Third-trimester ultrasound for antenatal diagnosis of placenta accreta spectrum in women with placenta previa: results from the ADoPAD study.

OBJECTIVE: To evaluate the performance of third-trimester ultrasound for the diagnosis of clinically significant placenta accreta spectrum disorder (PAS) in women with low-lying placenta or placenta previa. METHODS: This was a prospective multicenter study of pregnant women aged ≥ 18 years who were diagnosed with low-lying placenta (< 20 mm from the internal cervical os) or placenta previa (covering the internal cervical os) on ultrasound at ≥ 26 + 0 weeks' gestation, between October 2014 and January 2019. Ultrasound suspicion of PAS was raised in the presence of at least one of these signs on grayscale ultrasound: (1) obliteration of the hypoechogenic space between the uterus and the placenta; (2) interruption of the hyperechogenic interface between the uterine serosa and the bladder wall; (3) abnormal placental lacunae. Histopathological examinations were performed according to a predefined protocol, with pathologists blinded to the ultrasound findings. To assess the ability of ultrasound to detect clinically significant PAS, a composite outcome comprising the need for active management at delivery and histopathological confirmation of PAS was considered the reference standard. PAS was considered to be clinically significant if, in addition to histological confirmation, at least one of these procedures was carried out after delivery: use of hemostatic intrauterine balloon, compressive uterine suture, peripartum hysterectomy, uterine/hypogastric artery ligation or uterine artery embolization. The diagnostic performance of each ultrasound sign for clinically significant PAS was evaluated in all women and in the subgroup who had at least one previous Cesarean section and anterior placenta. Post-test probability was assessed using Fagan nomograms. RESULTS: A total of 568 women underwent transabdominal and transvaginal ultrasound examinations during the study period. Of these, 95 delivered in local hospitals, and placental pathology according to the study protocol was therefore not available. Among the 473 women for whom placental pathology was available, clinically significant PAS was diagnosed in 99 (21%), comprising 36 cases of placenta accreta, 19 of placenta increta and 44 of placenta percreta. The median gestational age at the time of ultrasound assessment was 31.4 (interquartile range, 28.6-34.4) weeks. A normal hypoechogenic space between the uterus and the placenta reduced the post-test probability of clinically significant PAS from 21% to 5% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 9% in the subgroup with previous Cesarean section and anterior placenta. The absence of placental lacunae reduced the post-test probability of clinically significant PAS from 21% to 9% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 36% in the subgroup with previous Cesarean section and anterior placenta. When abnormal placental lacunae were seen on ultrasound, the post-test probability of clinically significant PAS increased from 21% to 59% in the whole cohort and from 62% to 78% in the subgroup with previous Cesarean section and anterior placenta. An interrupted hyperechogenic interface between the uterine serosa and bladder wall increased the post-test probability for clinically significant PAS from 21% to 85% in women with low-lying placenta or placenta previa and from 62% to 88% in the subgroup with previous Cesarean section and anterior placenta. When all three sonographic markers were present, the post-test probability for clinically significant PAS increased from 21% to 89% in the whole cohort and from 62% to 92% in the subgroup with previous Cesarean section and anterior placenta. CONCLUSIONS: Grayscale ultrasound has good diagnostic performance to identify pregnancies at low risk of PAS in a high-risk population of women with low-lying placenta or placenta previa. Ultrasound may be safely used to guide management decisions and concentrate resources on patients with higher risk of clinically significant PAS. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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 midgut volvulus: report of eight cases.

OBJECTIVE: To evaluate whether prenatal diagnosis of intestinal midgut volvulus (a rare condition due to the small bowel loops twisting) can improve the prognosis of the newborns. METHODS: In our Prenatal Diagnosis Center, eight cases of intestinal volvulus observed between 2007 and 2014 were retrospectively considered. Ultrasonographic signs can be direct and specific (whirlpool sign, coffee bean sign) or indirect and non-specific (abdominal mass, dilated bowel loops, pseudocysts, ascites, polyhydramnios). RESULTS: Prenatal diagnosis was performed at 20-34 weeks of gestation. All newborns were exposed to an emergency surgery: the major complication was due to cystic fibrosis. CONCLUSIONS: An early suspicion of intestinal volvulus allows the clinician to refer the patient to a tertiary center so to confirm the diagnosis and perform an appropriate follow-up in order to identify the proper time of delivery. The prognosis of the babies with prenatal intestinal volvulus depends on the length of the segment involved, on the level of intestinal obstruction, on the presence of meconium peritonitis and on the gestational age at birth. Our experience, according with the literature, suggests that ascites and absence of abdominal peristalsis are ultrasonographic signs that, in the third trimester of pregnancy, correctly lead to an immediate delivery intervention.

Trisomy 18: Fetal ultrasound findings at different gestational ages.

The aim of this article is evaluate the sonograhic findings in fetuses with trisomy 18 at different gestational ages. The cases were recruited from pregnant women, who underwent to prenatal diagnosis in the period from October 1995 to September 2006. Seventy-one fetuses with trisomy 18 were diagnosed. On review of the sonograms the majority of these cases had ultrasound anomalies (sensitivity of 91.5%). The most frequent anomalies were abnormalities of extremities (40.8%) and fetal growth restriction (35.2%). More frequently (54.9%) two or more anomalies were present. Nearly all fetuses with trisomy 18 had sonographic abnormalities. Likely improved high-resolution equipment and attention to details by skilled operators led to the detection of most anomalies to trisomy 18. Knowledge of types of specific ultrasound findings can improve prenatal diagnosis in order to provide invasive procedures only when indicated, and to avoid amniocentesis when ultrasound signs are not observed in women at high risk from positive biochemical testing.

First-trimester fetal heart block and increased nuchal translucency: an indication for early fetal echocardiography.

Prevalence of congenital heart disease increases with nuchal translucency (NT) thickness. First-trimester fetal bradycardia may result from heart block associated with complex congenital heart disease. We report two cases detected in the first trimester of pregnancy, in which both fetuses showed an increased nuchal translucency and bradycardia. Fetal karyotype was normal in both fetuses. First-trimester fetal echocardiography was performed and, in both cases, complex congenital heart disease was diagnosed. We discuss the added role of fetal heart rate in first-trimester ultrasound screening, in fetuses with increased nuchal translucency and normal karyotype. We stress, as well, the importance of echocardiography performed in the first trimester as a potential tool for early diagnosis in selected cases.

Fetal nasal bone and trisomy 21 in the second trimester.

OBJECTIVES: To assess the feasibility of measuring nasal bone length in the second trimester of pregnancy and to confirm if fetal nasal bone absence or hypoplasia is a marker for Down syndrome. METHODS: Fetal nasal bone assessment was performed in 439 consecutive singleton pregnancies at high risk of Down syndrome between 15 and 21 weeks. All ultrasound examinations were performed transabdominally by five skilled sonographers. If the nasal bone was present, its length was measured. The biparietal diameter: nasal bone length ratio (BPD/NBL) was also calculated. RESULTS: Nasal bone assessment was successfully achieved in all fetuses. The nasal bone was absent in 2(0.47%) of the 417 unaffected fetuses and in 10(55.5%) of the 18 fetuses with trisomy 21. Of the 8 Down syndrome cases with a nasal bone present, 4 had nasal bone hypoplasia and 4 had a normal nasal bone. BPD/NBL was 9 or greater in 7 of the 8 fetuses affected by trisomy 21 with nasal bone present and in 86 (20.6%) of the 417 normal fetuses; it was 10 or greater in 5 of the 8 (62.5%) fetuses affected by trisomy 21 and in 41 of the 417 (9.8%) euploid fetuses. CONCLUSIONS: Nasal bone absence is a marker for Down syndrome in the second trimester of pregnancy. Inclusion of nasal bone length into the second-trimester screening protocol could potentially obviate the false-negative cases from other screening tests. The measurement of nasal bone length in the second trimester seems to provide additional benefits beyond the assessment of the presence or absence of the nasal bone.

Anomalies of the fetal venous system: a report of 26 cases and review of the literature.

OBJECTIVE: To evaluate sonographic appearance, natural history, and neonatal outcome of fetal venous anomalies. METHODS: We performed an observational study, including all fetuses affected by abnormalities of the venous system diagnosed by ultrasound during the prenatal period. RESULTS: 26 fetuses were identified. Other malformations were present in 5 cases (19.2%), 1 fetus had trisomy 21, and 1 fetus had intrauterine growth retardation (IUGR). Twenty-five pregnancies ended in liveborn infants, and there was 1 case of unexplained intrauterine death in the fetus with IUGR affected by varix of the umbilical vein. CONCLUSIONS: Fetal venous anomalies are very rare and may be associated with fetal malformations or IUGR. Conservative management appears to be an adequate medical practice in the absence of other fetal problems, but in the presence of a varix of the umbilical vein, serial follow-up scans are needed to exclude the onset of hydrops or thrombosis of the varix.

Ultrasound evaluation of fetal nasal bone at 11 to 14 weeks in a consecutive series of 1906 fetuses.

OBJECTIVE: The aim of this study is to evaluate the significance of nasal bone ossification as a marker for trisomy 21 at 11 to 14 weeks' gestation in an unselected obstetric population referred to our Centre. METHODS: A total of 1906 consecutive fetuses undergoing nuchal translucency scan at 11 to 14 weeks' gestation were evaluated for the presence of hypoplasia/absence of nasal bone. The data obtained were correlated with fetal karyotype. RESULTS: A successful view of the fetal profile was obtained in 1752 fetuses (91.9%). The nasal bone was hypoplastic/absent in 12 of 19 fetuses with chromosomal abnormalities. There were 10 cases of trisomy 21, in 8 of which hypoplastic/absent nasal bone was observed. Furthermore, absence of nasal bone was recorded in 24 of 1733 chromosomally normal fetuses. CONCLUSIONS: Nasal bone evaluation may improve the detection of trisomy 21 in the first trimester in an unselected obstetric population. Although numerically limited, our experience confirms that delayed nasal bone ossification (hypoplasia/absence of nasal bone) is rarely observed in chromosomally normal fetuses (1.4%). An appropriate training of operators is mandatory in order to achieve an acceptable performance.

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.

Prenatal diagnosis of isolated unilateral pulmonary agenesis in the second trimester.

Unilateral pulmonary agenesis is a very rare developmental malformation that is often associated with other anomalies including non-immune hydrops. We describe a case of isolated unilateral pulmonary agenesis diagnosed in the second trimester by gray-scale and color Doppler ultrasound.

Three-dimensional ultrasound evaluation of short-rib polydactyly syndrome type II in the second trimester: a case report.

Prenatal diagnosis of short-rib polydactyly syndrome is possible and has been reported in literature, but a precise ultrasound diagnosis is not easy. We report a case in which three-dimensional ultrasound was used in the evaluation of the disorder. The contribution and potential application of three-dimensional sonography in the prenatal diagnosis of short-rib polydactyly syndrome and other fetal skeletal malformations is discussed.

Minor sonographic signs of trisomy 21 at 15-20 weeks' gestation in fetuses born without malformations: a prospective study.

A prospective study was performed on 2119 pregnancies that underwent genetic amniocentesis. Indications for amniocentesis were either maternal age (> or =35) or triple-test results (risk> or =1/380). The study covered a 36-month period and assessed the prevalence of minor ultrasound markers both in fetuses with Down syndrome and normal control fetuses at 15-19 week' gestation. Only fetuses with normal karyotype or trisomy 21 were considered. Six minor sonographic markers were considered: nuchal thickness, pyelectasia, femur observed/expected and humerus observed/expected ratios, bowel echogenicity, and choroid plexus cysts. One or more ultrasound soft markers were present in 23 out of 33 fetuses with Down syndrome (70%) and in 572 out of 2069 normal fetuses (28%).

Umbilical Doppler waveforms and placental villous angiogenesis in pregnancies complicated by fetal growth restriction.

OBJECTIVE: To test the hypothesis that the characteristics of umbilical artery Doppler flow velocity waveforms in growth-restricted fetuses indicate angiogenesis within placental stem and gas-exchanging villi. METHODS: We examined 18 placentas from singleton fetuses that were normal structurally and chromosomally but were growth-restricted, preterm, and complicated by preeclampsia. Ten cases with positive end-diastolic flow and eight with absent or reverse end-diastolic flow were compared with six gestational age-matched controls. Sections of villous placenta were examined to determine structural composition (percentage of fibrinoid, intervillous space, and villous tissue), relative proportion of villous types (stem, immature intermediate, and gas-exchanging villi), and the frequency distribution of stem arterial vessel calibers and their branching pattern. RESULTS: Placentas with positive end-diastolic flow had a significantly (P < .05) higher percentage of gas-exchanging villi (median 69.6%, range 62.5-80.8%) than those with absent or reverse end-diastolic flow (58.3%, 29.9-71.9%) or controls (60.8%, 43.1-65.6%). The gas-exchanging villi from placentas with absent or reverse end-diastolic flow were slender, elongated, poorly branched, and poorly capillarized. There was a progressive trend toward reduced branching of the stem arteries from the controls (median 22%, range 2-38%), through the positive end-diastolic group (17%, 11-20%), to the absent or reverse end-diastolic group (13%, 4-23%). CONCLUSION: Compared with absent or reverse end-diastolic flow, the placentas from growth-restricted fetuses with positive end-diastolic flow showed a normal pattern of stem artery development, accompanied by increased capillary angiogenesis and terminal villous development. These features suggest an adaptive pathway for the placenta in the face of uteroplacental ischemia.

Accuracy of routine ultrasonography in screening heart disease prenatally. Gruppo Piemontese for Prenatal Screening of Congenital Heart Disease.

The aim of the present study was to assess the accuracy of the four-chamber view as a screening test for detection of congenital heart disease (CHD) prenatally in a low-risk population. A prospective observational study was conducted in 17 ultrasound units of the Piemonte Region, Italy, in pregnancies with no risk factors for CHD. At each routine scan, from 18 weeks of gestational age, the four-chamber view of the heart was looked for. When an anomaly was suspected, the patients were referred to a specialized unit. Follow-up of the babies until discharge from the hospital was obtained. 11,232 sonograms were performed on 8299 pregnancies. Cardiac malformations were diagnosed in 40 newborns (4.8/1000). Six of them (15 per cent) had been recognized in utero. The sensitivity, specificity, and positive and negative predictive values were 15, 99.9, 50, and 99.6 per cent, respectively. When malformations that are not associated with an abnormal four-chamber view were excluded from the analysis, the sensitivity increased to 35.3 per cent. The sensitivity found in this study is low, but it is probably realistic since it is comparable to that reported in other multicentric studies. This type of study should reflect the state of the art of the method applied in the field. Although the sensitivity is low, it would be nil if the test were not performed. Moreover, it will probably increase with better training of the operators and by extending the examination to the ventriculo-arterial connections.

[Prenatal diagnosis of thanatophoric dysplasia at the 20th week of pregnancy using ultrasonography]. / Diagnosi prenatale di displasia tanatofora alla 20a settimana di gravidanza mediante ultrasonografia.

We report on prenatal diagnosis of a fetus with thanatophoric dysplasia type 1 at 20 weeks gestation. The ultrasonographic examination showed shortened bowed limbs, narrow chest, relatively large head, protuberant abdomen, and hydramnios. Radiological and histological studies confirmed the aborted fetus had thanatophoric dysplasia. The differential prenatal diagnosis with other skeletal dysplasia is discussed.