflect possible pathological conditions. Ultrasound (US) assessment of the IVC is a promising technique for evaluating these conditions, because it is fast, non-invasive, inexpensive, and without side effects. However, the standard M-mode approach for measuring IVC diameter is prone to errors due to the vein movements during respiration. B-mode US produces two-dimensional images that better capture the IVC shape and size. In this review, we discuss the pros and cons of current IVC segmentation techniques for B-mode longitudinal and transverse views. We also explored several scenarios where automated IVC segmentation could improve medical diagnosis and prognosis.

Appropriate Delivery Timing in Fetuses with Fetal Growth Restriction to Reduce Neonatal Complications: A Case-Control Study in Romania

(1) Background: The main challenge in cases of early onset fetal growth restriction is management (i.e., timing of delivery), trying to determine the optimal balance between the opposing risks of stillbirth and prematurity. The aim of this study is to determine the likelihood of neonatal complications depending on the time of birth based on Doppler parameters in fetuses with early onset fetal growth restriction; (2) Methods: A case-control study of 205 consecutive pregnant women diagnosed with early onset FGR was conducted at the Obstetrics Clinic of the Municipal Emergency Hospital in Timisoara, Romania; The case group included newborns who were delivered at the onset of umbilical arteries absent/reversed end-diastolic flow, and the control included infants delivered at the onset of reversed/absent ductus venosus A-wave. (3) Results: The overall neonatal mortality rate was 2.0%, and there was no significant statistical difference between the two study groups. In infants delivered up to 30 gestational weeks, grades III/IV intraventricular hemorrhage and bronchopulmonary dysplasia were statistically significantly more frequent in the control group. Moreover, univariate binomial logistic regression analysis on fetuses born under 30 gestational weeks shows that those included in the control group are 30 times more likely to develop bronchopulmonary dysplasia and 14 times more likely to develop intraventricular hemorrhage grades III/IV; (4) Conclusions: Infants delivered according to the occurrence of umbilical arteries absent/reversed end-diastolic flow are less likely to develop intraventricular hemorrhage grades III/IV and bronchopulmonary dysplasia.

Fetal adrenal gland size and umbilical artery Doppler in growth-restricted fetuses

OBJECTIVES

In fetal growth restriction (FGR), Doppler ultrasound is the most important method for the detection and management. However, additional parameters are needed to improve the distinction between constitutionally small fetuses and fetuses affected by FGR.

METHODS

A total of 445 singleton pregnancies between 23 and 40 weeks of gestation were included in our retrospective study, of which 67 with FGR and 378 normal fetuses. A 2D-plane of the fetal adrenal gland was obtained and the adrenal gland ratio was measured. Spearman's correlation coefficient was calculated to assess the association of fetal Doppler and adrenal gland ratio with outcome parameters. Logistic regression analysis was performed to assess the statistical significance of "PI of the umbilical artery" and "adrenal gland ratio" as prognostic factors for intrauterine growth restriction (IUGR).

RESULTS

PI of the umbilical artery was shown to correlate with outcome parameters (WG_Delivery: r=-0.125, p=0.008; birth weight: r=-0.268, p<0.001; birth weight centile: r=-0.248, p<0.001; APGAR at 5 min: r=-0.117, p=0.014). Adrenal gland ratio showed no correlation with any of the outcome parameters. In logistic regression however, both PI of the umbilical artery and the adrenal ratio were shown to be significantly associated with fetal IUGR. When combining the two parameters, predictive value was superior to the predictive value of each individual parameter (AUC 0.738 [95% CI 0.670; 0.806]).

CONCLUSIONS

The adrenal gland ratio can be a useful addition to Doppler ultrasound when it comes to the detection of fetal FGR. Prospective studies are needed to establish references ranges and cut-off values for clinical decision-making.

Clinical significance of intermittent absent end-diastolic flow of the umbilical artery in fetal growth restriction

BACKGROUND

Fetal growth restriction can result from a variety of maternal, fetal, and placental conditions. Umbilical artery Doppler assesses the impedance to blood flow along the fetal component of the placental unit. An abnormal umbilical artery waveform reflects the presence of placental insufficiency and can help differentiate a growth-restricted fetus from the constitutionally small, thus guiding further management. The presence of persistently absent end-diastolic flow and reversed end-diastolic flow is an indication for inpatient antenatal surveillance and preterm delivery. There is no consensus on the optimal management of intermittent absent end-diastolic flow owing to a lack of data to support the ideal delivery timing for growth-restricted fetuses with this finding.

OBJECTIVE

This study aimed to estimate the risks of adverse perinatal outcomes among growth-restricted pregnancies with persistently elevated, intermittently absent, and persistently absent end-diastolic flow. Fetal growth restriction is a common condition that is associated with an increased risk of fetal morbidity and mortality. Intermittently absent umbilical artery end-diastolic flow may be identified among pregnancies with fetal growth restriction. The fetal risks associated with persistently absent end-diastolic flow have been described. However, the risks associated with intermittent absent end-diastolic flow are not as well-known.

STUDY DESIGN

We performed a retrospective cohort study including nonanomalous, singleton, growth-restricted pregnancies that received umbilical artery Doppler assessment at our institution from 2009 to 2020. Fetuses were classified into the following 3 categories: elevated umbilical artery Doppler, intermittent absent end-diastolic flow, and persistently absent end-diastolic flow. The Doppler categories were classified by the most severe in the pregnancy. The primary outcome was a composite of neonatal morbidity.

RESULTS

Total 233 fetuses met the criteria. Of which 78 (33.0%) had elevated umbilical artery Doppler waveforms, 37 (16.0%) had intermittent absent end-diastolic flow, and 119 (51.0%) had absent end-diastolic flow. The composite outcome was statistically different between the groups, occurring in 16.9% with elevated umbilical artery Doppler waveforms (13/77), 35.1% (12/39) with intermittent absent end-diastolic flow, and 56.3% (65/127) with absent end-diastolic flow (P<.001). The odds ratio for the composite outcome was significantly increased in absent end-diastolic flow (odds ratio, 6.15; 95% confidence interval, 3.14-12.80) and was not significantly increased for intermittently absent end-diastolic flow (odds ratio, 2.46; 95% confidence interval, 0.98-6.19) when compared with elevated umbilical artery Doppler waveforms. When adjusted for gestational age at delivery and antenatal steroids, no difference was seen in the primary outcome for intermittent absent end-diastolic flow (adjusted odds ratio, 0.73; 95% confidence interval, 0.20-2.68) and absent end-diastolic flow (adjusted odds ratio, 1.44; 95% confidence interval, 0.51-4.07).

CONCLUSION

Among growth-restricted pregnancies, intermittent absent end-diastolic flow is associated with a similar rate of composite neonatal morbidity as persistently elevated Doppler waveforms. In addition, there is no difference in composite neonatal morbidity between the 3 groups when corrected for gestational age at delivery and antenatal steroid administration. These similar outcomes should be considered when creating an antenatal surveillance plan and discussing the potential for outpatient management.

Invasive or More Direct Measurements Can Provide an Objective Early-Stopping Ceiling for Training Deep Neural Networks on Non-invasive or Less-Direct Biomedical Data

Early stopping is an extremely common tool to minimize overfitting, which would otherwise be a cause of poor generalization of the model to novel data. However, early stopping is a heuristic that, while effective, primarily relies on ad hoc parameters and metrics. Optimizing when to stop remains a challenge. In this paper, we suggest that for some biomedical applications, a natural dichotomy of invasive/non-invasive measurements, or more generally proximal vs distal measurements of a biological system can be exploited to provide objective advice on early stopping. We discuss the conditions where invasive measurements of a biological process should provide better predictions than non-invasive measurements, or at best offer parity. Hence, if data from an invasive measurement are available locally, or from the literature, that information can be leveraged to know with high certainty whether a model of non-invasive data is overfitted. We present paired invasive/non-invasive cardiac and coronary artery measurements from two mouse strains, one of which spontaneously develops type 2 diabetes, posed as a classification problem. Examination of the various stopping rules shows that generalization is reduced with more training epochs and commonly applied stopping rules give widely different generalization error estimates. The use of an empirically derived training ceiling is demonstrated to be helpful as added information to leverage early stopping in order to reduce overfitting.

Perinatal outcomes of two consecutive strategies for the management of fetal growth restriction: a before-after study

PURPOSE

We aim to compare the perinatal outcomes of two consecutive management strategies for fetal growth restriction (FGR), with or without the inclusion of additional Doppler parameters.

METHODS

A quasi-experimental before/after study was conducted in which we compared a composite perinatal outcome, prematurity rate, and neonatal complications between two management strategies in small fetuses. In the strategy 1 (S1), the management was based on fetal biometry and umbilical artery Doppler. The second strategy (S2) added the assessment of uterine and middle cerebral artery Doppler. We also compared outcomes between strategies according to early (≤ 32 weeks) and late (> 32 weeks) diagnosis subgroups.

RESULTS

We included 396 patients, 163 in S1 and 233 in S2. There were no significant differences in the perinatal composite outcome (p 0.98), prematurity (p 0.19), or in the subgroup analysis. We found a significant reduction in respiratory distress syndrome (RDS) rate with S2 both globally (OR 0.50, p 0.02), and in the early diagnosis subgroup (OR 0.45, p 0.01). In addition, we observed a significant reduction in the incidence of sepsis with S2 both globally (OR 0.30, p 0.04) and in the early diagnosis subgroup (OR 0.25, p 0.02). We did not observe significant differences in necrotizing enterocolitis (p 0.41) and intraventricular hemorrhage (p 1.00).

CONCLUSION

The expanded strategy for the management of FGR did not show significant differences in the primary composite outcome or prematurity. However, it was associated with a lower incidence of RDS and neonatal sepsis.

Hyperactivation of Wnt/β-catenin and Jak/Stat3 pathways in human and zebrafish foetal growth restriction models: Implications for pharmacological rescue

Foetal Growth Restriction (FGR), previously known as Intrauterine Growth Restriction (IUGR), is an obstetrical condition due to placental insufficiency, affecting yearly about 30 million newborns worldwide. In this work, we aimed to identify and pharmacologically target signalling pathways specifically involved in the FGR condition, focusing on FGR-related cardiovascular phenotypes. The transcriptional profile of human umbilical cords from FGR and control cases was compared with the response to hypoxia of zebrafish (Danio rerio) transgenic lines reporting in vivo the activity of twelve signalling pathways involved in embryonic development. Wnt/β-catenin and Jak/Stat3 were found as key pathways significantly dysregulated in both human and zebrafish samples. This information was used in a chemical-genetic analysis to test drugs targeting Wnt/β-catenin and Jak/Stat3 pathways to rescue a set of FGR phenotypes, including growth restriction and cardiovascular modifications. Treatments with the Wnt/β-catenin agonist SB216763 successfully rescued body dimensions, cardiac shape, and vessel organization in zebrafish FGR models. Our data support the Wnt/β-catenin pathway as a key FGR marker and a promising target for pharmacological intervention in the FGR condition.

Perinatal outcomes in twin late preterm pregnancies: results from an Italian area-based, prospective cohort study

BACKGROUND

Multiple gestations represent a considerable proportion of pregnancies delivering in the late preterm (LP) period. Only 30% of LP twins are due to spontaneous preterm labor and 70% are medically indicated; among this literature described that 16-50% of indicated LP twin deliveries are non-evidence based. As non-evidence-based delivery indications account for iatrogenic morbidity that could be prevented, the objective of our observational study is to investigate first neonatal outcomes of LP twin pregnancies according to gestational age at delivery, chorionicity and delivery indication, then non evidence-based delivery indications.

METHODS

Prospective cohort study among twins infants born between 34 + 0 and 36 + 6 weeks, in Emilia Romagna, Italy, during 2013-2015. The primary outcome was a composite of adverse perinatal outcomes.

RESULTS

Among 346 LP twins, 84 (23.4%) were monochorionic and 262 (75.7%) were dichorionic; spontaneous preterm labor accounted for 85 (24.6%) deliveries, preterm prelabor rupture of membranes for 66 (19.1%), evidence based indicated deliveries were 117 (33.8%), while non-evidence-based indications were 78 (22.5%). When compared to spontaneous preterm labor or preterm prelabor rupture of membranes, pregnancies delivered due to maternal and/or fetal indications were associated with higher maternal age (p <  0.01), higher gestational age at delivery (p <  0.01), Caucasian race (p 0.04), ART use (p <  0.01), gestational diabetes (p <  0.01), vaginal bleeding (p <  0.01), antenatal corticosteroids (p <  0.01), diagnosis of fetal growth restriction (FGR) (p <  0.01), and monochorionic (p <  0.01). Two hundred twenty-six pregnancies (65.3%) had at least one fetus experiencing one composite of adverse perinatal outcome. Multivariate analysis confirmed that delivery indication did not affect the composite of adverse perinatal outcomes; the only characteristic that affect the outcome after controlling for confounding was gestational age at delivery (p <  0.01). Moreover, there was at least one adverse neonatal outcome for 94% of babies born at 34 weeks, for 73% of those born at 35 weeks and for 46% of those born at 36 weeks (p <  0.01).

CONCLUSION

Our study suggests that the decision to deliver or not twins in LP period should consider gestational age at delivery as the main determinant infants' prognosis. Delivery indications should be accurately considered, to avoid iatrogenic early birth responsible of preventable complications.

Value of shear-wave elastography and cerebral-placental-uterine ratio in women diagnosed with preeclampsia and fetal growth restriction in prediction of adverse perinatal outcomes

PURPOSE

The aim of this study was to measure placental stiffness with shear-wave elastography technique and to evaluate the relationship with cerebral-placental-uterine ratio (CPUR) and adverse perinatal outcomes in patient groups diagnosed with preeclampsia (PE) and fetal growth restriction (FGR) in the second and third trimesters compared to the control group.

MATERIALS AND METHODS

This prospective cross-sectional study was conducted at our hospital between March 2019 and March 2020. The study groups were divided into three groups: PE, FGR, and low risk pregnancy (LRP) group. The study population had singleton pregnancies and the placental site was at the anterior wall. Both shear-wave elasticity (SWE) and shear-wave velocity (SWV) were measured in the placenta during pregnancy. CPUR was calculated for each group.

RESULTS

A total of 147 patients were included in this study. The mean SWE (kilopascals) values in the PE group were significantly higher than in the FGR and controls (difference of means = 3.67, 9.45; 95% CI (1.23-6.1, 7-11.8); p < .05), respectively. The mean SWV values were significantly higher in PE and FGR groups than controls (p < .05). CPUR showed correlation with central maternal surface of placenta (p: .02, r: -0.184), central fetal surface of placenta (p < .001, r: -0.288), peripheral maternal surface of placenta (p: .002, r: -0.252), and peripheral fetal surface of placenta SWE values (p: .03, r: -0.181). NICU admission was correlated with central fetal surface of placenta SWE values (p: .002, r: 0.258).

CONCLUSION

In conclusion, we demonstrated increased placental stiffness in both the PE and the FGR group. Also, this difference was found to be more prominent in preeclampsia. This technique seems useful for assessment of placental function and may strengthen the utility of Doppler parameters for predicting adverse perinatal outcomes in high-risk pregnancies.

Doppler Ultrasound of the Umbilical Artery: Clinical Application

OBJECTIVE

 To provide a survey of relevant literature on umbilical artery Doppler ultrasound use in clinical practice, technical considerations and limitations, and future perspectives.

METHODS

 Literature searches were conducted in PubMed and Medline, restricted to articles written in English. Additionally, the references of all analyzed studies were searched to obtain necessary information.

RESULTS

 The use of this technique as a routine surveillance method is only recommended for high-risk pregnancies with impaired placentation. Meta-analyses of randomized trials have established that obstetric management guided by umbilical artery Doppler findings can improve perinatal mortality and morbidity. The values of the indices of Umbilical artery Doppler decrease with advancing gestational age; however, a lack of consensus on reference ranges prevails.

CONCLUSION

 Important clinical decisions are based on the information obtained with umbilical artery Doppler ultrasound. Future efforts in research are imperative to overcome the current limitations of the technique.

Antenatal Doppler screening for fetuses at risk of adverse outcomes: a multicountry cohort study of the prevalence of abnormal resistance index in low-risk pregnant women

INTRODUCTION

Few interventions exist to address the high burden of stillbirths in apparently healthy pregnant women in low- and middle-income countries (LMICs). To establish whether a trial on the impact of routine Doppler screening in a low-risk obstetric population is warranted, we determined the prevalence of abnormal fetal umbilical artery resistance indices among low-risk pregnant women using a low-cost Doppler device in five LMICs.

METHODS

We conducted a multicentre, prospective cohort study in Ghana, India, Kenya, Rwanda and South Africa. Trained nurses or midwives performed a single, continuous-wave Doppler screening using the Umbiflow device for low-risk pregnant women (according to local guidelines) between 28 and 34 weeks' gestation. We assessed the prevalence of abnormal (raised) resistance index (RI), including absent end diastolic flow (AEDF), and compared pregnancy and health service utilisation outcomes between women with abnormal RI versus those with normal RI.

RESULTS

Of 7151 women screened, 495 (6.9%) had an abnormal RI, including 14 (0.2%) with AEDF. Caesarean section (40.8% vs 28.1%), labour induction (20.5% vs 9.0%) and low birth weight (<2500 g) (15.0% vs 6.8%) were significantly more frequent among women with abnormal RI compared with women with normal RI. Abnormal RI was associated with lower birth weights across all weight centiles. Stillbirth and perinatal mortality rates were similar between women with normal and abnormal RI.

CONCLUSION

A single Doppler screening of low-risk pregnant women in LMICs using the Umbiflow device can detect a large number of fetuses at risk of growth restriction and consequent adverse perinatal outcomes. Many perinatal deaths could potentially be averted with appropriate intervention strategies.

TRIAL REGISTRATION NUMBER

CTRI/2018/07/01486.

Analysis of the Correlation/Agreement of Maternal-fetal Doppler Parameters in Normal and Growth-Restricted Fetuses

OBJECTIVE

 To assess the degree of correlation/agreement of maternal-fetal Doppler parameters between normal and growth-restricted fetuses (fetal growth restriction [FGR]).

METHODS

 The present observational and retrospective study included 274 singleton pregnancies. The following maternal-fetal Doppler parameters were assessed: uterine artery (UAt), umbilical artery (UA), middle cerebral artery (MCA), cerebroplacental ratio (CPR), and umbilical-cerebral ratio (U/C). The assessment of FGR was based on the Figueiras and Gratacós9 criteria. Spearman correlation coefficients were estimated to assess the correlation between resistance (RI) and pulsatility (PI) indices of Doppler parameters. The agreement between two Doppler parameters was assessed by the Kappa coefficient.

RESULTS

 In total, 502 Doppler examinations were included, and FGR was observed in 19 out of 274 fetuses. A strong correlation was observed between RI and PI of UAt, UA, and MCA in all of the samples (p < 0.001). Of the 502 Doppler examinations, there was agreement between U/C and CPR percentiles for 480 (95.6%) and disagreement for 22 (4.4%), with Kappa coefficient of 0.26, thereby corresponding to weak agreement. Of the 68 cases with estimated fetal weight ≤ 9^th percentile (small for gestational age [SGA]), there was agreement between U/C > 1.0 and CPR < 5^th percentile in 61 (88.4%) and disagreement in 7 (5.8%) with Kappa coefficient of 0.49, thereby corresponding to moderate agreement.

CONCLUSION

 Strong correlation was observed among RI and PI UAt, UA, and MCA Doppler examinations in the present study; however, weak agreement was observed between U/C and CPR in the normal and FGR fetuses. In SGA, U/C and CPR demonstrated moderate agreement.

Reassurance from second trimester sonographic placental scan for pregnancies complicated by abnormal first trimester biomarkers

OBJECTIVE

Enhanced first trimester aneuploidy screening (eFTS) combines serum biomarkers and ultrasound. Abnormal biomarkers are associated with placental complications, such as fetal growth restriction (FGR). We aimed to evaluate whether a Midtrimester placental scan can provide reassurance regarding FGR in women with abnormal eFTS biomarkers.

METHODS

We conducted a retrospective cohort study of women who had eFTS and delivered at a single referral center. Women with abnormal biomarkers had a mid-trimester scan of the placenta (morphologic assessment, fetal biometry and uterine artery pulsatility index). We compared pregnancies with abnormal eFTS biomarkers and normal placental scans (study group) with those who had normal eFTS biomarkers (control group).

RESULTS

A total of 6,514 women were included, of whom 343 (5.3%) comprised the study group. Women in the study group had an increased risk of hypertensive disorders of pregnancy [(aOR)1.96(95%CI 1.21-3.16)], and preterm birth <37 weeks [aOR1.98(95%CI 1.33-2.95)] compared to the control group. Yet, their neonates were not at higher risk for FGR <3^rd, 5^th, or 10^th percentile [aOR1.16(95%CI 0.83-1.63), 1.14(95%CI 0.70-1.87), and 0.47(95%CI 0.17-1.27), respectively].

CONCLUSION

A normal second trimester placental scan provided reassurance regarding the risk of FGR in women at high risk based on abnormal eFTS biomarkers.

Delivery indication matters for perinatal outcomes in late preterm newborns

BACKGROUND

The late preterm (LP) rate in Western countries is 3-6% of all births, accounting for about two-thirds of the entire preterm population. However, all LP babies are not the same.

AIMS

To identify pregnancies at risk for adverse outcomes in the LP period, we investigated how gestational age (GA) at delivery, delivery indication and prenatal risk factors may affect neonatal outcomes.

STUDY DESIGN

Prospective cohort study among singleton infants born between 34 + 0 and 36 + 6 weeks, in Emilia Romagna, Italy, during 2013-2015.

OUTCOMES MEASURES

The primary outcome was a composite of adverse perinatal outcomes. Multivariate logistic regression models were used to, respectively, investigate the effects of GA at delivery, circumstances at parturition and prenatal risk factors, on study outcomes after controlling for confounding variable.

RESULTS

Among 1867 births, 302, 504, and 1061 infants were born at 34, 35, and 36 weeks, respectively. There were no neonatal deaths. An increased risk of composite neonatal outcome was observed among 34 and 35 weeks deliveries compared with 36 weeks, and among indicated deliveries compared with spontaneous. When studying prenatal risk factors, neonatal morbidity was associated with pre gestational diabetes, preterm premature rupture of membranes (pPROM), maternal obesity, bleeding and polyhydramnios; instead, preeclampsia had a protective effect.

CONCLUSION

LP with indicated deliveries at 34 or 35 weeks, or with specific prenatal risk factors have worse neonatal outcome when compared to 36. Such differences should be considered when counseling patients and planning interventions such as timing of delivery in LP period.

Comparative study of the umbilical artery Doppler indices of healthy and growth-restricted foetuses in Lagos

Aim of the Study:

This study compared the umbilical artery Doppler indices (UADI) in normal and foetal growth-restricted (FGR) foetuses to determine the relationship between the UADI and pregnancy outcomes.

Materials and Methods:

This was a case-control study that recruited one hundred and eighty pregnant women comprising 90 with FGR pregnancies and 90 with normal pregnancies. Foetal biometric parameters and UADI were measured in all the participants. The UADI and clinical outcomes (preterm delivery, birth weight, perinatal death, etc.) of the normal and FGR foetuses were compared.

Results:

The mean estimated foetal weights of the FGR pregnancies (subjects) and normal pregnancies (controls) were 2.76 ± 0.66 kg and 3.62 ± 0.37 kg, respectively (P < 0.0001). The mean APGAR score at 5 min was 6.93 ± 1.72 for subjects and 8.03 ± 0.94 for controls (P < 0.0001). Abnormal umbilical artery Doppler waveforms were detected: decreased end-diastolic flow in 25 (27.8%), absent end-diastolic in 7 (7.8%) and reversed end-diastolic flow in 4 (4.4%) of the FGR pregnancies. There were 74 (82.2%) preterm deliveries among the subjects, while only 7 (7.8%) of the controls had preterm deliveries. Six deaths (two perinatal and four neonatal deaths) were recorded among the subjects, while no death occurred among the controls.

Conclusion:

Foetuses with FGR showed significantly higher quantitative Doppler indices (increased RI, PI, SD ratio), and a higher prevalence of abnormal umbilical artery waveform pattern (qualitative) than the healthy foetuses (controls).

Factors Associated with Occurrence of Stillbirth before 32 Weeks of Gestation in a Contemporary Cohort

OBJECTIVE

We sought to quantify the distribution of stillbirths by gestational age (GA) in a contemporary cohort and to determine identifiable risk factors associated with stillbirth prior to 32 weeks of gestation.

STUDY DESIGN

Population-based case-control study of all stillbirths in the United States during the year 2014, utilizing vital statistics data, obtained from the National Center for Health Statistics. Distribution of stillbirths were stratified by 20 to 44 weeks of GA, in women diagnosed with stillbirth in the antepartum period. Pregnancy characteristics were compared between those diagnosed with stillbirth <32 versus ≥32 weeks of gestation. Multivariate logistic regression estimated the relative influence of various factors on the outcome of stillbirth prior to 32 weeks of gestation.

RESULTS

There were 15,998 nonlaboring women diagnosed with stillbirth during 2014 in the United States between 20 and 44 weeks. Of them, 60.1% (n = 9,618) occurred before antenatal fetal surveillance (ANFS) is typically initiated (<32 weeks) and 39.9% (n = 6,380) were diagnosed at ≥32 weeks. Women with stillbirth prior to 32 weeks were more likely to be of non-Hispanic Black race (29.0 vs. 23.9%, p < 0.001), nulliparous (53.8 vs. 50.6%, p = 0.001), have chronic hypertension (CHTN; 6.0 vs. 4.3%, p < 0.001), and fetal growth restriction as evidenced by small for GA (SGA < 10th%) birth weight (44.8 vs. 42.1%, p < 0.001) as opposed to women with stillbirth after 32 weeks. After adjustment, SGA birth weight (adjusted odds ratio [aOR] = 1.2, 95% confidence interval [CI]: 1.1-1.3), Black race (aOR = 1.2, 95% CI: 1.1-1.3), and CHTN (aOR = 1.3, 95% CI: 1.1-1.5) were associated with stillbirth prior to 32 weeks of gestation as opposed to stillbirth after 32 weeks.

CONCLUSION

More than 6 out of 10 stillbirths in this study occurred <32 weeks of gestation, before ANFS is typically initiated under American College of Obstetricians and Gynecologists recommendations. Among identifiable risk factors, CHTN, Black race, and fetal growth restriction were associated with higher risk of stillbirth before 32 weeks of gestation. Earlier ANFS may be warranted at in certain "at risk" women.

KEY POINTS

· Six out of 10 stillbirths occur before 32 weeks of gestation.. · We evaluated factors associated with stillbirth <32 weeks.. · Hypertension and fetal growth restriction were associated with early stillbirth..

Evaluation of the relationship between placental stiffness measured by shear wave elastography and perinatal outcomes in women with gestational diabetes mellitus

BACKGROUND

Recently, studies on placental elastography in high-risk pregnancies continue to increase. The shear wave technique can contribute to the management of gestational diabetes mellitus (GDM) and improve perinatal outcomes by measuring placental stiffness.Purpose: To evaluate the relationship between placental stiffness measured by shear wave elastography (SWE) and perinatal outcomes in women with GDM.Material and Methods: This prospective cross-sectional study was conducted at our hospital between March and October 2020. The participants were divided into three groups: GDM-A1 group (regulated by dietary modifications); GDM-A2 group (needed pharmacologic treatment); and low-risk pregnancy (LRP) group. Both SWE and shear wave velocity (SWV) were measured in the placenta during pregnancy.

RESULTS

In total, 111 women were included in the study. The mean SWE (kPa) values for the GDM-A1, GDM-A2, and LRP groups were 10.4 (range 3.1-23.3), 13 (range 4.3-29.6), and 8.3 (range 3.2-15.1), respectively. The mean HbA1c and fasting glucose values of diabetes groups showed strongly positive correlation with mean SWE and SWV values (P < 0.001, r=0.875; P < 0.001, r=0.856; P < 0.001, r=0.791; P < 0.001, r=0.740), respectively. The SWE values of central maternal and fetal surfaces of the placenta (P=0.01, r=0.242; P < 0.001, r=0.333) showed a moderately positive correlation with admission to the neonatal intensive care unit.

CONCLUSION

Placental stiffness has increased in the GDM-A2 group when compared to the GDM-A1 and LRP groups. We also observed a strong positive correlation between HbA1c, fasting glucose values, and increased elasticity values in diabetic patients with metabolic dysregulation that may have clinical value.

Predicting Adverse Outcomes in Monochorionic-Diamniotic Twins: The Role of Intertwin Discrepancy in Middle Cerebral Artery Doppler Measurements and the Cerebroplacental Ratio

OBJECTIVE

This study was aimed to evaluate the role of intertwin discrepancy in middle cerebral artery peak systolic velocity (MCA-PSV) and cerebroplacental ratio (CPR) for the prediction of adverse outcomes in monochorionic-diamniotic (MCDA) twin pregnancies.

STUDY DESIGN

A retrospective cohort study of MCDA pregnancies that underwent ultrasound surveillance at a perinatal referral center from 2007 to 2017. Intertwin MCA-PSV discrepancy (MCA-Δ_PSV-MoM) was defined as the absolute difference of MCA-PSV multiple of the median (MoM) for gestational age between twins. Intertwin CPR discrepancy (CPR-Δ) was defined as the absolute difference of CPR between twins. The maximum MCA-Δ_PSV-MoM and CPR-Δ before and after 26 weeks of gestation were assessed as predictors of pregnancy and neonatal outcomes through simple logistic regression models and Pearson's correlation coefficients. Receiver operating characteristic (ROC) curves were generated to determine the predictive value of maximum MCA-Δ_PSV-MoM and CPR-Δ.

RESULTS

A total of 143 MCDA pregnancies met inclusion criteria. There was a significant association between MCA-Δ_PSV-MoM at <26 weeks and the development of twin anemia-polycythemia sequence (TAPS; p = 0.007), intrauterine fetal demise (IUFD; p = 0.009), and neonatal intensive care unit (NICU) admission (p < 0.05). MCA-Δ_PSV-MoM at ≥26 weeks was associated with the development of TAPS (p < 0.001). CPR-Δ at <26 weeks was associated with the development of twin-twin transfusion syndrome (TTTS; p = 0.03) and NICU admission (p = 0.02). MCA-Δ_PSV-MoM at ≥26 weeks was highly predictive of TAPS (area under curve [AUC] = 0.92). A cut-off of 0.44 would identify TAPS with 100% sensitivity and 73% specificity.

CONCLUSION

In MCDA pregnancies, intertwin MCA and CPR discrepancies are associated with adverse pregnancy and neonatal outcomes, including TAPS, TTTS, IUFD, and NICU admission. Evaluation of intertwin MCA and CPR differences demonstrated the potential for clinical predictive utility in the surveillance of MCDA twin pregnancies.

KEY POINTS

· Intertwin discrepancy of MCA-PSV and CPR is associated with adverse pregnancy outcomes.. · Intertwin differences in Doppler ultrasound may occur prior to meeting diagnostic criteria for TTTS or TAPS.. · There is potential clinical predictive utility in MCA and CPR surveillance of MCDA twin pregnancies..

Links Between Maternal Cardiovascular Disease and the Health of Offspring

Maternal cardiovascular disease (CVD) during pregnancy is on the rise worldwide, as both more women with congenital heart disease are reaching childbearing age, and conditions such as diabetes, hypertension, and obesity are becoming more prevalent. However, the extent to which maternal CVD influences offspring health, as a neonate and later in childhood and adolescence, remains to be fully understood. The thrifty phenotype hypothesis, by which a fetus adapts to maternal and placental changes to survive a nutrient-starved environment, may provide an answer to the mechanism of maternal CVD and its impact on the offspring. In this narrative review, we aim to provide a review of the literature pertaining to the impact of maternal cardiovascular and hypertensive disease on the health of neonates, children, and adolescents. This review demonstrates that maternal CVD leads to higher rates of complications among neonates. Ultimately, our review supports the hypothesis that maternal CVD leads to intrauterine growth restriction (IUGR), which, through the thrifty phenotype hypothesis and vascular remodelling, can have health repercussions, including an impact on CVD risk, both in the immediate newborn period as well as later throughout the life of the offspring. Further research remains crucial in elucidating the mechanism of maternal CVD long-term effects on offspring, as further understanding could lead to preventive measures to optimise offspring health, including modifiable lifestyle changes. Potential treatments for this at-risk offspring group could mitigate risk, but further studies to provide evidence are needed.

Growth Velocity and Doppler Evaluation to Predict Nonreassuring Fetal Heart Rate at Birth in Low-Risk Women: A Prospective, Longitudinal Study

INTRODUCTION

This study investigated whether fetal growth deceleration in term, appropriate-for-gestational-age (AGA) fetuses is associated with placental insufficiency and nonreassuring fetal heart rate (NRFHR) at birth.

METHODS

In this prospective study, 246 low-risk, singleton pregnancies at term with AGA fetuses were recruited. Correlation between decreased growth velocity (decline in estimated fetal weight [EFW] percentile), low EFW (EFWQ1 = latest EFW between 11 and 25% percentiles), umbilical artery (UA) pulsatility index (PI), middle cerebral artery (MCA) PI, and cerebro-placental ratio (CPR) with cesarean and instrumental deliveries due to NRFHR were tested.

RESULTS

The median change between fetal weight estimates (percentiles/week) was +0.49% (95% CI: -4 to +5%). Ten percent had decreased EFW percentile >3.5%/week. Fetal growth velocity/week was associated with MCA (r = 0.21, p < 0.001) and CPR (r = 0.24, p < 0.001) and inversely correlated with UA PI (r = -0.28, p < 0.001). NRFHR and cesarean section (CS) rates due to NRFHR were associated with decreased growth velocity, EFWQ1, and low CPR. The combination of abnormal CPR with decreased growth velocity occurred in 12 pregnancies, of which 5 (42%) had urgent CS due to NRFHR. The combination of abnormal CPR with EFWQ1 occurred in 9 pregnancies, of which 4 (44%) had urgent CS due to NRFHR. These combinations increased the likelihood ratio of CS due to NRFHR two-fold (8.41; 2.54-24.5) but did not significantly alter the number needed to treat by elective CS (3.78-4.68).

CONCLUSION

Fetal growth velocity, EFW between 10 and 25th percentiles (EFWQ1), and abnormal CPR improves prediction of unplanned CS due to NRFHR among term AGA fetuses. This should be considered when counseling about the delivery method.

The accuracy of prenatal diagnosis of selective fetal growth restriction with second trimester Doppler ultrasound in monochorionic diamniotic twin pregnancies

Background

Selective fetal restriction growth (sFGR) is one of the common diseases of monochorionic diamniotic (MCDA) twin pregnancies, resulting in many adverse outcomes. At present, second trimester ultrasonography is widely used in the prenatal diagnosis of sFGR, but the diagnostic effectiveness is still uncertain. The aim of this study is to assess the diagnostic accuracy of second trimester Doppler ultrasound measurements for sFGR.

Methods

A retrospective study included 280 pregnant women (118 with and 162 without sFGR) with MCDA pregnancies was conducted in the fetal medicine center from Leiden University Medical Center from January 2008 to December 2013. The women participating had already undergone an ultrasound examination in the second trimester. The postnatal criteria of sFGR was a single birth weight (BW) < 3 rd percentile in a twin, or birth weight discordance (BWD)≥25% between two twins, while the BW of the smaller twin < 10th percentile. Early prenatal diagnosis of sFGR was defined as a single EFW < 3 rd percentile in a twin, or at least 2 of the following 4 parameters must be met (fetal weight of one fetus < 10th percentile, AC of one fetus <10th percentile, EFW discordance≥25%, UA pulsatility index (PI) of the smaller fetus > 95th percentile). According to the diagnosis of sFGR after birth, we evaluate diagnostic effectiveness of Doppler ultrasound in the second trimester for sFGR.

Results

Of these 280 participants, the mean age was 32.06 ± 4.76 years. About 43.9% of pregnant women were primiparas. The ability of second trimester Doppler ultrasound to accurately diagnosed sFGR is 75.4%, missed diagnosis rate and the misdiagnosis rate were 24.6% and 10.5% respectively. The ROC curve indicated that the combination of AC discordance, EFW discordance, and small fetal UA blood flow was the best diagnostic indicator of sFGR in MCDA pregnancy with the AUC was 0.882 (95%CI, 0.839–0.926).

Conclusions

Second trimester Doppler and ultrasound measurements is an effective method for early prenatal diagnosis of sFGR. The combined indicator of AC discordance, EFW discordance, and the small fetal UA blood flow reaches highest diagnostic value.

Cardiac function in fetal growth restriction

Fetal growth restriction (FGR) is defined as the inability of the fetus to reach its growth potential. According to the onset of the disease is defined early (<32 weeks) or late (≥32 weeks). FGR is associated with an increased risk of adverse short- and long-term outcomes, including hypoxemic events and neurodevelopmental delay compared to normally grown fetuses and increased risk of complications in the infanthood and adulthood. The underlying cause of FGR is placental insufficiency leading to chronic fetal hypoxia that affects cardiac hemodynamic with different mechanism in early and late onset growth restriction. In early onset FGR adaptive mechanisms involve the diversion of the cardiac output preferentially in favor of the brain and the heart, while abnormal arterial and venous flow manifest in the case of further worsening of fetal hypoxia. In late FGR the fetal heart shows a remodeling of its shape and function mainly related to a reduction of umbilical vein flow. In this review we discuss the modifications occurring at the level of the fetal cardiac hemodynamic in fetuses with early and late FGR.

Assessment of fetal Doppler parameters in pregnant women with COVID-19 infection: a prospective case-control study

OBJECTIVES

To investigate the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on fetal Doppler parameters.

METHODS

This was a prospective case-control study conducted in Ankara City Hospital with confirmed SARS-CoV-2 infected pregnants between August 1, 2020 and October 1, 2020. There were 54 COVID-19 confirmed pregnant women and 97 age-matched pregnant women as a control group between 28 and 39 weeks. Infection was confirmed based on positive real-time polymerase-chain reaction results. Demographic features, uterine artery (right, left), umblical artery, middle cerebral artery, ductus venosus, cerebro-placental ratio, and cerebral-placental-uterine ratio Doppler parameters were investigated in both groups.

RESULTS

Two groups were similar in terms of demographic features and no difference was found for fetal Doppler parameters.

CONCLUSIONS

COVID-19 seems to have no adverse effect on fetoplacental circulation in mild and moderate patients during the acute phase of the infection.

Antepartum Fetal Surveillance: ACOG Practice Bulletin, Number 229

The goal of antepartum fetal surveillance is to reduce the risk of stillbirth. Antepartum fetal surveillance techniques based on assessment of fetal heart rate (FHR) patterns have been in clinical use for almost four decades and are used along with real-time ultrasonography and umbilical artery Doppler velocimetry to evaluate fetal well-being. Antepartum fetal surveillance techniques are routinely used to assess the risk of fetal death in pregnancies complicated by preexisting maternal conditions (eg, diabetes mellitus) as well as those in which complications have developed (eg, fetal growth restriction). The purpose of this document is to provide a review of the current indications for and techniques of antepartum fetal surveillance and outline management guidelines for antepartum fetal surveillance that are consistent with the best scientific evidence.

Trial of Labor After Cesarean of Small for Gestational Age Neonates Among Women with No Prior Vaginal Delivery - a Retrospective Study

To evaluate the characteristics and outcomes of women who had never delivered vaginally and underwent a trial of labor after cesarean (TOLAC) of small for gestational age (SGA) neonates, and to identify risk factors for unplanned repeat cesarean delivery. A retrospective cohort study from two tertiary medical centers. All women undergoing a TOLAC with no prior vaginal delivery, delivering a singleton SGA neonate at term between 2005 and 2020 were included. Factors associated with successful vaginal delivery were examined by a multivariable analysis. Of the 255 women who met the inclusion criteria and underwent TOLAC, 72.2% delivered vaginally. In a multivariable analysis, maternal height [adjusted odds ratio (aOR) (95% CI): 1.10 (1.02-1.19), p = 0.012] and epidural administration [aOR (95% CI): 2.78 (1.0-7.73), p = 0.050] were positively independently associated with TOLAC success, and hypertensive disorders were negatively independently associated with TOLAC success [aOR (95% CI): 0.52 (0.004-0.74), p = 0.029]. The success rate of TOLAC among women with no prior vaginal delivery, delivering a SGA neonate is relatively high. Maternal height, hypertensive disorders, and epidural administration are independent factors associated with TOLAC success. Epidural administration is a modifiable factor and should be taken in consideration during TOLAC management.

Sonographic Diagnosis of Velamentous and Marginal Placental Cord Insertion

Routine second trimester ultrasound (US) examinations include an assessment of the umbilical cord given its vital role as a vascular conduit between the maternal placenta and fetus during fetal development. Placental cord insertion abnormalities can be identified during prenatal US screening and are increasingly recognized as independent risk factors for various complications during pregnancy and delivery. The purpose of this pictorial review is to illustrate examples of velamentous and marginal placental cord insertion with an emphasis on how to differentiate their morphology using color Doppler US.

Clinical monitoring of late fetal growth restriction

Late fetal growth restriction (FGR) poses its own challenges in respect of diagnosis, surveillance and delivery timing. Perinatal morbidity is relatively rare, and mortality extremely unusual, but given that late FGR is much more frequent than early FGR, the burden on neonatal services must not be underestimated. Doppler findings are more subtle than in early FGR, and growth rate rather than absolute fetal size may be important in defining the condition. Though umbilical artery Doppler changes form the basis for triggering delivery: reversed end diastolic flow at 32 weeks, absent at 34 weeks and raised PI at 36 weeks, other modalities of monitoring - for example cardiotocography and cerebral Doppler - are important in surveillance and timing follow up of the condition.

Towards Transabdominal Functional Photoacoustic Imaging of the Placenta: Improvement in Imaging Depth Through Optimization of Light Delivery

Functional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue's scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

Prevalence of umbilical artery Doppler waveform abnormality during the early second trimester and the subsequent variation of waveforms in monochorionic diamniotic twin pregnancies: A prospective cohort study

AIM

To investigate the prevalence of qualitative abnormal umbilical artery Doppler waveforms (Abnormal UA) during the early second trimester and the subsequent variation of waveforms in monochorionic diamniotic (MCDA) twin pregnancies.

METHODS

This prospective cohort study included 153 MCDA twin pregnancies. Pulsed Doppler examinations for UA were performed at four points, including the free-loop (FL) and near the placental cord insertion site (CI) of each UA, between 16 and 17 weeks' gestation. Cases were classified into positive diastolic waveforms (Type I), persistent Abnormal UA (Type II), and intermittent Abnormal UA (Type III). When the diastolic velocity in UA Doppler was positive twice after different sequential recordings, the cases were determined to have achieved normalization. Follow-up Doppler examinations of the UA were performed at 24, 28, and 32 weeks' gestation.

RESULTS

Of all 153 cases, 38 (25%; 19 Type II and 19 Type III cases) showed Abnormal UA at the first examination. Abnormal UA was detectable at FL in all selective intrauterine growth restriction (sIUGR) cases, whereas it was noted only at CI site in some non-sIUGR cases. Abnormal UA normalized in 12 (63%) Type II and 15 (79%) Type III cases.

CONCLUSIONS

A quarter of MCDA twin pregnancies in the early second trimester demonstrated Abnormal UA. In MCDA twins with Abnormal UA between 16 and 17 weeks' gestation, it is preferable to follow them up to consider the possibility of normalization of Abnormal UA as well as features of UA waveforms specific to FL and CI.

Outcome of early-onset fetal growth restriction with or without abnormal umbilical artery Doppler flow

Introduction

Early‐onset fetal growth restriction is a pregnancy complication often coinciding with abnormal Doppler flow in the umbilical artery. Absent or reversed end‐diastolic flow in the umbilical artery is associated with adverse perinatal outcome. As the optimal management of this condition is unclear, the objective of this study was to analyze the time interval from admission to delivery of pregnancies with early‐onset fetal growth restriction, while pursuing a policy of postponing delivery unless active management of labor would be required because of fetal distress or maternal condition. We also assessed short‐ and long‐term perinatal outcome.

Material and methods

In this historical cohort study, all pregnant women with singleton pregnancies, admitted during 2004–2015 with early‐onset fetal growth restriction were included. Pregnancies with absent or reversed end‐diastolic flow (AREDF) were compared with pregnancies with a positive end‐diastolic Doppler flow (PEDF). Time until delivery was determined and perinatal outcome was assessed for both groups.

Results

In our study, 111 women were allocated to the PEDF group and 109 to the AREDF group. In the AREDF group, fetal distress was more often an indication for delivery, in comparison with the PEDF group (p = .004). Median time until delivery in patients admitted between 26 and 28 weeks’ gestation was 6+5 weeks in the PEDF group and 1+4 weeks in the AREDF group (p = .001). No statistically significant difference was found between the Doppler groups in the composite adverse neonatal outcome, which includes at least one of the following outcomes: infant respiratory distress syndrome, sepsis, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage >grade 2, periventricular leukomalacia and perinatal death (p = .63).

Conclusions

In this study, comprising pregnancies with early‐onset fetal growth restriction, fetal distress was observed more frequently in the AREDF group with the consequence of delivery at an earlier stage of gestation, compared with the PEDF group. AREDF was not associated with increased perinatal morbidity and mortality compared with PEDF.

Perinatal outcomes after intrauterine growth restriction and umbilical artery Doppler pulsatility index of less than the fifth percentile

Objective: To analyze perinatal morbidity and stillbirth after intrauterine growth restriction (IUGR) with an umbilical artery Doppler pulsatility index (UA PI) less than the fifth centile.Study design: This retrospective cohort study included nonanomalous singleton, IUGR pregnancies receiving UA PI testing at a tertiary-care prenatal diagnostic center. Women with persistently elevated UA PI, absent or reversed end-diastolic flow on UA PI, or who had only one UA PI result were excluded. Low UA PI was defined as having ≥1 UA PI <5%. Women with low UA PI were matched by gestational age at IUGR diagnosis in a random 1 case: 4 control computer-generated algorithm to those with normal UA PI (≤95% and ≥5%). The primary outcome was composite neonatal morbidity and mortality (stillbirth, mechanical ventilation, sepsis, intraventricular hemorrhage, and necrotizing enterocolitis). Secondary outcomes included 5-minute Apgar, umbilical artery pH, delivery type, and interval from IUGR diagnosis to delivery. We compared outcomes after low UA PI to those after normal UA PI with multivariable logistic regression, adjusting for gestational age at delivery, betamethasone use, infant gender, and maternal factors.Results: Of the 1893 IUGR pregnancies, 25 (1.3%) had low UA PI <5% and were randomly matched via computer algorithm to 100 controls. There were no stillbirths in either group; the odds of composite neonatal morbidity was similar among IUGR pregnancies with UA PI <5% versus normal (adjusted odds ratio 0.89 (95% confidence interval 0.27-2.75)). There was no difference in 5-minute Apgars, umbilical artery pH, rate of cesarean delivery for fetal distress, or interval from IUGR diagnosis to delivery between the two groups.Conclusion: Among IUGR pregnancies, UA PI <5% is uncommon and not associated with improved neonatal outcomes compared to normal UA PI. These findings suggest low UA PI can continue to be managed as normal UA PI.

Doppler assessment of the fetus in pregnant women recovered from COVID-19

OBJECTIVE

The aim of this study was to evaluate the maternal-fetal Doppler patterns in pregnant women recovered from COVID-19.

METHODS

This prospective case-control study was conducted in Ankara City Hospital between July 1, 2020 and August 30, 2020. Thirty pregnant women who were diagnosed with COVID-19 and completed the quarantine process were compared with 40 healthy pregnant women in terms of the fetal Doppler parameters. All pregnant women diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were followed up in our clinic and their diagnoses have been confirmed in nasopharyngeal and oropharyngeal samples by quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) method. Doppler ultrasonographic assessment of the uterine arteries (UtA) and middle cerebral artery (MCA) were used in addition to umbilical artery (UA) Doppler between 23 and 40 weeks of gestation. Also, cerebroplacental ratio (CPR) was calculated according to gestational age.

RESULTS

The pulsatility and resistance indices of umbilical and UtA showed a significant increase in pregnant women in the study group compared to the control group (p < 0.05). Multivariable logistic regression analysis revealed that pulsatility and resistance indices of the mean UtA were independently associated with disease (OR > 1000, 95%CI 9.77 to >1000, p = 0.009; OR 0,000 95%CI 0,000-0,944, p = 0,049), respectively. Medical treatment was given to 16/30 (53%) of pregnant women diagnosed with COVID-19.

CONCLUSION

In conclusion, uterine artery Doppler indices in the third trimester may have clinical value in pregnant women recovered from COVID-19.

Intrapartum Doppler ultrasound: where are we now?

Intrapartum hypoxic events most commonly occur in low-risk pregnancies with appropriately grown fetuses. Continuous intrapartum monitoring by means of cardiotocography has not demonstrated a reduction in the frequency of adverse perinatal outcome but has been linked with an increase in the caesarean section rate, particularly among women considered at low risk. Available data from the literature suggests that abnormalities in the uterine artery Doppler and in the ratio between fetal cerebral and umbilical Doppler (i.e. cerebroplacental ratio [CPR]) are associated with conditions of subclinical placental function occurring in fetuses who have failed to achieve their growth potential regardless of their actual size. In this review we summarize the available evidence on the use of intrapartum Doppler ultrasound for the fetal surveillance during labor and the identification of the fetuses at risk of intrapartum distress.

A review of fetal cardiac monitoring, with a focus on low- and middle-income countries

There is limited evidence regarding the utility of fetal monitoring during pregnancy, particularly during labor and delivery. Developed countries rely on consensus ‘best practices’ of obstetrics and gynecology professional societies to guide their protocols and policies. Protocols are often driven by the desire to be as safe as possible and avoid litigation, regardless of the cost of downstream treatment. In high-resource settings, there may be a justification for this approach. In low-resource settings, in particular, interventions can be costly and lead to adverse outcomes in subsequent pregnancies. Therefore, it is essential to consider the evidence and cost of different fetal monitoring approaches, particularly in the context of treatment and care in low-to-middle income countries.

This article reviews the standard methods used for fetal monitoring, with particular emphasis on fetal cardiac assessment, which is a reliable indicator of fetal well-being. An overview of fetal monitoring practices in low-to-middle income counties, including perinatal care access challenges, is also presented. Finally, an overview of how mobile technology may help reduce barriers to perinatal care access in low-resource settings is provided.

Prenatal prediction of neonatal haemodynamic adaptation after maternal hyperoxygenation

Abstract

The reactivity of the pulmonary vascular bed to the administration of oxygen is well established in the post-natal circulation. The vasoreactivity demonstrated by the fetal pulmonary artery Doppler waveform in response to maternal hyperoxia has been investigated. We sought to investigate the relationship between the reactivity of the fetal pulmonary arteries to hyperoxia and subsequent neonatal cardiac function in the early newborn period.

Methods

This explorative study with convenience sampling measured pulsatility index (PI), resistance index (RI), acceleration time (AT), and ejection time (ET) from the fetal distal branch pulmonary artery (PA) at baseline and following maternal hyperoxygenation (MH). Oxygen was administered for 10 min at a rate of 12 L/min via a partial non-rebreather mask. A neonatal functional echocardiogram was performed within the first 24 h of life to assess ejection fraction (EF), left ventricular output (LVO), and neonatal pulmonary artery AT (nPAAT). This study was conducted in the Rotunda Hospital, Dublin, Ireland.

Results

Forty-six women with a singleton pregnancy greater than or equal to 31 weeks’ gestational age were prospectively recruited to the study. The median gestational age was 35 weeks. There was a decrease in fetal PAPI and PARI following MH and an increase in fetal PAAT, leading to an increase in PA AT:ET. Fetuses that responded to hyperoxygenation were more likely to have a higher LVO (135 ± 25 mL/kg/min vs 111 ± 21 mL/kg/min, p < 0.01) and EF (54 ± 9% vs 47 ± 7%,p = 0.03) in the early newborn period than those that did not respond to MH prenatally. These findings were not dependent on left ventricular size or mitral valve (MV) annular diameter but were related to an increased MV inflow. There was no difference in nPAAT.

Conclusion

These findings indicate a reduction in fetal pulmonary vascular resistance (PVR) and an increase in pulmonary blood flow and left atrial return following MH. The fetal response to hyperoxia reflected an optimal adaptation to postnatal life with rapid reduction in PVR increasing measured cardiac output.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03403-y.

Intra-cardiac lidocaine administration to induce fetal demise before late second-trimester abortion: Retrospective review

OBJECTIVE

To determine the efficacy and safety of intra-cardiac lidocaine administration to induce fetal demise before second-trimester medication abortion in a teaching hospital in Addis Ababa, Ethiopia.

METHODS

We performed a retrospective chart review to collect selected sociodemographic and clinical information. All patients who received fetal intra-cardiac lidocaine between January 1, 2019 and April 30, 2019 were included in the study. Fetal demise was considered successful if achieved within 24 hours after fetal intra-cardiac lidocaine administration. We analyzed the data using SPSS version 20. We used frequency tables to describe the data and performed a multivariable analysis to determine associations between variables.

RESULTS

A total of 80 fetuses were given intra-cardiac lidocaine.The mean gestational age was 23⁺¹  weeks (range 21⁺⁰ -27⁺⁵  weeks). Twenty-four hours after lidocaine administration 76 (95%) pregnancies showed negative fetal cardiac activity. Fetuses at gestational ages of 21-23⁺⁶  weeks were five times more likely to have negative cardiac activity compared with those with gestational ages between 24 and 28 weeks (P=0.001). Two women developed nausea, vomiting, and a metallic taste, but no serious adverse events were reported.

CONCLUSIONS

Intra-cardiac lidocaine is effective at inducing fetal demise before late second-trimester medication abortion with no associated serious adverse events or complications.

Perinatal outcome after persistence of abnormal umbilical artery Doppler indices in the growth-restricted fetus following betamethasone administration

BACKGROUND

An optimal approach for providing sufficient antenatal surveillance for fetal growth restriction (FGR) has yet to be elucidated. Moreover, there is scant literature on the fetal response to betamethasone and its effect on fetal Dopplers.

OBJECTIVE

To compare persistence of umbilical artery Doppler abnormalities after corticosteroid administration and adverse perinatal outcome in growth restricted fetuses.

METHODS

Retrospective cohort study (2008-2018) of singleton gestations with FGR (EFW <10th percentile) and umbilical artery Doppler abnormalities (absent or reversed end diastolic velocity) between 24 and 34 weeks of gestation at two institutions. Included patients had Dopplers performed before betamethasone administration and again within 1 week. Excluded were multiple gestations, chromosomal abnormalities, fetal anomalies, or missing outcome information. Pregnancies with persistently abnormal Dopplers were compared with those in which an improvement of Dopplers was noted. The primary outcome was a composite that consisted of indicated preterm birth <32 weeks, 1 or 5 min APGAR score <7, intrauterine fetal demise, and neonatal demise. Secondary outcomes included length of NICU stay, ventilator support, gestational age at delivery, interval between steroids and delivery, and birth weight.

RESULTS

Fifty-three FGR pregnancies met inclusion criteria. Umbilical artery Dopplers improved after steroids in 32% (n = 17). No difference in the frequency of the primary outcome was observed between the persistently abnormal Doppler and improved Doppler groups (72.2% vs. 70.6%, respectively), and there was no difference in any of the secondary outcomes.

CONCLUSIONS

Perinatal outcomes in FGR pregnancies were not affected by improved versus persistently abnormal umbilical artery Dopplers after betamethasone administration.

Routine third-trimester ultrasound in low-risk pregnancies and perinatal death: a systematic review and meta-analysis

OBJECTIVE

This study aimed to determine whether routine third-trimester ultrasounds in low-risk pregnancies decrease the rate of perinatal death compared with regular antenatal care with serial fundal height measurements.

DATA SOURCES

This was a systematic review and meta-analysis of randomized control trials to identify relevant studies published from inception to October 2019. The databases used were Ovid, PubMed, Scopus, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials using a combination of key words related to "third trimester ultrasound" and "low-risk."

STUDY ELIGIBILITY CRITERIA

We included all randomized control trials of singleton, nonanomalous low-risk pregnancies that were randomized to either one or more third-trimester ultrasounds (ultrasound group) or serial fundal height (fundal height group). Exclusion criteria were patients with multiple gestations, maternal medical complications, or fetal abnormalities requiring a third-trimester ultrasound.

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary outcome was the rate of perinatal death. The secondary outcomes were rates of fetal growth restriction, suspected large for gestational age, polyhydramnios, oligohydramnios, fetal anomalies, antenatal interventions, stillbirth, neonatal death, cesarean delivery, induction of labor, and other neonatal outcomes. This meta-analysis was performed with the use of the random effects model of DerSimonian and Laird to produce relative risk or mean difference with a corresponding 95% confidence interval.

RESULTS

A total of 7 randomized control trials with 23,643 participants (12,343 in the ultrasound group vs 11,300 in the fundal height group) were included. The total rate of perinatal death was similar among the groups (41 of 11,322 [0.4%] vs 34 of 10,285 [0.3%]; relative risk, 1.14; 95% confidence interval, 0.68-1.89). The rate of fetal growth restriction was higher in the ultrasound group (763 of 10,388 [7%] vs 337 of 9021 [4%]; relative risk, 2.11; 95% confidence interval, 1.86-2.39) and the rate of suspected large for gestational age (1060 of 3513 [30%] vs 375 of 3558 [11%]; relative risk, 2.84; 95% confidence interval, 2.6-3.2). Polyhydramnios was also significantly higher in the ultrasound group than the fundal height group (18 of 323 [6%] vs 4 of 322 [1%] relative risk, 3.93; 95% confidence interval, 1.4-11). The rates of the remainder of the secondary outcomes were similar among the groups.

CONCLUSION

Routine third-trimester ultrasounds do not decrease the rate of perinatal death compared with serial fundal height in low-risk pregnancies. Ideally, an adequately powered trial is warranted to determine whether perinatal mortality in the fundal height group can be reduced by one-third with third-trimester ultrasound.

Maternal Amino Acid Profiles to Distinguish Constitutionally Small versus Growth-Restricted Fetuses Defined by Doppler Ultrasound: A Pilot Study

OBJECTIVE

Fetuses measuring below the 10th percentile for gestational age may be either constitutionally small for gestational age (SGA) or have pathologic fetal growth restriction (FGR). FGR is associated with adverse outcomes; however, identification of low-risk SGA cases is difficult. We performed a pilot study evaluating maternal markers of pathologic FGR, hypothesizing there are distinct amino acid signatures that might be used for diagnosis and development of new interventions.

STUDY DESIGN

This was a cohort study of healthy women with sonographic fetal estimated fetal weight <5th percentile divided into two groups based upon umbilical artery (UmA) Doppler studies or uterine artery (UtA) Doppler studies. We collected maternal blood samples prior to delivery and used ion pair reverse phase liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry to assess 44 amino acids.

RESULTS

Among 14 women included, five had abnormal UmA, and three had abnormal UtA Doppler results. Those with abnormal UmA showed elevated ornithine. Those with abnormal UtA had lower dimethylglycine, isoleucine, methionine, phenylalanine, and 1-methylhistidine.

CONCLUSION

We found several amino acids that might identify pregnancies affected by pathologic FGR. These findings support the feasibility of future larger studies to identify maternal metabolic approaches to accurately stratify risk for small fetuses.