Trimester-specific diagnostic accuracy of ultrasound for detection of placenta accreta spectrum: systematic review and meta-analysis.

OBJECTIVE: To assess the diagnostic accuracy of ultrasound for detecting placenta accreta spectrum (PAS) during the first trimester of pregnancy and compare it with the accuracy of second- and third-trimester ultrasound examination in pregnancies at risk for PAS. METHODS: PubMed, EMBASE and Web of Science databases were searched to identify relevant studies published from inception until 10 March 2023. Inclusion criteria were cohort, case-control or cross-sectional studies that evaluated the accuracy of ultrasound examination performed at < 14 weeks of gestation (first trimester) or ≥ 14 weeks of gestation (second/third trimester) for the diagnosis of PAS in pregnancies with clinical risk factors. The primary outcome was the diagnostic accuracy of sonography in detecting PAS in the first trimester, compared with the accuracy of ultrasound examination in the second and third trimesters. The secondary outcome was the diagnostic accuracy of each sonographic marker individually across the trimesters of pregnancy. The reference standard was PAS confirmed at pathological or surgical examination. The potential of ultrasound and different ultrasound signs to detect PAS was assessed by computing summary estimates of sensitivity, specificity, diagnostic odds ratio and positive and negative likelihood ratios. RESULTS: A total of 37 studies, including 5764 pregnancies at risk of PAS, with 1348 cases of confirmed PAS, were included in our analysis. The meta-analysis demonstrated that ultrasound had a sensitivity of 86% (95% CI, 78-92%) and specificity of 63% (95% CI, 55-70%) during the first trimester, and a sensitivity of 88% (95% CI, 84-91%) and specificity of 92% (95% CI, 85-96%) during the second/third trimester. Regarding sonographic markers examined in the first trimester, lower uterine hypervascularity exhibited the highest sensitivity (97% (95% CI, 19-100%)), and uterovesical interface irregularity demonstrated the highest specificity (99% (95% CI, 96-100%)). In the second/third trimester, loss of clear zone had the highest sensitivity (80% (95% CI, 72-86%)), and uterovesical interface irregularity exhibited the highest specificity (99% (95% CI, 97-100%)). CONCLUSIONS: First-trimester ultrasound examination has similar accuracy to second- and third-trimester ultrasound examinations for the diagnosis of PAS. Routine first-trimester ultrasound screening for patients at high risk of PAS may improve detection rates and allow earlier referral to tertiary care centers for pregnancy management. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Longitudinal assessment of spiral and uterine arteries in normal pregnancy using novel ultrasound tool.

OBJECTIVES: To use superb microvascular imaging (SMI) to evaluate longitudinally spiral artery (SA) and uterine artery (UtA) vascular adaptation in normal human pregnancy, and to develop reference ranges for use at various gestational ages throughout pregnancy. METHODS: The data for this study were obtained from the National Institutes of Health (NIH)-funded Human Placenta Project. Women aged 18-35 years, with a body mass index < 30 kg/m2 , without comorbidities, with a singleton gestation conceived spontaneously, and gestational age at or less than 13 + 6 weeks were eligible for inclusion. The current analysis was restricted to uncomplicated pregnancies carried to term. Exclusion criteria included maternal or neonatal complications, fetal or umbilical cord anomalies, abnormal placental implantation or delivery < 37 weeks. Women who fulfilled the inclusion criteria formed the reference population of the Human Placenta Project study. Each participant underwent eight ultrasound examinations during pregnancy. The pulsatility index (PI) of both the left and right UtA were obtained twice for each artery and the presence or absence of a notch was noted. Using SMI technology, the total number of SA imaged was recorded in a sagittal placental section at the level of cord insertion. The PI and peak systolic velocity (PSV) were also measured in a total of six SA, including two in the central portion of the placenta, two peripherally towards the uterine fundal portion, and two peripherally towards the lower uterine segment. RESULTS: A total of 90 women fulfilled the study criteria. Maternal UtA-PI decreased throughout the first half of pregnancy from a mean ± SD of 1.39 ± 0.50 at 12-13 weeks' gestation to 0.88 ± 0.24 at 20-21 weeks' gestation. The mean number of SA visualized in a sagittal plane of the placenta increased from 8.83 ± 2.37 in the first trimester to 16.99 ± 3.31 in the late-third trimester. The mean SA-PI was 0.57 ± 0.12 in the first trimester and decreased progressively during the second trimester, reaching a nadir of 0.40 ± 0.10 at 24-25 weeks, and remaining constant until the end of pregnancy. SA-PSV was highest in early pregnancy with a mean of 57.16 ± 14.84 cm/s at 12-13 weeks' gestation, declined to a mean of 49.38 ± 17.88 cm/s at 20-21 weeks' gestation and continued to trend downward for the remainder of pregnancy, reaching a nadir of 34.50 ± 15.08 cm/s at 36-37 weeks' gestation. A statistically significant correlation was noted between SA-PI and UtA-PI (r = 0.5633; P < 0.001). Multilevel regression models with natural cubic splines were used to create reference ranges of SA-PSV and SA-PI for given gestational ages. CONCLUSION: From early gestation, we have demonstrated the ability to image and quantify SA blood flow in normal pregnancy, and have developed reference ranges for use at various gestational ages throughout pregnancy. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

First-trimester ultrasound diagnostic features of placenta accreta spectrum in low-implantation pregnancy.

OBJECTIVE: Low-implantation pregnancy (LIP) is an important marker for the diagnosis of placenta accreta spectrum (PAS) in the first trimester. Many grayscale and color Doppler ultrasound markers of PAS have been defined in the second and third trimesters of pregnancy, but have not been studied in the first trimester. The aim of this study was to determine whether PAS sonographic markers could be used in the first trimester to differentiate patients with LIP who develop PAS from those who do not. METHODS: This was a retrospective case-control study of women who delivered at our institution between 2009 and 2019. Cases were women with PAS who delivered by Cesarean hysterectomy and who had undergone first-trimester ultrasound demonstrating LIP. Controls were women with persistent placenta previa without PAS who delivered by Cesarean section without postpartum hemorrhage and who had undergone first-trimester ultrasound demonstrating LIP. Sonographic images were reviewed by an investigator blinded to pregnancy outcome and ultrasound reports. Images were reviewed for presence of abnormal uteroplacental interface, increased lower uterine segment hypervascularity and placental lacunae, with or without swirling on grayscale or color Doppler ultrasound. RESULTS: Following review of the electronic health records, 21 cases and 46 controls met the inclusion criteria. Placental lacunae were present in 18/21 (85.7%) cases and 7/46 (15.2%) controls (odds ratio (OR), 33.4; 95% CI, 7.7-144.4; P < 0.001). The number of lacunae was significantly higher in cases compared with controls, with a median of five lacunae present in cases compared with a median of one lacuna in controls (P < 0.001). The median size of the lacunae was also significantly larger in cases compared with controls, measuring 10.03 (interquartile range (IQR), 7.3-12.05) mm and 4.15 (IQR, 4.05-5.05) mm, respectively (P = 0.001). Lacunae swirling on grayscale or color Doppler ultrasound was noted only in PAS cases, with 10/12 (83.3%) having swirling on grayscale ultrasound and 12/12 (100%) having swirling on color Doppler (P < 0.001). Presence of an abnormal uteroplacental interface was also observed only in PAS cases, at a rate of 17/20 (85.0%) (P < 0.001). Lower uterine segment (uterovesical, subplacental and/or intraplacental) hypervascularity was present in 14/14 (100%) cases and only 1/12 (8.3%) controls (P < 0.001). CONCLUSION: In women at risk of PAS, ultrasound markers of PAS can and should be assessed as early as in the first trimester. The use of a first-trimester prenatal ultrasound screening protocol and standardized approach to ultrasound examination in at-risk mothers may help increase detection of PAS and enable planning for optimal management of affected pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Influence of maternal body mass index on interobserver variability of fetal ultrasound biometry and amniotic-fluid assessment in late pregnancy.

OBJECTIVE: To determine the interobserver reproducibility of fetal ultrasound biometric and amniotic-fluid measurements in the third trimester of pregnancy, according to maternal body mass index (BMI) category. METHODS: This was a prospective cohort study of women with a singleton gestation beyond 34 weeks, recruited into four groups according to BMI category: normal (18.0-24.9 kg/m2 ), overweight (25.0-29.9 kg/m2) , obese (30.0-39.9 kg/m2 ) and morbidly obese (≥ 40 kg/m2 ). Multiple pregnancies, women with diabetes and pregnancies with a fetal growth, structural or genetic abnormality were excluded. In each woman, fetal biometric (biparietal diameter (BPD), head circumference, abdominal circumference (AC), femur length (FL) and estimated fetal weight) and amniotic-fluid (amniotic-fluid index (AFI) and maximum vertical pocket (MVP)) measurements were obtained by two experienced sonographers or physicians, blinded to gestational age and each other's measurements. Differences in measurements between observers were expressed as gestational age-specific Z-scores. The interobserver intraclass correlation coefficient (ICC) and Cronbach's reliability coefficient (CRC) were calculated. Bland-Altman analysis was used to assess the degree of reproducibility. RESULTS: In total, 110 women were enrolled prospectively (including 1320 measurements obtained by 17 sonographers or physicians). Twenty (18.2%) women had normal BMI, 30 (27.3%) women were overweight, 30 (27.3%) women were obese and 30 (27.3%) women were morbidly obese. Except for AFI (ICC, 0.65; CRC, 0.78) and MVP (ICC, 0.49; CRC, 0.66), all parameters had a very high level of interobserver reproducibility (ICC, 0.72-0.87; CRC, 0.84-0.93). When assessing reproducibility according to BMI category, BPD measurements had a very high level of reproducibility (ICC ≥ 0.85; CRC > 0.90) in all groups. The reproducibility of AC and FL measurements increased with increasing BMI, while the reproducibility of MVP measurements decreased. Among the biometric parameters, the difference between the BMI categories in measurement-difference Z-score was significant only for FL. Interobserver differences for biometric measurements fell within the 95% limits of agreement. CONCLUSION: Obesity does not seem to impact negatively on the reproducibility of ultrasound measurements of fetal biometric parameters when undertaken by experienced sonographers or physicians who commonly assess overweight, obese and morbidly obese women. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Fetal cardiac axis in tetralogy of Fallot: associations with prenatal findings, genetic anomalies and postnatal outcome.

OBJECTIVE: To compare prenatal findings, associated genetic anomalies and postnatal outcome in fetuses with tetralogy of Fallot (TOF) with normal cardiac axis (CAx) and those with abnormal CAx. METHODS: In this retrospective cohort study, 85 cases diagnosed with TOF by prenatal ultrasound at our clinic between 2005 and 2015 were reviewed. Follow-up ultrasound and postnatal outcome were available for 68 cases. One case complicated with absent pulmonary valve syndrome and a further seven cases diagnosed postnatally with anomalies other than TOF were excluded from the study. The remaining 60 cases of postnatally confirmed TOF were divided according to CAx into two groups: those with normal CAx (n = 33) and those with abnormal CAx (n = 27). CAx was defined as the angle between the interventricular septum and midline of the fetal thorax at the level of the four-chamber view. CAx > 65° or < 25° was considered abnormal. Prenatal sonographic findings, associated genetic anomalies and postnatal outcome were compared between the two groups. RESULTS: Fetuses with TOF and abnormal CAx were more likely to have pulmonary atresia (40.7% vs 15.2%; P = 0.026) and right-sided aortic arch (48.1% vs 21.2%; P = 0.028) than those with normal CAx. Postnatal death occurred in 30.4% of infants with abnormal CAx vs 6.5% with normal CAx (P = 0.028). Incidence of tested genetic anomalies was similar between the two groups. CONCLUSION: In fetuses with TOF, abnormal CAx is associated with the presence of pulmonary atresia, right-sided aortic arch and a higher risk of postnatal death. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Intrathymic and other anomalous courses of the left brachiocephalic vein in the fetus.

OBJECTIVE: The left brachiocephalic vein (LBCV), or innominate vein, connects the left jugular vein to the right superior vena cava. Its course is posterior to the thymus and directly anterior and superior to the aortic arch. Pediatric and adult cardiology studies have reported on the subaortic or retrotracheal courses of the LBCV and the presence of double LBCV. We observed recently in the fetus that the LBCV may have a course through the thymus (intrathymic) or be absent in the presence of a left superior vena cava. The aim of this study was to report the prevalence of isolated intrathymic and absent LBCV in normal fetuses undergoing second-trimester ultrasound screening, as well as the prevalence of other courses in association with cardiac anomalies. METHODS: In the prospective part of this study, consecutive second-trimester ultrasound examinations were evaluated to assess the presence and course of the fetal LBCV. In the retrospective case-control part of this study, the databases of two fetal medicine centers were reviewed for cardiac anomalies and the pattern and prevalence of anomalous courses of the LBCV were reported. RESULTS: One thousand four hundred and eighteen consecutive fetuses were examined prospectively. An intrathymic course of the LBCV with a typical bent shape was found in 1.76% (1 : 57) of cases and the absence of a LBCV in association with a persistent left superior vena cava (LSVC) was found in 0.28% (1 : 350). All fetuses with an isolated intrathymic course or absence of the LBCV had a normal outcome. Over a period of 4.5 years, a total of 1544 fetuses with cardiac malformations were reviewed at two centers. Among these, an anomalous course of the LBCV was noted in eight (0.5%) cases: six subaortic, one retrotracheal and one double LBCV. CONCLUSION: An intrathymic LBCV is a common condition and appears to be a normal variant in the fetus. The prevalence of a LSVC in our screening population was similar to that reported in previous studies. Anomalous courses of the LBCV are seen occasionally in cases with cardiac malformation. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Cardiac axis shift within the cardiac cycle of normal fetuses and fetuses with congenital heart defect.

OBJECTIVES: To investigate changes in the cardiac axis (CAx) within the cardiac cycle of normal fetuses and fetuses with congenital heart defects (CHD). METHODS: This was a retrospective case-control study in which stored videoclips of four-chamber views from 527 prenatal ultrasound examinations performed at 18 + 0 to 36 + 6 weeks of gestation were reviewed. Among the ultrasound scans included, 287 were of normal fetuses (controls) and 240 were of fetuses with CHD. In each case, the CAx was measured at end systole (just before the atrioventricular (AV) valve opened) and at end diastole (just before the AV valve closed). CAx measurements of fetuses with CHD were compared to those of controls. RESULTS: The mean CAx in the control group was 45.9 ± 8.5° at end systole and 38.3 ± 8.4° at end diastole (P < 0.001), resulting in an average difference of 7.6 ± 3.2°. The mean CAx in fetuses with CHD was 53.4 ± 17.8° at end systole and 47.5 ± 17.3° at end diastole (P < 0.001), resulting in an average difference of 5.9 ± 6.3°. However, in some forms of CHD, such as hypoplastic left heart syndrome and L-transposition of the great arteries, the CAx was greater at end diastole than at end systole, with a difference of more than 5°. In 21.3% of control fetuses, there was a CAx shift within the cardiac cycle of ≥ 10°. Abnormal CAx measured at end systole was strongly associated with CHD. CONCLUSIONS: Measurement of the CAx at end systole provides values that differ from those when measured at end diastole, in both normal fetuses and those with CHD. We recommend that the CAx be measured at end systole as a greater proportion of fetuses with CHD and fewer normal fetuses have an abnormal CAx at this stage compared to at end diastole. The occurrence of an abnormal CAx and the CAx shift within the fetal cardiac cycle depend on the type of CHD.

Nuchal Translucency Quality Review (NTQR) program: first one and half million results.

OBJECTIVE: To evaluate the performance of first-trimester nuchal translucency (NT) measurement by providers (physician-sonologists and sonographers) within the Nuchal Translucency Quality Review (NTQR) program. METHODS: After training and credentialing providers, the NTQR monitored performance of NT measurement by the extent to which an individual's median multiple of the normal median (MoM) for crown-rump length (CRL) was within the range 0.9-1.1 MoM of a published normal median curve. The SD of log10 MoM and regression slope of NT on CRL were also evaluated. We report the distribution between providers of these performance indicators and evaluate potential sources of variation. RESULTS: Among the first 1.5 million scans in the NTQR program, performed between 2005 and 2011, there were 1 485 944 with CRL in the range 41-84 mm, from 4710 providers at 2150 ultrasound units. Among the 3463 providers with at least 30 scans in total, the median of the providers' median NT-MoMs was 0.913. Only 1901 (55%) had a median NT-MoM within the expected range; there were 89 above 1.1 MoM, 1046 at 0.8-0.9 MoM, 344 at 0.7-0.8 MoM and 83 below 0.7 MoM. There was a small increase in the median NT-MoM according to providers' length of time in the NTQR program and number of scans entered annually. On average, physician-sonologists had a higher median NT-MoM than did sonographers, as did those already credentialed before joining the program. The median provider SD was 0.093 and the median slope was 13.5%. SD correlated negatively with the median NT-MoM (r = -0.34) and positively with the slope (r = 0.22). CONCLUSION: Even with extensive training, credentialing and monitoring, there remains considerable variability between NT providers. There was a general tendency towards under-measurement of NT compared with expected values, although more experienced providers had performance closer to that expected.

Indications for caesarean sections at ≥34 weeks among nulliparous women and differential composite maternal and neonatal morbidity.

OBJECTIVE: To compare composite maternal and neonatal morbidities (CMM, CNM) among nulliparous women with primary indications for caesarean section (CS) as acute clinical emergency (group I; ACE), non-reassuring fetal heart rate (group II) and arrest disorder (group III). DESIGN: A multicentre prospective study. SETTING: Nineteen academic centres in the USA, with deliveries in 1999-2002. POPULATION: Nulliparous women (n = 9829) that had CS. METHODS: Nulliparous women undergoing CS for three categories of indications were compared using logistic regression model, adjusted for five variables. MAIN OUTCOME MEASURES: CMM was defined as the presence of any of the following: intrapartum or postpartum transfusion, uterine rupture, hysterectomy, cystotomy, ureteral or bowel injury or death; CNM was defined as the presence of any of the following: umbilical arterial pH <7.00, neonatal seizure, cardiac, hepatic, renal dysfunction, hypoxic ischaemic encephalopathy or neonatal death. RESULTS: The primary reasons for CS were ACE in 1% (group I, n = 114) non-reassuring FHR in 29% (group II; n = 2822) and failed induction/dystocia in the remaining 70% (group III; n = 6893). The overall risks of CMM and CNM were 2.5% (95% confidence intervals, CI, 2.2-2.8%) and 1.9% (95% CI 1.7-2.2), respectively. The risk of CMM was higher in group I than in group II (RR 4.1, 95% CI 3.1, 5.3), and group III (RR 3.2, 95% CI 2.7, 3.7). The risk of CNM was also higher in group I than in group II (RR 2.8, 95% CI 2.3, 3.4) and group III (RR 14.1, 95% CI 10.7, 18.7). CONCLUSIONS: Nulliparous women who have acute clinically emergent caesarean sections are at the highest risks of both composite maternal and neonatal morbidity and mortality.

Fetal left brachiocephalic vein in normal and abnormal conditions.

OBJECTIVES: To establish values of fetal left brachiocephalic vein (LBCV) dimensions during normal pregnancy and determine whether routine assessment of the LBCV may help in identifying fetuses with congenital abnormalities of this vessel. METHODS: Fetal LBCV was assessed prospectively during ultrasound examinations in 431 normal singleton pregnancies. The visualization rate of the transverse view of the upper fetal chest at the level of drainage of the LBCV into the superior vena cava (SVC) by two-dimensional (2D) and 2D plus color Doppler ultrasound was evaluated. Reference ranges of LBCV diameter during non-complicated pregnancies were established. Interobserver and intraobserver measurement variability was analyzed. In addition, a retrospective review of the hospital medical records of 91 pregnancies with fetuses diagnosed with LBCV abnormalities was performed. RESULTS: Sonographic assessment of the fetal LBCV was consistently achieved in the second and third trimesters and in some fetuses in the first trimester of pregnancy. In normal fetuses LBCV diameter increased significantly throughout pregnancy, with a mean value of 0.7 mm at 11 weeks and 4.9 mm at term. Dilation of the fetal LBCV was noted in five cases of intracranial arteriovenous malformation and six cases of supracardiac type total anomalous pulmonary venous connection. Abnormal course of the LBCV was noted in 12 fetuses. In 63 fetuses with a persistent left SVC and a right SVC the LBCV was absent. CONCLUSION: This is the first study describing an effective sonographic approach for the assessment of fetal LBCV dimensions during pregnancy. The normative data may provide an additional means of detecting rare anomalies of systemic and pulmonary veins during pregnancy.

Defining the fetal cardiac axis between 11 + 0 and 14 + 6 weeks of gestation: experience with 100 consecutive pregnancies.

OBJECTIVE: The purpose of this study was to establish normal fetal cardiac axis values during the first and early second trimesters of pregnancy. METHODS: This was a prospective observational cohort study in which the fetal cardiac axis was assessed during ultrasound examinations in 100 consecutive fetuses between 11 + 0 and 14 + 6 weeks of gestation. Transabdominal, and, when indicated, transvaginal, approaches were used. Intraobserver and interobserver reproducibility were calculated. RESULTS: The cardiac axis ranged from 34.5 to 56.8° (mean (SD) 47.6 ± 5.6°) in 94 fetuses with normal cardiac anatomy. The fetal cardiac axis tended to be significantly higher in fetuses at 11 + 0 to 11 + 6 weeks of gestation than in fetuses at 12 + 0 to 14 + 6 weeks of gestation. Congenital heart defects were found in six out of 100 fetuses, four of which had abnormal cardiac axis values at 11 + 0 to 14 + 6 weeks of gestation. CONCLUSION: Cardiac axis measurement is possible in the first and early second trimesters of pregnancy. The assessment of cardiac axis at an early gestational age may help to identify pregnancies at high risk for congenital heart defects. Copyright

Automated retrieval of standard diagnostic fetal cardiac ultrasound planes in the second trimester of pregnancy: a prospective evaluation of software.

OBJECTIVE: To evaluate prospectively the performance of software that automatically retrieves, from a three-dimensional (3D) volume of the fetal chest, three diagnostic cardiac planes in the second trimester of pregnancy. METHODS: 3D static volumes of the fetal chest were acquired at the level of the four-chamber view in 72 fetuses between 18 and 23 weeks of gestation. Standardization of 3D volumes was performed in Plane A (the reference plane: four-chamber view) alone. Tomographic ultrasound imaging (TUI) was added to the display of each diagnostic plane. The left ventricular outflow plane (Cardiac plane 1: five-chamber view, aorta), the right ventricular outflow plane (Cardiac plane 2: pulmonary artery) and the abdominal circumference plane (Cardiac plane 3: abdominal circumference, stomach) were retrieved by the software from the 3D volumes and the data were analyzed to determine whether Cardiac planes 1-3 were displayed correctly in each volume. RESULTS: The automated software displayed, in at least one TUI plane, target Cardiac plane 1 in 94.4% of volumes, target Cardiac plane 2 in 91.7% of volumes and target Cardiac plane 3 in 97.2% of volumes. CONCLUSION: Our results validate the concept of automated sonography and its potential clinical applicability.

Calcium channel blockers as tocolytics.

This article reviews the clinical and basic science investigations regarding the safety and efficacy of calcium channel blockers as tocolytic agents. The authors reviewed the English language literature on the pharmacology and clinical applications of calcium antagonists in obstetrics. A MEDLINE (1966-2000) search was performed with the terms "calcium channel blockers," "randomized controlled trial," "preterm labor," "calcium antagonist," "tocolysis," and "nifedipine." References from these data sources were then used to find additional studies. Animal data and clinical trials in humans were included. The safety of these agents was researched in published data from the nonobstetric as well as obstetric literature. The calcium channel blockers most commonly used as tocolytics are nifedipine and nicardipine. These agents act to inhibit calcium influx across cell membranes, thereby decreasing tone in the smooth muscle of the vasculature. They act as profound vasodilatory agents and have minimal effect on the cardiac conduction system. Numerous randomized clinical trials have shown them to be as effective as beta-mimetics and magnesium in achieving tocolysis. When used for tocolysis, calcium antagonists have fewer maternal side effects than other tocolytics and have no adverse effect on fetal outcome.

Long-term outcome in twin-twin transfusion syndrome treated with serial aggressive amnioreduction.

OBJECTIVE: The purpose of this study was to determine long-term outcomes among pregnancies complicated by twin-twin transfusion syndrome and treated in a tertiary center with serial aggressive amnioreduction. STUDY DESIGN: Thirty-three pregnancies with a diagnosis of twin-twin transfusion syndrome were treated with > or =1 amnioreduction. The perinatal outcome was assessed according to 15 parameters, whereas the main outcome at age > or =2 years was the absence of cerebral palsy. RESULTS: Gestational age at diagnosis ranged from 14.5 to 33 weeks' gestation (median, 20.6 weeks' gestation), whereas gestational age at delivery was between 18.5 and 37 weeks' gestation (median, 30.5 weeks' gestation). The number of amnioreductions per pregnancy ranged from 1 to 15 (median, 2). At initial examination hydrops of the recipient and absence of the end-diastolic velocity of the umbilical artery in one of the twins were associated with poor prognosis. Fifty-one (77%) twins were born alive. At 24 months after birth both infants from 57% of the pregnancies (19/33) were alive, whereas at least one infant from 70% of the pregnancies (23/33) was alive. Thirty-three infants (78% of the survivors) were older than 36 months at last follow-up. Cerebral palsy was diagnosed in 2 of 42 infants (4.7%). One of the affected infants was born after the fetal death of the cotwin; the other infant was born with congenital cardiac malformations. CONCLUSIONS: In the group of fetuses in which both twins were delivered alive after 27 weeks' gestation without congenital malformations and survived the neonatal period, no major neurologic handicaps developed in any of the infants. At initial examination both hydrops of the recipient and absence of end-diastolic flow velocity waveforms of the umbilical artery in one of the twins were poor prognostic signs.