Marjorie C. Treadwell

Ultrasonographic examination of the uterine cervix is better than cervical digital examination as a predictor of the likelihood of premature delivery in patients with preterm labor and intact membranes

OBJECTIVE The purpose of this study was to compare the diagnostic performance of ultrasonographic and digital examination of the cervix in the prediction of preterm delivery in patients presenting with preterm labor and intact membranes. STUDY DESIGN Endovaginal ultrasonography was performed in 59 patients admitted with preterm labor (20 to 35 weeks) and cervical dilatation of < 3 cm. Cervical parameters evaluated included endocervical length, the presence of funneling, funnel length, funnel width, cervical index ([Funnel length + 1]/Endocervical length), and cervical dilatation and effacement as determined by digital examination. Outcome variables were the occurrence of preterm delivery (< 36 weeks) and the admission-to-delivery interval. RESULTS The prevalence of preterm delivery was 37.3% (22/59). Receiver-operator characteristic curve and logistic regression analyses indicated a significant relationship between the occurrence of preterm delivery and ultrasonographic cervical parameters (p < 0.005 for each) but not with the results of digital examination of the cervix. Survival analysis demonstrated a shorter admission-to-delivery interval for patients with an abnormal cervical index or endocervical length (p < 0.005 for each). CONCLUSIONS Endovaginal ultrasonographic examination of the uterine cervix is more accurate than digital examination of the cervix in the assessment of the risk for preterm delivery in patients with preterm labor and intact membranes.

The impact of maternal obesity on midtrimester sonographic visualization of fetal cardiac and craniospinal structures

OBJECTIVE: To examine the impact of maternal obesity on the rate of suboptimal ultrasound visualization (SUV) of fetal anatomy and determine the optimal timing of prenatal ultrasound examination for the obese gravida.METHODS: A computerized ultrasound database was used to identify ultrasound examinations for singleton gestations performed between 140/7 and 236/7 weeks at a tertiary care, university-based hospital. Patients were divided into four groups and categorized based on body mass index (BMI): nonobese (BMI <30 kg/m2), class I obesity (30≤BMI<35 kg/m2), class II obesity (35≤BMI<40 kg/m2), and extreme obesity (BMI ≥40 kg/m2). The rates of SUV for fetal cardiac and craniospinal structures were calculated for each group and compared.RESULTS: A total of 11 019 pregnancies were studied, of which 38.6% of the patients were obese. Overall, the rate of SUV of the fetal structures was higher for obese compared to nonobese women for both cardiac (37.3 [1723/4200] vs 18.7% [1275/6819]; P<0.0001) and craniospinal structures (42.8 [1798/4200] vs 29.5% [2012/6819]; P<0.0001). Increased severity of maternal obesity was associated with SUV rate for both the cardiac (nonobese 18.7% [1275/6819], class I 29.6% [599/2022], class II 39.0% [472/1123], and extreme obesity 49.3% [580/1055]; P<0.0001) and for the craniospinal structures: (nonobese 29.5% [2012/6819], class I 36.8% [744/2022], class II 43.3% [486/1123], and extreme obesity 53.4% [563/1055]; P<0.0001). With increasing gestational age at examination, the rate of SUV decreased for both obese and nonobese women. However, for obese women there was minimal improvement in visualization after 18–20 weeks. Even after adjustment for gestational age and the type of ultrasound machine, obese women (class I, class II, and extreme obesity) were still associated with increased odds for SUV of the fetal cardiac and craniospinal structures compared to nonobese women.CONCLUSION: Maternal obesity increases the rate of SUV for the fetal cardiac structures by 49.8% and for the craniospinal structures by 31%. The optimal gestational age for visualization of fetal cardiac and craniospinal anatomy in obese patients may be after 18–20 weeks.

Three‐dimensional ultrasound fetal lung volume measurement: a systematic study comparing the multiplanar method with the rotational (VOCAL) technique

This study was designed to compare a conventional multiplanar technique for three‐dimensional (3D) ultrasound measurement of fetal lung volume with a rotational method using VOCAL™ (Virtual Organ Computer‐aided AnaLysis).

Suboptimal second-trimester ultrasonographic visualization of the fetal heart in obese women: should we repeat the examination?

The purpose of this study was to determine whether a repeated antenatal ultrasound examination improves fetal cardiac visualization for the obese and nonobese population.

Middle cerebral artery peak systolic velocity: a new Doppler parameter in the assessment of growth-restricted fetuses.

The aims of this study were to determine if there is a relationship between middle cerebral artery (MCA) peak systolic velocity (PSV) and perinatal mortality in preterm intrauterine growth‐restricted (IUGR) fetuses, to compare the performance of MCA pulsatility index (PI), MCA‐PSV and umbilical artery (UA) absent/reversed end‐diastolic velocity (ARED) in predicting perinatal mortality, to determine the longitudinal changes that occur in MCA‐PI and MCA‐PSV in these fetuses, and to test the hypothesis that MCA‐PSV can provide additional information on the prognosis of hypoxemic IUGR fetuses.

Fetal cardiac dysfunction in preterm premature rupture of membranes

BACKGROUND Preterm premature rupture of membranes (PROM) is associated with one-third of preterm births. In about 50% of preterm PROM cases, the fetuses will elicit a fetal inflammatory response syndrome (FIRS). FIRS is associated with the impending onset of preterm labor, periventricular leukomalacia, neonatal sepsis, and long-term handicap, including the development of bronchopulmonary dysplasia and cerebral palsy. The fetal myocardium is a potential target organ of proinflammatory cytokines released during FIRS. The objective of this study was to determine whether preterm PROM is associated with functional changes in the fetal heart, as determined by fetal echocardiography. METHODS A retrospective study was conducted to assess the diastolic function of fetuses with preterm PROM with documented microbial invasion of the amniotic cavity (n = 25), preterm PROM without microbial invasion of the amniotic cavity (n = 42), and fetuses from normal pregnancies (control group = 150). Pregnancies with multiple gestation, fetal distress, fetuses that were small for gestational age, and major congenital anomalies were excluded. Fetal echocardiography studies were performed with two-dimensional ultrasound, color Doppler imaging and pulsed Doppler ultrasound. Non-parametric statistics were used for comparisons. A p value of < 0.05 was considered significant. RESULTS The prevalence of positive amniotic fluid cultures for micro-organisms in patients with preterm PROM was 35.8% (24/67). Ureaplasma urealyticum was the most frequent isolate, either alone (41.7%; 10/24) or with other micro-organisms (29.2%; 7/24). Fetuses with preterm PROM had a higher delta early diastolic filling/atrial contraction (E/A) peak velocity ratio, a higher delta E/A velocity-time integral (VTI) ratio, a lower delta A peak velocity, a lower delta A VTI, and a lower A VTI/total VTI ratio in the mitral valve compared to those with uncomplicated pregnancies. The delta E/A peak velocity ratio was significantly higher and the delta A VTI significantly lower in fetuses with preterm PROM and microbial invasion of the amniotic cavity than in those with preterm PROM without microbial invasion of the amniotic cavity. CONCLUSIONS Preterm PROM is associated with changes in fetal cardiac function consistent with increased left ventricular compliance. These observations were also noted in fetuses with microbial invasion of the amniotic cavity. Our findings suggest that fetal cardiac function is altered in preterm PROM and, in particular, in cases with intra-amniotic infection.

Prognostic factors and complication rates for cervical cerclage: A review of 482 cases

Charts from 482 singleton pregnancies undergoing cerclage placement in patients over a 6-year period were reviewed. Cervical dilatation at time of surgery, number of previous spontaneous losses, and gestational age at placement were key determinants of outcome. The most frequent complication, premature rupture of the membranes, ultimately occurred in 38% of patients. The 6.6% infection rate was increased in patients undergoing emergent versus elective surgery (12.7% vs 4.7%, p less than 0.005) and in patients at increased dilatation at time of surgery (5.7% for less than or equal to 2 cm vs 41.7% for greater than 2 cm, p less than 0.005). McDonald and Shirodkar procedures had similar obstetric outcomes in patients undergoing their first cerclage. The subgroup of patients with prior cerclage surgery showed improved birth weight when the Shirodkar procedure was performed instead of the McDonald cerclage (mean birth weight 3020 vs 2470 gm, p less than 0.005). An increased rate of primary cesarean section was found in the Shirodkar group (31% vs 17%, p less than 0.005). Complication rates and pregnancy outcome appear to reflect cervical dilatation more than gestational age at time of surgery.

Four-Dimensional Ultrasonography of the Fetal Heart Using Color Doppler Spatiotemporal Image Correlation

Objective. To describe clinical and research applications of 4‐dimensional imaging of the fetal heart using color Doppler spatiotemporal image correlation. Methods. Forty‐four volume data sets were acquired by color Doppler spatiotemporal image correlation. Seven subjects were examined: 4 fetuses without abnormalities, 1 fetus with ventriculomegaly and a hypoplastic cerebellum but normal cardiac anatomy, and 2 fetuses with cardiac anomalies detected by fetal echocardiography (1 case of a ventricular septal defect associated with trisomy 21 and 1 case of a double‐inlet right ventricle with a 46,XX karyotype). The median gestational age at the time of examination was 21 3/7 weeks (range, 19 5/7–34 0/7 weeks). Volume data sets were reviewed offline by multiplanar display and volume‐rendering methods. Representative images and online video clips illustrating the diagnostic potential of this technology are presented. Results. Color Doppler spatiotemporal image correlation allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double‐inlet right ventricle with a double‐outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. Conclusions. Color Doppler spatiotemporal image correlation has the potential to simplify visualization of the outflow tracts and improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3‐dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale.

Four-dimensional ultrasonography of the fetal heart using a novel Tomographic Ultrasound Imaging display

Abstract Objective: The objective of this study was to investigate the feasibility of examining the fetal heart with Tomographic Ultrasound Imaging (TUI) using four-dimensional (4D) volume datasets acquired with spatiotemporal image correlation (STIC). Material and methods: One hundred and ninety-five fetuses underwent 4D ultrasonography (US) of the fetal heart with STIC. Volume datasets were acquired with B-mode (n=195) and color Doppler imaging (CDI) (n=168), and were reviewed offline using TUI, a new display modality that automatically slices 3D/4D volume datasets, providing simultaneous visualization of up to eight parallel planes in a single screen. Visualization rates for standard transverse planes used to examine the fetal heart were calculated and compared for volumes acquired with B-mode or CDI. Diagnoses by TUI were compared to postnatal diagnoses. Results: (1) The four- and five-chamber views and the three-vessel and trachea view were visualized in 97.4% (190/195), 88.2% (172/195), and 79.5% (142/195), respectively, of the volume datasets acquired with B-mode; (2) these views were visualized in 98.2% (165/168), 97.0% (163/168), and 83.6% (145/168), respectively, of the volume datasets acquired with CDI; (3) CDI contributed additional diagnostic information to 12.5% (21/168), 14.2% (24/168) and 10.1% (17/168) of the four- and five-chamber and the three-vessel and trachea views; (4) cardiac anomalies other than isolated ventricular septal defects were identified by TUI in 16 of 195 fetuses (8.2%) and, among these, CDI provided additional diagnostic information in 5 (31.3%); (5) the sensitivity, specificity, positive- and negative-predictive values of TUI to diagnose congenital heart disease in cases where both B-mode and CDI volume datasets were acquired prenatally were 92.9%, 98.8%, 92.9% and 98.8%, respectively. Conclusion: Standard transverse planes commonly used to examine the fetal heart can be automatically displayed with TUI in the majority of fetuses undergoing 4D US with STIC. Due to the retrospective nature of this study, the results should be interpreted with caution and independently confirmed before this methodology is introduced into clinical practice.

A Systematic Approach to Prenatal Diagnosis of Transposition of the Great Arteries Using 4-Dimensional Ultrasonography With Spatiotemporal Image Correlation

patiotemporal image correlation (STIC) is a recent technological advance in ultrasonographic imaging that allows dynamic multiplanar slicing and surface rendering of the fetal heart.1–5 In a previous study, a technique was developed to systematically visualize the outflow tracts from volume data sets acquired with STIC.3,4 The addition of color and power Doppler imaging to STIC technology made it possible to dynamically display rendered views of the outflow tracts with minimal manipulation of the volume data set.5 Prenatal diagnosis of transposition of the great arteries (TGA) is associated with a significant reduction in both preoperative and postoperative mortality, a decrease in the rate of metabolic acidosis and multiorgan failure during the neonatal period, reduced need for ventilatory support, and shorter hospitalization time.6,7 Unfortunately, prenatal detection rates for TGA have been low in most of the studies published to date.8–15 Among the reasons for failure to prenatally detect most cases of TGA are the absence of risk factors to identify a target population for screening and the need to systematically examine the outflow tracts to establish the diagnosis.6,16 Despite recommendations by scientific societies such as the American Institute of Ultrasound in Medicine to extend the basic fetal cardiac examination to include visualization of the outflow tracts whenever technically feasible,17 this examination remains a technical challenge for many sonographers.6,18 Four-dimensional volume data set acquisition followed by a systematic approach to image the outflow tracts may reduce the operator dependency of prenatal ultrasonography. Volume acquisition is still operator dependent with current commercially available technology. However, once a good-quality volume data set is acquired, the outflow tracts can be systematically imaged by following algorithms developed for gray scale,3,4 color, or power Doppler5 imaging. It is anticipated that algorithms developed to image specific cardiac structures with 3or 4-dimensional volume data sets may eventually become automated by computer software (automated multiplanar imaging).19 Received April 22, 2004, from the Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan USA (L.F.G., B.B., M.C.T.); Perinatology Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland USA (L.F.G., J.E., R.R.); Division of Fetal Imaging, William Beaumont Hospital, Royal Oak, Michigan USA (W.L.); and Division of Cardiology, Children’s Hospital of Michigan, Wayne State University, Detroit, Michigan USA (R.H.). Revision requested May 24, 2004. Revised manuscript accepted for publication June 1, 2004. Address correspondence and reprint requests to Roberto Romero, MD, Perinatology Research Branch, National Institute of Child Health and Human Development, Department of Obstetrics and Gynecology, Wayne State University/Hutzel Hospital, 4707 St Antoine Blvd, Detroit MI 48201 USA. E-mail: warfiela@mail.nih.gov. Abbreviations STIC, spatiotemporal image correlation; TGA, transposition of the great arteries