Corpus callosum length by gestational age as evaluated by fetal MR imaging.

Although suspected corpus callosum abnormality is a common indication for fetal MR imaging, biometric data specific to MR imaging are sparse. We sought to characterize growth in corpus callosum length by EGA with fetal MR imaging. Corpus callosum segments were assessed and overall corpus callosum length was measured and plotted against the EGA for 68 anatomically normal fetal brains ranging in EGA from 18.5 to 37.7 weeks, and linear and polynomial regression models were calculated. The body of the corpus callosum was identified in all fetuses, followed in frequency by the splenium (91.2%), genu (85.3%), and rostrum (32.4%). Measurements of corpus callosum length by MR imaging were in agreement with values established by sonography. A second-degree polynomial function was the best fit for callosal length by EGA. Understanding this normal growth pattern may enhance detection of subtle growth abnormalities.

Endometrial thickness predicts intrauterine pregnancy in patients with pregnancy of unknown location.

OBJECTIVE: To determine whether endometrial thickness and other parameters are useful predictors of normal intrauterine pregnancy (IUP) in the setting of vaginal bleeding and sonographic diagnosis of pregnancy of unknown location (PUL). METHODS: We reviewed the clinical and sonographic records of all 591 patients with vaginal bleeding and a sonographic diagnosis of PUL between 1 July 2005 and 30 June 2006. Data on maternal age, gravidity, parity, estimated gestational age by last menstrual period (EGA by LMP), endometrial thickness and serum beta-human chorionic gonadotropin (beta-hCG) were collected. Complete data were available for 517 patients, 40 (7.7%) of whom ultimately had normal IUPs. A logistic regression model was constructed using a stepwise procedure to identify variables significantly associated with the outcome of normal IUP. The validity of the model was assessed by receiver-operating characteristics (ROC) curve and Hosmer-Lemeshow Chi-square analysis. RESULTS: Four variables (maternal age, EGA by LMP, endometrial thickness and serum beta-hCG) were significant in the prediction of normal IUP (area under the ROC curve = 0.86). As maternal age, EGA by LMP and beta-hCG increased, the likelihood of a normal IUP decreased, while as the endometrial thickness increased, the likelihood of a normal IUP increased. For each millimeter increase in endometrial thickness, the odds increased by 27% that the patient would have a normal IUP. No normal IUP had an endometrial thickness < 8 mm. CONCLUSION: Increased endometrial thickness predicts normal IUP in patients who present with vaginal bleeding and PUL.

Single uterine axial fast acquisition magnetic resonance fetal survey: is it feasible?

OBJECTIVES: To determine which non-biometric components of the ultrasound fetal survey can routinely be seen on a single fast acquisition magnetic resonance (MR) sequence aligned axial to the maternal uterus. STUDY DESIGN: The non-biometric components of the routine fetal ultrasound examination were applied retrospectively to the initial MR single-shot fast spin-echo acquisition aligned axial to the maternal uterus in the normal fetus to determine whether these parameters could be routinely evaluated. Nineteen women with anatomically normal fetuses had a total of 31 MR studies performed for fetal or maternal indications, either as part of an indicated examination or as part of a study protocol approved by the institutional review board. The images in these 31 MR studies were reviewed by two independent examiners who were blinded to the other's assessment; concordance was necessary for a component to be adequately assessed. The Wilcoxon rank sum test was used to determine the effect of gestational age and fetal lie on the ability to assess non-biometric parameters. RESULTS: Assessment was possible in 85% of the non-biometric parameters. Cord insertion, external genitalia and the four-chamber view of the heart were most problematic. In only two cases was the four-chamber view of the heart identified. Longitudinal lie allowed significantly more parameters (82%) to be evaluated than transverse lie (45%) (p < 0.003). No difference based on gestational age was found. CONCLUSION: A single fast acquisition axial MR sequence can evaluate 85% of the non-biometric components of the fetal ultrasound survey. Fetal lie is an important confounder in the ability to resolve fetal anatomy with a single MR axial uterine acquisition.

Maternal and fetal artery Doppler findings in women with chronic hypertension who subsequently develop superimposed pre-eclampsia.

OBJECTIVE: To carry out a prospective study of Doppler velocimetry of the fetomaternal circulation in women with chronic hypertension, to evaluate whether the subsequent development of superimposed pre-eclampsia can be predicted. STUDY DESIGN: Serial Doppler studies of the maternal uterine and renal arteries, and fetal middle cerebral and umbilical arteries, were performed at 16-20 and at 28-32 weeks' gestation in 56 women with chronic hypertension. Pulsatility indices were compared using the Wilcoxon rank sum method. A p value of < 0.05 was considered significant. RESULTS: Uterine artery impedance was significantly elevated as early as 16-20 and at 28-32 weeks' gestation, while the cerebroplacental ratio was lower at 28-32 weeks' gestation, in the 14 women who developed superimposed pre-eclampsia. The maternal renal artery impedance remained constant throughout gestation, regardless of the development of pre-eclampsia. CONCLUSIONS: Uterine artery Doppler velocimetry at 16-20 and at 28-32 weeks' gestation showing increased impedance is predictive for the development of superimposed pre-eclampsia in women with chronic hypertension. The cerebroplacental ratio suggested early fetal brain sparing at 28-32 weeks' gestation in these women.

Utility of Doppler velocimetry in predicting outcome in twin reversed-arterial perfusion sequence.

OBJECTIVE: The aim of this study was to describe Doppler velocimetric findings in pregnancies complicated by the twin reversed-arterial perfusion sequence and to determine the association of these findings with pregnancy outcome. STUDY DESIGN: Six twin pregnancies complicated by twin reversed-arterial perfusion sequence had ultrasonographic and Doppler studies performed between 1990 and 1997. Pulsatile vessels in the umbilical cords of the pump and acardiac twins were insonated, and reversal of flow was confirmed in all cases. Resistive index values were calculated, and the difference in resistive index between the pump and acardiac twin in each pair was evaluated as a marker of pregnancy outcome. RESULTS: Five of 6 pump twins survived the immediate neonatal period. Although 5 of the acardiac twins had abnormally elevated Doppler index values, no ratio of systolic to diastolic velocity or resistive index value of the acardiac twin alone was associated with either a good or poor prognosis for the pump twin. Among the 3 pump twins with good outcomes, all had a resistive index difference >0.20. Among the 3 pump twins with poor outcomes, all had small resistive index differences (<0.05). CONCLUSION: We found larger differences in resistive index to be associated with improved outcome of the pump twin in pregnancies complicated by twin reversed-arterial perfusion sequence. Smaller resistive index differences were associated with poor outcome, including cardiac failure and central nervous system hypoperfusion.

Fetal syphilis: clinical and laboratory characteristics.

OBJECTIVE: To examine the pathophysiology of fetal syphilis and correlate hematologic, immunologic, and sonographic findings. METHODS: Twenty-four women with untreated syphilis during pregnancy were prospectively identified. Sonography with amniocentesis and percutaneous umbilical blood sampling were performed. Darkfield examination, rabbit infectivity testing, and polymerase chain reaction for detection of Treponema pallidum were performed on amniotic fluid. Hematologic and chemical testing of fetal blood was performed using standard techniques. Fetal antitreponemal IgM was detected by Western blot assay. Maternal syphilis was treated with 2.4 to 4.8 million units of benzathine penicillin G intramuscularly. Neonatal outcomes and signs of congenital syphilis were recorded. RESULTS: Six women had primary, 12 had secondary, and six had early latent syphilis. Sixty-six percent of fetuses (95% confidence interval [CI] 47%, 82%) had either congenital syphilis or detection of Treponema pallidum in amniotic fluid. Sixty-six percent had hepatomegaly, including three fetuses (12.5%, 95% CI 4%, 31%) with ascites. Fetal antitreponemal IgM was detected in three cases. Abnormal liver transaminases were found in 88% (CI 69%, 96%), anemia in 26% (CI 13%, 47%), and thrombocytopenia in 35% (CI 19%, 55%). Maternal treatment was successful in 83% (CI 64%, 93%). Risk of treatment failure was significantly increased when hepatomegaly and ascites were present (P =.01). CONCLUSION: Findings with fetal syphilis are similar to those of neonatal syphilis. We hypothesize that fetal transaminase elevation occurs early in the course of infection; hematologic abnormalities and hydrops occur later. Severity of disease may be associated with risk of treatment failure.

Predictive value of serial middle cerebral and renal artery pulsatility indices in fetuses with oligohydramnios.

OBJECTIVE: To determine if unexplained changes in the amniotic fluid index or pulsatility indices of the fetal renal, middle cerebral, or umbilical artery are predictive of perinatal outcome in pregnancies complicated by oligohydramnios. METHODS: Changes in amniotic fluid measurements and fetal vessel velocimetry in patients with oligohydramnios were evaluated for correlation with fetal outcome. Fourteen fetuses with oligohydramnios underwent serial sonography evaluating the amniotic fluid index and fetal middle cerebral, renal, and umbilical velocimetry. Matched controls and neonatal outcomes were obtained. RESULTS: Change in amniotic fluid index and in renal artery pulsatility index were inversely correlated. Change in the middle cerebral artery pulsatility index was different in infants with normal outcome compared to infants with adverse outcome CONCLUSIONS: Serial velocimetry of the middle cerebral artery may identify fetuses with oligohydramnios at risk for adverse outcomes.

Pregnancy outcomes after antepartum diagnosis of oligohydramnios at or beyond 34 weeks' gestation.

OBJECTIVE: Our purpose was to assess whether antepartum oligohydramnios is associated with adverse perinatal outcomes. STUDY DESIGN: Women delivered between July 1, 1991, and September 30, 1996, who underwent ultrasonography at >/=34 weeks' gestation were analyzed. Oligohydramnios was defined as an amniotic fluid index 50 mm. RESULTS: In our analysis of 6423 pregnancies, 147 (2.3%) were complicated by oligohydramnios. This complication was associated with increased labor induction (42% vs 18%; P <.001), stillbirth (1. 4% vs 0.3%; P <.03), nonreassuring fetal heart rate (48% vs 39%; P <. 03), admission to the neonatal intensive care nursery (7% vs 2%; P <. 001), meconium aspiration syndrome (1% vs 0.1%; P <.001), and neonatal death (5% vs 0.3%; P <.001). CONCLUSION: Antepartum oligohydramnios is associated with increased perinatal morbidity and mortality.

Color flow mapping for myometrial invasion in women with a prior cesarean delivery.

OBJECTIVES: Our aim was to evaluate the utility of color flow mapping in the prediction of placental myometrial invasion in women with Cesarean delivery. METHODS: Ultrasound color flow mapping was performed on placental implantations in potential proximity to the hysterotomy scar. The smallest myometrial thickness was measured under the placenta to evaluate the degree of myometrial attenuation in this area and note was made of unusual vascular lakes. RESULTS: Two hundred fifteen women with placentas in proximity to the prior hysterotomy scar underwent color Doppler mapping. Of 20 women with placenta previa and Cesarean delivery, 15 had Cesarean hysterectomy for bleeding complications and nine had the pathological diagnosis of placental invasion. The measurement of <1 mm for the smallest myometrial thickness or presence of large intraplacental lakes was predictive of myometrial invasion (sensitivity 100%, specificity 72%, PPPV 72%, and NPV 100%). CONCLUSIONS: Color flow mapping predicted myometrial invasion when the smallest myometrial thickness was <1 mm and large intraplacental lakes were demonstrated.

The Ovarian Tumor Index predicts risk for malignancy.

BACKGROUND: Prediction of ovarian malignancy by ultrasonographic findings and patient age in the scenario of clinically suspected adnexal masses is a desirable goal. METHODS: Prospective evaluation of clinically suspected adnexal masses was performed with transvaginal ultrasound using real-time, Doppler velocimetry, and color-flow mapping. Continuous ultrasound variables included ovarian volume, the Sassone morphology scale, and Doppler determination of angle-corrected systole, diastole, and time-averaged velocity, in addition to patient age. The Doppler pulsatility index (PI), vessel location, presence of a diastolic notch, and echogenic predominance of the lesion, suggestive of dermoid, also were assessed. RESULTS: Of 244 women with follow-up, 214 had nonmalignant findings (85 of which were benign neoplasms), and 30 had malignant neoplasms. Age and all ultrasound continuous variables except systole were found to be statistically significant (P < 0.05) between patients with both malignant (N = 30) and nonmalignant masses (N = 214), as well as those with benign (N = 85) and malignant (N = 30) neoplasms. By adding the continuous measures (age [in years], ovarian volume [mL], and Sassone morphology scale [1-15]) and weighting other variables ([-10] x PI, central or septal location [+10], peripheral location [-10], and echogenic [-10]), a receiver operating characteristic curve was generated (area under the curve = 0.91), which was found to be discriminating, predictive, and able to replicate the more complex logistic regression model. Prediction of malignancy was generated from the population-based data of the current study. CONCLUSIONS: The Ovarian Tumor Index, which combines patient age with specific ultrasonographic markers, is an accurate method for predicting ovarian malignancy in the clinical scenario of suspected adnexal masses.

Pitfalls in ultrasonic cervical length measurement for predicting preterm birth.

OBJECTIVE: To describe the anatomic and technical difficulties encountered with transvaginal ultrasound imaging of the cervix in a consecutive series of women at risk for preterm delivery. METHODS: Three groups of women had cervical ultrasound examinations: those with histories of preterm birth, those with incompetent cervices, and those admitted for preterm labor that did not progress. Standardized ultrasound examinations of the cervix involved measuring the length of the endocervical canal, funneling length, and internal os dilation with and without fundal pressure. RESULTS: Sixty consecutive women had transvaginal ultrasound examinations for assessment of the cervix. Forty-six had histories of preterm birth, five had incompetent cervices, and nine had arrested preterm labor. Six types of problems arose, which can be divided into anatomic or technical considerations, with an overall frequency of 27% (95% confidence interval 16%, 40%). Anatomic pitfalls that hampered identification of the internal os included an undeveloped lower uterine segment (n = 5), a focal myometrial contraction (n = 1), rapid and spontaneous cervical change (n = 1), and an endocervical polyp (n = 1). Technical pitfalls included incorrect interpretation of internal os dilation because of vaginal probe orientation (n = 7) and artificial lengthening of the endocervical canal because of distortion of the cervix by the transducer (n = 1). CONCLUSION: We caution those who perform cervical length examinations to be wary of falsely reassuring findings due to potential anatomic and technical pitfalls.

Ultrasonographic prediction of fetal outcome in suspected skeletal dysplasias with use of the femur length-to-abdominal circumference ratio.

OBJECTIVE: Our purpose was to determine whether the femur length-to-abdominal circumference ratio can be used antenatally to predict a lethal skeletal dysplasia. STUDY DESIGN: All obstetric sonograms performed from January 1990 to October 1995 were reviewed (44,020 studies) to find those scans suggestive of a skeletal dysplasia. Thirty patients were identified. The femur length/abdominal circumference ratio was then calculated from each patient's initial and subsequent sonograms. Birth outcomes were obtained on the 27 patients who elected to continue their pregnancies. RESULTS: All fetuses with a lethal skeletal dysplasia (n = 12) had a ratio <0.16. The fetuses with a nonlethal dysplasia (n = 8) had ratios between 0.134 and 0.193, with only 1 fetus with a ratio <0.16. All fetuses with no evidence of a skeletal dysplasia after birth (n = 7) had femur length/abdominal circumference ratios >0.18. The 1 fetus with a ratio <0.16 who survived the neonatal period had extreme bowing and demonstrates the limitation of the ratio when bowing is present. CONCLUSIONS: A stillbirth or neonatal death occurred in 12 of 13 patients with a femur length/abdominal circumference ratio <0.16, independent of gestational age. Conversely, no fetus with a ratio >0.16 was found to have a lethal skeletal dysplasia. This information may be useful in counseling women when ultrasonography suggests the diagnosis of a skeletal dysplasia.

The four-chamber view and its sensitivity in detecting congenital heart defects.

We sought to determine the sensitivity of detecting congenital heart defects with routine antenatal ultrasound including the four-chamber view in a population at low risk for cardiac anomalies. Neonatal outcome and anomaly databases were reviewed to identify cases of morphologic cardiac defects from 1988-1992. Of 176 cases identified, 62 (35%) had routine antenatal ultrasound including the four-chamber view. Thirteen of these 62 (21%) were diagnosed by ultrasound and 18 of the 116 (15%) total defects present were seen. Of these, only 16 of 25 (64%) defects reasonably expected to be seen by the four-chamber cardiac view alone were detected. The routine ultrasound four-chamber cardiac evaluation is limited and detection depends on the type of cardiac defect present.

Imaging of puerperal septic thrombophlebitis: prospective comparison of MR imaging, CT, and sonography.

OBJECTIVE: Our objective was to compare prospectively the abilities of MR imaging, CT, and sonography to reveal puerperal septic thrombophlebitis in the pelvis. SUBJECTS AND METHODS: Seventy-six women with puerperal fever for 5 days refractory to antimicrobial therapy underwent MR imaging, CT, and sonography. We obtained unenhanced axial CT images followed by enhanced images after the administration of an oral contrast agent for which we followed a specific protocol. Axial T1- and T2-weighted spin-echo MR images with phase reconstruction and sagittal T1-weighted MR images were obtained. Real-time sonography was performed using Doppler color flow mapping and spectral waveform analysis. RESULTS: Of the 76 women, 64 completed studies with all three techniques. Ovarian vein thrombosis was diagnosed in 12 women. True-positive results were indicated when at least two of the three studies showed the presence of a clot; true-negative results were indicated when at least two of the three studies showed a lack of thrombosis. MR imaging and CT revealed both ovarian veins in all cases (64/64). Sonography revealed 33 (52%) of 64 right ovarian veins and 15 (23%) of 64 left ovarian veins. MR imaging (sensitivity, 92%; specificity, 100%) and CT (sensitivity, 100%; specificity 99%) were comparable in all but two cases. In one such case, MR imaging showed patency, CT revealed findings interpreted as thrombosis, and sonography showed flow in the partially occluded vein. In the second such case, bilateral thrombosis was seen on CT, but interpretations based on sonography and MR imaging were left-sided thrombosis only. Sonography correctly revealed six of the 12 cases of ovarian vein thrombosis. CONCLUSION: CT and MR imaging proved to be the studies of choice in the evaluation of ovarian vein thrombosis.

The developmental outcome of children with antenatal mild isolated ventriculomegaly.

OBJECTIVE: To evaluate standardized developmental test performance of infants and children who as fetuses had mild isolated cerebral ventriculomegaly diagnosed by ultrasound. METHODS: Ultrasound records from 1990 to 1996 were searched for cases of mild isolated ventriculomegaly, and standardized developmental testing of the children was offered to their parents. Each consented child was matched to a normal antepartum subject with respect to sex, race, indication for ultrasound, and gestational age (+/- 2 weeks) at the time of ultrasound. Tests of cognitive, motor, and adaptive behavior were then administered by examiners blinded to the subjects' case or comparison status. RESULTS: Twenty-two cases and an equal number of matched comparison subjects completed the testing. The ventriculomegaly and comparison groups were similar with respect to parental age, maternal education, and household income. The ventriculomegaly subjects scored significantly lower than the comparison group on both the Bayley Scales of Infant Development: mental development index (88.95 versus 99.68, P = .017) and psychomotor development index (95.99 versus 103.95, P = .039). Eight of the 22 ventriculomegaly children were classified as developmentally delayed on the mental developmental index compared with one of 22 children in the comparison group (P = .021). Adaptive behavior skills, as measured by the Vineland Behavior Scales (99.64 versus 102.68), were not significantly different between the groups (P = .571). CONCLUSION: Mild isolated ventriculomegaly detected on antepartum sonographic examination is associated with a significant risk for developmental delay. Insofar as these children were judged to be completely normal at birth, our findings represent an important application of antepartum sonography for identifying infants who could be targeted for early childhood intervention.

Cerebral blood flow and cranial magnetic resonance imaging in eclampsia and severe preeclampsia.

OBJECTIVE: To measure cerebral blood flow in women with eclampsia and severe preeclampsia using phase-contrast magnetic resonance imaging (MRI). METHODS: Women with eclampsia and severe preeclampsia were studied and compared with normotensive cohorts. Magnetic resonance imaging studies were performed initially in hypertensive women after seizure treatment or prophylaxis was given. Magnetic resonance imaging flow measurements were made using a phase contrast velocity imaging technique in each middle and posterior cerebral artery. Conventional brain MRI and magnetic resonance angiography of the circle of Willis were performed at the time of flow measurement. Women with preeclampsia and eclampsia served as their own controls and were matched with normotensive cohorts. All of the hypertensive women were studied again 4-5 weeks postpartum. Paired t test analysis and an analysis of variance were performed. Considering a 20% minimum detectable difference in flow, the power was 0.80, 0.92, 0.86, and 0.96 for the left and right middle cerebral arteries and the left and right posterior cerebral arteries, respectively. RESULTS: All 28 women enrolled were studied initially within 24 hours of delivery or of their most recent seizure. There were no significant differences in blood flow in either the posterior or middle cerebral arteries in women with eclampsia or severe preeclampsia between the initial studies and those 4-5 weeks postpartum, or compared with their normal counterparts. No findings of vasospasm were seen. T2-weighted brain images were markedly abnormal in all eight women with eclampsia, mildly abnormal in two of ten with severe preeclampsia, and normal in all ten controls. CONCLUSIONS: No flow changes were seen in the posterior or middle cerebral arteries of women with eclampsia and severe preeclampsia despite the presence of remarkable brain lesions in all women with eclampsia. These findings question the role of vasospasm and cerebral hypoperfusion, although a vasodilatory effect of magnesium could not be excluded.

In utero infection with Treponema pallidum in early pregnancy.

Amniocentesis was performed under sonographic guidance in gravidas (< 20 weeks' gestation) with untreated syphilis. Five to ten millilitres of amniotic fluid from each patient was used for rabbit infectivity testing (RIT) and polymerase chain reaction (PCR) to detect amniotic fluid infection with Treponema pallidum. Gravidas were treated with benzathine penicillin G. Newborns were examined for clinical and laboratory signs of congenital syphilis including immunoglobulin M (IgM) antibody to T. pallidum by Western blotting (immunoblotting). Eleven patients were enrolled at a mean gestational age of 16.8 weeks. T. pallidum was recovered from amniotic fluid by RIT in four cases (36 per cent), and PCR was positive in three of the amniotic fluid specimens (27 per cent). There were no false-positive PCR results. None of the newborns had clinical evidence of congenital syphilis and their sera lacked IgM reactivity to T. pallidum antigens by immunoblotting. These findings confirm in utero infection with T. pallidum in continuing early pregnancy and indicate that in utero treponemal infection can be eradicated by maternal treatment.

MURCS association: ultrasonographic findings and pathologic correlation.

MURCS association is a rare, lethal and unusual constellation of nonrandom findings that includes mullerian duct aplasia, renal aplasia, and cervicothoracic somite dysplasia.1-3 It has been described in 30 patients by Duncan and coworkers2 in 1979, in which report the authors proposed an embryologic cause for these defects.3 Antenatal ultrasonographic findings included a massive, cystic umbilical cord related to a patent urachus, enlarged bladder, single small kidney, and suspicion of urethral obstruction in a fetus of female phenotype. These findings are rare in a case of MURCS and were all confirmed on pathologic examination.

Fetal hypokinesia syndrome in the monochorionic pair of a triplet pregnancy secondary to severe disruptive cerebral injury.

We report a set of triplets, two of whom were monochorionic diamnionic and demonstrated cerebellar hypoplasia and progressive arthrogryposis on an antenatal sonogram. At delivery the infants exhibited a Pena-Shokier phenotype. At autopsy, the twins were concordant for severe disruptive lesions of the cerebrum. The mechanism resulting in the devastating symmetric lesions may have been a transient cerebral vascular compromise associated with placenta vascular anastomoses characteristic of monochorionic twinning. This report accentuates the vulnerability of the monochorionic twin for ischemic cerebral injury.