The role of uterine artery Doppler in predicting adverse pregnancy outcome

Abnormal uterine artery remodelling in the stroke prone spontaneously hypertensive rat

INTRODUCTION

The stroke prone spontaneously hypertensive rat (SHRSP) is an established model of human cardiovascular risk. We sought to characterise the uteroplacental vascular response to pregnancy in this model and determine whether this is affected by the pre-existing maternal hypertension.

METHODS

Doppler ultrasound and myography were utilised to assess uterine artery functional and structural changes pre-pregnancy and at gestational day 18 in SHRSP (untreated and nifedipine treated) and in the normotensive Wistar-Kyoto (WKY) rat. Maternal adaptations to pregnancy were also assessed along with histology and expression of genes involved in oxidative stress in the placenta.

RESULTS

SHRSP uterine arteries had a pulsatile blood flow and were significantly smaller (70906 ± 3903 μm(2) vs. 95656 ± 8524 μm(2) cross-sectional area; p < 0.01), had a significant increase in contractile response (57.3 ± 10.5 kPa vs 27.7 ± 1.9 kPa; p < 0.01) and exhibited impaired endothelium-dependent vasorelaxation (58.0 ± 5.9% vs 13.9 ± 4.6%; p < 0.01) compared to WKY. Despite significant blood pressure lowering, nifedipine did not improve uterine artery remodelling, function or blood flow in SHRSP. Maternal plasma sFLT-1/PlGF ratio (5.3 ± 0.3 vs 4.6 ± 0.1; p < 0.01) and the urinary albumin/creatinine ratio (1.9 ± 0.2 vs 0.6 ± 0.1; p < 0.01) was increased in SHRSP vs WKY. The SHRSP placenta had a significant reduction in glycogen cell content and an increase in Hif1α, Sod1 and Vegf.

DISCUSSION

We conclude that the SHRSP exhibits a number of promising characteristics as a model of spontaneous deficient uteroplacental remodelling that adversely affect pregnancy outcome, independent of pre-existing hypertension.

Hyperbaric index in the primary prevention of hypertensive complications in high-risk pregnancy

INTRODUCTION

Preeclampsia (PE) is a major cause of fetal morbidity and mortality. In the Western World, PE affects 2-7% of pregnancies and is responsible for 50,000 deaths annually. Early detection is a priority as it can change the clinical course, but there are no biomarkers or instrumental methods with high sensitivity and specificity. Only the hyperbaric index has a sensitivity and specificity of 99% for early identification of pregnant women at risk of developing PE, but its use is not widespread.

OBJECTIVE

To assess the usefulness of the hyperbaric index in the primary prevention of hypertensive pregnancy complications in a public healthcare area.

MATERIAL AND METHODS

This is a retrospective study of pregnancies that occurred in our area during the period 2007-2012 (N=11,784). The diagnosis was established by the hyperbaric index and pregnant women at risk were treated with ASA at night.

RESULTS

In pregnant patients referred to the nephrology clinic (38.2%), diagnosed as high-risk for PE, and treated with 100mg ASA/night (from week 17), the incidence of PE episodes was reduced by 96.94.

Uterine artery Doppler in the management of early pregnancy loss: a prospective, longitudinal study

Background

The pharmacological management of early pregnancy loss reduced substantially the need for dilation and curettage. However, prognostic markers of successful outcome were not established. Thus the major purpose of this study was to determine the sensitivity and specificity of the uterine artery pulsatility (PI) and resistance (RI) indices to detect early pregnancy loss patients requiring dilation and curettage after unsuccessful management.

Methods

A cohort prospective observational study was undertaken to include women with early pregnancy loss, ≤ 12 weeks of gestation, managed with mifepristone (200 mg) and misoprostol (1600 μg) followed by PI and RI evaluation of both uterine arteries 2 weeks after. At this time, in 173/315 patients, incomplete miscarriage was diagnosed. Among them, 32 underwent uterine dilatation and curettage at 8 weeks of follow-up.

Results

The cut-off points for the uterine artery PI and RI, leading to the maximum values of sensitivity (69.5%, CI_95%: 61.5%-76.5% and 75.0%, CI_95%: 57.9%-86.8%, respectively) and specificity (75.0%, CI_95%: 57.9%-86.8% and 65.6%, CI_95%: 48.3%-79.6%, respectively), for the discrimination between the women who needed curettage from those who resolved spontaneously were 2.8 and 1, respectively.

Conclusions

The potential usefulness of uterine artery Doppler evaluation to predict the need for uterine curettage in patients submitted to medical treatment for early pregnancy loss was demonstrated.

Recent advances in the diagnosis and management of pre-eclampsia

Pre-eclampsia complicates around 5% of pregnancies and hypertensive disorders of pregnancy are responsible for over 60,000 maternal deaths worldwide annually. Pre-eclampsia is characterized by hypertension and features of multiple organ disease. Diagnosis remains a challenge as clinical presentation is highly variable and even with severe disease a woman can be asymptomatic. Pre-eclampsia is characterized by abnormal placentation with subsequent maternal inflammatory and vascular response. Improved understanding of the underlying pathophysiology relating to the role of angiogenic factors, has emerged and placed intense interest on their role in prognostic modelling or diagnosis of pre-eclampsia. This article summarizes new developments in diagnosis with a focus on angiogenic biomarkers for prediction of disease onset, and recent advances in management strategies for patients with pre-eclampsia.

Shear wave elastography in placental dysfunction: comparison of elasticity values in normal and preeclamptic pregnancies in the second trimester

OBJECTIVES

The aim of this study was to determine whether shear wave elastography of the placenta differs between normal pregnancies and pregnancies complicated by preeclampsia between 20 and 23 weeks' gestation.

METHODS

A prospective study was performed with 204 consecutive singleton pregnancies that had routine anomaly scanning between 20 and 23 weeks' gestation. One hundred twenty-nine of these patients were examined with shear wave elastography; 101 women who had clinically normal pregnancies with normal fetal biometric measurements and normal deliveries without any perinatal complications formed group A, and 28 women who had a clinical diagnosis of early-onset preeclampsia before anomaly scanning formed group B. Women with either posterior placentations (n = 63) or other obstetric disorders (n = 12) were excluded from the study.

RESULTS

Shear wave elastographic values for group B were significantly higher than those for group A (P < .05). No statistically significant difference was found between the elasticity values measured at the center or edge of the placenta (P > .05).

CONCLUSIONS

Shear wave elastography differentiates between the placental elasticity of normal pregnancies and pregnancies complicated by preeclampsia when performed during the second trimester. As a new method for tissue characterization, shear wave elastography is useful for evaluation of placental function and can be used as a supplement to existing methods for prediction of preeclampsia.

Haptoglobin phenotype and abnormal uterine artery Doppler in a racially diverse cohort

OBJECTIVE

The anti-oxidant and proangiogenic protein haptoglobin (Hp) is believed to be important for implantation and pregnancy, although its specific role is not known. The three phenotypes (1-1, 2-1 and 2-2) differ in structure and function. Hp 2-2 is associated with increased vascular stiffness in other populations. We examined whether Hp phenotype is associated with abnormal uterine artery Doppler (UAD) in pregnancy.

METHODS

We conducted a secondary analysis of a preeclampsia prediction cohort nested within a larger placebo-controlled randomized clinical trial of antioxidants for prevention of preeclampsia. We determined Hp phenotype in 2184 women who completed UAD assessments at 17 weeks gestation. Women with notching were re-evaluated for persistent notching at 24 weeks' gestation. Logistic regression was used to assess differences in UAD indices between phenotype groups.

RESULTS

Hp phenotype did not significantly influence the odds of having any notch (p = 0.32), bilateral notches (p = 0.72), or a resistance index (p = 0.28) or pulsatility index (p = 0.67) above the 90th percentile at 17 weeks' gestation. Hp phenotype also did not influence the odds of persistent notching at 24 weeks (p = 0.25).

CONCLUSIONS

Hp phenotype is not associated with abnormal UAD at 17 weeks' gestation or with persistent notching at 24 weeks.

Preeclampsia is associated with lower production of vascular endothelial growth factor by peripheral blood mononuclear cells

BACKGROUND

Recent studies show that vascular endothelial growth factor (VEGF) downregulation is implicated in preeclampsia (PE) pathophysiology. This study assessed the relationship between PE and VEGF levels produced by peripheral blood mononuclear cells (PBMCs) and their serum levels.

METHODS

A cross-sectional design was performed in 36 patients who had hypertensive disorders during pregnancy. We also used a longitudinal design with 12 pregnant women with risk factors for PE development and/or abnormal uterine arteries by Doppler study. VEGF and soluble fms-like tyrosine kinase-1 (sFlt-1) levels were measured for all patients in both designs.

RESULTS

sFlt-1 serum was higher in preeclamptic patients (n = 26), whereas VEGF produced by stimulated PBMCs was lower than in healthy pregnant women and VEGF levels produced by stimulated PBMCs were even lower (p <0.003) in severe PE (n = 16). The receiver-operating characteristic curve analysis allowed establishing a cut-off value to identify patients with PE. VEGF production by PBMCs was 339.87 pg/mL. In addition, a robust linear regression model was performed to adjust the variance in VEGF levels. The patients' age decreased VEGF levels and was adjusted by weeks of gestation (WG) in our model. In the longitudinal study, 7/12 patients developed PE. VEGF produced by PBMCs cells was significantly lower in PE at 24-26 WG.

CONCLUSIONS

VEGF production by PBMCs is inhibited during PE, creating a downregulation of the microenvironment; this deficiency may contribute to the pathogenesis of disease.

Elevation of soluble form of receptor for advanced glycation end products (sRAGE) in recurrent pregnancy losses (RPL): possible participation of RAGE in RPL

OBJECTIVE

To determine whether the soluble receptor for advanced glycation end products (sRAGE) and immune inflammatory markers are associated with recurrent pregnancy losses (RPL).

DESIGN

Prospective case-control study.

SETTING

University clinic.

PATIENT(S)

A total of 93 women (age 35.8±4.6 years) were enrolled including 63 women with three or more recurrent pregnancy losses (RPL), and age-matched fertile controls with a history of at least one live birth and no history of pregnancy losses (n=30).

INTERVENTION(S)

Peripheral blood collection.

MAIN OUTCOME MEASURE(S)

Assessment of anthropometric, metabolic, and inflammatory immune variables.

RESULT(S)

Levels of sRAGE were statistically significantly higher in RPL patients than in control patients (1,528.9±704.5 vs. 1,149.9±447.4 pg/mL). In the multivariate analysis, the levels of insulin, plasminogen activator inhibitor-1, the resistance index of the uterine radial artery, and the ratio of tumor necrosis factor-α/interleukin-10 producing T helper cells were statistically significantly associated with the serum sRAGE level.

CONCLUSION(S)

Elevated levels of serum sRAGE are associated with RPL. The soluble receptor for advanced glycation end products might contribute to RPL by reducing uterine blood flow and subsequently causing ischemia in the fetus via inflammatory and thrombotic reactions.

Presymptomatic prediction of preeclampsia with angiogenic factors, in high risk pregnant women

INTRODUCTION

The aim of this study was to investigate the value of placental growth factor (PLGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and sFlt-1/PLGF ratio, in predicting symptomatic preeclampsia (PE).

METHODS

A prospective longitudinal study was carried out on 71 high risk preeclamptic women cohort. All of them had normal blood pressure level (≤140/90 mmHg) at the time of enrolment, 26.8 ± 1.5 weeks. Maternal blood was collected and plasma was stored in a freezer at -80 °C. PE was defined according to the National High Blood Pressure Education Program Working Group Criteria. Accuracy of angiogenic factors in predicting PE was evaluated using Receiver-operating characteristics.

RESULTS

Maternal plasma concentrations of PLGF and sFlt-1 were able to predict PE (0.90, p < 001; 0.78, p = 0.003, area under the curve, respectively) but the sFlt-1/PLGF ratio presented the best prediction potential over the others (0.95, area under the curve, p < 0.001).

CONCLUSION

All angiogenesis factors were effective biomarkers in predicting PE during the second trimester, before the clinical onset of PE.

VEGF and eNOS expression in umbilical cord from pregnancy complicated by hypertensive disorder with different severity

Background. Reduced blood flow in hypertensive pregnancy may influence the production vasoconstrictors; subsequently the vessel remains in highly contracted state. NO is a vasodilator; VEGF influences its synthesis by regulating eNOS production. Aim of our study was to evaluate the expression of VEGF and eNOS in different severity of hypertensive pregnancy. Methods. Study was conducted in 4 groups with 40 members: group 1—control, group 2—gestational hypertension, group 3—mild preeclampsia, and group 4—severe preeclampsia. Fetal end of umbilical cord was taken and follows IHC staining protocol for VEGF and eNOS antibody. Staining intensity were measured by semiquantitative scoring method. Mann Whitney U test was used to compare each group. Results. Decreased expression of both VEGF and eNOS was found in hypertensive condition than in normal condition. Among hypertensive group, severe preeclamptic group showed more intensity in staining than gestational hypertension and mild preeclampsia. Conclusion. Reduction of VEGF and eNOS in gestational hypertension may lead to hypoperfusion and subsequent hypoxia of fetus in hypertensive pregnancy. The developed hypoxic state may upregulate the synthesis of VEGF and thereby eNOS. Increased expression of VEGF and eNOS in severe group may be a compensatory mechanism to dilate the blood vessels and to improve blood flow of fetus.

Doppler ultrasonographic assessment of maternal and fetal arteries during normal feline gestation

The aim of this study was to describe Doppler parameters of uterine, umbilical, fetal abdominal aorta, fetal renal and fetal internal carotid arteries, as well as fetal heart rate (FHR), during normal feline gestation. Fifteen, 1-4 years of age, weighing 2.5-3.9kg, domestic short-hair pregnant queens, which were born in our institutional cat colony were included in this study. Color and pulsed-wave Doppler evaluations of uterine arteries were performed every 10 days (Day 0, 10, 20, 30, 40, 50, 60) from mating. Fetal Doppler and M-mode ultrasonography were performed to assess umbilical, fetal abdominal aorta, fetal renal, fetal internal carotid arteries and FHR. Both peak systolic velocity (PSV) and end diastolic velocity (EDV) of uterine artery increased up to parturition (P<0.01), while resistance index (RI) decreased from Day 10 onwards (P<0.01). From Day 40 onwards, RI of umbilical artery diminished, while PSV and EDV augmented (P<0.01). Fetal abdominal aorta (P<0.01), renal (P<0.01) and internal carotid (P<0.01) arteries diminished their RI from Days 40, 60 and 40 onwards, respectively. Both PSV and EDV of these three arteries increased progressively. Fetal heart rate was first registered on Day 20 when it began to increase up to Day 40 and then diminished to the end of gestation (P<0.01). It is concluded that blood flow of uterine, umbilical, fetal abdominal aorta, fetal renal and fetal internal carotid arteries progressively increased during normal feline pregnancy, while FHR rose to mid gestation and then decreased up to parturition.

Internal iliac and uterine arteries Doppler ultrasound in the assessment of normotensive and chronic hypertensive pregnant women

The objective of this work was to compare Doppler flows pulsatility index (PI) and resistance indexes (RI) of uterine and internal iliac arteries during pregnancy in low risk women and in those with stage-1 essential hypertension. From January 2010 and December 2012, a longitudinal and prospective study was carried out in 103 singleton uneventful pregnancies (72 low-risk pregnancies and 31 with stage 1 essential hypertension)at the 1^st, 2^nd and 3^rd trimesters. Multiple linear regression models, fitted using generalized least squares and whose errors were allowed to be correlated and/or have unequal variances, were employed; a model for the relative differences of both arteries impedance was utilized. In both groups, uterine artery PI and RI exhibited a gestational age related decreasing trend whereas internal iliac artery PI and RI increased. The model testing the hemodynamic adaptation in women with and without hypertension showed similar trend. Irrespective of blood pressure conditions, the internal iliac artery resistance pattern contrasts with the capacitance pattern of its immediate pelvic division, suggesting a pregnancy-related regulatory mechanism in the pelvic circulation.

Mid-trimester maternal serum HCG and alpha fetal protein levels: clinical significance and prediction of adverse pregnancy outcome

CONTEXT

Maternal serum human Chorionic Gonadotropin (hCG) and Alpha Fetal Protein (AFP) were originally introduced to detect trisomy 21 and neural tube defects. However, in the absence of aneuploidy or neural tube defects, mid-trimester maternal serum hCG and/or maternal serum AFP associated with adverse pregnancy outcomes. Pregnancies with unexplained mid-trimester elevation in maternal serum hCG and/or maternal serum AFP, are at increased risk for pregnancy complications resulting from placental insufficiency.

EVIDENCE ACQUISITION

Mid-trimester maternal serum hCG>2.5 MoM associated with an increased risk for pregnancy complications including: late fetal loss, gestational hypertension, preeclampsia, intrauterine growth restriction (IUGR), preterm delivery and intrauterine fetal death(IUFD). Mid-trimester maternal serum AFP levels >2.5 MoM are thought to reflect a defect in placentation and associated with an increased risk for pregnancy complications including: late fetal loss, gestational hypertension, preeclampsia, IUGR, preterm delivery and IUFD.

RESULTS

Combined mid-trimester elevation in maternal serum hCG and AFP levels suggest a more complex type of placental pathology. They have stronger association with pregnancy complications including: late fetal loss, gestational hypertension, preeclampsia, IUGR, preterm delivery and IUFD.

CONCLUSIONS

Mid-trimester maternal serum hCG or AFP levels alone cannot detect all pregnant women with increased risk to develop pregnancy complications. Multiparameter testing of placental function in mid-trimester (maternal serum hCG and AFP screening, uterine artery Doppler and placental morphology) may allow us to identify women with increased risk to develop severe placental insufficiency and pregnancy complications. However, future prospective studies are needed to confirm the prognostic significance of multiparameter testing of placental function in mid-trimester.

The utility of uterine artery Doppler velocimetry in prediction of preeclampsia in a low-risk population

OBJECTIVE

The underlying pathophysiology of preeclampsia is thought to be abnormal trophoblast invasion of the spiral arteries leading to maldevelopment of uteroplacental perfusion. We estimated whether uterine artery Doppler measurements made in the early second trimester would predict the subsequent development of preeclampsia.

METHODS

Uterine artery Doppler measurements before 21 weeks of gestation (median 16.6 weeks) were correlated with subsequent development of preeclampsia in a cohort of 2,188 low-risk nulliparous women in a randomized control trial of antioxidant supplementation for prevention of preeclampsia. Preeclampsia developed in 165 (7.5%) women.

RESULTS

Development of preeclampsia overall was associated with increased resistance index, pulsatility index, a pulsatility index or resistance index multiple of the median at or above the 75th percentile but not the presence of a notch or a bilateral notch before 21 weeks of gestation. The sensitivity was 43% (95% confidence interval [CI] 35-51) and specificity 67% (95% CI 65-69) for prediction of preeclampsia overall. The presence of a notch or bilateral notch, resistance index, and pulsatility index multiple of the median was significantly associated with early onset (before 34 weeks of gestation) compared with late onset or no preeclampsia (odds ratio [OR] 6.9, 95% CI 2.3-20.9; sensitivity 78%, 95% CI 52-94; specificity 66%, 95% CI 64-68). The presence of a notch or resistance index multiple of the median at or above the 75th percentile increased the odds of developing severe compared with mild or no preeclampsia (OR 2.2, 95% CI 1.4-3.7; sensitivity 53%, 95% CI 40-65; specificity 66%, 95% CI 64-68).

CONCLUSION

Our data show poor sensitivity of second-trimester Doppler ultrasound measurements for prediction of preeclampsia overall in a well-characterized, low-risk, nulliparous population. The technique has utility in identifying poor trophoblast invasion of spiral arteries of a magnitude that severely compromises uteroplacental blood flow and gives early-onset disease.

LEVEL OF EVIDENCE

II.

Comparison of two different sites of measurement for transabdominal uterine artery Doppler velocimetry at 11-13 weeks

OBJECTIVES

To compare the feasibility of two transabdominal approaches for performing first-trimester uterine artery (UtA) Doppler and to evaluate the correlation with pulsatility index (PI) in the second trimester.

METHODS

This was a prospective longitudinal Doppler study of the uterine arteries at 11-13 and 21-22 weeks' gestation. Transabdominal ultrasound and color Doppler were used to measure the UtA-PI of the ascending branch of the uterine artery at the level of the internal cervical os (Site A) and at the level of the apparent crossover with the external iliac artery (Site B) at 11-13 weeks, and at Site B only at 21-22 weeks. In all cases the measured left and right PI were converted to a multiple of the median (MoM) for gestational age, and the intercorrelation between the measurements at different sites and gestational ages was calculated using non-parametric analysis (Spearman's rank correlation).

RESULTS

Satisfactory measurements were obtained at 11-13 weeks from both uterine arteries in all 81 women at Site A and in 50 (62%; 95% CI, 50-72%) at Site B (P < 0.01). Measurements were obtained at Site B at 21-22 weeks in all cases. In the 50 cases with measurements from both sites at 11-13 weeks, the correlation of PI-MoMs between Sites A and B at 11-13 weeks was only moderate (ρ = 0.61). The correlation between first-trimester UtA-PI MoMs at Site A and second-trimester UtA-PI MoMs was stronger than that between first-trimester UtA-PI MoMs at Site B and second-trimester UtA-PI MoMs (ρ = 0.73 vs ρ = 0.47, P < 0.01).

CONCLUSION

Evaluation of UtA-PI at 11-13 weeks can be achieved at the level of the internal cervical os in a greater proportion of women than at the level of the apparent crossover with the external iliac vessels, and the measurements obtained correlate better with second-trimester UtA-PI.

Fetal growth restriction and reversed middle cerebral artery end-diastolic flow with subchorionic placental lake

Fetal growth restriction (FGR) is frequently associated with uteroplacental insufficiency. Placental lakes are avillous spaces filled with maternal venous blood that usually do not compromise the pregnancy outcome; however, a few reports describe FGR in association with placental lakes. Reversed middle cerebral artery (MCA) end-diastolic flow is a rare event and a potential indicator of poor fetal outcome due to placental insufficiency. We report a case of severe FGR associated with a huge subchorionic placental lake concomitant with reversed MCA end-diastolic flow. We also conducted a literature review.

Thymic volume in healthy, small for gestational age and growth restricted fetuses

OBJECTIVE

The aim of this study was to verify the hypothesis that a difference in thymic size exists between small for gestational age (SGA) fetuses, likely constitutional, and intrauterine growth restricted (IUGR) fetuses because of placental causes.

METHODS

We studied 27 SGA and 36 control fetuses. SGA was defined as fetal abdominal circumference (AC) and birthweight <10th percentile for gestational age. We defined as constitutional SGA those with normal uterine and umbilical artery Doppler flow velocity waveforms (FVW), and as IUGR those with abnormal uterine FVW. IUGR were further divided based on normal or abnormal umbilical FVW. Fetal thymic volume (TV) was acquired by three-dimensional ultrasound and reconstructed with virtual organ computer-aided analysis. To correct for the influence of fetal size on thymic dimension, TV/AC ratio was calculated.

RESULTS

Controls presented a higher TV/AC compared with each group of SGA (p < 0.001). TV/AC was significantly lower in IUGR with abnormal umbilical FVW compared with both constitutional SGA (p = 0.01) and IUGR with normal umbilical FVW (p = 0.01).

CONCLUSIONS

The differences in TV/AC between constitutional SGA and IUGR with abnormal umbilical FVW suggest that, in the latter, a specific 'trigger' might compromise trophoblastic invasion and thymic development; however, some kind of alteration of the immune system might occur in all SGA fetuses.

Comparison of uterine artery Doppler in pregnant women with thrombophilia treated by LMWHs and without thrombophilia

OBJECTIVE

The aim of this study was to use uterine artery Doppler ultrasonography to investigate the cases of women with thrombophilia who used LMWH during the 18-22-week period of gestation.

METHODS

This retrospective study was conducted at our university between January 2005 and July 2010. 64 patients were treated with low-dose LMWHs (enoxaparine 40 mg) from the beginning of pregnancy until 36 weeks of gestation. Fifty control subjects were also included in this study. Transabdominal ultrasound examination and bilateral uterine artery Doppler measurements pulsatility index (PI), resistive index (RI), and systole/diastole measurement (S/D) were performed during the 18-22-weeks period of gestation.

RESULTS

No significant differences were found between the groups with respect to maternal age or gestational age at the time of uterine artery Doppler. However, the mean PI (1.07 ± 0.46 for LMWH group and 0.91 ± 0.31 for control, p = 0.036) and the mean RI (0.59 ± 0.12 for LMWH group and 0.54 ± 0.10 for control, p = 0.021) were significantly higher in the trombophilia group.

CONCLUSION

Women with trombophilia still have an increased mean PI and RI, as determined by uterine artery Doppler ultrasonography during the 18-22-week period of gestation, even if they use LMWH.

Doppler assessment of the fetus with intrauterine growth restriction

OBJECTIVE

We sought to provide evidence-based guidelines for utilization of Doppler studies for fetuses with intrauterine growth restriction (IUGR).

METHODS

Relevant documents were identified using PubMed (US National Library of Medicine, 1983 through 2011) publications, written in English, which describe the peripartum outcomes of IUGR according to Doppler assessment of umbilical arterial, middle cerebral artery, and ductus venosus. Additionally, the Cochrane Library, organizational guidelines, and studies identified through review of the above were utilized to identify relevant articles. Consistent with US Preventive Task Force suggestions, references were evaluated for quality based on the highest level of evidence, and recommendations were graded.

RESULTS AND RECOMMENDATIONS

Summary of randomized and quasirandomized studies indicates that, among high-risk pregnancies with suspected IUGR, the use of umbilical arterial Doppler assessment significantly decreases the likelihood of labor induction, cesarean delivery, and perinatal deaths (1.2% vs 1.7%; relative risk, 0.71; 95% confidence interval, 0.52-0.98). Antepartum surveillance with Doppler of the umbilical artery should be started when the fetus is viable and IUGR is suspected. Although Doppler studies of the ductus venous, middle cerebral artery, and other vessels have some prognostic value for IUGR fetuses, currently there is a lack of randomized trials showing benefit. Thus, Doppler studies of vessels other than the umbilical artery, as part of assessment of fetal well-being in pregnancies complicated by IUGR, should be reserved for research protocols.

Analysis of perinatal outcome by combination of first trimester maternal plasma homocysteine with uterine artery Doppler velocimetry

OBJECTIVE

To analyse the pregnancy outcome by combining plasma homocysteine with uterine artery Doppler velocimetry at 11 to 14 weeks of gestation.

METHOD

A prospective cohort study with 103 healthy pregnant women. Uterine artery Doppler velocimetry was performed at between 11 and 14 weeks of gestation. Abnormal blood flow was defined as average pulsatility index >1.5 and presence of unilateral or bilateral diastolic notch. Doppler scores were calculated by a modified scoring method of uterine artery flow velocity waveforms. Serum for measurement of homocysteine, vitamin B(12) and folate levels were collected when the ultrasonographic measurement was performed.

RESULTS

Pre-eclampsia developed in five, gestational hypertension in three, intrauterine growth restriction in two and preterm birth in eight patients. There was a significant difference between mean plasma homocysteine levels at different Doppler scores (p<0.001) and a weak positive correlation between Doppler scores and occurrence of pregnancy complications (r(s) = 0.232, p<0.05). Mean homocysteine level increased with increasing Doppler scores. Any uterine artery abnormality had a sensitivity of 88.9% in predicting obstetric complications. Addition of hyperhomocytenemia to Doppler scores did not change the sensitivity.

CONCLUSION

Maternal serum homocysteine level is increased in 11 to 14 weeks of gestation that is complicated with pre-eclampsia, gestational hypertension, intrauterine growth restriction and preterm birth. Addition of homocysteine determination to uterine artery Doppler in the first trimester does not add any advantage in predicting adverse perinatal outcome.

Association of placental volume measured by MRI and birth weight percentile

PURPOSE

To investigate if placental volume in the second trimester of pregnancy is related to uterine artery blood flow and neonatal birth weight.

MATERIALS AND METHODS

In 83 singleton pregnancies at 24-29 weeks' gestation, uterine artery pulsatility index (PI) was measured by Doppler ultrasound and placental volume was calculated from images obtained by magnetic resonance imaging (MRI) at 1.5T. The significance of the association between placental volume, uterine artery PI, and birth weight was examined.

RESULTS

In 37 normal pregnancies resulting in delivery of neonates with birth weight at or above the 10th percentile, the median placental volume increased with gestational age from 363 cm(3) at 24 weeks to 515 cm(3) at 29 weeks. In 46 pregnancies that resulted in delivery of small for gestational age (SGA) neonates with birth weight below the 10th percentile the median placental volume, corrected for gestational age, was significantly decreased by 120 cm(3) (P < 0.0001) and median uterine artery PI was increased (1.87 vs. 1.59, P < 0.0001). There were significant associations between placental volume and both uterine artery PI (r = -0.677, P < 0.0001) and birth weight percentile (r = 0.658, P < 0.0001).

CONCLUSION

Placental volume during the second trimester is smaller in pregnancies that subsequently deliver SGA neonates and the measurement is related to placental perfusion.

Pregnancy outcome after oocyte donation in patients with Turner's syndrome and partial X monosomy

BACKGROUND

Fertility expectations for patients with Turner's syndrome (TS) have clearly changed in the last three decades. However, medical risks during pregnancy are supposed to be highly increased. The aim of the study was to assess clinical outcome and obstetrical complications in a series of patients with TS in an oocyte donor programme.

METHODS

A retrospective study was carried out on 24 women with TS seeking a pregnancy in the Fertility Clinic of the Erasme Hospital from 1992 up until March 2011.

RESULTS

Twenty-three patients with TS were included in an oocyte donation cycle. Forty-nine oocyte donation cycles were performed, which led to 45 fresh and 10 frozen-thawed embryo transfers. Altogether, 18 pregnancies were obtained, 10 deliveries (9 singletons and 1 pair of twins), 3 miscarriages and 5 biochemical pregnancies. The clinical pregnancy rate per transfer was 24.4% in fresh cycles and 20% in frozen replacement cycles. Complications of pregnancy occurred in 5 of 10 pregnancies (50%), which led to three premature deliveries because of pregnancy-induced hypertensive disorders. The mean birthweight (g) (±SD) for singletons and twins was 2728 ± 577 and 2335 ± 318, respectively. Four babies were below the 10th percentile. No cardiac complications were observed in any of the pregnant women.

CONCLUSIONS

Pregnancy rates after oocyte donation in patients with TS are comparable with those previously published but a high risk of pregnancy hypertensive disorders and a high risk of low birthweight can be highlighted from our study. Strict inclusion criteria and single embryo transfer are necessary to minimize complications during pregnancy in this high-risk group.

Doppler ultrasonographic assessment of maternal and fetal blood flow in abnormal canine pregnancy

The aim of this study was to describe the changes of uterine artery, umbilical artery and fetal abdominal aorta, renal and internal carotid arteries blood flow in abnormal canine pregnancy. Twenty-two, Brucella-negative pregnant bitches were retrospectively classified into abnormal (which had either interrupted their pregnancy between days 52 and 60 or had perinatal death >60% of the litter; n=11) and normal (which had delivered healthy puppies at term; n=11). In all the animals, color and pulsed-wave Doppler examinations of uterine artery were conducted every 10 days from Day 20 to 50 from estimated luteinizing hormone peak. Doppler ultrasonography was also conducted in the fetuses to assess umbilical artery, abdominal aorta, renal and internal carotid arteries from Day 40 to 60 of gestation. Throughout the study, resistance index (RI) of uterine, umbilical and fetal renal arteries decreased up to -15% compared to -36% (P<0.01), -11% compared to -23% (P<0.05) and 2% compared to -13% (P<0.05), respectively in the abnormal and normal bitches. Fetal abdominal aorta and internal carotid did not differ between groups (P>0.05). It is concluded that in dogs, uterine artery, umbilical artery and fetal renal artery RI differ between normal and abnormal gestation being useful for the prediction of adverse obstetric outcome.

Maternal arterial stiffness in women who subsequently develop pre-eclampsia

Background/Objectives

Pre-eclampsia (PE) is associated with profound changes in the maternal cardiovascular system. The aim of the present study was to assess whether alterations in the maternal arterial stiffness precede the onset of PE in at risk women.

Methodology/Principal Findings

This was a cross sectional study involving 70 pregnant women with normal and 70 women with abnormal uterine artery Doppler examination at 22–24 weeks of gestation. All women had their arterial stiffness (augmentation index and pulse wave velocity of the carotid-femoral and carotid-radial parts of the arterial tree) assessed by applanation tonometry in the second trimester of pregnancy, at the time of the uterine artery Doppler imaging. Among the 140 women participating in the study 29 developed PE (PE group) and 111 did not (non-PE group). Compared to the non-PE group, women that developed PE had higher central systolic (94.9±8.6 mmHg vs 104.3±11.1 mmHg; p = <0.01) and diastolic (64.0±6.0 vs 72.4±9.1; p<0.01) blood pressures. All the arterial stiffness indices were adjusted for possible confounders and expressed as multiples of the median (MoM) of the non-PE group. The adjusted median augmentation index was similar between the two groups (p = 0.84). The adjusted median pulse wave velocities were higher in the PE group compared to the non-PE group (carotid-femoral: 1.10±0.14 MoMs vs 0.99±0.11 MoMs; p<0.01 and carotid-radial: 1.08±0.12 MoMs vs 1.0±0.11 MoMs; p<0.01).

Conclusions/Significance

Increased maternal arterial stiffness, as assessed by pulse wave velocity, predates the development of PE in at risk women.

Uterine artery Doppler and adverse pregnancy outcome in women with extreme levels of fetoplacental proteins used for Down syndrome screening

OBJECTIVE

To evaluate the use of second-trimester uterine artery (UtA) Doppler to predict adverse pregnancy outcome in women with extreme levels of fetoplacental proteins used for Down syndrome screening.

METHODS

At a single institution, women screened for Down syndrome were offered second-trimester UtA Doppler examination if they had one of the following on analysis of maternal serum: pregnancy-associated plasma protein-A ≤ 0.28 multiples of the median (MoM) (1% of screened population), inhibin ≥ 3.0 MoM (2%), human chorionic gonadotropin ≥ 4.0 MoM (2%), alpha-fetoprotein (AFP) ≥ 2.5 MoM (2%), estriol ≤ 0.5 MoM (1%). Abnormal UtA Doppler was defined as bilateral or unilateral notching or mean pulsatility index ≥ 1.45.

RESULTS

Of 240 women studied, 92 (38.3%) had an adverse pregnancy outcome: small for gestational age (either < 10(th) customized centile (SGA(10) ) or < 5(th) customized centile (SGA(5) )), low birth weight (LBW, < 2.5 kg), preterm delivery (< 37 + 0 weeks of gestation), fetal loss (late miscarriage or stillbirth), placental abruption and gestational hypertension. Of 167 women screened with all five hormones, those with two or more extreme levels (n = 18, 10.8%) were significantly at risk of adverse pregnancy outcome compared with those with only one marker (61.1% vs. 35.6%, P = 0.04). UtA Doppler was abnormal in 20% (32 of 159 women screened) and increased the risk of adverse pregnancy outcome (RR 2.5, 65.6% vs. 26.0%, P < 0.001). SGA(10) , SGA(5) and LBW were significantly more common in women with abnormal UtA Doppler (RR 2.98, 56.2% vs. 18.9%, P < 0.001, RR 4.6, 43.7% vs. 9.4%, P < 0.001 and RR 4.4, 31.2% vs. 7.1%, P < 0.001, respectively). Women with normal Doppler examination still had a 26% risk of adverse pregnancy outcome.

CONCLUSIONS

In women with extreme levels of feto-placental proteins used for Down syndrome screening, an abnormal second-trimester UtA Doppler examination confers a high risk of adverse pregnancy outcome and SGA in particular, but a normal examination does not rule out an adverse pregnancy outcome.

Assisted conception and placental perfusion assessed by uterine artery Doppler at 11-13 weeks' gestation

BACKGROUND

Pregnancies conceived by IVF are at increased risk of pre-eclampsia (PE). This study examines the potential mechanism for such association by examining the effect of method of conception on placentation as assessed by uterine artery Doppler at 11-13 weeks' gestation.

METHODS

This prospective screening study at 11(+0)-13(+6) weeks for PE in singleton pregnancies used a combination of maternal history and uterine artery pulsatility index (PI). Regression analysis was performed to examine the association between the method of conception and both uterine artery PI and development of PE, after adjustment for maternal characteristics and obstetric history.

RESULTS

In the study population of 27 461 pregnancies, conception was spontaneous in 26 538 (96.6%), by IVF in 426 (1.6%) and by use of ovulation induction (OI) drugs in 497 (1.8%) pregnancies. Conception by IVF was associated with an increase in risk for early-PE, requiring delivery before 34 weeks [odds ratio 3.94, 95% confidence interval (CI) 1.51-10.27] but not for late-PE. In the OI group, the risk of early- and late-PE was not increased. In addition to IVF, other significant contributors to the prediction of early-PE were maternal weight, height, African and South Asian racial origin, previous and family history of PE and history of chronic hypertension. Significant contributions in explaining log(10) uterine artery PI were provided from maternal characteristics but not from the method of conception. The median uterine artery PI multiple of the median (MoM) in the IVF group (1.02 MoM) and in the OI group (1.03 MoM) were not significantly different from that of the spontaneous conception group (1.01 MoM; P= 0.870 and P= 0.296, respectively).

CONCLUSIONS

Conception by IVF substantially increases the risk for early-PE, through a mechanism unrelated to clinically measurable impairment in placental perfusion.

Maternal insulin resistance and preeclampsia

OBJECTIVE

The purpose of this study was to determine whether mid-trimester insulin resistance is associated with subsequent preeclampsia.

STUDY DESIGN

This was a secondary analysis of 10,154 nulliparous women who received vitamin C and E or placebo daily from 9-16 weeks gestation until delivery. Of these, 1187 women had fasting plasma glucose and insulin tested between 22 and 26 weeks gestation. Insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index.

RESULTS

Obese women were twice as likely to have a HOMA-IR result of ≥75th percentile. Hispanic and African American women had a higher percentage at ≥75th percentile for HOMA-IR than white women (42.2%, 27.2%, and 16.9%, respectively; P < .001). A HOMA-IR result of ≥75th percentile was higher among the 85 nulliparous women who subsequently had preeclampsia, compared with women who remained normotensive (40.5% vs 24.8%; adjusted odds ratio, 1.9; 95% confidence interval, 1.1-3.2). Quantitative insulin sensitivity check index results were similar to the HOMA-IR results.

CONCLUSION

Midtrimester maternal insulin resistance is associated with subsequent preeclampsia.

Placental oxidative DNA damage and its repair in preeclamptic women with fetal growth restriction

Preeclampsia is frequently accompanied by fetal growth restriction (FGR). Preeclampsia increases oxygen free radical production, and the resulting oxidative stress impairs placental blood flow. To determine whether placental oxidative stress is associated with FGR in preeclamptic women, we evaluated placental oxidative DNA damage and its repair in 13 preeclamptic women with FGR, 10 preeclamptic women without FGR, and 11 healthy pregnant women without complications. We measured maternal and umbilical serum derivatives of reactive oxygen metabolites (d-ROMs), as a marker of oxygen free radicals, and pulsatility index (PI) of uterine and umbilical arteries, and performed an immunohistochemical analysis to measure the proportion of nuclei in the placental trophoblast that stained positive for 8-hydroxy-2'-deoxyguanosin (8-OHdG), an indicator of oxidative DNA damage, and redox factor-1 (ref-1), indicative of the repair function towards oxidative DNA damage. D-ROMs were increased in the maternal blood of both preeclamptic groups (with FGR, 687.3 ± 50.4 CARR U, p < 0.01; without FGR, 750.4 ± 87.2 CARR U, p < 0.001) compared with controls (504.7 ± 25.0 CARR U). In contrast, d-ROM levels in the umbilical artery were elevated in preeclamptic women with FGR (134.9 ± 13.3 CARR U, p < 0.01), but not in preeclamptic women without FGR (44.0 ± 7.3 CARR U) compared with controls (38.2 ± 5.0 CARR U). Mean PI for uterine arteries was significantly increased in both preeclamptic groups, and the PI in preeclamptic women with FGR was significantly greater than that in women without FGR (0.94 ± 0.07 vs. 1.31 ± 0.07, p < 0.001). The PI for umbilical arteries was significantly increased in preeclamptic women with FGR (0.90 ± 0.05vs. 1.19 ± 0.07, p < 0.001), but not in preeclamptic women without FGR. The proportion of nuclei positive for 8-OHdG was higher in both groups of preeclamptic women than in the control group, but was higher in preeclamptic women with FGR (0.21 ± 0.05 vs. 0.87 ± 0.01, p < 0.001). The proportion of nuclei positive for ref-1 was higher in preeclamptic women without FGR (0.54 ± 0.06, p < 0.001) than in the control group, whereas the proportion did not differ significantly between normal and preeclamptic women with FGR. Our findings indicate that increased oxidative stress and disrupted compensatory reaction against placental oxidative DNA damage may be associated with FGR in preeclamptic women.