Accuracy of ultrasound in antenatal diagnosis of placental attachment disorders.

OBJECTIVES: To evaluate the accuracy of ultrasound in the diagnosis of placenta accreta and its variants, and to assess the impact of prenatal diagnosis in our population. METHODS: A total of 314 women with placenta previa were enrolled prospectively and underwent transabdominal and transvaginal ultrasound examinations. An ultrasound diagnosis (grayscale and color/power Doppler) of placental attachment disorder (PAD) was based on the detection of at least two of the following ('two-criteria system'): loss/irregularity of the retroplacental clear zone, thinning/interruption of the uterine serosa-bladder wall interface, turbulent placental lacunae with high velocity flow, myometrial thickness < 1 mm, increased vascularity of the uterine serosa-bladder wall interface, loss of vascular arch parallel to the basal plate and/or irregular intraplacental vascularization. Definitive diagnosis was made at delivery by Cesarean section. Maternal outcome in cases diagnosed antenatally was compared with that in cases diagnosed at delivery. RESULTS: There were 37/314 cases of PAD (29 anterior and eight posterior). The two-criteria system identified 30 cases of placenta accreta, providing a sensitivity of 81.1% and specificity of 98.9%. When anterior and posterior placentae were considered separately, the detection rates of PAD were 89.7 and 50.0%, respectIvely. Maternal outcome was better in women with prenatal diagnosis of PAD, as seen by less blood loss and shorter hospitalization. CONCLUSIONS: Our data confirmed that grayscale and color Doppler ultrasound have good performance in the diagnosis of PAD and that prenatal diagnosis improves maternal outcome. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Fetal short femur length in the second trimester and the outcome of pregnancy.

We reviewed 86 consecutive cases with fetal femur length (FL) below the 10th centile of our reference ranges at midtrimester ultrasonography. Three groups were identified based on perinatal outcome: normal infants (n= 28), newborns with structural and/or chromosomal anomalies (n= 40), small-for-gestational age (SGA) newborns (n= 18). Fetuses with skeletal dysplasias (n= 13) had significantly shorter FL. Aneuploidies were only found in fetuses with malformations other than skeletal dysplasias. The diagnosis of SGA, based on ultrasound abdominal circumference measurement <10th centile, was made 9 weeks (range 5-14) after the finding of a short FL. Half of these cases also developed pre-eclampsia.

Investigation of placental stem villi arteries in fetally growth-restricted pregnancies: a multivariate analysis.

Thirteen placentas were studied from 5 normal pregnancies and 8 from pregnancies complicated by fetal growth restriction (4 with present, 3 with absent, and 1 with reversed end-diastolic velocities at Doppler interrogation of the umbilical arteries). On immunohistochemically stained slides, the diameter (d) and the wall thickness (t) of the arterial vasculature of the stem villi were measured for a total of approximately 10,000 vessels. A multivariate 'mixed effect model' statistical analysis was performed using d and t as dependent variables and gestational age, delivery mode, fetal and placental weight, the degree of vascular collapse and Doppler blood flow patterns as independent variables. Gestational age, Doppler pattern and the degree of vascular collapse significantly affected both d and t, the mode of delivery influenced d while fetal and placental weights scarcely affected the dependent variables. The above parameters should therefore be taken into account when investigating placental stem vessel morphometry.

Fetal heart rate tracings: observers versus computer assessment.

UNLABELLED: Cardiotocography (CTG) is widely used despite the fact that its diagnostic accuracy is far from satisfying. This is due, among other reasons, to the great intra- and interobserver variation in reading the fetal heart rate tracings. Computerized analysis might be a means to overcome the latter problem. OBJECTIVE: the present study was designed to assess the reproducibility of CTG readings among observers and between observers and a computer system. STUDY DESIGN: 63 fetal heart rate tracings were read by 4 clinicians (2 experienced and 2 inexperienced) and by the 2CTG computerized system. The variables considered were: baseline fetal heart rate (FHR), long-term variability (amplitude bandwidth around the baseline), number of large accelerations and number and type of decelerations. RESULTS: the agreement among observers, assessed by means of kappa coefficient, ranges from fair to good. The agreement between each of the observers and the computer readings, ranges from 0.18 to 0.48 for FHR baseline, from 0.16 to 0.74 for variability, from 0.37 to 0.64 for the number of accelerations and from 0.41 to 0.54 for the number of decelerations. The agreement on the type of decelerations is very low (0.01-0.25). CONCLUSION: it is concluded that interobserver variability between experienced observers, inexperienced observers and 2CTG is considerable and that the use of a computer system should overcome this problem.

Accuracy of the umbilical arteries Doppler flow velocity waveforms in detecting adverse perinatal outcomes in a high-risk population.

OBJECTIVE: To define the accuracy of the umbilical artery Doppler flow velocity waveforms, according to different cut-off values, in predicting adverse perinatal outcomes among fetuses at high risk of hypoxic complications. SUBJECTS: Two hundred and sixty-five pregnant women with diagnosis of small for gestational age fetus and/or pregnancy induced hypertension studied in four Italian ultrasound units. METHODS: Prospective study. Serial Doppler ultrasound measurements of the umbilical artery were performed. Results were not available for clinical management. Cut-off curves, corresponding to different age-specific centiles of the pulsatility index distribution among pregnancies resulting in healthy newborns, regardless of birthweight, were computed by regression methods. Sensitivity, specificity, positive predictive value and negative predictive value of such cut-off curves, and of absent/reverse end-diastolic flow, in predicting different adverse outcomes were estimated. The adverse outcomes were: perinatal or neonatal death (OUTCOME 1). Death or Apgar<7 at 5' or need for admission to intensive care unit or other hypoxic related abnormalities (OUTCOME 2). Either OUTCOME 2 or birthweight

Performance of Doppler ultrasonography as a screening test in low risk pregnancies: results of a multicentric study.

To assess the efficacy of the Doppler velocimetry of the uterine and umbilical arteries as a screening test for preeclampsia and fetal growth retardation, we studied 916 low risk pregnancies. The S/D ratios of the uterine and umbilical arteries were obtained at 19 to 24 weeks and at 26 to 31 weeks of gestational age. Mean values, receiver operator curves, and the diagnostic accuracy of the tests were calculated for the following end-points: (1) pregnancy-induced hypertension, (2) low birth weight for gestational age, (3) small for gestational age with abnormal outcome, (4) pregnancy-induced hypertension needing preterm delivery. The prevalences for these outcomes were 3.4%, 4.6%, 1%, and 0.7%, respectively. The study was blinded. The umbilical and uterine artery S/D ratios were significantly higher in the abnormal than in the normal outcome group. When uterine arteries were studied at 19 to 24 weeks, sensitivity was 59% in the detection of pregnancy-induced hypertension, 11% in the detection of small for gestational age fetuses, 33% in the detection of small for gestational age fetuses with abnormal outcome, and 83% in the detection of pregnancy induced hypertension needing preterm delivery; the corresponding values for specificity were 69%, 94%, 94%, and 68%. At 26 to 31 weeks the sensitivity values were respectively, 69%, 58%, 75%, and 100% and specificity values were 80%, 59%, 39%, and 79%. When umbilical arteries were studied at 19 to 24 weeks, sensitivity was 38% in the detection of pregnancy-induced hypertension, 46% in the detection of small for gestational age fetuses, 78% in the detection of small for gestational age fetuses with abnormal outcome, and 67% in the detection of pregnancy-induced hypertension needing preterm delivery. The corresponding values of specificity were 74% for all four groups. At 26 to 31 weeks the sensitivity values were 38%, 43%, 87%, and 67%, respectively, and specificity values were 80% for all four groups. We concluded that Doppler examinations of the uterine and umbilical arteries can detect, at midpregnancy, the severe forms of pregnancy-induced hypertension and small for gestational age fetuses but they cannot be used to screen a low risk population in which the prevalence of the disease is low, and hence the positive predictive value is low.