Fetal Myocardial Performance Index in the Third Trimester of Pregnancy: Feasibility and Reproducibility of Conventional Spectral Doppler versus Spectral Tissue Doppler Technique.

OBJECTIVE: This study aims to compare completion rates and reproducibility of myocardial performance index (MPI) using conventional spectral Doppler versus tissue Doppler in an unselected high-risk third trimester population. STUDY DESIGN: This was a prospective cross-sectional study of high-risk pregnancies at ≥28 + 0 weeks' gestation. Conventional spectral and tissue Doppler MPI of the left ventricle (LV) and right ventricle (RV) was attempted on all patients. RESULTS: Seventy-nine pregnancies were evaluated. LV tissue Doppler MPI was completed more frequently than LV conventional spectral Doppler MPI (63/79, 79.7% vs. 45/79, 55.7%), p-value <0.01. RV tissue Doppler MPI was completed more frequently than RV conventional spectral Doppler MPI (68/79, 86% vs. 42/79, 53.2%), p-value <0.01. In obese subjects (n = 50) LV tissue Doppler MPI was completed more frequently than LV conventional spectral Doppler MPI (37/50, 74% vs. 26/50, 52%), p-value <0.01. RV tissue Doppler MPI was completed more frequently than RV conventional spectral Doppler MPI (40/50, 80% vs. 25/50, 50%), p-value <0.01. intraclass correlation coefficient for all modalities ranged between 0.73 and 0.93, except for LV conventional spectral Doppler intraobserver variability which was 0.22. CONCLUSION: Tissue Doppler had statistically higher completion rates than conventional spectral Doppler, including the obese subgroup, with evidence of strong reproducibility in the third trimester.

Prevalence of Sonographic Markers of Placenta Accreta Spectrum in Low-Risk Pregnancies.

OBJECTIVE: This study was aimed to evaluate the prevalence of sonographic markers for placenta accreta spectrum (PAS) in pregnancies at low-risk for PAS. STUDY DESIGN: Pregnant women at low-risk for PAS presenting for routine second trimester ultrasound who enrolled in the study were evaluated prospectively for sonographic markers of PAS during two ultrasounds at 18 to 24 and 28 to 34 weeks. Frequencies of PAS markers were compared between the second and third trimester and between those with and without prior cesarean deliveries (CD). RESULTS: Overall, 174 women were included. Several markers were seen frequently in the second trimester: vascular cervical invasion (57%), lacunae (46%), subplacental hypervascularity (37%), and irregularity of the posterior bladder wall (37%). Other markers were seen infrequently or not at all: loss of the retroplacental clear zone, uterovesical interface < 1 mm, bridging vessels, placental bulge or focal exophytic mass. Frequencies of markers did not differ between women with and without prior CD. Lacunae were larger and more numerous in the third trimester. Two or more PAS markers were observed in 98% of second trimester ultrasounds. CONCLUSION: Several PAS sonographic markers occur commonly in low-risk pregnancies. In the absence of risk factors, the independent predictive value of these markers is questionable.

The Role of Early Gestation Ultrasound in the Assessment of Fetal Anatomy in Maternal Obesity.

OBJECTIVES: The 2012 Eunice Kennedy Shriver National Institute of Child Health fetal imaging consensus suggested that fetal anatomy ultrasound in obese pregnancies be performed at 20 to 22 weeks, with follow-up in 2 to 4 weeks if anatomy is incomplete. It was postulated that imaging in early gestation may improve visualization, although no prospective trials had been done to date. METHODS: We performed a prospective longitudinal blinded trial comparing an early gestation ultrasound (13 + 0 to 15 + 6 weeks) with the traditional second-trimester ultrasound for completion of the fetal anatomy survey in obese patients. Inclusion criteria included singleton gestation, body mass index (BMI) more than 30, less than 16 + 0 weeks' gestation, and no karyotype abnormality; exclusion criteria included age younger than 18 years, more than 16 weeks' gestation at time of consent, and BMI less than 30. Participants received a transvaginal and/or transabdominal sonogram for fetal anatomic survey at 13 + 0 to 15 + 6 weeks' gestation (US1). Images from US1 were blinded to physicians and sonographers performing subsequent examinations. All participants underwent the traditional transabdominal sonogram at 18 to 24 weeks (US2). If US2 failed to complete the anatomic survey, a repeat transabdominal sonogram (2-US2) was performed 2 to 4 weeks later. RESULTS: A total of 152 pregnancies met the criteria. Anatomy completion rate was 57.2% for US1 and 62.5% for US2, which was not statistically significant, even when stratified by BMI. Excluding the philtrum, the US1 performed better than US2 for class III obesity (65.5% versus 45.5% [P = .035]). Combination of US1 + US2 yielded a higher completion rate than US2 + 2-US2 (94.1% versus 83.6% [P = .0023]). CONCLUSIONS: In the setting of maternal obesity, the addition of an ultrasound in early gestation may be of highest benefit for patients with class III obesity (BMI > 40 kg/m2 ).