Fetal Doppler: umbilical artery, middle cerebral artery, and venous system

Evaluation of Doppler indices (MCA & UA) and fetal outcomes: a retrospective case-control study in women with hypertensive disorders of pregnancy

BACKGROUND

Hypertensive disorders of pregnancy (HDP) is associated with an increased risk of adverse outcomes. The fetal middle cerebral artery (MCA) and umbilical artery (UA) blood flow detected by ultrasound are recommended to evaluate the oxygenation of the fetus. It is necessary to analyze the relationship between MCA & UA doppler indices or cerebroplacental ratio (CPR) and fetal outcomes and describe MCA and UA blood flow values across gestation.

METHODS

Hospital-based retrospective case-control study during 2016 to 2020. 800 singleton pregnant women: 400 normotensive control, 219 gestational hypertension (GH), and 181 preeclampsia (PE)/eclampsia (EC). An analysis of the outcomes of mothers and neonates was performed. The fetal MCA and UA blood flow values across gestation were established, and MCA-resistance index (RI) and CPR were used to predict fetal distress and small for gestational age (SGA).

RESULTS

In the normotensive control, GH and PE/EC groups, the mean gestational age (GA) was 38.9 ± 1.2 weeks, 39.0 ± 1.0 weeks, and 38.6 ± 1.3 weeks respectively, and the mean birth weight (BW) was 3.195 ± 0.387 kilograms, 3.198 ± 0.428 kilograms, and 2.987 ± 0.544 kilograms respectively. There were differences in GA, BW, fetal distress, SGA and intraventricular hemorrhage I-II between the hypertension group and normotensive control group (p < 0.05). The MCA-RI (sensitivity: 70.1%, specificity: 64.3%) and MCA-RI (sensitivity: 52.4%, specificity: 84.6%) were the best indices to predict fetal distress and SGA, respectively during GA of 35-40 weeks.

CONCLUSIONS

Fetal MCA blood flow values and CPR are of great benefit for obstetricians to evaluate the status of fetus evidentially in singleton pregnancy.

Obstetric vascular Doppler velocimetry: clinical applications and overuses

A safe and non-intrusive assessment of fetal health is not only crucial in low-risk gestations, but it is also the standard of care in high-risk pregnancies. Therefore, measuring blood flow across different vessels with non-invasive ultrasound methods has been accurately and painstakingly studied and published. Amongst these state-of-the-art techniques, umbilical artery (blood flow) Doppler velocimetry (UADV) has allowed for fetal well-being follow-ups and assess uteroplacental function, which obtains a more complete and clearer picture; particularly in regard to complicated pregnancies. Additionally, there are other modalities with diverse clinical applications that have emerged, including their clinical and research utilization in conditions such as fetal growth restriction (FGR), preeclampsia, fetal anemia, monochorionic twins vascular blood flow mismatch such as is in twin-to-twin transfusion syndrome, twin anemia polycythemia sequence, and twin reverse arterial perfusion sequence. Nevertheless, their applications regarding various other maternal-fetal diagnoses in the same way as premature births and/or multiple gestation surveillance have not been reported to hold strong clinical evidence. With that in regard, the purpose of this unique study was to give update of the multiple clinical applications of this very important obstetrical tool. Additionally, to review the pathophysiology as well as revisit their reported significant valid uses and occasional overuses. We also delved into quality control measures as related to the application of Doppler in obstetrics. Lastly, it is essential to look through and reflect on the future developments of this valuable, non-invasive, high-risk marvelous modern device.

Timing and duration of nutrient restriction and its impacts on placental development and umbilical blood flow in adolescent sheep

We hypothesized that nutrient restriction from day 50-90 of gestation decreases umbilical blood flow and that umbilical blood flow would recover to control values upon realimentation during late gestation (d 90 to 130) or remain reduced in ewes that continued to be nutrient restricted. On d 50 of gestation, young nulliparous whiteface ewes (6-8 mo; n = 41) carrying singletons were randomly assigned to two dietary treatments: 100% of NRC recommendations (CON) or 60% of CON (RES). On d 90 of gestation, ewes either remained on CON or RES until d 130, or CON ewes were RES from d 90 to 130, or RES ewes were realimented to CON from d 90 to 130. This resulted in 4 treatment groups on day 130: CON-CON, CON-RES, RES-RES, RES-CON. Umbilical blood flow and fetal and placental measurements were obtained via ultrasonography every 10 days from day 50-110. Non-survival surgeries were performed on days 50, 90, and 130 (n = 6-7 ewes/group) where uterine artery and umbilical blood flows were measured during surgery via ultrasonography. Conceptus weights were recorded and placentomes collected to determine binucleate cell numbers. The study was conducted as a completely randomized design arrangement with repeated measures. Data were analyzed using the MIXED procedure of SAS. There was a nutritional treatment by day interaction (P < 0.01) with CON ewes having greater umbilical blood flow compared with RES by d 90. Fetal biparietal distance, abdominal width, and kidney area increased (P < 0.05) in CON-RES with all these measurements increasing during late gestation. We partially accept our hypothesis as nutrient restriction during mid gestation decreased umbilical blood flow. However, blood flow did not return to control levels upon realimentation. By d 130, fetal and placental weights were similar between RES-RES and CON-CON. Binucleate cell numbers in the fetal trophoblast were not influenced by nutritional treatments. Our findings suggest that refeeding previously nutrient restricted pregnant adolescent ewes to control levels does not reestablish umbilical blood flow. Adequate placental development during mid gestation could protect the fetus from a decreased umbilical blood flow later in gestation when nutrients were limited by 40%.

The Effect of External Cephalic Version on Fetal Circulation: A Prospective Cohort Study

External cephalic version (ECV) is a cost-effective and safe treatment option for breech presentation at term. Following ECV, fetal well-being is assessed via a non-stress test (NST). An alternative option to identify signs of fetal compromise is via the Doppler indices of the umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV). Inclusion criteria were an uncomplicated pregnancy with breech presentation at term. Doppler velocimetry of the UA, MCA and DV were performed up to 1 h before and up to 2 h after ECV. The study included 56 patients who underwent elective ECV with a success rate of 75%. After ECV, the UA S/D ratio, UA pulsatility index (PI) and UA resistance index (RI) were increased compared to before the ECV (p = 0.021, p = 0.042, and p = 0.022, respectively). There were no differences in the Doppler MCA and DV before or after ECV. All patients were discharged after the procedure. ECV is associated with changes in the UA Doppler indices that might reflect interference in placental perfusion. These changes are probably short-term and have no detrimental effects on the outcomes of uncomplicated pregnancies. ECV is safe; yet it is a stimulus or stress that can affect placental circulation. Therefore, careful case selection for ECV is important.

Alterations in Fetal Doppler Parameters Before and Twenty-Four Hours After Radiofrequency Ablation for Twin Reversed Arterial Perfusion Sequence

Objective

To evaluate alterations in the fetal Doppler parameters of pump fetuses before and 24 h after radiofrequency ablation surgery for twin reversed arterial perfusion sequence (TRAPs).

Methods

This is a retrospective study of 28 pump fetuses in TRAPs and 28 normal control twins between 2016 and 2021. The fetal Doppler parameters, including the umbilical artery pulsatility index (UA-PI), middle cerebral artery peak systolic velocity (MCA-PSV), middle cerebral artery pulsatility index (MCA-PI), and cerebroplacental ratio (CPR), of the controls, and pump fetuses before and 24 h after surgery were compared.

Results

An increasing trend and a further increase in the MCA-PSV, MCA-PI, MCA-PSV Z score, and MCA-PI Z score after surgery were observed in pump fetuses with gestational age (GA) ≥20 weeks; however, such changes were not observed in those with a GA of <20 weeks. The UA-PI and CPR before and after surgery were not different between control and pump fetuses, whether the GA was ≥20 or <20 weeks.

Conclusion

In the middle second trimester, the pump fetus might suffer from high cardiac output rather than hypoxemia before surgery and congestive heart failure, or hemodilutional anemia after surgery. This may provide some theoretical evidence in favor of early intervention, rather than waiting for a more advanced GA, to avoid unnecessary hemodynamic alterations.

Fetal Hemodynamic Response to Maternal Oxygenation in Normal and Complicated Pregnancies

Maternal oxygenation (MO) is widely applied in obstetrics. Scholars have conducted numerous studies on maternal hyperoxygenation and have reported many theoretical and applied achievements and a number of different points of view. The main purpose of this article is to discuss the effect of maternal oxygenation on fetal circulation during normal and complicated pregnancies and to ascertain its potential side effects and research gaps in this field. In complicated pregnancies, the fetus may benefit from oxygen therapy. However, large randomized controlled trials and longitudinal studies are necessary to support the widespread application of maternal oxygenation in this context.

A retrospective cohort study comparing a novel, spherical, resorbable particle against five established embolic agents for uterine fibroid embolisation

AIM

To evaluate the effectiveness of a novel, resorbable, spherical embolic agent compared with other established agents, by studying percentage fibroid infarction (the best indicator of long-term symptom improvement) in patients undergoing uterine fibroid embolisation (UFE).

MATERIALS AND METHODS

This retrospective cohort study examined six different embolic agents used for fibroid embolisation, including a new gelatin-based, fully resorbable, spherical agent. The primary effectiveness outcomes were magnetic resonance imaging (MRI)-determined dominant fibroid infarct percentage (DF%) and all fibroid percentage infarct (AF%) at 3 months post-embolisation. MRI-determined uterine artery patency rate was the secondary outcome. Chi-squared test (χ²), relative risk (RR) calculation (primary outcomes), and analysis of variance (ANOVA) (secondary outcome) were the statistical tests employed.

RESULTS

One hundred and twenty patients were treated with six embolic agents (20 consecutive patients per group, overall mean age 44.8±6.4, initial uterine volume 570±472 ml, dominant fibroid volume 249±324 ml). Fibroid infarctrates were similar between the cohorts with no significant difference between the new gelatin-based resorbable particle and other embolics in either DF% (χ²=3.92, p=0.56) or AF% (χ²=2.83, p=0.73). Complete DF% RR=1.07 (0.90-1.27) and AF% RR=1.09 (0.85-1.41) suggest non-inferiority of the resorbable particle (d=0.67, p<0.05). A favourable uterine artery patency rate was demonstrated for the resorbable particle compared with gelatin slurry (82.5% versus 27.5%, p<0.001 after Bonferroni adjustment).

CONCLUSIONS

This new gelatin-based, fully resorbable particle is an effective embolic agent for fibroid embolisation and achieves an infarct rate non-inferior to established embolics.

Therapeutic role of enoxaparin in intra-uterine growth restriction: A randomized clinical trial

OBJECTIVE

Intrauterine growth restriction is a leading cause of perinatal mortality and morbidity. Using enoxaparin may enhance the placental circulation and improve the intrauterine growth. This study was conducted to assess the efficacy and safety of enoxaparin in treatment of intra-uterine growth restriction.

STUDY DESIGN

125 women with intrauterine growth restriction were randomized to control group and intervention group (receiving routine high risk pregnancy prenatal care plus daily subcutaneous injection of 40 mg enoxaparin). Prolongation of pregnancy, fetal birth weight, fetal outcome and enoxaparin side effects were compared in 2 groups.

RESULTS

Baseline characteristics were similar in 2 groups. Mean gestational age at delivery was 36.73(±2.71) in enoxaparin group and 36.85(±2.17) in control group which showed no statistically significant difference. Mean fetal birth weight had also no statistically significant difference in enoxaparin and control group (2370.16 ± 580.72 g versus 2456.07 ± 543.06 g). Rate of betamethasone administration, intubation, NICU admission, sepsis, necrotizing enterocolitis, intra-ventricular hemorrhage, hypoglycemia and low apgar score were similar in two groups. No major adverse effect was seen.

CONCLUSION

Enoxaparin did not prolong the pregnancy and fetal birth weight and did not improve the fetal outcome even in patients with impaired baseline Doppler findings.

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.

Prognostic accuracy of cerebroplacental ratio for adverse perinatal outcomes in pregnancies complicated with severe pre-eclampsia; a prospective cohort study

OBJECTIVE

The current study aims to assess the efficacy of fetal middle cerebral artery/umbilical artery pulsatility index ratio (cerebroplacental ratio CPR) in predicting the occurrence of adverse perinatal outcomes in pregnancies complicated with severe pre-eclampsia.

MATERIALS AND METHODS

This cohort study included 100 pregnant women between 34 and 40 weeks of gestation attended the labor ward and diagnosed with severe pre-eclampsia. Doppler evaluation was carried out to measure the CPR. Apgar score and fetal umbilical artery pH were assessed within 5 min of delivery. The rate of neonatal intensive care unit (NICU) admission was obtained.

RESULTS

Apgar score at 5 min >7 was in 82 cases (82%) and 12 cases (12%) scored < 7. Fetal blood PH was >7.2 in 67% of cases while 33% of cases had PH <7.2. As regard the NICU admission; 66% of neonates did not need admission while 34% of neonates were admitted to the NICU. There was a significant association between CPR and low Apgar score at 5 min (P < 0.001). The sensitivity of CPR in detection of Apgar score <7 was 50%, and specificity 88.1%. CPR had a poor predictive value of the low umbilical artery PH <7.2 (P = 0.318) with 43.75% sensitivity and 69.05% specificity. There was a significant association between CPR and NICU admission (P = 0.009).

CONCLUSIONS

Adding CPR ratio to routine antepartum fetal surveillance from 34 weeks gestation may help with patient counseling regarding adverse neonatal outcomes for women with severe pre-eclampsia as there is a strong correlation between it and adverse neonatal outcomes.

Red Blood Cell Alloimmunization in the Pregnant Patient

Alloimmunization to red blood cell (RBC) antigens represents a challenge for physicians caring for women of child bearing potential. Exposure to non-self RBC antigens may occur during transfusion or pregnancy leading to the development of antibodies. If a subsequent fetus bears that antigen, maternal antibodies may attack the fetal red blood cells causing red cell destruction and clinically significant hemolytic disease of the fetus and newborn (HDFN). In the most severe cases, HDFN may result in intrauterine fetal demise due to high output cardiac failure, effusions and ascites, known as "hydrops fetalis". This article reviews strategies for management and prevention of RBC alloimmunization in women of child bearing potential.

Use of Doppler velocimetry in diagnosis and prognosis of intrauterine growth restriction (IUGR): A Review

Intrauterine growth restriction (IUGR) is a condition which has been difficult to assess at an early stage, resulting in the delivery of children who have poor genetic growth potential. Currently, IUGR classification is based upon the system of ultrasound biometry. Doppler velocimetry allows the measurement of hemodynamic flow of major fetal vessels, comparing the flow indices and patterns of normal and IUGR cases. In this review, the effectiveness of Doppler velocimetry in assessing blood flow in major vessels including the umbilical artery, ductus venosus, and middle cerebral artery was studied for both diagnostic and prognostic screening of IUGR. The umbilical artery is the most frequently studied vessel in Doppler velocimetry due to its accessibility and the strength of its associations with fetal outcomes. Abnormalities in the ductus venosus waveform can be indicative of increased resistance in the right atrium due to placental abnormalities. The middle cerebral artery is the most studied fetal cerebral artery and can detect cerebral blood flow and direction, which is why these three vessels were selected to be examined in this context. A potential mathematical model could be developed to incorporate these Doppler measurements which are indicative of IUGR, in order to reduce perinatal mortality. The purpose of the proposed algorithm is to integrate Doppler velocimetry with biophysical profiling in order to determine the optimal timing of delivery, thus reducing the risks of adverse perinatal outcomes.

Evaluation of Abdominal Fetal Electrocardiography in Early Intrauterine Growth Restriction

Objectives: This descriptive study was performed to evaluate the capability of a non-invasive transabdominal electrocardiographic system to extract clear fetal electrocardiographic (FECG) measurements from intrauterine growth restricted (IUGR) fetuses and to assess whether abdominal FECG parameters can be developed as markers for evaluating the fetal cardiac status in IUGR.

Methods: Transabdominal FECG was attempted in 20 controls and 15 IUGR singleton pregnancies at 20+0−33+6 weeks gestation. Standard ECG parameters were compared between the study groups and evaluated for their correlation. Accuracy for the prediction of IUGR by cut off values of the different FECG parameters was also determined.

Results: Clear P-QRST complexes were recognized in all cases. In the IUGR fetuses, the QT and QTc intervals were significantly prolonged (p = 0.017 and p = 0.002, respectively). There was no correlation between ECG parameters and Doppler or other indices to predict IUGR. The generation of cut off values for detecting IUGR showed increasing sensitivities but decreasing specificities with the prolongation of ECG parameters.

Conclusion: The study of fetal electrocardiophysiology is now feasible through a non-invasive transabdominal route. This study confirms the potential of FECG as a clinical screening tool to aid diagnosis and management of fetuses after key limitations are addressed. In the case of IUGR, both QT and QTc intervals were significantly prolonged and thus validate earlier study findings where both these parameters were found to be markers of diastolic dysfunction. This research is a useful prelude to a test of accuracy and Receiver Operating Characteristics (ROC) study.

Color doppler indices of proximal and distal parts of middle cerebral artery in fetuses with intrauterine growth restriction

INTRODUCTION

Intrauterine growth restriction (IUGR) is a major clinical issue for pregnant women. The purpose of this study was to evaluate color Doppler indices of the proximal and distal parts of the middle cerebral artery (MCA) of the fetus.

METHODS

In this cross-sectional study, 350 pregnant patients, with gestation age of 32-40 who were suspected to have intrauterine growth restriction, participated. The patients were referred for color Doppler sonography at the Imam Reza Hospital (Kermanshah, Iran) from May 2011 to September 2012. The following indices were measured for the proximal and distal part of the MCA: pulsatility index (PI), resistive index (RI), fetal heart rate (FHR), systolic to diastolic (S/D) ratio, and peak systolic velocity (PSV). The data were analyzed applying Tukey's-test, Paired-Samples t-test, and simple linear regression analysis using SPSS 19.

RESULTS

Average age of the mother, the frequency of pregnancy, and fetus gestational age were 27.79±0.17 years, 2.09±1.3, and 34.19±2.52 weeks, respectively. For gestation age of <36weeks, all Doppler indices of the distal part of the fetus MCA were significantly different from those of proximal part (p<0.05). Comparing indices of gestation age <36 weeks with those of >36 weeks, significant difference was found between the Doppler indices of the proximal parts as well as for the distal parts (p<0.05).

CONCLUSION

Measurement of fetus MCA indices may depend to the sampling location; however, this needs further investigation in order to find a clear probe location.

The alteration in placental volume and placental mean grey value in growth-restricted pregnancies assessed by 3D ultrasound (Growth Restriction & 3D Ultrasonography)

We aimed to evaluate the volumetric and echogenic alterations in placentas between the intrauterine growth restriction (IUGR) and normal pregnancies using three-dimensional ultrasound and virtual organ computer-aided analysis (VOCAL) software. This case-control prospective study consisted of 48 singleton pregnancies complicated by IUGR and 60 healthy singleton pregnancies matched for maternal age, gestational age and parity. Placental volume (PV) and placental volumetric mean grey values (MGV) were evaluated. PV (cm(3)) was analysed using the VOCAL imaging analysis program, and 3D histogram was used to calculate the volumetric MGV (%). PV was 278.50 ± 63.68 and 370.98 ± 97.82 cm(3) in IUGR and control groups, respectively (p = 0.004). MGV of the placenta was 38.24 ± 8.41 and 38.24 ± 8.41 in IUGR and control groups, respectively (p = 0.30). receiver operator curve (ROC) curve analysis revealed that area under curve was 0.731 for PV. Correlation analysis revealed that PV was significantly associated with estimated fetal weight (r = 0.319, p = 0.003), biparietal diameter (r = 0.346, p = 0.002), head circumference (r = 0.269, p = 0.019), abdominal circumference (r = 0.344, p = 0.002) and femur length (r = 0.328, p = 0.004). PV was inversely related to the umbilical artery pulsatility index (r = - 0.244, p = 0.017). To the best of our knowledge, this is the first study evaluating volumetric MGV in IUGR placentas by comparing them with healthy pregnancies. Our study showed that PV diminishes significantly in IUGR pregnancies, whereas volumetric MGV does not alter significantly.

Review of the correlation between blood flow velocity and polycythemia in the fetus, neonate and adult: appropriate diagnostic levels need to be determined for twin anemia-polycythemia sequence

Twin anemia-polycythemia sequence (TAPS) is recognized increasingly antenatally by the demonstration of an anemic twin and a polycythemic cotwin using the middle cerebral artery peak systolic velocity (MCA-PSV). While the MCA-PSV has been shown to correlate well with anemia in singleton fetuses, the evidence to support its use to diagnose fetal polycythemia appears to be less clear-cut. We aimed to evaluate fetal, neonatal and adult literature used to support the use of MCA-PSV for the diagnosis of polycythemia. Comprehensive literature searches were performed for ultrasound evidence of polycythemia in the human fetus, neonate and adult using key search terms. Only manuscripts in the English language with an abstract were considered for the review, performed in June 2014. Fifteen manuscripts were found for the human fetus, including 38 cases of TAPS. Nine of these defined fetal polycythemia as MCA-PSV < 0.8 multiples of the median (MoM), five used < 1.0 MoM and one used 0.8-1.0 MoM. Only two studies, involving a total of 15 cases, proposed a diagnostic level, acknowledging false-positive and -negative cases, though neither reported sensitivities or specificities. Six neonatal studies (96 neonates) demonstrated evidence of decreased cerebral velocities in polycythemia and a consequent increase with hemodilution. In the adult, five studies (57 polycythemic adults) demonstrated increased flow or velocity with hemodilution. Neither neonatal nor adult studies conclusively defined levels for screening for polycythemia. Despite widespread adoption of a cut-off of < 0.8 MoM in the published literature for the polycythemic fetus in TAPS, this is based upon minimal evidence, with unknown sensitivity and specificity. We recommend caution in excluding TAPS based purely upon the absence of a reduced MCA-PSV.

Doppler for growth restriction: the association between the cerebroplacental ratio and a reduced interval to delivery

OBJECTIVE

Evaluation of the cerebroplacental ratio (CPR) as an adjunct to umbilical artery Doppler (UA) to assess risk of delivery before 32 weeks and/or delivery within 2 weeks from diagnosis of fetal growth restriction (FGR).

STUDY DESIGN

In a cohort of fetuses with suspected FGR, UA Doppler was performed, and when abnormal the CPR was calculated (middle cerebral pulsatility index/umbilical artery pulsatility index). Doppler characteristics were used to determine three study groups: (1) normal UA, (2) abnormal UA with normal CPR and (3) abnormal UA with abnormal CPR. The primary outcomes were delivery before 32 weeks and delivery within 2 weeks. Adjusted odds ratio (aOR) with 95% confidence intervals (CIs) were calculated controlling for maternal age, chronic hypertension and tobacco use. We performed a linear regression analysis comparing the value of the CPR with the gestational age at delivery. Kaplan-Meier survival curve analysis with log-rank tests for probability was performed.

RESULTS

We included 154 patients: 91, 31 and 32 in Group 1, 2 and 3, respectively. Subjects in Group 3 had higher rates of the two primary outcomes: there was a fivefold increased risk (aOR=5.2 (95% CI=2.85-9.48)) for delivery before 32 weeks and over a fourfold increased risk for delivery within 2 weeks (aOR=4.76 (95% CI=2.32-9.76)) compared with those with a normal CPR (Group 1). In contrast, subjects in Group 2 (abnormal UA Doppler but normal CPR) had a similar rate of delivery before 32 weeks (aOR=1.16 (95% CI=0.55-2.48)) and within 2 weeks (aOR=1.07 (95% CI=0.43-2.69)). The median gestational age at delivery was 36, 36 and 29 weeks in Groups 1, 2 and 3, respectively (P<0.001). Linear regression analysis revealed a strong correlation between the value of the CPR and gestational age at delivery: R(2)=0.56, correlation coefficient=0.75. Kaplan-Meier analysis revealed a significantly decreased latency to delivery in Group 3, as opposed to Groups 1 and 2 (Cox-Mantel hazard ratio (HR) of Group 2 versus Group 1 HR=1.20 (95% CI=0.78-1.83) and Group 3 versus Group 1 HR=5.00 (95% CI=2.4-10.21)).

CONCLUSION

The CPR differentiates those fetuses with suspected growth restriction most at risk for delivery before 32 weeks and delivery within 2 weeks from those likely to have a more prolonged latency until delivery is required. In patients with suspected FGR and an abnormal UA, the CPR can be used to guide management decisions, such as maternal hospitalization and/or transport, aggressive fetal monitoring and antenatal corticosteroid administration.

Estimation of the growth rate in fetuses with an abnormal cerebroplacental ratio compared to those with suspected growth restriction without evidence of centralization of blood flow

OBJECTIVES

To evaluate the growth rate in fetuses with suspected growth restriction according to their Doppler characteristics.

METHODS

A retrospective cohort of fetuses with suspected growth restriction was identified. We reviewed umbilical artery and middle cerebral Doppler pulsatility indices and calculated the cerebroplacental ratio. Three study groups were determined: (1) normal umbilical artery Doppler findings; (2) abnormal umbilical artery findings with a normal cerebroplacental ratio; and (3) abnormal umbilical artery findings with an abnormal cerebroplacental ratio. The primary outcome was the growth rate as estimated by fetal biometry from serial sonographic evaluations. Analysis of the mean growth rate in each study group was performed by analysis of variance. In addition, linear regression analysis comparing the cerebroplacental ratio to the growth rate was performed.

RESULTS

Fetal growth restriction was suspected in 416 patients; 176 patients were included in this analysis: 113, 38, and 25 in groups 1, 2, and 3 respectively. The estimated mean (SD) growth rate in group 3 was significantly lower than in groups 1 and 2: 8.3 (4.4) versus 19.6 (6.0) and 18.6 (7.7) g/d, respectively (P < .001). Linear regression analysis revealed a strong correlation between the growth rate and cerebroplacental ratio (r = 0.76; R(2) = 0.58) as well as the birth weight and cerebroplacental ratio (r = 0.78; R(2) = 0.61).

CONCLUSIONS

In fetuses with suspected growth restriction and abnormal umbilical artery Doppler findings, an abnormal cerebroplacental ratio is strongly associated with reduced fetal growth. In contrast, if the cerebroplacental ratio is normal, even in the setting of abnormal umbilical artery Doppler findings, fetuses grow similarly to those with normal umbilical artery findings.

Association between an abnormal cerebroplacental ratio and the development of severe pre-eclampsia

OBJECTIVE

To study the association between the cerebroplacental ratio (CPR) and the development of pre-eclampsia.

STUDY DESIGN

Three study groups were determined: Group 1-normal umbilical artery (UA; referent), Group 2-abnormal UA and normal CPR and Group 3-abnormal UA and an abnormal CPR. The primary outcome was the development of severe pre-eclampsia.

RESULTS

We included 270 women. Women in Group 3 had significantly elevated rates of severe pre-eclampsia versus those in Group 1 and Group 2, 52.5% versus 5.1% and 15.4%, respectively, (P<0.01), adjusted odds ratio 4.14 (95% confidence interval, 2.59 to 6.61). Kaplan-Meier analysis revealed earlier delivery in women with pre-eclampsia in Group 3 versus Group 1, Cox-Mantel hazard ratio 2.39 (1.17 to 4.88), log rank P=0.01.

CONCLUSION

An abnormal CPR is associated with a higher rate severe pre-eclampsia with delivery at earlier gestational ages than with a normal UA or an abnormal UA, but normal CPR.

Three-dimensional ultrasonographic placental volume in gestational diabetes mellitus

OBJECTIVES

We aimed to evaluate the placental volume and placental mean gray value in gestational diabetes mellitus (GDM) and healthy placentas using three-dimensional (3D) ultrasound and Virtual Organ Computer-aided AnaLysis (VOCAL).

METHODS

This case-control prospective study consisted of 39 singleton pregnancies complicated by GDM and 42 healthy singleton pregnancies matched for gestational age, maternal age and parity. Placental volume and placental volumetric mean gray values were evaluated. The placental volume (cm(3)) was analyzed using the VOCAL imaging analysis program and 3D histogram was used to calculate the volumetric mean gray value (%).

RESULTS

Placental volume was significantly larger in GDM (411.59 ± 170.82 versus 343.86 ± 128.94 cm(3); p = 0.046). There was no significant difference in mean gray value between GDM and healthy placentas (36.65 ± 7.02 versus 38.71 ± 7.91, respectively; p = 0.277). Placental volume was significantly correlated with gestational week (r = 0.219, p = 0.035) and parity (r = 0.228, p = 0.048). There was negative significant relation between placental volume and umbilical artery systolic/diastolic ratio, pulsatility index and resistance index (r = -0.278, p = 0.007; r = -0.315, p = 0.002; r = -0.322, p = 0.001, respectively).

CONCLUSIONS

Placental volume increases significantly in GDM, whereas mean gray values do not alter significantly. These data may reflect the placental changes in GDM placentas that may help to understand the pathophysiology better.

Combined sonographic testing index and prediction of adverse outcome in preterm fetal growth restriction

OBJECTIVE

We sought to test the hypothesis that a combined sonographic scoring system (CSTI) that incorporates features of the biophysical profile (BPP) and multivessel Doppler evaluation improves prediction of adverse outcomes in preterm intrauterine growth restriction.

METHODS

This was a prospective cohort study of growth-restricted fetuses with abnormal umbilical artery (UA) Doppler studies, defined as pulsatility index (PI) > 95 th percentile for gestational age or absent/reversed end diastolic flow. Fetuses were followed with weekly BPP and Doppler evaluation of the UA, middle cerebral artery (MCA), and ductus venosus (DV) until the time of delivery. The cerebroplacental Doppler ratio (CPR) was then calculated (MCA PI/UA PI). MCA PI < 5 th percentile, MCA peak systolic velocity (PSV) > 1.5 multiples of the median, DV PI > 95 th percentile with or without absent/reversed flow, and CPR < 1.08 were considered abnormal. Using logistic regression modeling, a weighted scoring index for the prediction of a composite fetal vulnerability index (FVI), which included 5-minute Apgar score < 3, cord pH < 7.2, seizures, necrotizing enterocolitis, grade 4 intraventricular hemorrhage, periventricular leukomalacia, and neonatal death, was developed. A receiver operating characteristic (ROC) curve was used to identify the best score associated with the FVI.

RESULTS

Of 66 patients meeting inclusion criteria over a 5-year period, 17 (25.8%) had a positive FVI. Abnormal BPP (< 8), MCA PI, MCA PSV, DV PI, and CPR were observed in 6, 27.3, 13.6, 56.1, and 33.3% of patients, respectively. From the logistic regression model, a CSTI was developed including a score of 1 for abnormal BPP, 3 for MCA PSV, 1 for DV, 6 for CPR, and 3 for oligohydramnios. The ROC curve identified a score of ≥ 7 to be the best predictor of FVI with sensitivity of 35.1% and specificity of 91.8% and a positive likelihood ratio of 4.3 (area under ROC curve 0.73). These test characteristics were better than those for any of the individual component antenatal tests.

CONCLUSION

Although this novel scoring system performs modestly in predicting adverse outcomes in FGR, it appears to perform better than any individual antenatal test currently available.

DALI: Vitamin D and lifestyle intervention for gestational diabetes mellitus (GDM) prevention: an European multicentre, randomised trial - study protocol

Background

Gestational diabetes mellitus (GDM) is an increasing problem world-wide. Lifestyle interventions and/or vitamin D supplementation might help prevent GDM in some women.

Methods/design

Pregnant women at risk of GDM (BMI≥29 (kg/m²)) from 9 European countries will be invited to participate and consent obtained before 19+6 weeks of gestation. After giving informed consent, women without GDM will be included (based on IADPSG criteria: fasting glucose<5.1mmol; 1 hour glucose <10.0 mmol; 2 hour glucose <8.5 mmol) and randomized to one of the 8 intervention arms using a 2×(2×2) factorial design: (1) healthy eating (HE), 2) physical activity (PA), 3) HE+PA, 4) control, 5) HE+PA+vitamin D, 6) HE+PA+placebo, 7) vitamin D alone, 8) placebo alone), pre-stratified for each site. In total, 880 women will be included with 110 women allocated to each arm. Between entry and 35 weeks of gestation, women allocated to a lifestyle intervention will receive 5 face-to-face, and 4 telephone coaching sessions, based on the principles of motivational interviewing. The lifestyle intervention includes a discussion about the risks of GDM, a weight gain target <5kg and either 7 healthy eating ‘messages’ and/or 5 physical activity ‘messages’ depending on randomization. Fidelity is monitored by the use of a personal digital assistance (PDA) system. Participants randomized to the vitamin D intervention receive either 1600 IU vitamin D or placebo for daily intake until delivery. Data is collected at baseline measurement, at 24–28 weeks, 35–37 weeks of gestation and after delivery. Primary outcome measures are gestational weight gain, fasting glucose and insulin sensitivity, with a range of obstetric secondary outcome measures including birth weight.

Discussion

DALI is a unique Europe-wide randomised controlled trial, which will gain insight into preventive measures against the development of GDM in overweight and obese women.

Trial registration

ISRCTN70595832

Peripartum consultations expand the role of the fetal/neonatal neurologist

The peripartum period entails the next prenatal interval when novel neuroprotective strategies will be designed and tested. Research development will lead to novel evaluations for maternal-fetal pairs who require inpatient treatment and possible delivery for worsening or acute neurologic problems. Future studies should critically compare serial fetal surveillance assessments with postnatal clinical findings to detect and treat more accurately fetal/neonatal brain disorders that begin or worsen during the peripartum period. Clinical management decisions require an interdisciplinary treatment approach. Protocols may begin before and during parturition, and continue through neonatal resuscitation and early postnatal periods into infancy. Appropriate choices of preventive, rescue, and repair neuroprotective interventions must consider both the timing and etiologies of encephalopathies in the context of maternal, fetal, placental, and neonatal diseases.

Umbilical venous blood flow and its measurement in the human fetus

In this review, we evaluate the published methodologies to describe a noninvasive technique for the quantitative assessment of umbilical venous blood flow in the human fetus. We identify a number of variations in the reported methodologies and address some of the common errors associated with Doppler assessment of umbilical venous flow volume. The potential role of umbilical venous flow volumetry in the management of intrauterine growth restriction is briefly evaluated including its utility and reliability in everyday clinical practice.

Diagnostic laboratory technologies for the fetus and neonate with isoimmunization

Maternal-fetal blood group incompatibility is common but less commonly results in hemolytic disease of the fetus and newborn (HDFN). HDFN is associated with greater peak bilirubin, at an earlier age, and for longer duration than other causes of hyperbilirubinemia. It poses a substantial risk for kernicterus and accounts for the majority of exchange transfusions for hyperbilirubinemia. Advances in diagnosis and management are described, from identification of the alloimmunized pregnancy by maternal ABO and Rh typing, antibody screen (indirect Coombs test), identification and titration; laboratory evaluation of the maternal-fetal unit with a critical maternal antibody titer to prompt fetal antigen status determination; assessment of fetomaternal hemorrhage by conventional Kleihauer-Betke testing or by flow cytometric methodology; to antenatal management of isoimmunization and fetal status assessments using the systems of Liley, Queenan, and serial Doppler fetal middle cerebral artery peak velocity measurements. The utility of laboratory diagnostics in the approach to hemolysis in the neonate, including hematology, chemistry, and peripheral blood smear review, is reviewed. The goal of management, to deliver a healthy infant at or near term, is attained for the majority of cases using current modalities; future directions include noninvasive genotyping of fetal blood from maternal serum to fully eliminate RhD alloimmunization and HDFN; and development of prophylaxis and intervention strategies for non-RhD alloimmunizations for which immune globulin is currently unavailable.

Clinical and placental characteristics in four new cases of twin anemia-polycythemia sequence

We report and analyze four new cases of spontaneous twin anemia-polycythemia sequence (TAPS) and discuss antenatal management by fetoscopic laser coagulation for this uncommon form of chronic intertwin transfusion. The clinical course and placental characteristics of four pairs of monochorionic-diamniotic (MCDA) twins with spontaneous TAPS, of which one was treated with fetoscopic laser surgery, are described. For the three cases that did not undergo intrauterine intervention, serial Doppler measurement revealed a gradual increase in the middle cerebral artery peak systolic velocity (MCA-PSV) in the donor and a concomitant decrease in the recipient. These twins were born at between 32 and 34 weeks' gestation by Cesarean section. At birth, the donor twins were severely anemic and the recipient twins were polycythemic. Placental injection studies revealed a few small arteriovenous (AV) and venoarterial anastomoses. In the fourth case, because of the high suspicion of TAPS on MCA-PSV data at 24 weeks' gestation, fetoscopic laser coagulation of three small AV anastomoses was successfully performed. No hematological abnormalities were detected at birth. TAPS is a newly described form of chronic twin-to-twin transfusion associated with chronic anemia in the donor and polycythemia in the recipient, without twin oligo-polyhydramnios sequence (TOPS). The monitoring of MCDA pregnancies should include measurement of MCA-PSV in both fetuses even in the absence of intertwin discordance in amniotic fluid volume. Early detection of TAPS could indicate fetoscopic laser coagulation of AV anastomoses.