Low-resistance endometrial arterial flow in the exclusion of ectopic pregnancy revisited

Conventional and modern markers of pregnancy of unknown location: Update and narrative review

Pregnancy of unknown location (PUL) is a temporary pathologic or physiologic phenomenon of early pregnancy that requires follow up to determine the final pregnancy outcome. Evidence indicated that PUL patients suffer a remarkably higher rate of adverse pregnancy outcomes, represented by ectopic gestation and early pregnancy loss, than the general population. In the past few decades, discussion about PUL has never stopped, and a variety of markers have been widely investigated for the early and accurate evaluation of PUL, including serum biomarkers, ultrasound imaging features, multivariate analysis, and the diagnosis of ectopic pregnancy based on risk stratification. So far, machine learning (ML) methods represented by M4 and M6 logistic regression have gained a level of recognition and are continually improving. Nevertheless, the heterogeneity of PUL markers, mainly caused by the limited sample size, the differences in population and technical maturity, etc., have hampered the management of PUL. With the advancement of multidisciplinary integration and cutting-edge technologies (e.g. artificial intelligence, prediction model development, and telemedicine), novel markers, and strategies for the management of PUL are expected to be developed. In this review, we summarize both conventional and novel markers (represented by artificial intelligence) for PUL assessment and management, investigate their advancements, limitations and challenges, and propose insights on future research direction and clinical application.

Pulsatile vessel at the posterior bladder wall: A new sonographic marker for placenta percreta

OBJECTIVE

We investigated using "pulsatile vessels at the posterior bladder wall" as a novel sonographic marker to demonstrate the severity of placenta accreta spectrum (PAS).

METHODS

This observational case-control study of 30 pregnant women was performed at Hackensack Meridian Health's Center for Abnormal Placentation in 2020. The case group was made up of women with historically described sonographic signs of PAS and was compared against two control groups: (1) women with uncomplicated placenta previa and (2) women with no evidence of placenta previa sonographically. All patients were evaluated with Color Flow Doppler ultrasound to assess the presence of arterial vessels at the posterior bladder wall. The flow characteristics and resistance indices (RI) were noted in the presence of pulsatile vessels. All patients' placentation was clinically confirmed at delivery. Patients with clinical invasive placentation underwent histopathological diagnosis to confirm disease presence.

RESULTS

Hundred percent of subjects in our series with suspected PAS exhibited pulsatile arterial vessels at the posterior bladder wall sonographically with a low RI of 0.38 ± 0.1 at an average of 24.6 ± 5.2 gestational weeks. Cases were histopathologically confirmed to have placenta percreta after delivery. Patients in either of the control groups did not display pulsatile vessels at the posterior bladder wall during antenatal sonographic evaluations and had no clinical evidence of PAS.

CONCLUSION

The presence of posterior urinary bladder wall pulsatile arterial vessels with low RI, in addition to traditional sonographic markers increases the suspicion of severe PAS. Thus, these findings allow for the greater opportunity for coordination of patient care prior to delivery.

Normal and Abnormal US Findings in Early First-Trimester Pregnancy: Review of the Society of Radiologists in Ultrasound 2012 Consensus Panel Recommendations

Since being introduced more than 30 years ago, endovaginal ultrasonography (US) and quantitative testing of serum levels of the beta subunit of human chorionic gonadotropin have become the standard means of establishing the presence of normal intrauterine pregnancy (IUP), failed IUP, and ectopic pregnancy. Appropriate use of these powerful tools requires clear, standardized interpretations based on conservative criteria to protect both the pregnancy and the mother. Since diagnoses are assigned earlier and available medical treatments for ectopic pregnancy and failed IUP are expanding, emphasis must carefully shift toward watchful waiting when the mother is clinically stable and a definitive location for the pregnancy cannot be established with US. To this end and to prevent inadvertent harm to early normal pregnancies, the Society of Radiologists in Ultrasound convened a consensus panel of radiologists, obstetricians, and emergency medicine physicians in 2012 with the goal of reviewing current literature and clinical practices and formulating modern criteria and terminology for the various first-trimester outcomes.

Sonographic findings of transvaginal color Doppler ultrasound in ectopic pregnancy

PURPOSE

The objective of this study was to retrospectively assess whether the sonographic findings from transvaginal color Doppler ultrasound (TV-CDU) are helpful in the diagnosis of ectopic pregnancy.

METHODS

Thirty-four patients who received surgery for ectopic tubal pregnancies were preoperatively evaluated using TV-CDU. The presence or absence of color vascularity within the ectopic masses was examined. The relationship between the presence or absence of blood flow in the tubal mass and the corpus luteum cyst, or the serum β-hCG values, was evaluated.

RESULTS

Color vascularity within the adnexal mass was detected in 27 of 34 (79.4%) patients with ectopic pregnancies by TV-CDU. Color vascularity within the mass was observed in 18 of 24 (75.0%) patients with a questionable adnexal mass that had no obvious gestational sac in B-mode images. Moreover, color vascularity was seen in all four patients with a serum β-human chorionic gonadotropin (β-hCG) value of less than 500 mIU/ml. However, it was difficult to identify the blood flow of the adnexal mass in six of the nine (66.7%) patients with a corpus luteum cyst in the ipsilateral ovary. No relationship was observed between the serum β-hCG concentrations and the resistance indices, or the peak systolic velocity.

CONCLUSIONS

The detection of color vascularity by TV-CDU in patients with an ectopic pregnancy is helpful for diagnosis, especially for patients with either a questionable adnexal mass in B-mode images or lower serum β-hCG concentrations.

Assessment of uterine circulation in ectopic pregnancy by transvaginal color Doppler

OBJECTIVE

The aim of our study was to determine the effect of abnormal implantation on uterine circulation and to evaluate whether the assessment of uterinal blood flow can provide additional information for the diagnosis of tubal pregnancies.

METHODS

Forty-nine patients with ectopic pregnancy were examined by transvaginal color Doppler immediately before surgery. Resistance and pulsatility indices of blood flow in the uterine and tubal arteries were measured.

RESULTS

The blood flow parameters of the uterine and tubal arteries did not change with gestational age. There was a significant increase in blood flow on the side with the tubal gestation. Differences between sides were higher in the tubal arteries than in the main uterine arteries and showed no dependence on gestational age.

CONCLUSION

The abnormal implantation and tubal trophoblast invasion in ectopic pregnancy (EP) can cause more marked blood flow changes in the adjacent supplying vessels than in the main uterine arteries.

The Ectopic Pregnancy: A Well-Deserved Review

An ectopic pregnancy results from a pregnancy following the implantation of a blastocyst at any location other than the endometrial lining of the uterine cavity. Although an ectopic pregnancy is more readily diagnosed due to improved testing techniques available today, it is a life-threatening condition and remains a major source of patient morbidity and mortality. Furthermore, the disease state can easily become more complex as the patient faces the loss of a child and fears for her own health.