Uteroplacental circulation in patients with first-trimester threatened abortion

Color Doppler ultrasound of spiral artery blood flow in mid first trimester (4-8 weeks) in cases of threatened abortion and in normal pregnancies

Introduction

The aim of the study was to evaluate and compare the spiral artery flow in mid first trimester (4–8 weeks) in cases of threatened abortion and in normal pregnancies.

Material and methods

Spiral artery was sonographically evaluated in 50 patients comprising two groups of 25 women each. The first group included patients presenting with threatened miscarriage (vaginal bleeding/spotting with or without abdominal pain). The second group comprised of females who had no complications, but had no desire to continue the pregnancy. Spiral artery flow velocity measurements were performed using Color Doppler (Pulsatility Indices, Resistive Indices and Systolic/diastolic values) in mid first trimester (between 4–8 weeks of gestation), each measurement was performed twice. Statistical analysis was performed using Statistical package for social sciences software. Values were rounded off to two digits after decimal point.

Results

Significant differences were noted in the spiral artery Doppler values in the two groups. In particular, the Resistive Indices was higher in cases of women with threatened miscarriage. The difference in Pulsatility Indices was also statistically significant between the two groups.

Conclusion

Doppler values of spiral artery may be used as a useful parameter in assessing the prognosis in cases presenting with threatened miscarriage.

Uterine artery flow velocity waveform (FVW) type and subednometrial vascularity in recurrent pregnancy loss

Purpose: To assess the subendometrial and uterine artery blood flow and pattern of the waveform of the uterine artery in cases of recurrent pregnancy loss compared with normal controls.Subjects and methods: Fifty women with a history of two or more successive pregnancy losses were investigated by Doppler transvaginal ultrasound to assess the subendometrial blood flow resistance index (RI), type of Doppler waveform of the uterine artery, and uterine artery pulsatility index (PI) in the mid-luteal phase. Fifty normal women acted as controls.Results: Subendometrial blood flow RI and uterine artery PI were higher in cases than controls. The majority of cases of recurrent pregnancy loss had a waveform pattern of A, or loss of diastolic flow, whereas the controls were mainly C wave.Conclusions: Some sort of endometrial and subendometrial ischemia can be suggested in cases of recurrent pregnancy loss, waveform pattern of uterine artery changes may be used to monitor changes in vascularity of endometrium if vascular enhancers are given in such cases.

Endometrial and subendometrial vascularity is higher in pregnant patients with livebirth following ART than in those who suffer a miscarriage

BACKGROUND

Blood flow towards the peri-implantation endometrium may have effects on miscarriage and live birth following assisted reproduction treatment, in addition to its role in implantation.

METHODS

Three-dimensional ultrasound examination with power Doppler was performed on the day of oocyte retrieval in stimulated IVF cycles and on LH + 1 day in frozen thawed-embryo transfer (FET) cycles to measure endometrial thickness, endometrial pattern, uterine artery Doppler flow indices, endometrial volume, vascularization index (VI), flow index (FI), vascularization flow index (VFI) of endometrial and subendometrial regions.

RESULTS

In stimulated IVF cycles, 45 (28.0%) out of 161 pregnant patients subsequently miscarried. Patients in the live birth group had significantly higher endometrial VI and VFI and subendometrial VI, FI and VFI, when compared with those in the miscarriage group. In a multiple logistic regression analysis, only endometrial VI was significantly associated with the chance of live birth with an odds ratio of 1.384 [95% confidence interval (CI) 1.025-1.869, P = 0.034]. For FET cycles, patients in the live birth group had significantly higher endometrial VFI, subendometrial VI and VFI than those in the miscarriage group.

CONCLUSIONS

Endometrial and subendometrial vascularity was significantly higher in pregnant patients with live birth following stimulated IVF and FET treatment than in those who suffered a miscarriage.

First-trimester Doppler investigation of the uterine circulation

There is now strong evidence that fetal events can significantly impact postnatal health and disease development. Doppler velocimetry can identify some early pathologic changes in pregnancy. Many investigators have tried to delineate the normal and pathologic models of the uterine circulation in the first trimester, but much has yet to be defined. A discrete amount of confusion derives from the incomplete knowledge of the initial placental development, and particularly the development of the intervillous circulation. This article comprehensively reviews the literature on first-trimester Doppler in both normal and complicated pregnancies, and briefly discusses potential future areas of application.

The role of ultrasound imaging in diagnosing and investigating early pregnancy failure

The advent of high-resolution transvaginal ultrasound (TVS) has revolutionized our understanding of the pathophysiology and the management of early pregnancy failure. Knowledge of the ultrasound appearances of normal early pregnancy development and a good understanding of its pitfalls are essential for the diagnosis and management of early pregnancy failure. Ultrasound imaging has rapidly replaced all other techniques used to study normal human development in the first trimester, and ultrasound features of the early gestational sac have corroborated anatomical studies showing that the first structures to appear are the celomic cavity and the secondary yolk sac. No single ultrasound measurement of the different anatomical features in the first trimester has been shown to have a high predictive value for determining early pregnancy outcome. Similarly, Doppler studies have failed to demonstrate abnormal blood flow indices in the first-trimester uteroplacental circulation of pregnancies that subsequently end in miscarriage. Ultrasound parameters combined with maternal serum hormone levels, maternal age, smoking habits, obstetric history and the occurrence of vaginal bleeding have all been combined in multivariate analyses, with mixed results. Combined ultrasound and in-vitro experiments have demonstrated that the maternal circulation inside the placenta starts at the periphery at around 9 weeks of gestation and that this is associated with a physiological oxidative stress which could be the trigger for the formation of the placental membranes. Abnormal development of these membranes can result in subchorionic hemorrhage and threatened miscarriage with subsequent long-term consequences such as preterm rupture of the membranes and preterm labor, irrespective of the finding of a hematoma on ultrasound. In both euploid and aneuploid missed miscarriages there is clear ultrasound evidence for excessive entry of maternal blood at a very early stage inside the developing placenta resulting in oxidative stress and subsequent degeneration of villous tissue. The finding of blood flow in the intervillous space in cases of first-trimester miscarriage using color Doppler also appears to be useful in the prediction of success of expectant management. Miscarriages with blood flow within the intervillous space are up to four times more likely to complete with expectant management. TVS is considered the gold standard in the diagnosis and management of incomplete miscarriage. Expectant management of miscarriage, using ultrasound parameters to determine eligibility, could significantly reduce the number of unnecessary evacuations of the retained products of conception, depending on the criteria used.

Slow fetal heart rate may predict pregnancy outcome in first-trimester threatened abortion

Two hundred forty pregnant women presented with first-trimester threatened abortion were examined by transvaginal ultrasound. Women with a slow fetal heart rate of less than 120 beats per minute may eventually be at increased risk for pregnancy loss.

T-helper 2-cytokine levels in women with threatened abortion

OBJECTIVE

Considering that successful embryo development has been immunologically attributed to a T-helper 2 phenomenon and that threatened abortion is a very frequent but pathogenetically not well-defined clinical entity, our purpose was to investigate serum levels of the main T-helper 2-type cytokines during the evolution of this condition.

STUDY DESIGN

Three T-helper 2-type cytokines (interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-13 (IL-13)) were measured by an enzyme-linked immunosorbent assay (ELISA) in serum of 12 women with threatened abortion both at hospital admission and discharge time. Fourteen women with missed abortion, 14 normal pregnant women and 14 normal non-pregnant women represent study control groups.

RESULTS

Serum concentrations of the selected T-helper 2-type cytokines showed no significant differences in women with threatened abortion with those of normal pregnant and non-pregnant women, whereas showed significantly lower values in women with missed abortion.

CONCLUSION

Our data (a) confirm the concept that first-trimester normal pregnancy is a T-helper 2 phenomenon, (b) show that threatened abortion, when T-helper 2-biased, may tend to a positive evolution of the condition, (c) display that interleukin-10, particularly, may represent a useful diagnostic and prognostic marker for predicting the normal continuance of the pregnancy in threatened abortion, (d) confirm the existence of a T-helper 2-type pattern deficiency in missed abortion, and finally (e) may open the way to new T-helper 2-biased immune therapies in case of difficult first-trimester pregnancies.

Early vaginal bleeding and first-trimester markers for Down syndrome

OBJECTIVES

To assess the effect of early vaginal bleeding on first-trimester markers for Down syndrome.

METHODS

A retrospective study was conducted on 2330 normal singleton fetuses who underwent first-trimester combined screening for Down syndrome based on ultrasound and maternal serum markers. Fetal nuchal translucency (NT), maternal serum pregnancy-associated plasma protein A (PAPP-A), free beta-hCG and the false-positive rate of the test were compared between pregnancies with (n = 253) and without (n = 2077) a history of early vaginal bleeding.

RESULTS

The mean +/- SD log(10) MoM for NT, PAPP-A and free beta-hCG was -0.024 +/- 0.101, 0.007 +/- 0.244, 0.047 +/- 0.273 and -0.011 +/- 0.108, -0.006 +/- 0.223, 0.008 +/- 0.264 in pregnancies with and without a history of early vaginal bleeding, with a p value of 0.07, 0.40 and 0.03 respectively. The false-positive rate was 2.4% and 3.6% (p = 0.33).

CONCLUSIONS

An earlier episode of vaginal bleeding is associated with an increase in maternal serum free beta-hCG levels at first-trimester combined screening for Down syndrome. However, this phenomenon is unlikely to significantly affect the false-positive rate of the test.

Comparison of ultrasonographic and Doppler mapping of the intervillous circulation in normal and abnormal early pregnancies

OBJECTIVE

To assess the value of ultrasonography and Doppler imaging in characterizing the intervillous circulation in normal and abnormal early pregnancy.

DESIGN

Cross-sectional study.

SETTING

Tertiary care academic hospital.

PATIENT(S)

Eighty-five normal pregnancies and 125 missed miscarriages at 7 to 13 weeks of gestation.

INTERVENTION(S)

Grey-scale ultrasonography was used to evaluate the placental anatomy and detect moving echoes inside the intervillous space, and color power Doppler imaging was used to detect continuous venous-like flow in the placental tissue.

MAIN OUTCOME MEASURE(S)

Degree of agreement between two investigators for use of grey-scale imaging, comparison of detection of moving echoes in normal and abnormal pregnancies, and comparison of detection of intervillous circulation with grey-scale and color Doppler imaging in abnormal pregnancies.

RESULT(S)

The overall degree of agreement between the two investigators was good. A significantly different distribution of blood flow was found between normal and abnormal pregnancies at 7 to 9 weeks and 10 to 11 weeks but not at 12 to 13 weeks. Intervillous moving echoes were detected by grey-scale imaging significantly more frequently than an intervillous blood flow was detected with color Doppler imaging.

CONCLUSION(S)

In early pregnancy failure, there is a premature and diffuse onset of intervillous blood flow that can be detected by grey-scale imaging. This abnormal blood flow pattern may increase the oxidative stress on the early placental tissue and subsequently impair placental development.

Impaired uterine arterial blood flow in pregnant women with recurrent pregnancy loss

OBJECTIVE

This study was undertaken to evaluate uterine perfusion, which regulates uterine receptivity, in women with recurrent pregnancy loss.

METHODS

We evaluated the blood flow resistance in the uterine arteries of 104 pregnant women at 4 to 5 weeks' gestation by transvaginal pulsed Doppler ultrasonography (control group, n = 52; and recurrent pregnancy loss group, n = 52). Blood tests for antinuclear and antiphospholipid antibodies were also performed.

RESULTS

The uterine arterial pulsatility index in the recurrent pregnancy loss group was significantly higher than that in the control group. Women with antinuclear or antiphospholipid antibodies had an elevated pulsatility index in the uterine artery, which is prominent in women with recurrent pregnancy loss. Coagulopathy and vascular dysfunction caused by autoantibodies may impair uterine perfusion. However, the uterine arterial pulsatility index in the recurrent pregnancy loss group was significantly higher than that in the control group even among women without antinuclear antibodies or among women without antiphospholipid antibodies. This observation strongly suggests that the uterine artery pulsatility index may be an independent index for recurrent pregnancy loss.

CONCLUSIONS

The introduction of pulsed Doppler ultrasonography has provided the means for noninvasive evaluation of uterine impedance and may identify patients with recurrent pregnancy loss associated with impaired uterine perfusion.

Assessment of uterine artery blood flow in normal first-trimester pregnancies and in those complicated by uterine bleeding

OBJECTIVE

To compare uterine artery blood flow in normal first-trimester pregnancies with those complicated by uterine bleeding.

METHODS

Uterine artery blood flow was investigated by transvaginal color Doppler in 46 pregnant women affected by uterine bleeding and in a control group of 35 women with normal intrauterine pregnancy. Gestational age ranged from the 6th to the 12th week. Three blood flow values were calculated, the pulsatility index, the resistance index and the peak systolic velocity. Results were compared between the two groups.

RESULTS

Of the 46 patients affected by uterine bleeding, 18 had an incomplete miscarriage, eight had a blighted ovum, five had a missed miscarriage and 15 continued their pregnancy until term and delivered liveborn infants. No significant differences were found in any of the three vascular indices between the normal and the pathological groups of patients. Uterine artery pulsatility and resistance indices decreased with gestational age in both normal and abnormal pregnancies but this change was not statistically significant. The peak systolic velocity significantly increased with gestational age in the control group but not in the pathological group. In patients with a retroplacental hematoma, uterine vascular resistance appeared higher than in those without a hematoma, while the peak systolic velocity showed no difference between the two groups.

CONCLUSION

Doppler analysis of the uterine artery blood flow is unlikely to have a clinical role in the management of early pregnancies complicated by uterine bleeding.

Uteroplacental circulation during the first trimester of normal and abnormal pregnancy

The aim of this study was to evaluate the uteroplacental vascular characteristics during the first trimester of normal and failed pregnancies. A clinical descriptive study was conducted using colour Doppler ultrasound in 45 women with normal pregnancies (group A) and 44 with non-embryonic sac or missed abortions (group B). The mean gestational age in these two groups was 9.3 and 7.6 weeks respectively (P < 0.01). The number of myometrial blood vessels (arteries and veins identified by power Doppler mapping), the quantity of intervillous flow, the resistance index (RI) for the arterial system, and the pulsatility index (PI) of the myometrial arteries were evaluated. The number of myometrial blood vessels in group A was lower than that in group B. The intervillous flow was observed in some cases from early pregnancy and more often after 10 weeks. This characteristic was observed significantly more frequently in group B than in group A. The RI and PI in the uterine arteries were significantly higher in group A than in group B. The RI and the PI of the uterine arteries decreased with the advance of gestational age in both groups. Colour Doppler ultrasound provides information about uteroplacental circulation during the first trimester and indicates early development of intervillous circulation. Although a greater uteroplacental blood circulation was observed in failed pregnancies, the overlapping between groups severely limits the application of this characteristic in clinical practice.