Assessment of placental perfusion using contrast-enhanced ultrasound: A longitudinal study in pregnant rabbit.

OBJECTIVES: The main aim of the study was to quantitatively characterize placental perfusion using contrast-enhanced ultrasound in a longitudinal study performed in pregnant rabbits. As a secondary objective, we qualitatively assessed the placental perfusion. METHODS: Three pregnant rabbits were used. Contrast-enhanced ultrasound was performed twice for each dam, either on embryo development (ED) day 14, 21 or 28 of pregnancy, under general anesthesia. Both qualitative and quantitative analyses were performed based on ultrasound assessment. RESULTS: Altogether, data from 29 fetuses were analyzed: 10 at ED-14; 12 at ED-21, and 7 at ED-28. Placental vascularization was mainly peripheral at the earliest gestational age and became gradually homogeneous within the whole placenta as pregnancy progressed. Intensity parameters and relative blood flows significantly increased with gestational age. The wash-in and wash-out rates were correlated and a significant increase in wash-in compared to in wash-out rates was observed with increased gestational age. CONCLUSION: Contrast-enhanced ultrasound is feasible in animal models and allows qualitative and quantitative analysis of placental vascularization during pregnancy.

New insights into human functional ultrasound imaging.

Ultrasound imaging is a vital tool for exploring in vivo the placental function which is essential to understand pathological phenomena such as preeclampsia or intrauterine growth restriction. As technology advances including ready availability of three-dimensional (3D) probes and novel software, new markers of placental function become possible. The objective of this review was to provide an overview of the new ultrasound markers of placental function with a focus on the potential clinical application of three-dimensional power Doppler (3DPD). A broad-free text literature search was undertaken based on human placental studies and sixty full-text studies were included in this review. Three-dimensional power Doppler is a promising technique to predict preeclampsia in the first trimester. However, the influence of external factors such as body mass index, parameter standardisation and machine settings still need to be addressed. Contrast-enhanced ultrasound is currently reserved for research, because the required injected contrast mediums are not currently approved for use in pregnancy, although the safety data is reassuring.

[Retrospective validation of a model to predict the outcome of pregnancies of unknown location]. / Évaluation rétrospective d'un algorithme d'aide à la décision concernant les grossesses de localisation indéterminée.

OBJECTIVE: The prediction model M6 classifies pregnancy of unknown location (PUL) into a low-risk or a high-risk group in developing ectopic pregnancy (EP). The aim of this study was to validate the two-step M6 model's ability to classify PUL in French women. MATERIAL AND METHODS: All women with a diagnosis of PUL over a year were included in this single center retrospective study. Patients with a diagnosis of EP at the first consultation of with incomplete data were excluded. For each patient, the M6 model calculator was used to classified them into "high risk of EP" and "low risk of EP" group. The reference standard was the final diagnostic: failed PUL (FPUL), intrauterine pregnancy (IUP) of EP. The statistical measures of the test's performance were calculated. RESULTS: Over the period, 255 women's consulted for a PUL, 197 has been included in the study. Final diagnosis were: 94 FPUL (94/197; 47.7%), 74 IUP (74/197; 37.6%) et 29 EP (29/197; 14.7%). The first step of the M6 model classified 16 women in the FPUL group of which 15 (15/16; 93.7%) correctly. The second step of the M6 model classified 181 women: 90 (90/181; 49.7%) in the "high risk of EP" group of which 63 (63/90; 70%) were FPUL/IUP and 27 (27/90; 30%) were EP. 91 (91/181; 50.3%) was classified in the "low risk of EP" group of which 90 (90/91; 98.9%) were FPUL/IUP and 1 (1/91; 1.1%) were EP. EP were correctly classified with sensitivity of 96.4%, negative predictive value of 98.9%, specificity of 58.8% and positive predictive value of 30.0%. CONCLUSIONS: The prediction model of PUL M6 classified EP in "high risk of EP group" with a sensitivity of 96.4%. It classified 50.3% of PUL in a "low risk of EP" group with a negative predictive value of 98.9%.

[Retrospective comparison of effectiveness of balloon catheter versus dinoprostone for cervical ripening]. / Comparaison rétrospective de l'efficacité du ballonnet extra-amniotique à la dinoprostone dans la maturation cervicale.

OBJECTIVE: To compare the effectiveness and the safety of cervical ripening between two methods: the Cook double balloon catheter and the dinoprostone pessary (Propess 10mg). METHODS: We performed a retrospective comparative study in a French maternity. We analyzed 404 women with induction of labour after 37 gestational weeks, with singleton cephalic live fetus, unscarred uterus, unruptured membranes, and Bishop score<6. The primary endpoint was the time between the start of the ripening and the delivery. Secondary endpoints include effectiveness and safety outcomes of the methods. RESULTS: Compared to dinoprostone pessary, the balloon catheter was associated with a longer time to delivery (34.4±16.5 vs 25.5±15.3h; P<0.001). This difference is found in both primiparous and multiparous women. Balloon catheter is also associated with a smaller improvement of the Bishop score (2.5±2.1 vs 4.2±2.9 Bishop's points; P<0.001) and more failure to achieve delivery in 24h (32.3% vs 56.7%; P<0.001). There was no difference in mother and fetal safety. CONCLUSION: In this retrospective study, cervical ripening using balloon catheter seems to lengthen the induction of labour. No difference in safety outcomes with dinoprostone was found.