Improved technical success, postnatal outcome and refined predictors of outcome for fetal aortic valvuloplasty.

OBJECTIVES: Fetal aortic valvuloplasty (FAV) may prevent progression of mid-gestation aortic stenosis to hypoplastic left heart syndrome (HLHS). The aim of this study was to evaluate whether technical success and biventricular (Biv) outcome after FAV have changed from an earlier (2000-2008) to a more recent (2009-2015) era and identify pre-FAV predictors of Biv outcome. METHODS: We evaluated procedural and postnatal outcomes in 123 fetuses that underwent FAV for evolving HLHS at Boston Children's Hospital between 2000 and 2015. The primary outcome measure was circulation type (Biv vs single ventricle) at the time of neonatal hospital discharge. Classification and regression tree (CART) analysis was performed to construct a stratification algorithm to predict Biv circulation based on pre-FAV fetal variables. RESULTS: The FAV procedure was technically successful in 101/123 (82%) fetuses, with a higher technical success rate in the more recent era than in the earlier one (49/52 (94%) vs 52/71 (73%); P = 0.003). In liveborn patients, the incidence of Biv outcome was higher in the recent than in the earlier era, both in the entire liveborn cohort (29/49 (59%) vs 16/62 (26%); P = 0.001) and in those in whom the procedure was technically successful (27/46 (59%) vs 15/47 (32%); P = 0.007). Independent predictors of Biv outcome were higher left ventricular (LV) pressure, larger ascending aorta, better LV diastolic function and higher LV long-axis Z-score. On CART analysis, fetuses with LV pressure > 47 mmHg and ascending aorta Z-score ≥ 0.57 had a 92% probability of Biv outcome (n = 24). Those with a lower LV pressure, or mitral dimension Z-score < 0.1 and mitral valve inflow time Z-score < -2 (n = 34) were unlikely to have Biv (probability of 9%). The remainder of the patients had an intermediate (∼40-60%) likelihood of Biv circulation. CONCLUSIONS: The proportion of patients achieving Biv outcome after FAV has increased, probably owing to an improved technical success rate and modified selection criteria. Fetal factors, including LV pressure, size of the ascending aorta and diastolic function, are associated with likelihood of Biv circulation after FAV. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Obstetric and gynecologic ultrasound curriculum and competency assessment in residency training programs: consensus report.

Ultrasound imaging has become integral to the practice of obstetrics and gynecology. With increasing educational demands and limited hours in residency programs, dedicated time for training and achieving competency in ultrasound has diminished substantially. The American Institute of Ultrasound in Medicine assembled a multi-Society Task Force to develop a consensus-based, standardized curriculum and competency assessment tools for obstetric and gynecologic ultrasound training in residency programs. The curriculum and competency-assessment tools were developed based on existing national and international guidelines for the performance of obstetric and gynecologic ultrasound examinations and thus are intended to represent the minimum requirement for such training. By expert consensus, the curriculum was developed for each year of training, criteria for each competency assessment image were generated, the pass score was established at or close to 75% for each, and obtaining a set of five ultrasound images with pass score in each was deemed necessary for attaining each competency. Given the current lack of substantial data on competency assessment in ultrasound training, the Task Force expects that the criteria set forth in this document will evolve with time. The Task Force also encourages use of ultrasound simulation in residency training and expects that simulation will play a significant part in the curriculum and the competency-assessment process. Incorporating this training curriculum and the competency-assessment tools may promote consistency in training and competency assessment, thus enhancing the performance and diagnostic accuracy of ultrasound examination in obstetrics and gynecology. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

FL/AC ratio: poor predictor of intrauterine growth retardation.

Early antenatal detection of intrauterine growth retardation (IUGR) may decrease the associated perinatal morbidity and mortality. A parameter based on sonographically measured femur length (FL) and abdominal circumference (AC), expressed as FL/AC X 100 and termed the FL/AC ratio, has recently been proposed by Hadlock et al as an age-independent predictor of IUGR. We studied 285 normal and 37 IUGR fetuses to verify that the FL/AC ratio is independent of gestational age (GA) and to assess its value as a predictor of IUGR. Our results confirm that the FL/AC ratio is age-independent above 20 weeks and that its mean value differs in normal (22.4 +/- 1.7) and IUGR (23.7 +/- 1.4) fetuses (P less than .01, t-test). Because of considerable overlap between these two groups, however, there is no cutoff value for the FL/AC ratio that yields both a high sensitivity and a high specificity, or that leads to a high positive predictive value. With a cutoff of 23.5, for example, the sensitivity is 56% and the specificity 74%, and, even assuming an IUGR prevalence rate of 10%, the likelihood of IUGR in a fetus with an FL/AC ratio above the cutoff is only 19%. We conclude that the FL/AC ratio, though an age-independent measure whose mean value differs in normal and IUGR fetuses, is not clinically useful as a predictor of IUGR.

Sonography of the musculoskeletal system.

High-resolution ultrasound is an imaging technique with increasing applications in the musculoskeletal system. With the development of high-frequency, realtime transducers, detailed images of small superficial structures can be provided. Tendons, muscles, and subcutaneous tissues can be assessed for disruption, masses, or fluid collections. Foreign bodies can be localized to guide surgical excision. Increased use of this diagnostic tool may lead to new applications as the technology improves.

The effect of operative technique and uterine size on blood loss during myomectomy: a prospective randomized study.

OBJECTIVES: To compare operative blood loss between two accepted blood loss-reducing techniques used during myomectomy and to evaluate the effect of preoperatively determined uterine volume on blood loss. DESIGN: Subjects were stratified by ultrasound-determined uterine volume < 600 cm3 (n = 11) and > or = 600 cm3 (n = 10) and then randomized into treatment groups. The same radiologist, surgeons, and anesthetic induction technique were involved in every case. In the pharmacologic technique, diluted vasopressin (20 U in 20 mL normal saline) was injected into the serosa and/or myometrium overlying the fibroid(s) before the uterine incision(s). In the mechanical technique, a penrose drain tourniquet was passed through defects created in the broad ligaments at the level of the internal os and secured posteriorly, occluding the uterine vessels. In addition, vascular clamps were placed on the infundibulopelvic ligaments, occluding anastomotic blood flow through the ovarian vessels. RESULTS: There was no difference in operative blood loss, operating time, preoperative and intraoperative mean arterial blood pressures, postoperative febrile morbidity, preoperative and postoperative hematocrits, transfusion rates, and length of hospital stay between groups. Blood loss was significantly greater for uteri with ultrasound-determined volumes > or 600 cm3 (627 +/- 175 mL, mean +/- SEM) than for those < 600 cm3 (228 +/- 49 mL). For all subjects, blood lost while operating on the uterus (mean, 379 mL; range, 35 to 1,968 mL) was positively correlated with the total weight of the fibroids resected and with time spent operating on the uterus. Total blood loss (mean, 418 mL; range, 42 to 1,968 mL) was also positively correlated with the time spent operating on the uterus and with total operating time. CONCLUSIONS: There were no demonstrable differences in blood loss, morbidity, or transfusion requirements between subjects undergoing myomectomy using pharmacologic vasoconstriction and mechanical vascular occlusion techniques. Blood loss during myomectomy is primarily incurred while operating on the uterus and is correlated with preoperative uterine size, total weight of fibroids removed, and operating time.

Sonography of multiple gestations.

Ultrasound plays an important role in the management of multiple gestations in several key areas: (1) diagnosing multiple gestation and determining fetal number; (2) determining placentation; (3) diagnosing complications; (4) guiding procedures; and (5) identifying fetal lie late in pregnancy. The information obtained from single or serial ultrasound examinations can lead to improved obstetric decision-making and thereby to improved outcome in these high-risk pregnancies.

Acute diseases of the scrotum.

Several imaging modalities are available for evaluating the patient with acute scrotal pain. Until recently, scintigraphy was the initial procedure of choice in most patients, as it was the only noninvasive technique for determining integrity of blood flow to the testicle. Ultrasound was valuable when the scintiscan was inconclusive or in the setting of scrotal trauma. With the advent of color Doppler sonography, information about both structure and blood flow can be obtained by means of a single imaging study. If initial promising results with this newer technique are borne out, color Doppler is likely to become the primary diagnostic test in patients with acute scrotal pain. The role of MRI and MRS has yet to be defined.

Fetal growth disturbances.

IUGR is a fetal disorder characterized by diminished fetal growth, especially in the third trimester. Growth retardation may be due to primary placental insufficiency or may result from a variety of maternal or fetal causes and is associated with elevated perinatal mortality and morbidity. Numerous conventional and Doppler ultrasound criteria have been proposed for diagnosing IUGR prenatally, but none on its own permits confident diagnosis of this condition. Diagnosis or exclusion of IUGR can best be achieved by the combined use of three parameters: estimated fetal weight, amniotic fluid volume, and maternal hypertension. When IUGR is suspected based on these parameters, Doppler ultrasound can help to determine the prognosis. Large fetuses, particularly those weighing more than 4,000 grams at birth, are at risk for perinatal morbidity and mortality due to obstetrical complications. These fetuses occur more frequently and are at especially high risk in diabetic mothers. The estimated fetal weight is the most direct parameter for diagnosing LGA and macrosomia and is moderately accurate with positive predictive values up to 67% in the general population and 77% in diabetics. It can be an important factor in deciding on the route of delivery in diabetic mothers.

Changes in left heart hemodynamics after technically successful in-utero aortic valvuloplasty.

OBJECTIVE: Severe aortic stenosis in the mid-gestation fetus can progress to hypoplastic left heart syndrome (HLHS). @ In-utero aortic valvuloplasty is an innovative therapy to promote left ventricular growth and function and potentially to prevent HLHS. This study evaluated the effects of mid-gestation fetal balloon aortic valvuloplasty on subsequent fetal left ventricular function and left heart Doppler characteristics. METHODS: We reviewed fetuses with aortic stenosis that underwent attempted in-utero aortic valvuloplasty between 2000 and 2006. Pre-intervention and the latest post-intervention fetal echocardiograms were analyzed to characterize changes in left heart function and Doppler characteristics in utero. RESULTS: Forty-two fetuses underwent attempted aortic valvuloplasty during the study period, 12 of which were excluded from analysis secondary to inadequate follow-up data, termination or fetal demise. Study fetuses (n = 30) underwent pre-intervention echocardiography at a median gestational age of 23 weeks, and were followed for a median of 66 +/- 23 days post-intervention. In 26 fetuses, aortic valvuloplasty was technically successful. Among these 26, left heart physiology was abnormal pre-intervention and improved or normalized after intervention in most cases: biphasic mitral inflow was present in 5/25 (20%) cases pre-intervention and in 21/23 (91%) post-intervention (P < 0.001); moderate or severe mitral regurgitation was present in 14/26 (54%) cases pre-intervention and in 5/23 (22%) post-intervention (P = 0.02); bidirectional flow across the patent foramen ovale was present in 0/26 cases pre-intervention and in 6/25 (24%) post-intervention (P = 0.01); antegrade flow in the transverse arch was present in 0/25 cases pre-intervention and in 17/26 (65%) post-intervention (P < 0.001). The left ventricular ejection fraction increased from 19 +/- 10% pre-intervention to 39 +/- 14% post-intervention (P < 0.001). These changes were not observed in control fetuses (n = 18). CONCLUSION: Fetal aortic valvuloplasty, when technically successful, improves left ventricular systolic function and left heart Doppler characteristics.

Factors affecting technical success of fetal aortic valve dilation.

OBJECTIVE: We have reported previously that valve dilation enhances growth of cardiac structures and may prevent hypoplastic left heart syndrome (HLHS) in fetuses with critical aortic stenosis. We aimed to investigate maternal/fetal factors which may affect the technical success of fetal valvuloplasty, and to describe perinatal complications of the procedure. METHODS: This was a descriptive series of 22 fetuses diagnosed with critical aortic stenosis developing into HLHS which underwent intervention by valvuloplasty. Initially this was attempted using a percutaneous approach; reassessment after our first five attempts, only one of which was successful, led to the introduction of the option of laparotomy. Technical success was defined as balloon inflation across the aortic annulus and a broader jet through the aortic valve as assessed by Doppler. Data collected included body mass index, demographic variables, ultrasound findings and postprocedure interventions. RESULTS: Technical success increased significantly if maternal laparotomy was an option (83.3% vs. 20.0%, P = 0.017). Laparotomy was performed in 66.6% (12/18) of cases. There was a learning curve that showed an increase in success rate and decrease in need for laparotomy over the 3-year study period. Neither the need for laparotomy nor the chances of technical success were predictable by gestational age, body mass index or placental location. Tocolysis was limited to perioperative prophylaxis; one woman experienced wound infection and fluid overload. Postoperatively, three fetuses died and two delivered prematurely, 2 and 7 weeks after intervention. CONCLUSION: Fetal aortic valvuloplasty can be performed with technical success, with low fetal loss rate and few maternal complications. While the need for laparotomy cannot be predicted, having it available as an option improves the technical success rate.

Sonographic evaluation of intrauterine growth retardation.

Intrauterine growth retardation (IUGR) may arise from a variety of causes, including placental insufficiency, maternal diseases, and fetal anomalies. Sonography plays a number of important roles in the diagnosis and management of growth retardation. Diagnosis of IUGR is based on fetal measurements, assessment of amniotic fluid volume, and other sonographic findings. Once IUGR has been diagnosed, sonography can help establish its cause. If a lethal cause is excluded, the fetus is monitored for the remainder of the pregnancy using sonography, including serial fetal measurements, biophysical profiles, and Doppler waveform indexes. Used appropriately, sonography can improve the outcome of fetuses with IUGR.

Slow embryonic heart rate in early first trimester: indicator of poor pregnancy outcome.

PURPOSE: To assess the outcome of early first-trimester pregnancies with slow embryonic heart rates. MATERIALS AND METHODS: Forty pregnant women had prenatal ultrasound scans obtained before 8 weeks gestation that demonstrated an embryonic heart rate of 90 beats per minute or less. Follow-up information was used to determine pregnancy status at the end of the first trimester. RESULTS: Thirty-two embryos died before the end of the first trimester, five survived the first trimester, and three were lost to follow-up. Fetal demise occurred in all seven embryos with heart rates of less than 70 beats per minute, 10 of 11 with heart rates of 70-79 beats per minute, and 15 of 19 with heart rates of 80-90 beats per minute. All 32 pregnancy losses occurred within 10.5 weeks gestation. CONCLUSION: An embryonic heart rate of 90 beats per minute or less early in the first trimester carries a dismal prognosis, with a very high likelihood of fetal demise before the end of the first trimester. Demise occurred in all embryos with heart rates less than 70 beats per minute.

Improved prediction of gestational age in the late third trimester.

A variety of formulas have been published for predicting GA in the second and third trimesters. We assessed these formulas for the presence of systematic errors. Our study population consisted of 1036 obstetrical sonograms at 14 to 42 weeks' gestation in patients with highly accurate dating based on a prior first trimester scan. Most formulas had mean errors (mean value of the difference between predicted and true GA) of no more than 1 week between 14 and 38 weeks' gestation. At 38 to 42 weeks, however, all formulas had large systematic underestimation biases, with mean negative errors in the range of 1.6 to 3 weeks. By regressing ln(GA) against one or more measurements, we developed new formulas that eliminate this underestimation bias, with mean errors of no more than 0.6 week throughout the entire 14 to 42 week period. As with current formulas, however, our formulas have wide 95% confidence ranges of +/- 3 weeks or greater at 38 to 42 weeks as a result of inherent biological variability. We recommend the use of these formulas in clinical practice, as they may prevent errors in diagnosis late in pregnancy.

Sonographic prediction of gestational age: accuracy of second- and third-trimester fetal measurements.

We measured the accuracy of second- and third-trimester sonographic predictors of gestational age against highly reliable gold standard (crown-rump length) in a group of fetuses. Using a prospectively collected computerized data base, we selected 460 fetal sonograms obtained at 14-42 weeks of gestation in which age could be reliably established on the basis of crown-rump length in the first trimester. We used data obtained from these sonograms to compare several predictors of fetal age. The accuracy of all predictors worsened progressively as pregnancy proceeded. In the second trimester, corrected biparietal diameter and head circumference were more accurate predictors of gestational age than were biparietal diameter, femoral length, and abdominal circumference (p less than .05, F test). In the third trimester, the corrected biparietal diameter, head circumference, and femoral length were the best predictors, significantly better than biparietal diameter and abdominal circumference (p less than .05, F test). Prediction of gestational age that relies on a single sonographic measurement should be based on the head circumference or corrected biparietal diameter in the second trimester and on one of these two predictors or the femoral length in the third trimester.