Uterine Artery Doppler Findings Research Articles

Placental angiogenic growth factors and uterine artery Doppler findings for characterization of different subsets in preeclampsia and in isolated intrauterine growth restriction

The purpose of this study was to evaluate possible relationships between placental markers and endothelial dysfunction in preeclampsia and intrauterine growth restriction. A prospective study was conducted in 76 patients with preeclampsia and 37 patients with intrauterine growth restriction that were classified as early onset (<34 weeks of gestational age) or late onset, and 40 control subjects. Plasma levels of placental growth factor, soluble fms-like tyrosine kinase-1, vascular cell adhesion molecule-1, and uterine artery Doppler indices were measured. In early-onset preeclampsia and intrauterine growth restriction, placental growth factor was lower and soluble fms-like tyrosine kinase-1 and vascular cell adhesion molecule-1 higher than in control subjects, although all changes were more pronounced in preeclampsia. In late-onset preeclampsia, those patients with abnormal uterine artery Doppler indices had higher soluble fms-like tyrosine kinase-1 and vascular cell adhesion molecule-1 levels. Biochemical changes in early-onset preeclampsia and intrauterine growth restriction point to a common placental disorder and a state of endothelial dysfunction, which may require interaction with other factors to explain the maternal disease in preeclampsia. Data in late-onset preeclampsia suggest that a proportion of them may occur with minimal placental involvement.

Uterine artery Doppler screening for adverse pregnancy outcome

This article reviews publications in the area of uterine artery Doppler screening that were published during the past year. Studies have shown that assessment of a woman's level of risk for pre-eclampsia by uterine artery Doppler performs better than maternal history alone. Combination of maternal history and uterine artery Doppler findings leads to even more accurate assessment of risk, and allows calculation of patient-specific risk. Combining screening with uterine artery Doppler and maternal serum biochemical markers has been explored in some studies, but data remain limited and larger prospective longitudinal studies are needed to asses the effectiveness of these techniques. A number of promising markers for development of the disease have been identified, however, including pregnancy associated plasma protein-A, inhibin-A, activin-A and fibronectin, as well as placental growth factor, vascular endothelial growth factor and soluble fms-like tyrosine kinase 1. Uterine artery Doppler has proved useful in identifying women at high and low risk for developing complications of uteroplacental insufficiency and may aid in stratifying antenatal care. In addition, it can identify women in whom biochemical markers should be measured in order to develop screening tests and aid in evaluation of the pathophysiology of impaired placentation and pre-eclampsia. Whether pharmacological intervention in women identified to be at high risk for pre-eclampsia on the basis of Doppler is effective in reducing the incidence of the disease remains to be established.

Avaliação prospectiva do índice de líquido amniótico em gestações normais e complicadas

OBJETIVO: Analisar, prospectivamente, o índice de líquido amniótico em gestantes de baixo risco que apresentaram ou não complicações da gestação e do período perinatal. MATERIAIS E MÉTODOS: Foi estudado, de modo prospectivo, o índice de líquido amniótico de 45 primigestas sem doenças no momento da inclusão no estudo. O índice foi avaliado em quatro períodos da gestação - 18-20, 24-26, 28-30 e 34-36 semanas - e seus valores foram correlacionados com o surgimento de complicações gestacionais e perinatais, Doppler das artérias uterinas, idade gestacional ao parto, vias de parto e o peso dos recém-nascidos. RESULTADOS: O índice de líquido amniótico não mostrou diferença estatística entre as pacientes com gestações normais e complicadas em nenhum dos quatro períodos estudados. Também não mostrou associação com a idade gestacional ao parto, as vias de parto e o peso dos recém-nascidos. Observou-se que a média do índice de líquido amniótico entre 28-30 semanas é mais elevada (p = 0,004) nas pacientes com incisura bilateral do que nas com Doppler normal. CONCLUSÃO: A avaliação prospectiva do índice de líquido amniótico em gestações de baixo risco parece não ser um bom preditor de complicações gestacionais ou perinatais.

Second‐trimester uterine artery Doppler and spontaneous preterm delivery

To assess the relationship between second-trimester uterine artery (UtA) Doppler measurements and spontaneous preterm delivery. This was a retrospective analysis of UtA Doppler findings at 18-23 weeks' gestation in 234 singleton pregnancies with spontaneous preterm labor and 5472 pregnancies delivered at term. Cases with fetal chromosomal or structural abnormalities, pre-eclampsia, small-for-gestational-age (SGA) fetuses, concurrent maternal disease, cervical cerclage or history of cone biopsy were excluded. UtA mean resistance index (RI) and number of protodiastolic notches were not significantly different in the spontaneous preterm labor group compared to the normal group. The 62 preterm deliveries not preceded by spontaneous preterm premature rupture of membranes (PPROM) showed a significantly higher RI and prevalence of bilateral notches than cases of preterm deliveries preceded by PPROM (n = 172). However, this difference was not confirmed in a logistic regression model. Despite pathological evidence suggesting that defective placentation is associated with spontaneous preterm delivery, second-trimester UtA resistance, as assessed by Doppler ultrasound investigation, is not different in pregnancies subsequently complicated by preterm labor compared to pregnancies delivered at term.

Uterine artery Doppler and mid-trimester maternal plasma homocysteine in subsequent pre-eclampsia

To investigate whether mid-trimester maternal plasma homocysteine concentration is elevated in women who develop pre-eclampsia and in those women identified at high risk by abnormal uterine artery Doppler examination. This was a multicenter study involving healthy women undergoing screening for pre-eclampsia by uterine artery Doppler velocimetry at 22-24 weeks' gestation. Abnormal uterine artery blood flow was defined as a mean pulsatility index (PI) above the 95th centile (1.6). Controls (mean PI < 1.6) were matched for gestational age and date of blood sample collection. Maternal plasma homocysteine concentration was measured retrospectively using a chemiluminescent immunoassay. In total, 683 women were recruited. Maternal plasma homocysteine concentration did not vary with gestation. Maternal plasma homocysteine concentration in women who subsequently developed pre-eclampsia (n = 80, 12%) was not significantly different from women with uncomplicated pregnancies (n = 536, 78%) (median 5.1, range 2.7-14.1 micromol/l vs. median 5.5, range 1.9-27.9 micromol/l, p = 0.44). There were no significant differences in the maternal plasma homocysteine concentration in women with abnormal uterine artery Doppler findings (n = 275) compared with controls (n = 408), (median 5.6, range 2.6-17.7 micromol/l vs. median 5.4, range 1.9-27.9 micromol/l, p = 0.13). Mid-trimester maternal plasma homocysteine concentration is not elevated in women who developed pre-eclampsia even in those at high risk defined by abnormal uterine artery Doppler velocimetry.

Uterine artery Doppler and mid-trimester maternal plasma homocysteine in subsequent pre-eclampsia

Objective: To investigate whether mid-trimester maternal plasma homocysteine concentration is elevated in women who develop pre-eclampsia and in those women identified at high risk by abnormal uterine artery Doppler examination. Methods: This was a multicenter study involving healthy women undergoing screening for pre-eclampsia by uterine artery Doppler velocimetry at 22-24 weeks' gestation. Abnormal uterine artery blood flow was defined as a mean pulsatility index (PI) above the 95th centile (1.6). Controls (mean PI < 1.6) were matched for gestational age and date of blood sample collection. Maternal plasma homocysteine concentration was measured retrospectively using a chemiluminescent immunoassay. Results: In total, 683 women were recruited. Maternal plasma homocysteine concentration did not vary with gestation. Maternal plasma homocysteine concentration in women who subsequently developed pre-eclampsia (n = 80, 12%) was not significantly different from women with uncomplicated pregnancies (n = 536, 78%) (median 5.1, range 2.7-14.1 μmol/l vs. median 5.5, range 1.9-27.9 μmol/l, p = 0.44). There were no significant differences in the maternal plasma homocysteine concentration in women with abnormal uterine artery Doppler findings (n = 275) compared with controls (n = 408), (median 5.6, range 2.6-17.7 μmol/l vs. median 5.4, range 1.9-27.9 μmol/l, p = 0.13). Conclusion: Mid-trimester maternal plasma homocysteine concentration is not elevated in women who developed pre-eclampsia even in those at high risk defined by abnormal uterine artery Doppler velocimetry.

Prognostic value of placental ultrasound in pregnancies complicated by absent end-diastolic flow velocity in the umbilical arteries

Our objective was to evaluate the utility of gray-scale placental ultrasound for the detection of pathological lesions in the placentas of preterm pregnancies with abnormal fetoplacental blood flow (defined by absent or reversed end-diastolic flow velocities [ARED] in the umbilical arteries) before 32 weeks of gestation. Sixty consecutive structurally and chromosomally normal singleton pregnancies were evaluated. Pre-defined criteria were used to describe placental appearances using gray-scale real-time ultrasound. Proximal uterine artery Doppler waveforms were recorded using pulsed and color Doppler ultrasound. Each patient had a thrombophilia profile. Following delivery, a single perinatal pathologist reviewed each placenta at a gross and microscopic level blinded to the placental ultrasound findings. Placental shape or texture was abnormal on gray-scale ultrasound in 43/59 (73%) and echogenic cystic lesions (ECL) were found in 16 (27%). Uterine artery Doppler was abnormal in 47/60 (78%) cases. Thirty-eight pregnancies were subsequently delivered by planned Caesarean section in the fetal and/or maternal interest (birthweights 540–2300 g, mean gestational age 30.6 weeks) and 21 pregnancies resulted in the vaginal delivery of a stillborn fetus where fetal weight and/or gestational age did not justify Caesarean section (birthweights 85–600 g, mean gestational age 24.9 weeks). ECL had a low positive predictive value for both villous infarcts (63%) and for focal/massive perivillous fibrin deposition (40%). Nevertheless, the combination of abnormal uterine artery Doppler and abnormal gray-scale findings (abnormal placental morphology or ECL) was strongly predictive of stillbirth (17/21; sensitivity 81%, PPV 52%, p=0.006 Fisher's exact test). Pregnancies with ARED in the umbilical arteries have a high perinatal mortality associated with pathology of the placental villi. Ultrasound examination of the placenta and its maternal blood supply may contribute to the perinatal management of these pregnancies.

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This was a screening study carried out in a low-risk population and consequently we excluded women with pre-existing hypertension or renal disease. Selection for the aspirin trial1 was based on abnormal second-trimester uterine artery Doppler findings. The incidence of pre-eclampsia in the abnormal Doppler group was 19%, confirming that uterine artery Doppler is a good method of identifying a high-risk group. We used mean uterine artery pulsatility index (PI) as an objective measure of impedance to flow, because the diagnosis of an early diastolic notch is often subjective. Nevertheless, the incidence of bilateral notches in the aspirin and placebo groups were similar (73% vs. 68%, P = 0.46). In terms of screening performance, for the same screen-positive rate the sensitivity of mean uterine artery PI > 95th centile is better than bilateral notches for both pre-eclampsia and fetal growth restriction although, if we combine bilateral notches with mean uterine artery PI > 95th centile, the positive predictive value and likelihood ratio are improved (Table 1). C. K. H. Yu*, K. H. Nicolaides*, * Harris Birthright Research Centre, King's College Hospital, Denmark Hill, London, SE5 9RS, UK

Effect of parity on second-trimester uterine artery Doppler flow velocity and waveforms.

To investigate the relationship between second-trimester uterine artery Doppler findings and parity in a large pregnant population. Uterine artery Doppler studies were performed in all singleton pregnancies at 18-23 weeks of gestation. The mean uterine artery resistance index and the presence or absence of protodiastolic notches were recorded. Two groups were identified: pregnancies not complicated by pre-eclampsia, and pregnancies with pre-eclampsia severe enough to require delivery at or before 32 weeks of gestation. In the 4132 pregnancies uncomplicated by pre-eclampsia, parity was shown to be an independent predictor for both mean uterine artery resistance index (beta = 0.073, P < 0.001) and the presence of bilateral protodiastolic notches (odds ratio = 0.67; 95% CI, 0.45-0.98). In the 17 pregnancies complicated with severe pre-eclampsia, uterine artery Doppler indices showed a trend towards being better predictors of disease in nulliparous compared with parous women. Parity has a significant effect on the resistance index and the prevalence of protodiastolic notching in the uterine artery flow waveforms. This difference is clinically noticeable in its effect on notching. These findings suggest that some permanent modification may persist in the maternal vessels after a successful pregnancy, altering their impedance in subsequent pregnancies.

Doppler assessment of the maternal interlobar renal and uterine arteries in mid‐pregnancy in women at low and high risk for pregnancy‐induced hypertension

Purpose The purpose of this study was to examine the relationship between vascular resistance of the maternal intrarenal arteries and the main uterine arteries in pregnant women at low and high risk for pregnancy-induced hypertension. Methods The resistance indices (RIs) in the main uterine arteries and the interlobar branches of the right renal artery were measured by duplex Doppler sonography in 338 pregnant women at 21–24 weeks of gestation, including 175 women at high risk for pregnancy-induced hypertension. Of those, 54 patients had repeat Doppler measurements during pregnancy. Results Cross-sectional data showed no correlation between the RIs in the right interlobar renal arteries and either uterine artery. Furthermore, no relationship existed between persistent diastolic notching in the uterine arteries and the RI in the renal circulation. The mean renal artery RI was 0.62. Compared to that in patients with a normal outcome, the renal artery RI was not significantly different in patients who developed proteinuric pregnancy-induced hypertension (PPIH) or severe pregnancy-induced hypertension (PIH) later during pregnancy. Multiple analysis of variance for longitudinal data showed no correlation between the RI in the maternal renal arteries and gestational age, severe PIH, or PPIH. Conclusions The RIs in the maternal intrarenal arteries and the main uterine arteries are not related to each other in pregnant women, even in patients with abnormal uterine artery Doppler findings, severe PIH, or PPIH. © 1998 John Wiley & Sons, Inc. J Clin Ultrasound 26:239–245, 1998.

Doppler assessment of the maternal interlobar renal and uterine arteries in mid-pregnancy in women at low and high risk for pregnancy-induced hypertension.

The purpose of this study was to examine the relationship between vascular resistance of the maternal intrarenal arteries and the main uterine arteries in pregnant women at low and high risk for pregnancy-induced hypertension. The resistance indices (RIs) in the main uterine arteries and the interlobar branches of the right renal artery were measured by duplex Doppler sonography in 338 pregnant women at 21-24 weeks of gestation, including 175 women at high risk for pregnancy-induced hypertension. Of those, 54 patients had repeat Doppler measurements during pregnancy. Cross-sectional data showed no correlation between the RIs in the right interlobar renal arteries and either uterine artery. Furthermore, no relationship existed between persistent diastolic notching in the uterine arteries and the RI in the renal circulation. The mean renal artery RI was 0.62. Compared to that in patients with a normal outcome, the renal artery RI was not significantly different in patients who developed proteinuric pregnancy-induced hypertension (PPIH) or severe pregnancy-induced hypertension (PIH) later during pregnancy. Multiple analysis of variance for longitudinal data showed no correlation between the RI in the maternal renal arteries and gestational age, severe PIH, or PPIH. The RIs in the maternal intrarenal arteries and the main uterine arteries are not related to each other in pregnant women, even in patients with abnormal uterine artery Doppler findings, severe PIH, or PPIH.

A cross-sectional study of platelet volume in healthy normotensive women with bilateral uterine artery notches.

High uterine artery resistance characterized by bilateral notches seen on Doppler ultrasound in the second half of pregnancy is associated with an increased risk of adverse outcome related to pre-eclampsia and intrauterine growth retardation. We sought to establish whether there was a difference in platelet volume in healthy, normotensive women with high-resistance uterine artery Doppler findings compared to those with normal uterine artery Doppler findings. Forty-seven women were allocated prospectively into 'bilateral notch' and 'no notch' groups at color Doppler imaging of the uterine arteries carried out at a mean of 26 weeks' gestation. The difference in platelet volume between the two groups and the relationship of adverse outcome with raised platelet volume and high-resistance uterine artery Doppler findings was investigated. Twenty-three women had no evidence of uterine artery notches and 24 had bilateral uterine artery notches. Platelet volume in the women with bilateral notches was greater than in those with no notches (8.28 fl vs. 7.46 fl; p = 0.01). However, unlike high-resistance uterine artery Doppler findings, increased platelet volume was not associated with adverse outcome. Uterine artery Doppler flow abnormalities have not previously been studied in combination with hematological or biochemical markers. Our findings show, for the first time, that women with bilateral uterine artery notches have an increased platelet volume compared to those with normal uterine artery Doppler findings many weeks before clinical signs of pre-eclampsia or fetal growth retardation are evident. Women with abnormal uterine artery flow at this gestation may have other cardiovascular and hematological differences compared to those with normal flow.

Uterine artery Doppler velocimetry in the detection of adverse obstetric outcomes in women with unexplained elevated maternal serum α-fetoprotein levels

OBJECTIVE: We hypothesized that in pregnancies complicated by unexplained elevations of maternal serum α-fetoprotein, second-trimester uterine artery Doppler findings would detect adverse obstetric outcomes. STUDY DESIGN: One hundred three subjects with unexplained elevations of maternal serum α-fetoprotein had uterine artery Doppler velocimetry studies performed at the time of targeted ultrasonographic examination (17 to 22 weeks). A resistance index >95th percentile or the presence of a uterine notch was considered abnormal. Adverse outcomes included preeclampsia, preterm birth, low birth weight, intrauterine growth restriction, abruptio placentae, and fetal death. Statistical analysis was performed by Student t test, χ 2 analysis, and stepwise logistic regression analysis. RESULTS: An elevated uterine resistance index was associated with an increased relative risk for both preeclampsia (relative risk 41.82, 95% confidence interval 5.36 to 326.13) and low birth weight (relative risk 4.65, 95% confidence interval 1.90 to 11.39). A uterine artery notch was associated with an increased risk of preeclampsia (relative risk 52.22, 95% confidence interval 6.82 to 399.70), preterm birth (relative risk 3.21, 95% confidence interval 1.32 to 7.81), and a low birth weight (relative risk 4.18, 95% confidence interval 1.64 to 10.66). when the presence of a uterine notch, vaginal bleeding, and level of maternal serum AFP were analyzed, by stepwise logistic regression, the presence of a notch was found to be the only significant factor (odds ratio 6.95, 95% confidence interval 1.24 to 39.10) for the development of an adverse outcome. CONCLUSIONS: Abnormal uterine artery Doppler findings are associated with an increased frequency of adverse obstetric outcomes in women with unexplained elevated maternal serum AFP levels. Abnormal Doppler findings demonstrated high sensitivity for the development of preeclampsia but were less sensitive in predicting other outcomes. the presence of a uterine artery notch is a better independent predictor of adverse outcome than are early vaginal bleeding or maternal serum AFP level.