First-trimester uterine artery Doppler indices in the prediction of small-for-gestational age pregnancy and intrauterine growth restriction

Role of Uterine Artery Doppler Study Between 11 and 14 Weeks as a Predictor of Preeclampsia

Introduction Preeclampsia is a serious complication marked by antepartum hemorrhage, resulting in severe maternal and fetal complications. Predicting this condition using placental dysfunction assessments, such as uterine artery Doppler ultrasound, is challenging due to the placenta's evolving structural and biochemical characteristics throughout different stages of pregnancy. Objectives To determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the uterine artery Doppler Pulsatility Index (PI) and Resistive Index (RI) in predicting preeclampsia. To compare the Doppler ultrasound measurements between normal pregnancies and those that develop preeclampsia. To assess the diagnostic accuracy of uterine artery Doppler ultrasound in predicting gestational hypertension in addition to preeclampsia. Methodology Conducted as a prospective study, 116 antenatal mothers with computed gestational ages and scan gestational ages between 11 and 14 weeks, and a previous history of preeclampsia were included. Subjects with chronic hypertension or multiple gestations were excluded. Participants underwent uterine artery Doppler screening, during which the PI and RI were measured upon obtaining three consecutive similar waveforms, and the mean PI of the left and right arteries was calculated. The outcomes of patients with normal pregnancies and those who developed preeclampsia were compared. Data were entered into Microsoft Excel (Microsoft® Corp., Redmond, WA, USA) and analyzed using IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, NY, USA). Results The mean PI among participants was 1.75 (±0.38), with a range from 1 to 2.75. The mean RI was 0.58 (±0.08), ranging from 0.45 to 0.8. The cutoff for the mean PI in predicting preeclampsia was 2.27, which showed a sensitivity of 92.9%, specificity of 97.1%, PPV of 81.47%, NPV of 99.01%, and a diagnostic accuracy of 96.59% (area under the curve (AUC): 0.982). The cutoff for the mean RI for predicting preeclampsia was 0.695, with a sensitivity of 85.7%, specificity of 98%, PPV of 85.47%, NPV of 98.04%, and diagnostic accuracy of 96.52% (AUC: 0.965). In predicting gestational hypertension, the cutoff for the mean PI was 1.975, with a sensitivity of 80%, specificity of 82.9%, PPV of 17.41%, NPV of 98.92%, and diagnostic accuracy of 82.78% (AUC: 0.848). The cutoff for the mean RI in predicting gestational hypertension was 0.615, showing a sensitivity of 80%, specificity of 80.2%, PPV of 15.4%, NPV of 98.89%, and diagnostic accuracy of 80.19% (AUC: 0.767). Conclusion The research demonstrated that aberrant readings in uterine Doppler ultrasound, specifically in the PI and RI, possess strong overall validity in forecasting the occurrence of preeclampsia.

Maternal cardiovascular profile is altered in the preclinical phase of normotensive early and late intrauterine growth restriction

BACKGROUND

The maternal cardiovascular profile of patients who develop late fetal growth restriction has yet to be well characterized, however, a subclinical impairment in maternal hemodynamics and cardiac function may be present before pregnancy and may become evident because of the hemodynamic alterations associated with pregnancy.

OBJECTIVE

This study aimed to investigate if maternal hemodynamics and the cardiovascular profile might be different in the preclinical stages (22-24 weeks' gestation) in cases of early and late fetal growth restriction in normotensive patients.

STUDY DESIGN

This was a prospective echocardiographic study of 1152 normotensive nulliparous pregnant women at 22 to 24 weeks' gestation. The echocardiographic evaluation included morphologic parameters (left ventricular mass index and relative wall thickness, left atrial volume index) and systolic and diastolic maternal left ventricular function (ejection fraction, left ventricular global longitudinal strain, E/A ratio, and E/e' ratio). Patients were followed until the end of pregnancy to note the development of normotensive early or late fetal growth restriction.

RESULTS

Of the study cohort, 1049 patients had no complications, 73 were classified as having late fetal growth restriction, and 30 were classified as having early fetal growth restriction. In terms of left ventricular morphology, the left ventricular end-diastolic diameter was greater in uneventful pregnancies (4.84±0.28 cm) than in late (4.67±0.26 cm) and in early (4.55±0.26 cm) (P<.001) fetal growth restriction cases, whereas left ventricular end-systolic diameter was smaller in uneventful pregnancies (2.66±0.39 cm) than in late (2.83±0.40 cm) and in early (2.82±0.38 cm) (P<.001) fetal growth restriction cases. The relative wall thickness was slightly higher in early (0.34±0.05) and late (0.35±0.04) fetal growth restriction cases than in uneventful pregnancies (0.32±0.05) (P<.05). In terms of systolic left ventricular function, at 22 to 24 weeks' gestation, cardiac output was higher in uneventful pregnancies (6.58±1.07 L/min) than in late (5.40±0.97 L/min) and in early (4.76±1.05 L/min) (P<.001) fetal growth restriction cases with the lowest values in the early-onset group. Left ventricular global longitudinal strain was lower in appropriate for gestational age neonates (-21.6%±2.0%) and progressively higher in late (-20.1%±2.2%) and early (-18.5%±2.3%) (P<.001) fetal growth restriction cases. In terms of diastolic left ventricular function, the E/e' ratio showed intermediate values in the late fetal growth restriction group (7.90±2.73) when compared with the appropriate for gestational age group (7.24±2.43) and with the early fetal growth restriction group (10.76±3.25) (P<.001). The total peripheral vascular resistance was also intermediate in the late fetal growth restriction group (1300±199 dyne·s·cm-5) when compared with the appropriate for gestational age group (993±175 dyne·s·cm-5) and the early fetal growth restriction group (1488±255 dyne.s.cm-5) (P<.001).

CONCLUSION

Early and late fetal growth restriction share similar maternal hemodynamic and cardiovascular profiles with a different degree of expression. These features are already present at 22 to 24 weeks' gestation and are characterized by a hypodynamic state. The degree of these cardiovascular changes may influence the timing of the manifestation of the disease; a hypovolemic, high resistance, low cardiac output state might be associated with early-onset fetal growth restriction, whereas a milder hypovolemic state seems to favor the development of the disease in the final stages of pregnancy.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Spiral, uterine artery doppler and placental ultrasound in relation to preeclampsia

Preeclampsia (PE) is a multiorgan disorder that complicates around 2-8% of pregnancies and is a major cause of perinatal and maternal morbidity and mortality. PE is a clinical syndrome characterized by hypertension secondary to systemic inflammation, endothelial dysfunction, and syncytiotrophoblast stress leading to hypertension and multiorgan dysfunction. The uterine arteries are the main blood vessels that supply blood to the uterus. They give off branches and plays an important role in maintaining blood supply during pregnancy. The arcuate artery originates from the uterine artery and runs medially through the myometrium. The arcuate arteries divide almost directly into anterior and posterior branches, from which the radial artery leads directly to the uterine cavity during their course. Near the endometrium-myometrium junction, the radial artery generates spiral arteries within the basal layer and functional endometrium. The walls of radial and spiral arteries are rich in smooth muscle, which is lost when trophoblast cells invade and become large-caliber vessels. This physiological transformation of uteroplacental spiral arteries is critical for successful placental implantation and normal placental function. In normal pregnancy, the luminal diameter of the spiral arteries is greatly increased, and the vascular smooth muscle is replaced by trophoblast cells. This process and changes in the spiral arteries are called spiral artery remodeling. In PE, this genetically and immunologically governed process is deficient and therefore there is decreased vascular capacitance and increased resistance in the uteroplacental circulation. Furthermore, this defect in uteroplacental spiral artery remodeling is not only associated with early onset PE, but also with fetal growth restriction, placental abruption, and spontaneous premature rupture of membranes. Doppler ultrasound allows non-invasive assessment of placentation, while the flow impedance decreases as the pregnancy progresses in normal pregnancies, in those destined to develop preeclampsia the impedance is increased.

Early changes in S100B maternal blood levels can predict fetal intrauterine growth restriction

OBJECTIVES

Intrauterine growth restriction (IUGR) represents one of the main causes of perinatal mortality and morbidity. Nowadays, IUGR early diagnosis is mandatory in order to limit the occurrence of multiorgan failure, especially the brain. Therefore, we investigated whether longitudinal S100B assessment in maternal blood could be a trustable predictor of IUGR.

METHODS

We conducted a prospective study in 480 pregnancies (IUGR: n=40; small for gestational age, SGA: n=40; controls: n=400) in whom S100B was measured at three predetermined monitoring time-points (T1: 8-18 GA; T2: 19-23 GA; T3: 24-28 GA).

RESULTS

Lower S100B in IUGR fetuses than SGA and controls (p<0.05, for all) at T1-T3. Receiver operating characteristic curve showed that S100B at T1 was the best predictor of IUGR (sensitivity: 100 %; specificity: 81.4 %) than T2, T3.

CONCLUSIONS

The early lower S100B concentration in pregnant women lately complicated by IUGR support the notion that non-invasive early IUGR diagnosis and monitoring is becoming feasible. Results open the way to further studies aimed at diagnosing and monitoring fetal/maternal diseases at earliest time.

Fetal Growth Restriction Is Associated with Pregnancy Associated Plasma Protein A and Uterine Artery Doppler in First Trimester

Fetal growth restriction (FGR) is a major cause of stillbirth and poor neurodevelopmental outcomes. The early prediction may be important to establish treatment options and improve neonatal outcomes. The aim of this study was to assess the association of parameters used in first-trimester screening, uterine artery Doppler pulsatility index and the development of FGR. In this retrospective cohort study, 1930 singleton pregnancies prenatally diagnosed with an estimated fetal weight under the third percentile were included. All women underwent first-trimester screening assessing maternal serum pregnancy-associated plasma protein A (PAPP-A), free beta-human chorionic gonadotrophin levels, fetal nuchal translucency and uterine artery Doppler pulsatility index (PI). We constructed a Receiver Operating Characteristics curve to calculate the sensitivity and specificity of early diagnosis of FGR. In pregnancies with FGR, PAPP-A was significantly lower, and uterine artery Doppler pulsatility index was significantly higher compared with the normal birth weight group (0.79 ± 0.38 vs. 1.15 ± 0.59, p < 0.001 and 1.82 ± 0.7 vs. 1.55 ± 0.47, p = 0.01). Multivariate logistic regression analyses demonstrated that PAPP-A levels and uterine artery Doppler pulsatility index were significantly associated with FGR (p = 0.009 and p = 0.01, respectively). To conclude, these two parameters can predict FGR < 3rd percentile.

Maternal Low Volume Circulation Relates to Normotensive and Preeclamptic Fetal Growth Restriction

This narrative review summarizes current evidence on the association between maternal low volume circulation and poor fetal growth. Though much work has been devoted to the study of cardiac output and peripheral vascular resistance, a low intravascular volume may explain why high vascular resistance causes hypertension in women with preeclampsia (PE) that is associated with fetal growth restriction (FGR) and, at the same time, presents with normotension in FGR itself. Normotensive women with small for gestational age babies show normal gestational blood volume expansion superimposed upon a constitutionally low intravascular volume. Early onset preeclampsia (EPE; occurring before 32 weeks) is commonly associated with FGR, and poor plasma volume expandability may already be present before conception, thus preceding gestational volume expansion. Experimentally induced low plasma volume in rodents predisposes to poor fetal growth and interventions that enhance plasma volume expansion in FGR have shown beneficial effects on intrauterine fetal condition, prolongation of gestation and birth weight. This review makes the case for elevating the maternal intravascular volume with physical exercise with or without Nitric Oxide Donors in FGR and EPE, and evaluating its role as a potential target for prevention and/or management of these conditions.

A Review of Roles of Uterine Artery Doppler in Pregnancy Complications

The invasion of trophoblasts into the uterine decidua and decidual vessels is critical for the formation of placenta. The defects of placentation are related to the etiologies of preeclampsia (PE), fetal growth restriction (FGR), and small-for-gestational age (SGA) neonates. It is possible to predict significant vascular events during pregnancy through uterine artery Doppler (UAD). From the implantation stage to the end of pregnancy, detecting changes in uterine and placental blood vessels can provide a favorable diagnostic instrument for pregnancy complications. This review aims to collect literature about the roles of UAD in pregnancy complications. We consider all relevant articles in English from January 1, 1983 to October 30, 2021. Predicting pregnancy complications in advance allows practitioners to carry out timely interventions to avoid or lessen the harm to mothers and neonates. Administering low-dose aspirin daily before 16 weeks of pregnancy can significantly reduce the incidence of pregnancy complications. From early pregnancy to late pregnancy, UAD can combine with other maternal factors, biochemical indicators, and fetal measurement data to identify high-risk population. The identification of high-risk groups can also lessen maternal mortality. Besides, through moderate risk stratification, stringent monitoring for high-risk pregnant women can be implemented, decreasing the incidence of adversities.

Prediction of late-onset fetal growth restriction using a combined first- and second-trimester screening model

BACKGROUND

Prediction models for early fetal growth restriction (FGR) have been exhibited in many researches. However, prediction models for late FGR are limited. Late-onset FGR is easy to miss clinically because of its insidious onset. This study aimed to develop a simple combined first- and second-trimester prediction model for screening late-onset FGR in fetuses.

METHODS

This retrospective study included 2746 women who had singleton pregnancies and received routine ultrasound scans as training dataset. Late FGR is that diagnosed >32 weeks. Multivariate logistic regression was used to develop a prediction model.

RESULTS

One hundred and twenty-nine fetuses were identified as late-onset FGR. The significant predictors for late-onset FGR were maternal height, weight, and medical history; the first-trimester mean arterial pressure, the second-trimester head circumference/ abdominal circumference ratio; and the second-trimester estimated fetal weight. This model achieved a detection rate (DR........) of 51.6% for late-onset FGR at a 10% false positive rate (FPR) (area under the curve (AUC): 0.80, 95%CI 0.76-0.84).

CONCLUSIONS

A multivariate model combining first- and second-trimester default tests can detect 51.6% of cases of late-onset FGR at a 10% FPR. Further studies with more screening markers are needed to improve the detection rate.

Perinatal outcomes in women affected by different types of headache disorders: A prospective cohort study

OBJECTIVE

This study aims to investigate pregnancy and perinatal outcomes in women with tension-type headache, migraine without aura and migraine with aura by comparing them to women without any headache disorders.

STUDY DESIGN

Prospective cohort study including singleton pregnancies attending the first trimester aneuploidy screening at the University Hospital of Modena, in Northern Italy, between June 2018 and December 2019.

RESULTS

A total of 515 consecutive women were included and headache disorders were reported in 43.5% of them (224/515). Tension-type headache was diagnosed in 24.3% of the cases, while 14% suffered from migraine without aura and 5.2% from migraine with aura. Birthweight was significantly lower in women affected by migraine with aura respective to other groups, and a significantly higher rate of small for gestational age infants was found in tension-type headache (10.4%) and in migraine with aura (24.9%) groups respective to the others (p < 0.001). Moreover, the admission to the neonatal intensive care unit was significantly higher in all the headache groups (p = 0.012). Multivariate analysis showed that women presenting tension-type headache (OR 4.19, p = 0.004), migraine with aura (OR 5.37, p = 0.02), a uterine artery pulsatility index >90th centile (OR 3.66, p = 0.01), low multiple of the median (MoM) of Pregnancy-associated plasma protein-A (PAPP-A) (OR 0.48, p = 0.05) and high MoM of Inhibin-A (OR 3.24, p = 0.03) at first trimester, are independently associated with the delivery of small for gestational age infants when compared to women without headache disorders.

CONCLUSION

Migraine with aura and tension type headache expose women to an increased risk of delivering small for gestational age infants, in association with some utero-placenta markers evaluated at first trimester. These women with headache disorders have an additional indication to undergo first trimester aneuploidy screening and would possibly benefit from specific interventions.

Evaluation of oxidative/nitrative stress and uterine artery pulsatility index in early pregnancy

Introduction

Increased oxidative/nitrative stress is characteristic not only in pathologic, but also in healthy pregnancy. High uterine artery pulsatility index (UtAPI) at the end of the first trimester is associated with altered placentation and elevated risk for adverse pregnancy outcomes. We aimed to examine the relationship of systemic oxidative/nitrative stress and uterine artery pulsatility index in the first trimester and their correlation to pregnancy outcomes.

Material and methods

Healthy pregnant women were recruited at 12-13th gestational week ultrasound examination; UtAPI was determined by color Doppler ultrasound. Patients were divided into high (UtAPI ≥ 2.3) (n = 30) and low (n = 31) resistance groups, and pregnancies were followed until labor. Systemic oxidative/nitrative stress was estimated by measuring total peroxide level, total antioxidant capacity and nitrotyrosine level.

Results

Plasma total peroxide level was significantly lower (2,510 ± 39 µM vs. 2,285 ± 59 µM), total antioxidant capacity was higher (781 ± 16 mM CRE vs. 822 ± 13 mM CRE) in the high UtAPI group, which were accompanied by lower birth weight (3,317 ± 64 vs. 3,517 ± 77 g, P < 0.05). Plasma total peroxide level showed a negative correlation (by Pearson) to UtAPI (P < 0.01) and positive correlation to birth weight (P < 0.05).

Conclusions

According to our results, lower systemic oxidative stress showed correlation with high UtAPI measured between the 12-13th weeks of gestation. We also found significant differences in the birth weight of healthy newborns; therefore it is worth examining this relationship in pathological pregnancies.

Spiral artery blood flow during pregnancy: a systematic review and meta-analysis

Background

Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta under all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed.

Methods

A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English written articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model.

Results

In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70–0.89) and 0.50 (95% CI: 0.47–0.54) in the first trimester to 0.50 (95% CI: 0.45–0.55, p < 0.001) and 0.39 (95% CI: 0.37–0.42, p < 0.001) in the second trimester and to 0.49 (95% CI: 0.44–0.53, p = 0.752) and 0.36 (95% CI: 0.35–0.38, p = 0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13–0.30 m/s) to 0.28 m/s (95% CI: 0.17–0.40 m/s, p = 0.377) and to 0.25 m/s (95% CI: 0.20–0.30 m/s, p = 0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p < 0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p = 0.349).

Conclusions

This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

Uterine Artery Doppler Ultrasonography for First Trimester Prediction of Preeclampsia in Individuals at Risk from Low-Resource Settings

Background and objectives: The objective of this study was to evaluate the potential of first trimester uterine artery Doppler ultrasonography for the early prediction of preeclampsia (PE), in at-risk pregnant women. Materials and Methods: This was a prospective longitudinal study, including 120 Caucasian pregnant women with risk factors for PE. The potential of pulsatility indexes (PI) and notch was assessed as a tool for preeclampsia screening. Results: Doppler examination of the uterine artery performed early at 11-14 WA allows the detection of pregnancies that will develop PE with a sensitivity of 61.5% and a specificity of 63.8% based on PI analysis. Predictive power increases slightly by adding bilateral notch (sensitivity = 65.4%; specificity = 66%). Conclusions: Uterine artery Doppler examination is an effective non-invasive screening test for the development of PE in pregnancies at risk, particularly appropriate in health systems with limited means of evaluating other biomarkers.

A bibliometric analysis of Intrauterine Growth Restriction research

Intrauterine growth restriction (IUGR) is not a new subject in pregnancy. Nevertheless, this concept has newly begun to be integrated into pregnancy studies. We recognized articles that were published in English from 1977 to 2019 through electronic searches of the Web of Science™ database. The WoS database was searched for all published articles that compared preeclampsia from 1977 to January 2020. About 1469 documents in obstetrics and gynecology areas were analyzed in WoS database. VOSviewer software was employed to visualize the networks. The survey resulted in a 1469 published documents from 1977 to 2020. 'Gratacos' from Spain and 'Cetin' from Italy contributed the most publications. The greatest contribution came from the 'USA' (n = 498), 'Italy' (n = 155), and 'England' (n = 147). Furthermore, our results found that among these journals, the 'AJOG' (n = 318) and the 'Reproductive Sciences' (n = 209) published the largest number of papers. The top 100 most cited papers showed that 30% were reported in the 'AJOG'. About half the articles were published in the last decade and the most common studies were research paper (77%). The co-occurrence and co-citation analysis showed that the study formed four clusters. Finally, the strategic map was designed. We found that there existed an increasing trend in the large amount of publication on IUGR from 1977 to 2020. The number of studies in IUGR has substantially improved in the last decade. Authors from the 'USA' appeared the most proactive in addressing the IUGR area. By studying these articles, we propose important to support not only for grinding the IUGR challenges field but also for designing a new trend in this area.

Can increased resistance to uterine artery flow be a risk factor for adverse neurodevelopmental outcomes in childhood? A prospective cohort study

A prospective cohort study was conducted to determine whether an increased uterine artery pulsatility index (UtA-PI) in the second trimester of pregnancy is a risk factor for neurodevelopmental outcomes in children 2-3 years of age. A group of pregnant women with a UtA-PI below the 90th percentile (P90) and a second group with a UtA-PI ≥ P90 in the second trimester were included in this study. The children of these women were evaluated during their second or third year of life using the Bayley III Screening Test. A total of 858 pregnancies with UtA-PI < P90 and 96 pregnancies with UtA-PI ≥ 90 were studied. The differences between the groups related to UtA-PI ≥ 90 were detected in relation to the variables of the Caucasian ethnicity, hypertension, newborn weight and stay in the intensive care unit after birth. However, adjusted neurodevelopmental outcomes did not differ between the groups: OR 0.53 (95% CI 0.27-1.04%). This study failed to demonstrate that the UtA-PI is a risk factor for adverse neurodevelopment in children.Impact statementWhat is already known on this subject? Early interventions in children at high risk for neurodevelopmental deficiency have proved to be beneficial. The complications associated with gestation and delivery negatively influence neurodevelopment. Several studies have shown that some adverse pregnancy outcomes such as preeclampsia, foetal growth restriction and foetal death can be predicted by increased resistance to flow in the uterine artery in the second trimester. However, there are no studies evaluating the association of the uterine artery with neurodevelopmental results.What do the results of this study add? This study concludes that neurodevelopment is influenced by multiple environmental and intrinsic factors and cannot be predicted by only one variable, such as the uterine artery blood flow. The brain has repair mechanisms to attenuate insults that occur during gestation and delivery.What are the implications of these findings for clinical practice and/or further research? This study was unable to demonstrate that blood flow in the uterine artery is a risk factor for neurodevelopment. Different, larger studies should be conducted by combining other factors with the uterine artery in an algorithm to allow the early identification of children at risk for neurodevelopmental impairment.

Do Doppler Changes Reflect Pathology of Placental Vascular Lesions in IUGR Pregnancies?

OBJECTIVES

Doppler assessment of uteroplacental (UP) and fetoplacental (FP) circulation detects abnormal waveforms in intrauterine growth-restricted (IUGR) pregnancies. Similarly, histopathology also reveals lesions of vascular compromise in IUGR placenta. We evaluated an association between Doppler and histopathological (HP) assessment of the maternal and fetal circulation in IUGR.

METHODS

IUGR cases with both Doppler and histopathology assessment were selected from our database. Doppler patterns recorded UP and FP insufficiency. The HP vascular lesions were classified as maternal vascular underperfusion and fetal thrombotic vasculopathy (FTV). IUGRs were grouped based on (i) presence of preeclampsia (PE), (ii) clinical onset (early vs late) of IUGR (early onset [EO]/late onset), and (iii) gestational age (term, T/preterm, PT).

RESULTS

Abnormal Doppler waveforms were present in 69 of the total 88 IUGR cases (78.4%). The most frequent pattern was fetoplacental insufficiency (FPI) (66%) which was combined with uteroplacental insufficiency (UPI) in 49%. HP showed vascular lesions in 52.3% and most frequent was FTV (38%). PE-associated IUGR (n = 49) had higher UPI pattern (75.5% vs 43.6%, P = .004), while normotensive IUGR had higher FPI pattern (28.2% vs 8.2%, P = .01). EO-IUGR (n = 55) and PT-IUGR (n = 52) had significant abnormal Doppler waveforms (P < .05) with higher combined patterns and brain sparing. Doppler was more sensitive for fetal vascular lesions than maternal (75.8% vs 66.7%). However, 42% of cases with normal Doppler findings showed HP vascular lesions.

CONCLUSION

IUGR pregnancies harbor significant vascular compromise. Fetal circulatory lesions were more common in IUGR pregnancies. In a significant number of cases with normal Doppler report, vascular lesions were identified on histopathology, emphasizing placental examination in all cases of IUGR.

The prediction of early preeclampsia: Results from a longitudinal proteomics study

OBJECTIVES

To identify maternal plasma protein markers for early preeclampsia (delivery <34 weeks of gestation) and to determine whether the prediction performance is affected by disease severity and presence of placental lesions consistent with maternal vascular malperfusion (MVM) among cases.

STUDY DESIGN

This longitudinal case-control study included 90 patients with a normal pregnancy and 33 patients with early preeclampsia. Two to six maternal plasma samples were collected throughout gestation from each woman. The abundance of 1,125 proteins was measured using high-affinity aptamer-based proteomic assays, and data were modeled using linear mixed-effects models. After data transformation into multiples of the mean values for gestational age, parsimonious linear discriminant analysis risk models were fit for each gestational-age interval (8-16, 16.1-22, 22.1-28, 28.1-32 weeks). Proteomic profiles of early preeclampsia cases were also compared to those of a combined set of controls and late preeclampsia cases (n = 76) reported previously. Prediction performance was estimated via bootstrap.

RESULTS

We found that 1) multi-protein models at 16.1-22 weeks of gestation predicted early preeclampsia with a sensitivity of 71% at a false-positive rate (FPR) of 10%. High abundance of matrix metalloproteinase-7 and glycoprotein IIbIIIa complex were the most reliable predictors at this gestational age; 2) at 22.1-28 weeks of gestation, lower abundance of placental growth factor (PlGF) and vascular endothelial growth factor A, isoform 121 (VEGF-121), as well as elevated sialic acid binding immunoglobulin-like lectin 6 (siglec-6) and activin-A, were the best predictors of the subsequent development of early preeclampsia (81% sensitivity, FPR = 10%); 3) at 28.1-32 weeks of gestation, the sensitivity of multi-protein models was 85% (FPR = 10%) with the best predictors being activated leukocyte cell adhesion molecule, siglec-6, and VEGF-121; 4) the increase in siglec-6, activin-A, and VEGF-121 at 22.1-28 weeks of gestation differentiated women who subsequently developed early preeclampsia from those who had a normal pregnancy or developed late preeclampsia (sensitivity 77%, FPR = 10%); 5) the sensitivity of risk models was higher for early preeclampsia with placental MVM lesions than for the entire early preeclampsia group (90% versus 71% at 16.1-22 weeks; 87% versus 81% at 22.1-28 weeks; and 90% versus 85% at 28.1-32 weeks, all FPR = 10%); and 6) the sensitivity of prediction models was higher for severe early preeclampsia than for the entire early preeclampsia group (84% versus 71% at 16.1-22 weeks).

CONCLUSION

We have presented herein a catalogue of proteome changes in maternal plasma proteome that precede the diagnosis of preeclampsia and can distinguish among early and late phenotypes. The sensitivity of maternal plasma protein models for early preeclampsia is higher in women with underlying vascular placental disease and in those with a severe phenotype.

First trimester Doppler velocimetry of the uterine artery ipsilateral to the placenta improves ability to predict early-onset preeclampsia

This study sought to investigate the effects of placental laterality on the measurements of uterine artery (UtA) Doppler velocimetry and their application in predicting early-onset preeclampsia (PE).We conducted a prospective cohort study on all women with singleton, uncomplicated pregnancies scheduled for first-trimester nuchal translucency at our institution. Pulsatility index (PI) for both UtAs was measured by Doppler velocimetry, and placental laterality was determined. Additionally, pregnancy outcome data were abstracted from the medical records. Receiver operating characteristic curves (ROCs) were plotted.Of the 304 patients enrolled, 247 met the inclusion criteria. Among these patients, 240 had uncomplicated delivery, while 7 had early delivery at <34 weeks due to PE. For the uncomplicated pregnancies, PI measurements of the UtA ipsilateral to the placenta were similar (left versus right UtA: 1.06 ± 0.38 vs. 1.04 ± 0.40; P = .745). However, PI measurements of the UtA contralateral to the placenta differed significantly (left versus right UtA: 1.45 ± 0.51 vs. 1.3 ± 0.47; P = .027). In predicting early-onset PE, the ideal cut-off value for the placental side PI was 1.91, with sensitivity 100% and specificity 96.3%. For nonplacental side PI, the ideal cut-off value for PI was 1.975, with sensitivity 57.1% and specificity 79.2%. Using the mean of the left and right UtA PI, the ideal cut-off value was 1.63, with sensitivity 100% and specificity 74.2%.ROC analysis confirmed that PI measurements of the UtA on the placental side were significantly lower than those on the contralateral side, PI measurements of the UtA ipsilateral to the placenta were similar.

Correlation between uterine artery Doppler and the sFlt-1/PlGF ratio in different phenotypes of placental dysfunction

OBJECTIVE

To explore correlations between the sFlt-1/PlGF ratio and uterine arteries (UtA) Doppler indexes in placental dysfunction-related disorders (PDD).

METHODS

We prospectively included women with a singleton pregnancy with preeclampsia (PE) only (n = 22), preeclampsia with fetal growth restriction (FGR) (n = 32), FGR only (n = 12), or normal pregnancy (n = 29).

RESULTS

In PDDs, significantly positive correlations between the sFlt-1/PlGF ratio and the mean UtA pulsatility (mPI-UtA), as well as the resistance index (mRI-UtA) were found (p = 0.015, p = 0.019, respectively), but not in normal pregnancies. PDD with signs of impaired placentation, evidenced by the increased sFlt-1/PlGF ratio and mPI-UtA, was found in 50.0%, and, by the increased sFlt-1/PlGF ratio and mRI-UtA, in 65.2%. PDD without signs of impaired placentation, evidenced by the increased sFlt-1/PlGF ratio but normal mPI-UtA, was found in 24.2%, and, by the increased sFlt-1/PlGF ratio but normal mRI-UtA, in 7.6%. A substantial proportion of women with signs of impaired placentation were diagnosed with FGR with or without PE.

CONCLUSION

In PDD, the sFlt-1/PlGF ratio and UtA Doppler indexes increase proportionally. Correlations between the sFlt-1/PlGF ratio and UtA Doppler indexes might help to distinguish between PDDs with and without impaired placentation. However, further studies are needed to explore the correlations in different phenotypes of PDD.

First-Trimester Uterine Artery Doppler for the Prediction of SGA at Birth: The Great Obstetrical Syndromes Study

OBJECTIVE

To estimate the role of first-trimester uterine artery pulsatility index (UtA-PI) for the prediction of small-for-gestational age (SGA).

METHODS

We conducted a prospective cohort study of nulliparous women with singleton pregnancy (Great Obstetrical Syndromes study). UtA-PI was performed at 11 + 0 to 13 + 6 weeks and was reported in multiple of median (MoM). SGA was defined as birth weight below the 10th percentile and stratified as term or preterm SGA. Receiver operating characteristic curves analyses with their area under the curve (AUC) were used to estimate the predictive values of UtA-PI, alone and UtA-PI combined with maternal characteristics. We computed the detection rate and false-positive rate (FPR) of the SOGC SGA screening guidelines in our population.

RESULTS

Of 4610 participants, SGA was identified in 486 pregnancies (10.3%), including 15 (0.3%) associated with preterm delivery. Compared with unaffected pregnancies, the mean log UtA-PI was significantly higher in term SGA and preterm SGA. The difference between preterm SGA and unaffected pregnancies remains significant after exclusion of SGA without preeclampsia. First-trimester UtA-PI was more predictive of preterm (AUC: 0.89) than term (AUC: 0.60) SGA (P < 0.01). Combined with maternal characteristics, UtA-PI could have predicted 64% of preterm and 20% of term SGA (10% FPR). The SOGC guidelines criteria for early screening of SGA had a detection rate of 21% for a FPR of 21%.

CONCLUSIONS

First-trimester UtA-PI can be used to predict SGA, but mainly preterm SGA. The current SOGC guidelines criteria for SGA screening are not efficient in nulliparous women.

Perinatal loss at term: role of uteroplacental and fetal Doppler assessment

OBJECTIVE

To examine the associations of uterine artery (UtA) Doppler indices and cerebroplacental ratio (CPR) with perinatal outcome at term.

METHODS

This was a retrospective cohort study conducted at a tertiary referral center that included all singleton pregnancies undergoing ultrasound assessment in the third trimester that subsequently delivered at term. Fetal biometry and Doppler assessment, including that of the umbilical artery (UA), fetal middle cerebral artery (MCA) and UtA, were recorded. Data were corrected for gestational age, and CPR was calculated as the ratio of MCA pulsatility index (PI) to UA-PI. Logistic regression analysis was conducted to examine for independent predictors of adverse perinatal outcome.

RESULTS

The study included 7013 pregnancies, 12 of which were complicated by perinatal death. When compared with pregnancies resulting in perinatal survival, pregnancies complicated by perinatal death had a significantly higher proportion of small-for-gestational-age infants (25.0% vs 5%; P = 0.001) and a higher incidence of low (< 5^th centile) CPR (16.7% vs 4.5%; P = 0.041). A subgroup analysis comparing 1527 low-risk pregnancies that resulted in fetal survival with pregnancies complicated by perinatal death demonstrated that UtA-PI multiples of the median (MoM), CPR < 5^th centile and estimated fetal weight (EFW) centile were all associated significantly with the risk of perinatal death at term (all P < 0.05). After adjusting for confounding variables, only EFW centile (odds ratio (OR) 0.96 (95% CI, 0.93-0.99); P = 0.003) and UtA-PI MoM (OR 13.10 (95%CI, 1.95-87.89); P = 0.008) remained independent predictors of perinatal death in the low-risk cohort.

CONCLUSION

High UtA-PI at term is associated independently with an increased risk of adverse perinatal outcome, regardless of fetal size. These results suggest that perinatal mortality at term is related not only to EFW and fetal redistribution (CPR), but also to indices of uterine perfusion. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Planning management and delivery of the growth-restricted fetus

A uniform approach to management of fetal growth restriction (FGR) improves outcome, prevents stillbirth, and allows appropriately timed delivery. An estimated fetal weight below the tenth percentile with coexisting abnormal umbilical artery (UA), middle cerebral artery (MCA), or cerebroplacental ratio Doppler index best identifies the small fetus requiring surveillance. Placental perfusion defects are more common earlier in gestation; accordingly, early-onset (≤32 weeks of gestation) and late-onset (>32 weeks) FGR differ in clinical phenotype. In early-onset FGR, progression of UA Doppler abnormality determines clinical acceleration, while abnormal ductus venosus (DV) Doppler precedes deterioration of biophysical variables and stillbirth. Accordingly, late DV Doppler changes, abnormal biophysical variables, or an abnormal cCTG require delivery. In late-onset FGR, MCA Doppler abnormalities precede deterioration and stillbirth. However, from 34 to 38 weeks, randomized evidence on optimal delivery timing is lacking. From 38 weeks onward, the balance of neonatal versus fetal risks favors delivery.

Diagnosis and surveillance of late-onset fetal growth restriction

By consensus, late fetal growth restriction is that diagnosed >32 weeks. This condition is mildly associated with a higher risk of perinatal hypoxic events and suboptimal neurodevelopment. Histologically, it is characterized by the presence of uteroplacental vascular lesions (especially infarcts), although the incidence of such lesions is lower than in preterm fetal growth restriction. Screening procedures for fetal growth restriction need to identify small babies and then differentiate between those who are healthy and those who are pathologically small. First- or second-trimester screening strategies provide detection rates for late smallness for gestational age <50% for 10% of false positives. Compared to clinically indicated ultrasonography in the third trimester, universal screening triples the detection rate of late smallness for gestational age. As opposed to early third-trimester ultrasound, scanning late in pregnancy (around 37 weeks) increases the detection rate for birthweight <3rd centile. Contrary to early fetal growth restriction, umbilical artery Doppler velocimetry alone does not provide good differentiation between late smallness for gestational age and fetal growth restriction. A combination of biometric parameters (with severe smallness usually defined as estimated fetal weight or abdominal circumference <3rd centile) with Doppler criteria of placental insufficiency (either in the maternal [uterine Doppler] or fetal [cerebroplacental ratio] compartments) offers a classification tool that correlates with the risk for adverse perinatal outcome. There is no evidence that induction of late fetal growth restriction at term improves perinatal outcomes nor is it a cost-effective strategy, and it may increase neonatal admission when performed <38 weeks.

Differential performance of first-trimester screening in predicting small-for-gestational-age neonate or fetal growth restriction

OBJECTIVE

To assess the ability of integrated first-trimester screening, combining maternal characteristics and biophysical and biochemical markers, to predict delivery of a small-for-gestational-age (SGA) neonate, and compare this with its ability to predict fetal growth restriction (FGR).

METHODS

This was a prospective cohort study of singleton pregnancies undergoing routine first-trimester screening. SGA was defined as birth weight (BW) < 10^th percentile and FGR was defined as an ultrasound estimated fetal weight < 10^th percentile plus Doppler abnormalities, or BW < 3^rd percentile. Logistic regression-based predictive models were developed for predicting SGA and FGR. Models incorporated the a-priori risk from maternal characteristics, and mean arterial pressure, uterine artery Doppler, placental growth factor and soluble fms-like tyrosine kinase-1.

RESULTS

In total, 9150 births were included. Of these, 979 (10.7%) qualified for a postnatal diagnosis of SGA and 462 (5.0%) for a prenatal diagnosis of FGR. For predicting SGA, the model achieved a detection rate of 35% for a false-positive rate (FPR) of 5% and 42% for a 10% FPR. The model's performance was significantly higher for predicting FGR (P < 0.001), with detection rates of 59% and 67%, for a FPR of 5% and 10%, respectively.

CONCLUSION

The predictive performance of first-trimester screening for cases with growth impairment by a combination of maternal characteristics and biophysical and biochemical markers is improved significantly when a prenatal and strict definition of FGR is used rather than a postnatal definition based on BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Lung and cardiac ultrasound for hemodynamic monitoring of patients with severe pre-eclampsia

OBJECTIVE

To evaluate lung and cardiac ultrasound for the assessment of fluid tolerance and fluid responsiveness before and after delivery in pregnant women with severe pre-eclampsia (PE).

METHODS

This was a prospective observational study of singleton pregnant women with severe PE and healthy term controls. Lung ultrasound echo comet score (ECS), which denotes the amount of extravascular lung water, was obtained using the 28-rib interspaces technique. The echocardiographic E/e' ratio, measured by pulsed-wave and tissue Doppler, was used as a marker of diastolic left ventricular function. Fluid responsiveness was assessed by measuring changes in stroke volume (SV) with passive leg raising (PLR). SV was calculated from the left ventricular flow velocity-time integral measured by pulsed-wave Doppler at baseline and after PLR. Change in SV ≥ 12% was considered to indicate fluid responsiveness. Measurements obtained 1 day before delivery and 1 and 4 days after delivery were compared in the two groups (PE vs controls).

RESULTS

We included 21 women with severe PE and 12 healthy controls. ECS and E/e' ratio were higher in women with PE than in controls, both before delivery (P = 0.002 and P = 0.02) and 1 day postdelivery (P = 0.02 and P = 0.03); however there was no difference at 4 days postdelivery (P = 0.63 and P = 0.90). The change in SV with PLR before (P = 0.26) and after (P = 0.71) delivery did not differ between groups. An increase in SV ≥ 12% was observed in three (14%) women with PE and four (33%) controls before delivery and in four (19%) women with PE and two (17%) controls 1 day after delivery.

CONCLUSIONS

Severe PE is associated with an increase in extravascular lung water, which could in part be caused by disturbed diastolic left ventricular function. Excess lung water can be identified by lung ultrasound assessment in women with severe PE before the appearance of clinical signs. Only a small proportion of these women are fluid responsive. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Human placental growth hormone is increased in maternal serum at 20 weeks of gestation in pregnancies with large-for-gestational-age babies

To investigate the relationship between maternal serum concentrations of placental growth hormone (GH-V), insulin-like growth factor (IGF)-1 and 2, IGF binding proteins (IGFBP)-1 and 3 and birth weight in appropriate-for-gestational-age (AGA), large-for-gestational-age (LGA) and small-for-gestational-age (SGA) cases in a nested case-control study. Maternal serum samples were selected from the Screening for Pregnancy Endpoints (SCOPE) biobank in Auckland, New Zealand. Serum hormone concentrations were determined by ELISA. We found that maternal serum GH-V concentrations at 20 weeks of gestation in LGA pregnancies were significantly higher than in AGA and SGA pregnancies. Maternal GH-V concentrations were positively correlated to birth weights and customized birth weight centiles, while IGFBP-1 concentrations were inversely related to birth weights and customized birth weight centiles. Our findings suggest that maternal serum GH-V and IGFBP-1 concentrations at 20 weeks' gestation are associated with fetal growth.

First-trimester screening with specific algorithms for early- and late-onset fetal growth restriction

OBJECTIVE

To develop optimal first-trimester algorithms for the prediction of early and late fetal growth restriction (FGR).

METHODS

This was a prospective cohort study of singleton pregnancies undergoing first-trimester screening. FGR was defined as an ultrasound estimated fetal weight < 10(th) percentile plus Doppler abnormalities or a birth weight < 3(rd) percentile. Logistic regression-based predictive models were developed for predicting early and late FGR (cut-off: delivery at 34 weeks). The model included the a-priori risk (maternal characteristics), mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1).

RESULTS

Of the 9150 pregnancies included, 462 (5%) fetuses were growth restricted: 59 (0.6%) early and 403 (4.4%) late. Significant contributions to the prediction of early FGR were provided by black ethnicity, chronic hypertension, previous FGR, MAP, UtA-PI, PlGF and sFlt-1. The model achieved an overall detection rate (DR) of 86.4% for a 10% false-positive rate (area under the receiver-operating characteristics curve (AUC): 0.93 (95% CI, 0.87-0.98)). The DR was 94.7% for FGR with pre-eclampsia (PE) (64% of cases) and 71.4% for FGR without PE (36% of cases). For late FGR, significant contributions were provided by chronic hypertension, autoimmune disease, previous FGR, smoking status, nulliparity, MAP, UtA-PI, PlGF and sFlt-1. The model achieved a DR of 65.8% for a 10% false-positive rate (AUC: 0.76 (95% CI, 0.73-0.80)). The DR was 70.2% for FGR with PE (12% of cases) and 63.5% for FGR without PE (88% of cases).

CONCLUSIONS

The optimal screening algorithm was different for early vs late FGR, supporting the concept that screening for FGR is better performed separately for the two clinical forms. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Maternal arterial elasticity in the first trimester as a predictor of birthweight

The early detection of foetal growth restriction and macrosomia is an important goal of modern obstetric care. Aberrant foetal growth is an important cause of perinatal morbidity and mortality. Current modalities for detecting the abnormal foetal growth are often inadequate. Pulse wave analysis using applanation tonometry is a simple and non-invasive test that provides information about the cardiovascular system. Arterial elasticity has previously been implicated in the pathophysiology of pre-eclampsia and cardiovascular disease. Our study examined the relationship between maternal arterial elasticity and birthweight by using pulse wave analysis. We discovered that increased large artery elasticity predicted a larger baby at birth. Large artery elasticity therefore has the potential to act as a useful screening tool which may help in the prediction of women who are at risk of aberrant foetal growth.

Value of third-trimester cerebroplacental ratio and uterine artery Doppler indices as predictors of stillbirth and perinatal loss

OBJECTIVE

Placental insufficiency contributes to the risk of stillbirth. Cerebroplacental ratio (CPR) is an emerging marker of placental insufficiency. The aim of this study was to evaluate the association of third-trimester fetal CPR, uterine artery (UtA) Doppler and estimated fetal weight (EFW) with stillbirth and perinatal death.

METHODS

This was a retrospective cohort study including 2812 women with a singleton pregnancy who underwent an ultrasound scan in the third trimester. EFWs were converted into centiles, and Doppler indices (UtA and CPR) were converted into multiples of the median (MoM), adjusting for gestational age. Regression analysis was performed to identify, and adjust for, potential confounders, and receiver-operating characteristics (ROC) curve analysis was used to assess the predictive value.

RESULTS

When adjusting for EFW centile and UtA mean pulsatility index (UtA-PI) MoM, CPR-MoM remained an independent predictor of stillbirth (odds ratio (OR) = 0.003 (95% CI, 0.00-0.11), P = 0.003) and perinatal mortality (OR = 0.001 (95% CI, 0.00-0.03), P < 0.001). UtA-PI ≥ 1.5 MoM was significantly associated with low CPR-MoM, even after adjusting for EFW centile (OR = 5.22 (95% CI, 3.88-7.04), P < 0.001) or small-for-gestational age (SGA; OR = 4.73 (95% CI, 3.49-6.41), P < 0.001). These associations remained significant, even when excluding pregnancies with SGA or including only cases in which Doppler indices were recorded at term (P < 0.01). For prediction of stillbirth, the area under the ROC curve, using a combination of these three parameters, was 0.88 (95% CI, 0.77-0.99) with a sensitivity of 66.7%, specificity of 92.1%, positive likelihood ratio (LR) of 8.46 and negative LR of 0.36.

CONCLUSIONS

Third-trimester CPR is an independent predictor of stillbirth and perinatal mortality. The role of UtA Doppler, CPR and EFW in assessing risk of adverse pregnancy outcome should be evaluated prospectively.

Mid-pregnancy fetal biometry, uterine artery Doppler indices and maternal demographic characteristics: role in prediction of small-for-gestational-age birth

INTRODUCTION

The aim of this study was to evaluate the role of mid-trimester fetal biometry, uterine artery Doppler indices and maternal demographics in prediction of small-for-gestational-age (SGA) birth.

MATERIALS AND METHODS

We conducted a retrospective cohort study in a single referral center. The study included 23 894 singleton pregnancies scanned between 19 and 24 weeks of gestation. Maternal demographics included age, body mass index and ethnicity. Fetal biometry, birthweight and uterine artery pulsatility index values were converted into centiles. Multivariable logistic regression analysis was performed and the predictive accuracy was assessed using receiver operating characteristic curve analysis. The main outcome measure was prediction of delivery of preterm and term SGA neonates defined as a birthweight in the lowest centile groups (<10th, <5th and <3rd centiles).

RESULTS

Maternal ethnicity, fetal biometry and uterine artery Doppler indices were significantly associated with the risk of SGA <5th centile (p < 0.01). Maternal factors or fetal biometry alone showed poor to moderate performance in prediction of term and preterm SGA <5th centile at a 10% false-positive rate. Uterine artery pulsatility index alone was able to predict 25, 60 and 77% of SGA <5th centile delivering at >37, <37 and <32 weeks of gestation respectively at a 10% false-positive rate; maternal factors, fetal biometry and uterine artery Doppler combined detected 40, 66 and 89% of term, preterm and very preterm SGA <5th centile at a 10% false-positive rate.

CONCLUSIONS

Second-trimester screening can identify the majority of pregnancies at high risk of SGA birth and showed a higher performance for earlier gestational ages at birth and lower birthweight centiles.

Number of episodes of reduced fetal movement at term: association with adverse perinatal outcome

OBJECTIVE

The aims of this study were evaluation of the association of reduced fetal movements (RFM) and small-for-gestational-age (SGA) birth at term and to explore if fetal and maternal outcomes are different with single vs repeated episodes of RFM and normal fetal assessment test results.

STUDY DESIGN

This was a retrospective cohort study of all singleton pregnancies referred for RFMs at a tertiary fetal medicine unit from January 2008 through September 2014. Ultrasound and Doppler indices were obtained from a computerized ultrasound database and pregnancy outcome was collected from hospital records.

RESULTS

Of the 21,944 women with a singleton pregnancy booked for maternity care during the study period, 1234 women (5.62%) reported RFMs >36+0 weeks. Of these, 1029 women (83.4%) reported a single episode of RFM and 205 (16.6%) had ≥2 presentations for RFM. Women with repeated RFMs had a significantly higher mean uterine artery pulsatility index in the second trimester. The prevalence of SGA baby at birth in women presenting with a single episode as compared to repeated episodes of RFM was 9.8% and 44.2%, respectively (odds ratio, 7.3; 95% confidence interval, 5.1-10.4; P < .05).

CONCLUSION

Repeated episodes of RFMs at term are more likely to occur in women with high second-trimester uterine artery Doppler resistance indices and are strongly associated with the birth of SGA infants. Women presenting with repeated episodes of RFM should be treated as being at high risk of placental dysfunction irrespective of the results of prenatal ultrasound and Doppler assessment.

Reproducibility of first- and second-trimester uterine artery pulsatility index measured by transvaginal and transabdominal ultrasound

OBJECTIVES

To examine and compare the reproducibility of measurement of first- and second-trimester uterine artery pulsatility index (UtA-PI) using transabdominal (TAS) and transvaginal (TVS) ultrasound.

METHODS

This was an observational study including women ≥ 18 years of age, with a singleton pregnancy, in the first trimester (between 11 + 0 and 13 + 6 weeks' gestation) or second trimester (between 20 and 26 weeks' gestation). UtA-PI and angle of insonation were assessed by two observers (one with 15 and the other with 3 years of experience) using both TAS and TVS. The more experienced observer performed two scans alternated by the other observer. The acquisitions were completely independent and the observers were blinded to each other and to their own measurements. Reproducibility of the measurements by TVS and TAS was assessed using the concordance correlation coefficients (CCCs), intraclass correlation coefficients (ICCs) and limits of agreement (LoA).

RESULTS

We analyzed data from 97 women in the first trimester and 96 in the second trimester. The mean ± SD UtA-PI was significantly higher when measured using TVS, compared with TAS, in both the first (1.60 ± 0.49 vs 1.52 ± 0.63, respectively; P = 0.03) and second (1.07 ± 0.33 vs 0.96 ± 0.32, respectively; P < 0.001) trimesters. The median angle of insonation was significantly lower when using TVS, compared with TAS, in both the first (8.0° (interquartile range (IQR), 2.5-16.3°) vs 12.5° (IQR, 2.5-20.0°), respectively; P = 0.04) and second (10.0° (IQR, 4.5-16.5°) vs 17.5° (IQR, 5.0-27.9°), respectively; P < 0.001) trimesters. Both ultrasound techniques had similar reproducibility: the intraobserver CCC ranged from 0.93 to 0.95 and the interobserver CCC ranged from 0.81 to 0.86; and the ICCs of both techniques were highly comparable (the intraobserver LoA was approximately ± 20-30% and the interobserver LoA was approximately ± 30-40%).

CONCLUSIONS

When measuring UtA-PI, assessment by TVS provides higher values and better insonation angle compared with TAS. The reproducibility of the ultrasound methods in both first and second trimesters of pregnancy was comparable and should not be considered as good. Future studies examining technical improvements with the aim of increasing the reproducibility of this technique should be encouraged.

Maternal clinic and home blood pressure measurements during pregnancy and infant birth weight: the BOSHI study

This prospective cohort study compared measurements of maternal home blood pressure (HBP) with clinic blood pressure (CBP) before 20 weeks' gestation to determine associations with the risk of delivering a lower birth weight infant. A total of 605 Japanese women were included. Exposures were initial CBP, made between 10 weeks 0 days and 19 weeks 0 days, and HBP for comparison made within 1 week of CBP. Outcome was infant's birth weight, categorized and ranked as follows: ⩾3500 g, 3000-3499 g, 2500-2999 g and <2500 g. The proportional odds model with possible confounding factors was applied to compare the associations between CBP and HBP on infant birth weight. When both CBP and HBP were included simultaneously, the adjusted odds ratios (ORs) per 1 standard deviation (1s.d.) increase in clinic and home diastolic BP (DBP) were 1.06 (95% confidence interval (CI): 0.87-1.30) and 1.28 (95% CI: 1.04-1.58), respectively. The adjusted ORs per 1s.d. increase in clinic and home mean arterial pressure (MAP) were 1.02 (95% CI: 0.83-1.24) and 1.29 (95% CI: 1.04-1.59), respectively. Systolic BP measurement was not associated with infant birth weight. In conclusion, high maternal home DBP and MAP before 20 weeks' gestation was associated with a higher risk of lower infant birth weight than clinic DBP and MAP. Therefore, in addition to CBP, it may be worth having pregnant women measure HBP to determine the risk of lower infant birth weight.

Evaluating the Optimal Definition of Abnormal First-Trimester Uterine Artery Doppler Parameters to Predict Adverse Pregnancy Outcomes

OBJECTIVES

To investigate the optimal definition of abnormal first-trimester uterine artery Doppler parameters associated with adverse pregnancy outcomes.

METHODS

A prospective cohort of women with singleton gestations between 11 and 14 weeks consented to uterine artery Doppler measurements. Doppler parameters were measured bilaterally, and mean pulsatility index (PI) and resistive index (RI) values were calculated. The presence of notching was also determined. Each parameter was evaluated for prediction of preeclampsia, early preeclampsia (<34 weeks), preterm birth (<37 weeks), early preterm birth (<34 weeks), and small for gestational age (SGA; birth weight <10th percentile). Descriptive statistics evaluated the association between abnormal Doppler indices and outcomes. A receiver operating characteristic (ROC) analysis was used to define the best cutoff points for mean PI and RI. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were calculated for bilateral notching and mean PI and RI percentiles.

RESULTS

Of 1192 patients with complete outcome data, preeclampsia was seen in 8.4%, early preeclampsia in 1.8%, preterm birth in 12.9%, early preterm birth in 5.6%, and SGA in 8.5%. A mean PI above the 75th percentile (>1.91) was the best index for predicting early preeclampsia (sensitivity, 45.0%; specificity, 75.5%; NPV, 98.7%; ROC area, 0.65). A mean PI above the 75th percentile was also the best index for predictive early preterm birth (sensitivity, 40.0%; specificity, 76.0%; NPV, 95.5%; ROC area, 0.65). None of the parameters were significant for predicting SGA.

CONCLUSIONS

A mean uterine PI above the 75th percentile is the most discriminative abnormal uterine artery Doppler parameter for predicting both early preeclampsia and early preterm birth.

Predictive accuracy of the first trimester Doppler scan: a meta-study

AIM

To determine sensitivity and cut-off indices of the uterine artery Doppler (UAD) in prediction of preeclampsia and fetal growth restriction (FGR).

METHODS

Seventy-six studies published in 1995-2014, present 298,329 prenatal Doppler screenings performed in nullipara in the first and early second trimesters of singleton pregnancies. The sample is stratified into four groups based on the Doppler sensitivity and specificity indices pertaining to the major clinical endpoints of the cohort.

RESULTS

The FGR diagnostic specificity (r = 0.728) and bilateral notching index (r = 0.803) correlations indicate that the UAD accuracy depends on the placental bed and the screening mode.

CONCLUSIONS

Predictive sensitivity of the UAD increases after 16 weeks + 3 days (115 days) of gestation. The best predictive parameter of preeclampsia and FGR is the placental side uterine artery resistance index which confers to the highest means when the placenta is on the midline (OR 0.9).

Can we measure the spiral and uterine artery blood flow by real-time sonography and Doppler indices to predict spontaneous miscarriage in a normal-risk population?

Introduction: The predictive value of spiral artery flow Doppler measurements of a subsequent early miscarriage in first trimester pregnancy is explored here. Objective: The aim of this study is to determine uterine and spiral artery blood flow changes in first trimester subsequent miscarriages and correlate within the mechanisms of the Doppler indicies. Study design: The uterine artery and spiral artery pulsatility and resistance indexes, systolic and diastolic ratios, acceleration times, and blood flow of both the right and left uterine arteries were obtained by trans vaginal color Doppler ultrasonography in consecutive viable pregnancies between 5 and 12 gestational week. Women were subsequently classified as having continuing pregnancies or pregnancy loss before 20 weeks gestation. To predict subsequent pregnancy loss, Doppler findings were adjusted for maternal age, history of previous abortion, presence of subchorionic hematoma, embryonic bradycardia, and gestational age by means of multivariate logistic regression analysis. The cut-off values are used for the ROC curve. Results: Twenty-five pregnancies (11.7%) were spontaneously aborted before 20 weeks of gestational age. In 29 (13.6%) cases there were previously abortion history, 30 (14%) had bradycardia, and 37 (17.3%) had subchoronic hematoma. Regarding the parameters of uterine and spiral artery pulsatility and resistive index, acceleration time, systolic/diastolic ratios and blood flows, only uterine artery S/D low values were significantly associated with pregnancy loss in the multivariate logistic regression analysis (P = 0.0001,95% CI: 4.968-55.675). Conclusion: The uterine artery systolic/diastolic ratios have a predictive value for early pregnancy loss and seem to be useful as a marker. On the other hand, spiral artery changes could be so local that they cannot be determined by the parameters of spectral Doppler techniques. This suggests that uterine vascular bed alterations should be measured to understand the prognosis of early pregnancy loss during the first trimester.

Associations of maternal retinal vasculature with subsequent fetal growth and birth size

OBJECTIVE

We aimed to study the maternal retinal microvasculature at mid-trimester and its relationship with subsequent fetal growth and birth size.

METHODS

We recruited 732 pregnant women aged 18-46 years in the first trimester with singleton pregnancies. All had retinal photography and fetal scan performed at 26-28 weeks gestation, and subsequent fetal scan at 32-34 weeks gestation. Infant anthropometric measurements were done at birth. Retinal microvasculature was measured using computer software from the retinal photographs.

RESULTS

In multiple linear regression models, each 10 μm narrowing in maternal retinal arteriolar caliber was associated with decreases of 1.36 mm in fetal head circumference at 32-34 weeks gestation, as well as decreases of 1.50 mm and 2.30 mm in infant head circumference and birth length at delivery, respectively. Each standard deviation decrease in maternal retinal arteriolar fractal dimension was associated with decreases of 1.55 mm in fetal head circumference at 32-34 weeks gestation, as well as decreases of 1.08 mm and 46.42 g in infant head circumference and birth weight at delivery, respectively.

CONCLUSIONS

Narrower retinal arteriolar caliber and a sparser retinal vascular network in mothers, reflecting a suboptimal uteroplacental microvasculature during mid-pregnancy, were associated with poorer fetal growth and birth size.

A description of the methods of the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be (nuMoM2b)

OBJECTIVE

The primary aim of the "Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be" is to determine maternal characteristics, which include genetic, physiologic response to pregnancy, and environmental factors that predict adverse pregnancy outcomes.

STUDY DESIGN

Nulliparous women in the first trimester of pregnancy were recruited into an observational cohort study. Participants were seen at 3 study visits during pregnancy and again at delivery. We collected data from in-clinic interviews, take-home surveys, clinical measurements, ultrasound studies, and chart abstractions. Maternal biospecimens (serum, plasma, urine, cervicovaginal fluid) at antepartum study visits and delivery specimens (placenta, umbilical cord, cord blood) were collected, processed, and stored. The primary outcome of the study was defined as pregnancy ending at <37+0 weeks' gestation. Key study hypotheses involve adverse pregnancy outcomes of spontaneous preterm birth, preeclampsia, and fetal growth restriction.

RESULTS

We recruited 10,037 women to the study. Basic characteristics of the cohort at screening are reported.

CONCLUSION

The "Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be" cohort study methods and procedures can help investigators when they plan future projects.

First-trimester prediction of small-for-gestational age neonates incorporating fetal Doppler parameters and maternal characteristics

OBJECTIVE

First-trimester screening for subsequent delivery of a small-for-gestational-age (SGA) infant typically focuses on maternal risk factors and uterine artery (UtA) Doppler. Our aim is to test if incorporation of fetal umbilical artery (UA) and ductus venosus (DV) Doppler improves SGA prediction.

STUDY DESIGN

Prospective screening study of singletons at 11-14 weeks. Maternal characteristics, serum concentrations of pregnancy-associated plasma protein-A (PAPP-A) and free β-human chorionic gonadotropin are ascertained and UtA Doppler, UA, and DV Doppler studies are performed. These parameters are tested for their ability to predict subsequent delivery of a SGA infant.

RESULTS

Among 2267 enrolled women, 191 (8.4%) deliver an SGA infant. At univariate analysis women with SGA neonates are younger, more frequently African-American (AA), nulliparous, more likely to smoke, have lower PAPP-A and free β-human chorionic gonadotropin levels. They have a higher incidence of UtA Doppler bilateral notching, higher mean UtA Doppler-pulsatility index z-scores (P < .001) and UA pulsatility index z-scores (P = .03), but no significant difference in DV-pulsatility index z-scores or in the incidence of abnormal qualitative UA and DV patterns. Multivariate logistic regression analysis identifies nulliparity and AA ethnicity (P < .001), PAPP-A multiple of the median and bilateral notching (P < .05) as determinants of SGA infant. Predictive sensitivity was low; receiver operating characteristic curve analysis yields areas under the curve of 0.592 (95% confidence interval, 0.548-0.635) for the combination of UtA Doppler and UA pulsatility index z-scores.

CONCLUSION

Delivery of a SGA infant is most frequent in nulliparous women of AA ethnicity. Despite the statistical association with UtA Doppler first-trimester SGA prediction is poor and not improved by the incorporation of fetal Doppler.

Risk of placental dysfunction disorders after prior miscarriages: a population-based study

OBJECTIVE

The objective of the investigation was to study the association between prior miscarriages and the risks of placental dysfunction disorders, including preeclampsia, stillbirth, birth of a small for gestational age (SGA) infant, placental abruption, and spontaneous preterm birth.

STUDY DESIGN

In a population-based cohort study including 619,587 primiparous women, we estimated risks of placental dysfunction disorders for women with 1 (n = 68,185), 2 (n = 11,410) and 3 or more (n = 3823) self-reported prior miscarriages. Risks were calculated as odds ratios by unconditional logistic regression analysis and adjustments were made for maternal age, early pregnancy body mass index, height, smoking habits, country of birth, years of formal education, in vitro fertilization, chronic hypertension, pregestational diabetes, hypothyroidism, systemic lupus erythematosis, fetal sex, and year of childbirth.

RESULTS

Compared with women with no prior miscarriage, women with 1 prior miscarriage had almost no increased risks. Women with 2 prior miscarriages had increased risks of spontaneous preterm birth, preterm (<37 weeks) SGA infant, and placental abruption. The rates of all disorders were higher for women with 3 or more prior miscarriages compared with women without prior miscarriages: preeclampsia, 5.83% vs 4.27%; stillbirth, 0.69% vs 0.33%, SGA infant, 5.09% vs 3.22%, placental abruption, 0.81% vs 0.41%; and spontaneous preterm birth, 6.45% vs 4.40%. The adjusted odds ratios for preterm (<37 weeks) disorders in women with 3 prior miscarriages were approximately 2.

CONCLUSION

History of 2 or more miscarriages is associated with an increased risk of placental dysfunction disorders and should be regarded as a risk factor in antenatal care.

Second-trimester prediction of delivery of a small-for-gestational-age neonate: integrating sequential Doppler information, fetal biometry, and maternal characteristics

OBJECTIVE

The aim of this study was to investigate the predictive accuracy of second-trimester ultrasound parameters, maternal characteristics, and sequential Doppler changes between first and second trimesters for the prediction of small-for-gestational-age (SGA) infants (birth weight < 10th percentile).

METHODS

We conducted a prospective study of singleton pregnancies enrolled in the first trimester with subsequent second-trimester follow-up. Maternal characteristics, uterine artery (UtA) pulsatility index (PI), fetal biometry, and umbilical artery (UA)-PI were ascertained. UtA and UA-PI change from first to second trimester was calculated (ΔUtA-PI and ΔUA-PI). These parameters were tested for their ability to predict delivery of an SGA infant.

RESULTS

Among 1982 women, 172 delivered an SGA neonate. African-American ethnicity, nulliparity, tobacco use, and low abdominal circumference (AC) z-score were independent predictors of SGA. No difference was found in the magnitude of ΔUtA-PI and ΔUA-PI between SGA and no-SGA. Receiver-operating characteristics curve analysis yielded an area under the curve of 0.700 for AC z-score. The combination of low AC and bilateral notching had high specificity (99%) but low sensitivity (7%) for SGA prediction.

CONCLUSIONS

A small second-trimester fetal AC is a specific marker for SGA when found with bilateral UtA notching. Only a small proportion is predicted by the factors studied, suggesting a small contributory role or later evolution of SGA.

First-trimester uterine artery Doppler and adverse pregnancy outcome: a meta-analysis involving 55,974 women

OBJECTIVES

To determine the accuracy with which uterine artery Doppler in the first trimester of pregnancy predicts pre-eclampsia and fetal growth restriction, particularly early-onset disease.

METHODS

We searched MEDLINE (1951-2012), EMBASE (1980-2012) and the Cochrane Library (2012) for relevant citations without language restrictions. Two reviewers independently selected studies that evaluated the accuracy of first-trimester uterine artery Doppler to predict adverse pregnancy outcome and performed data extraction to construct 2 × 2 tables. We synthesized sensitivity and specificity for various Doppler indices using a bivariate random-effects model.

RESULTS

From 1866 citations, we identified 18 studies (55,974 women). The sensitivity and specificity of abnormal uterine artery flow velocity waveform (FVW) in the prediction of early-onset pre-eclampsia were 47.8% (95% CI: 39.0-56.8) and 92.1% (95% CI: 88.6-94.6), and in the prediction of early-onset fetal growth restriction were 39.2% (95% CI: 26.3-53.8) and 93.1% (95% CI: 90.6-95.0), respectively. The sensitivities for predicting any pre-eclampsia and fetal growth restriction were 26.4% (95% CI: 22.5-30.8) and 15.4% (95% CI: 12.4-18.9), respectively, and the specificities were 93.4% (95% CI: 90.4-95.5%) and 93.3% (95% CI: 90.9-95.1), respectively. The number needed to treat (NNT) with aspirin to prevent one case of early-onset pre-eclampsia fell from 1000 to 173 and from 2500 to 421 for background risks varying between 1% and 0.4%, respectively.

CONCLUSIONS

First-trimester uterine artery Doppler is a useful tool for predicting early-onset pre-eclampsia, as well as other adverse pregnancy outcomes. Based on the NNT, abnormal uterine artery Doppler in low-risk women achieves a sufficiently high performance to justify aspirin prophylaxis in those who test positive.

First-trimester screening for early and late small-for-gestational-age neonates using maternal serum biochemistry, blood pressure and uterine artery Doppler

OBJECTIVE

To assess the effectiveness of first-trimester screening for early and late small-for-gestational-age (SGA) neonates using maternal serum biochemistry, blood pressure and uterine artery Doppler.

METHODS

This was a prospective study of 4970 women with a singleton pregnancy who underwent routine first-trimester screening between 2009 and 2011. A logistic regression-based predictive model for SGA, defined as birth weight < 10(th) percentile, divided into early- or late-onset based on gestational age at delivery before or after 34 weeks' gestation, was constructed. The model included maternal baseline characteristics: serum levels of pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin at 8-12 weeks and blood pressure and uterine artery Doppler at 11 + 0 to 13 + 6 weeks.

RESULTS

The prevalence of early and late SGA was 0.6% and 7.9%, respectively. Association with pre-eclampsia was 67% and 8%, respectively. At a false-positive rate of 15%, the detection rate for early SGA was 73%; however it differed substantially for cases with and without pre-eclampsia (90% vs 40%). For late SGA, at false-positive rates of 15 and 50%, detection rates were 32% and 70%, respectively, and did not substantially differ between cases with and without pre-eclampsia.

CONCLUSIONS

First-trimester screening predicts early SGA mainly because of its strong association with pre-eclampsia. Although prediction of late SGA was poorer, at a high false-positive rate it might be considered as part of a first-trimester strategy to select women requiring ultrasound assessment in the third trimester.