Uterine Artery Notching Research Articles

Impaired uterine artery blood flow at mid gestation and low levels of maternal plasma corticotropin-releasing factor.

Corticotropin-releasing factor (CRF) is a placental neuropeptide that plays a role in the control of uteroplacental blood flow regulation. Because CRF has a relaxant effect on uterine vasculature in pregnant rats, we aimed to evaluate mid-gestation plasma CRF levels in women with impaired uterine artery blood flow. Maternal plasma CRF was assayed by specific radioimmunoassay, and uterine artery resistance index (RI) was assessed by Doppler evaluation at 22-24 weeks' gestation in 55 healthy pregnant women, of whom 24 showed a unilateral or bilateral uterine artery notch, reflecting resistance. Statistical analysis was performed by the Kruskal-Wallis test followed by the post hoc Dunn's test and the Spearman rank test. The mean uterine artery RI was significantly (P <.001) higher in women with a notch than in healthy controls. Mean +/- standard error of the mean maternal plasma CRF levels were significantly lower in women with a unilateral (168.45 +/- 27.5 pg/mL; P <.01) or bilateral (186.07 +/- 34.5 pg/mL; P <.001) uterine artery notch than in healthy control pregnant women (375.06 +/- 21.77 pg/mL). Although no difference was found in CRF levels between patients with a unilateral or bilateral uterine artery notch, a significant inverse correlation was found between the mean RI and maternal plasma CRF levels (Spearman r = -0.6540; 95% confidence interval, -0.7865, -0.4640; P <.001). Reduced levels of circulating CRF were associated with increased uterine artery resistance, which supports the hypothesis that CRF may regulate uterine artery tone at mid gestation.

Hémodynamique utéroplacentaire et pratique du Doppler utérin à 12 semaines d’aménorrhée

Last years, feasibility and possible interest of uterine artery Doppler during the third month of gestation were confirmed. Doppler flow velocity waveforms can be obtained and assessed in both uterine arteries using abdominal ultrasonography at 12–14 weeks’ gestation. The no notch group (one third of women) has a low risk for hypertension, intra-uterine growth restriction, abruptio placentae. The “protecting” effect of the absence of uterine artery notch is as high as this physiological change occurs earlier.

Screening for pre-eclampsia and fetal growth restriction in twin pregnancies at 23 weeks of gestation by transvaginal uterine artery Doppler.

To assess the value of transvaginal uterine artery Doppler at 23 weeks of gestation in predicting the development of adverse perinatal outcomes in twin pregnancies. Women with twin pregnancies attending for routine ultrasound examination at 23 weeks in any one of seven hospitals underwent Doppler assessment of the uterine arteries. The right and left uterine arteries were identified using color flow mapping and velocity waveforms were obtained using pulsed Doppler. The mean pulsatility index (PI) of the two arteries was determined and the presence of uterine artery notching noted. Results were compared between monochorionic and dichorionic twins, and with our previously reported data from singleton pregnancies. Screening characteristics in the prediction of pre-eclampsia, fetal growth restriction (FGR), placental abruption, fetal death and early preterm delivery were calculated. Uterine artery Doppler at 22-24 weeks of gestation was performed in 360 twin pregnancies, including 324 dichorionic and 36 monochorionic diamniotic twins. Complete outcome data were available in 351 (97.5%). The mean uterine artery PI did not change significantly with gestation and there was no significant difference in mean PI between the dichorionic and monochorionic groups. However, the mean PI was significantly lower in twin pregnancies than in singletons. The pregnancy was complicated by pre-eclampsia in 6.0% of cases, FGR below the 5th centile of both twins in 8.8%, abruption in 0.9%, intrauterine fetal death in 1.7% and early preterm delivery at less than 32 completed weeks of gestation in 5.7% of cases. The respective sensitivities of uterine artery mean PI above the 95th centile for these complications were 33.3%, 9.7%, 66.6%, 33.3% and 18.6%. In twin pregnancies PI in the uterine arteries is lower than that in singleton pregnancies, but there is no significant difference between dichorionic and monochorionic twins. Doppler assessment of the uterine arteries at 23 weeks identifies a large proportion of twin pregnancies destined to develop adverse outcomes related to uteroplacental insufficiency.

Altered vascular function in healthy normotensive pregnant women with bilateral uterine artery notches

To assess endothelial function and vascular mechanical properties in normotensive pregnant women with high resistance in the uteroplacental circulation. Cross-sectional prospective study. Doppler ultrasound laboratory at university department of obstetrics and gynaecology referral centre for high risk pregnancies. Forty-two caucasian normotensive pregnant women: 23 with uncomplicated pregnancies and 19 with bilateral uterine artery notches. Flow-mediated dilatation of the brachial artery was measured by ultrasonography at 25 gestational weeks. Concentrations of nitrite and nitrate in the plasma were established at 25 and 32 gestational weeks. The elastic properties of the common carotid artery, abdominal aorta and popliteal artery were measured with an ultrasonic echo-tracking system. Flow-mediated dilatation at two minutes after cuff deflation was significantly lower in the bilateral notch group compared with the control group, 8.3% and 13.7%, respectively (P = 0.0007). The ability to sustain vasodilatation was reduced in the bilateral notch group (P = 0.02). Lower values of nitrite and nitrate in the plasma were found at 32 gestational weeks in the bilateral notch group than in the control group (mean 24.76 microM/L (SD 5.6) and 30.93 microM/L (8.2), respectively; P = 0.008). Nitrite and nitrate levels tended to be lower in the bilateral notch group even at 25 gestational weeks (29.45 microM/L (8.3) and 35.73 microM/L (11.0) in the bilateral notch and control group, respectively; P = 0.09). There was no difference in aortic, carotid or popliteal elasticity between the two groups. Healthy normotensive pregnant women with bilateral uterine artery notches show impaired endothelial function, but no differences in vascular mechanical properties.

Altered vascular function in healthy normotensive pregnant women with bilateral uterine artery notches

Objectives To assess endothelial function and vascular mechanical properties in normotensive pregnant women with high resistance in the uteroplacental circulation. Design Cross-sectional prospective study. Setting Doppler ultrasound laboratory at university department of obstetrics and gynaecology referral centre for high risk pregnancies. Participants Forty-two caucasian normotensive pregnant women: 23 with uncomplicated pregnancies and 19 with bilateral uterine artery notches. Methods Flow-mediated dilatation of the brachial artery was measured by ultrasonography at 25 gestational weeks. Concentrations of nitrite and nitrate in the plasma were established at 25 and 32 gestational weeks. The elastic properties of the common carotid artery, abdominal aorta and popliteal artery were measured with an ultrasonic echo-tracking system. Results Flow-mediated dilatation at two minutes after cuff deflation was significantly lower in the bilateral notch group compared with the control group, 8.3% and 13.7%, respectively ( P = 0.0007). The ability to sustain vasodilatation was reduced in the bilateral notch group ( P = 0.02). Lower values of nitrite and nitrate in the plasma were found at 32 gestational weeks in the bilateral notch group than in the control group (mean 24.76 μM/L (SD 5.6) and 30.93 μM/L (8.2), respectively; P = 0.008). Nitrite and nitrate levels tended to be lower in the bilateral notch group even at 25 gestational weeks (29.45 μM/L (8.3) and 35.73 μM/L (11.0) in the bilateral notch and control group, respectively; P = 0.09). There was no difference in aortic, carotid or popliteal elasticity between the two groups. Conclusions Healthy normotensive pregnant women with bilateral uterine artery notches show impaired endothelial function, but no differences in vascular mechanical properties.

Low dose acetylsalicylic acid in prevention of pregnancy‐induced hypertension and intrauterine growth retardation in women with bilateral uterine artery notches

To evaluate the efficacy of low-dose acetylsalicylic acid in the prevention of pregnancy-induced hypertension and intrauterine growth retardation in high-risk pregnancies as determined by transvaginal Doppler ultrasound study of the uterine arteries at 12 to 14 weeks of gestation. Randomised, double blind and placebo-controlled trial. The Department of Obstetrics and Gynaecology, Tampere University Hospital, Finland. One hundred and twenty pregnant women considered to be at high risk of pre-eclampsia or intrauterine growth retardation were screened by transvaginal Doppler ultrasound at 12 to 14 weeks of gestation. Ninety pregnant women with bilateral notches in the uterine arteries were randomised to receive acetylsalicyclic acid 0.5mg/kg/day (n = 45) or placebo (n = 45) from 12 to 14 weeks of gestation. Hypertensive disorders of pregnancy and intrauterine growth retardation. Forty-three women on acetylsalicyclic acid and 43 on placebo were successfully followed up. The use of acetylsalicyclic acid was associated with a statistically significant reduction in the incidence of pregnancy-induced hypertension (11.6% vs 37.2%, RR = 0.31, 95% CI 0.13-0.78) and pre-eclampsia (4.7% vs 23.3%, RR = 0.2, 95% Cl 0.05-0.86). The incidence of hypertension before 37 weeks of pregnancy was also significantly reduced (2.3% vs 20.9%, RR = 0.22, 95% CI 0.05-0.97). The reduction in the incidence of intrauterine growth retardation (2.3% vs 7%) was not statistically significant. Acetylsalicyclic acid was not associated with excess risk of maternal or fetal bleeding. In women rated in Doppler velocimetry waveform analysis to be at high risk of pre-eclampsia, low-dose acetylsalicyclic acid reduces the incidence of pregnancy-induced hypertension and especially proteinuric pre-eclampsia.

Low dose acetylsalicylic acid in prevention of pregnancy-induced hypertension and intrauterine growth retardation in women with bilateral uterine artery notches

Low dose acetylsalicylic acid in prevention of pregnancy-induced hypertension and intrauterine growth retardation in women with bilateral uterine artery notches

Ultrasound time domain and color M‐mode analysis of uterine blood flow in twin pregnancy: prediction of uteroplacental complications, placental insufficiency and intrauterine growth restriction

Objectives: A preliminary assessment of the usefulness of a non‐Doppler technique of uterine artery blood flow measurement in twin pregnancy, for the prediction of preeclampsia, utero‐placental insufficiency and intrauterine growth restriction. To compare the results obtained with the contemporary Doppler method.Methods: A prospective study of 32 twin pregnancies presenting consecutively for a routine second trimester ultrasound scan. Maternal demographic and physical characteristics were recorded in all cases. Using previously described methods, blood flow studies were then conducted using the two different techniques; pulsed color Doppler was used to measure blood flow velocity waveform resistance indices, while a time domain correlation technique with color M‐mode imaging was used to measure blood volume flow in both uterine arteries. The placental site and morphology, uterine artery waveform characteristics, and presence or absence of diastolic notches were recorded. The ultrasound fetal growth measurements were plotted on reference charts to assess individual fetal growth patterns, and the obstetric outcomes were recorded for all the pregnancies. Statistical analysis was performed to assess the predictive value of each method of blood flow measurement for the relevant obstetric complications.Exclusions: One mother with sickle cell trait (Hb A + S).Results: An abnormal uterine artery waveform (high resistance with persistence of uterine artery notching) was of limited value in the prediction of pre‐eclampsia and IUGR in twin pregnancies. There was close correlation between a significant reduction in uterine artery blood volume flow and early onset intrauterine growth restriction requiring delivery before 34 weeks gestation. Uterine artery blood volume flow may be less influenced by the placental site compared with traditionally used resistance and pulsatility indices.Conclusions: Uterine artery notching appears to be of limited value in the direct prediction of growth complications in twins. The volume flow method correctly identified all the pregnancies complicated by early onset intrauterine growth restriction. Both methods may well prove to be complementary in the antenatal management of twin pregnancy although further studies will be required.

Maternal carriership of factor V Leiden associated with pathological uterine artery Doppler measurements during pregnancy

To determine whether increased vascular resistance in the uterine artery is associated with carriership of factor V Leiden, a retrospective study was undertaken of 231 pregnant women who were monitored with Doppler velocimetry of the uterine arteries. These women had been part of a prospective study of 2,480 pregnant women in whom factor V Leiden had been analysed. When compared with non-carriers of factor V Leiden, carriers had a tendency towards an increased proportion of pathological Doppler measurements, including a significant increase in bilateral uterine artery notches (7/33 vs 16/198, relative risk 3.1; 95% CI 1.2-8.1). This suggests an increased vascular resistance in the uteroplacental circulation among carriers of factor V Leiden.

Maternal carriership of factor V Leiden associated with pathological uterine artery Doppler measurements during pregnancy

To determine whether increased vascular resistance in the uterine artery is associated with carriership of factor V Leiden, a retrospective study was undertaken of 231 pregnant women who were monitored with Doppler velocimetry of the uterine arteries. These women had been part of a prospective study of 2480 pregnant women in whom factor V Leiden had been analysed. When compared with non-carriers of factor V Leiden, carriers had a tendency towards an increased proportion of pathological Doppler measurements, including a significant increase in bilateral uterine artery notches (7/33 vs 16/198, relative risk 3.1; 95% CI 1.2–8.1). This suggests an increased vascular resistance in the uteroplacental circulation among carriers of factor V Leiden.

Uterine artery Doppler in predicting pregnancy outcome in women with antiphospholipid syndrome

OBJECTIVE: To assess midtrimester uterine artery Doppler in the prediction of preeclampsia and small for gestational age (SGA) infants in women with primary antiphospholipid syndrome. METHODS: One hundred seventy pregnant women with histories of recurrent miscarriage in association with antiphospholipid antibodies (32 lupus anticoagulant positive, 47 IgG anticardiolipin positive, 78 IgM anticardiolipin positive, and 13 lupus anticoagulant and anticardiolipin antibodies positive) treated with low-dose aspirin and heparin were recruited prospectively. Doppler assessment of the uterine arteries (presence or absence of notches and pulsatility index) were performed at 16–18 and 22–24 weeks. The main outcome measures were the delivery of a SGA infant and the development of preeclampsia. RESULTS: There were 164 live births and six midtrimester losses. The prevalence of preeclampsia and SGA was similar at 10%. In predicting preeclampsia or SGA, uterine artery pulsatility index at either interval was of no value, and the diagnostic accuracy of the Doppler was limited to bilateral uterine artery notches at 22–24 weeks in the subgroup of women with positive lupus anticoagulant. In this subgroup, bilateral uterine artery notches at 22–24 weeks in predicting preeclampsia generated a high likelihood ratio for positive test (12.8, 95% confidence interval 2.2, 75), sensitivity (75%), specificity (94%), positive (75%) and negative (94%) predictive value. In predicting SGA, the corresponding figures were respectively 13.6 (95% confidence interval 1.9, 96), 80%, 94%, 80%, 94%. Uterine artery Doppler was of limited value in pregnancies associated with anticardiolipin antibodies in isolation. CONCLUSION: In pregnancies associated with lupus anticoagulant, uterine artery Doppler at 22–24 weeks is a useful screening test in predicting preeclampsia and SGA infants.

Prediction of Smallness for Gestational Age by Maternal Serum Human Chorionic Gonadotropin Levels and by Uterine Artery Doppler Study

Objectives: To compare the utility of maternal serum human chorionic gonadotropin (MShCG) levels with that of uterine artery Doppler study in predicting small for gestational age (SGA) birth and pregnancy-induced hypertension (PIH). Methods: MShCG assay and uterine artery Doppler study were performed in 359 consecutive pregnant women with singleton pregnancies. MShCG levels ≧2.0 multiples of the median at 15–18 weeks’ gestation were considered to be elevated. An abnormal uterine artery Doppler velocimetry at 21–24 weeks’ gestation was defined as a mean pulsatility index above the 95th percentile or the presence of an early diastolic notch in either uterine artery. The predictive values of MShCG levels and uterine artery Doppler velocimetry were evaluated for the risk of SGA birth and PIH. Results: Forty-one subjects gave birth to SGA infants, and 20 developed PIH. Patients with MShCG elevation or abnormal uterine artery Doppler velocimetry showed a significantly higher incidence of SGA infants than the controls. The sensitivity and specificity of MShCG elevation for SGA birth were 17.1 and 93.4%, respectively, compared with abnormal uterine artery Doppler velocimetry, which had 24.4 and 94.3%, respectively. There was no significant difference between these methods. Elevated levels of MShCG and abnormal uterine artery Doppler velocimetry were not associated with PIH. Conclusion: Elevated levels of second-trimester MShCG were as sensitive and specific in predicting SGA births as abnormal uterine artery Doppler velocimetry.

One-stage screening for pregnancy complications by color Doppler assessment of the uterine arteries at 23 weeks’ gestation

Objective: To estimate the value of screening for preeclampsia and fetal growth restriction by performing color Doppler assessment of uterine arteries at 23 weeks’ gestation in predicting adverse pregnancy outcome. Methods: Women with singleton pregnancies who attended routine ultrasonography at 23 weeks had color Doppler uterine artery imaging. Bilateral uterine artery notches were noted and left and right uterine artery pulsatility indices (PI) were measured. A mean PI of more than 1.45 was considered increased. Screening characteristics for predicting preeclampsia and delivery of small-for-gestational-age infants were calculated. Results: Of 1757 pregnancies, increased PI was present in 89 (5.1%) and bilateral notches were noted in 77 (4.4%). Twenty-three of 65 women (35.3%; 95% confidence interval [CI] 23.9, 48.2) had increased PI and later developed preeclampsia, and 8 of 10 (80%; 95% CI 44.4, 97.5) with preeclampsia required delivery before 34 weeks. The respective values for women with bilateral notches were 21 of 65 (32.3%; 95% CI 21.2, 45.1) and 8 of 10 (80%; 95% CI 44.4, 97.5). The sensitivity of increased PI was 30 of 143 (21%; 95% CI 14.6, 28.6) for delivery of an infant with birth weight below the tenth percentile and 7 of 10 (70% 95% CI 34.8,93.3) for birth weight below the tenth percentile delivered before 34 weeks. The respective values for bilateral notches were 19 of 143 (13.3%; 95% CI 8.2, 20) and 5 of 10 (50%; 95% CI 18.7, 81.3). Conclusion: A one-stage color Doppler screening program at 23 weeks identified most women who subsequently developed serious complications of impaired placentation associated with delivery before 34 weeks. The screening results were similar when the high-risk group was defined as women with increased PI or bilateral notches.

The role of insulin-like growth factor binding protein-1 phosphoisoforms in pregnancies with impaired placental function identified by doppler ultrasound.

This study was performed to investigate the hypothesis that insulin-like growth factor binding protein-1 (IGFBP-1) is involved in the pathogenesis of trophoblast invasion and impaired placentation in human pregnancy. The role of total and non-phosphorylated IGFBP-1 in women with fetal growth restriction and in high risk pregnancies identified by uterine artery Doppler ultrasound screening was examined. This was a prospective study of women booked for antenatal care having second trimester anomaly scans and Doppler screening between 22-26 weeks gestation. Women were divided into three groups and compared: normal uterine artery Doppler and normal fetal growth (control group, n = 10); abnormal Doppler and normal fetal growth [bilateral uterine artery notches (BN; n = 16); abnormal Doppler and intrauterine growth restriction (IUGR; n = 8)]. Maternal serum was collected, stored and assayed simultaneously for total and non-phosphorylated IGFBP-1. There was elevated total and non-phosphorylated IGFBP-1 (mean 44.99 +/- 12.19 and 29.61 +/- 10.38 microg/l respectively) in the IUGR group compared with controls (mean 17.96 +/- 3.24 and 12.18 +/- 1.55 microg/l, P < 0.05). This finding suggests that the various IGFBP-1 isoforms, the degree of phosphorylation and the ratios of these different forms locally may be important during trophoblast invasion and may be implicated in clinical manifestations of impaired placentation later in the second trimester.

The reliability of the detection of an early diastolic notch with uterine artery Doppler velocimetry.

This study evaluates the ability of two reviewers to detect independently an early diastolic notch in 1371 uterine artery Doppler velocity waveform recordings. Agreement between the two reviewers for the detection of uterine artery notching was assessed by using the Kappa statistic. The inter-rater reliability for the detection of unilateral notching was 0.75 (95% CI 0.70-0.80), whereas that for the presence or absence of bilateral notching was 0.66 (95% CI 0.60-0.71). The results suggest that there was good reviewer agreement for the presence or absence of a notch on uterine artery Doppler velocimetry.

Uterine and umbilical artery velocimetry in pre-eclampsia.

The aim of the present study was to evaluate whether Doppler velocimetry of the placental circulation can predict adverse outcome of pregnancies complicated by pre-eclampsia and whether there is a correlation between maternal blood pressure, proteinuria and placental vascular resistance. One hundred and eight pregnant women with pre-eclampsia were followed and examined by Doppler velocimetry of the uterine arteries. The presence of a notch and the mean pulsatility index (PI) in the two arteries were recorded. The velocity waveforms in umbilical arteries were also evaluated. The Doppler velocimetry results were related to the perinatal outcome, maternal blood pressure and proteinuria. Abnormal arterial blood velocity waveforms on both sides of the placenta were significantly correlated with a shorter gestational age at delivery, lower birthweight, increased cesarean section rate and more frequent admissions to the neonatal intensive care unit. Bilateral rather than unilateral uterine artery notches were predictive of poor perinatal outcome. The combination of umbilical and uterine artery waveform results was the best predictor of adverse outcome. The uterine artery velocimetry was, however, not related to maternal blood pressure or the degree of proteinuria. Abnormal velocity waveforms in the uterine and umbilical arteries have clinical significance in pregnancies complicated by pre-eclampsia and predict adverse outcome of pregnancy, especially the fetal growth restriction and need for operative interventions during labor and delivery.

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.

Peak systolic over protodiastolic ratio as an objective substitute for the uterine artery notch.

To measure the inter-rater agreement for the identification of a uterine artery notch, as well as the association between an observed notch and the peak systolic over protodiastolic (A/C) ratio. Cohort study. Tertiary care university hospital. Six hundred and sixty-five nulliparous women in whom 1022 examinations of uterine artery velocity waveforms were performed by pulsed Doppler at 18 and at 26 weeks of gestation. Agreement between two independent raters was analysed using Cohen's kappa statistics. A/C ratios of flow velocity waveforms with or without a notch were compared. The agreement between A/C values and the presence of a notch was estimated by measuring the surface under the receiver operating characteristic (ROC) curve. Inter-rater agreement for the identification of a notch was 0.74 (95% CI 0.64-0.83) at 18 weeks and 0.72 (95% CI 0.64-0.80) at 26 weeks. A/C ratios were higher when a notch was present (P < 0.0001). The area under the ROC curve was 0.86 (95% CI 0.81-0.91) for the placental uterine artery and 0.93 (95% CI 0.90-0.96) for the nonplacental artery. An A/C value > or = 2.5 in any uterine artery had a sensitivity of 88% and a specificity of 86% to detect a notch. Although there is no definitive definition of the notch, its detection is reproducible within a center. However, published prevalences between centers in unselected populations vary. The measure of the A/C ratio can serve as an objective substitute.

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.

Color Doppler imaging of the uteroplacental circulation in the middle trimester: observations on the development of a low-resistance circulation.

We aimed to study the changes in the flow dynamics of the uteroplacental and umbilical circulations in the middle trimester of normal pregnancy, and establish normal ranges for indices of the Doppler flow velocity waveforms (FVWs) from both circulations at 14, 18 and 24 weeks. A longitudinal study was conducted with the use of color Doppler imaging to localize both uterine arteries and umbilical arteries and obtain FVWs from 106 healthy nulliparous women with a singleton pregnancy. Of these, 70 did not have a complicated pregnancy outcome, defined as hypertension, growth retardation, preterm delivery or perinatal death. We measured the resistance index (RI), pulsatility index (PI), systolic/diastolic (S/D) ratio and presence of early diastolic notching in both uterine arteries, and RI, PI and S/D in one umbilical artery. The results showed a fall in all measured indices of blood flow impedance in the uteroplacental and umbilical circulations and a marked reduction in the incidence of the early diastolic notch in the uterine artery FVWs during the mid-trimester. Our conclusion was that color Doppler imaging allows for the accurate localization of both uterine and umbilical arteries. Doppler FVWs then obtained confirm the development of the low-resistance uteroplacental and umbilical circulations in the mid-trimester. Diastolic notching is common at 14 weeks in normal pregnancy but uncommon at 24 weeks.