Faculty Bibliography

Sonographic fetal foot length is highly predictive of gestational age. In order to assess the reliability of this parameter in predicting gestational age in cases of abnormal fetal growth, we examined fetal foot length in small- and large-for-gestational-age fetuses. A nomogram of foot length versus gestational age between 15 and 37 weeks was constructed using cross-sectional data obtained from 5372 singleton fetuses. Fetal foot lengths for small-for-gestational-age fetuses (estimated fetal weight below the 10th percentile) and large-for-gestational-age fetuses (above the >90th percentile) fetuses were plotted against the foot length nomogram in order to determine the number of small-for-gestational-age fetuses and large-for-gestational-age fetuses with foot lengths below the 10th and above the 90th percentiles, respectively. Of the 586 small-for-gestational-age fetuses, 355 (60.6%) had foot lengths below the 10th percentile on the nomogram. When foot lengths from large-for-gestational-age fetuses were plotted on the foot length nomogram, 29.4% (219 of 744) had measurements above the 90th percentile. Fetal foot length can be influenced by growth restriction as well as states of accelerated fetal growth. Our findings imply that there are limitations to the use of fetal foot length for gestational age assessment, particularly in fetuses with growth abnormalities

OBJECTIVE: The aim of this study was to assess the role of cervical ultrasonography in the prediction of spontaneous preterm birth in triplet gestations and to compare various ultrasonographic cervical parameters with respect to predictive ability. STUDY DESIGN: This prospective cohort study included 51 triplet gestations longitudinally evaluated between 15 and 28 weeks' gestation on 274 occasions with transvaginal cervical ultrasonography and transfundal pressure. The cervical parameters obtained were funnel width and length, cervical length, percentage of funneling, and cervical index. RESULTS: Receiver operating characteristic curve analyses showed that cervical lengths of < or =2.5 cm and < or =2.0 cm between 15 and 24 weeks' gestation and between 25 and 28 weeks' gestation, respectively, were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth. A cervical length of < or =2.5 cm between 15 and 20 weeks' gestation had both a specificity and a positive predictive value of 100% for delivery at <28 weeks' gestation, and the sensitivities and negative predictive values ranged from 25% to 50% and from 72% to 91%, respectively, for deliveries at <28, <30, and <32 weeks' gestation. A cervical length of < or =2.5 cm between 21 and 24 weeks' gestation had an 86% sensitivity for prediction of spontaneous delivery at <28 weeks' gestation. A cervical length of < or =2.0 cm between 25 and 28 weeks' gestation had both a sensitivity and a negative predictive value of 100% for delivery at both <28 and <30 weeks' gestation. CONCLUSIONS: In triplet gestations cervical lengths of < or =2.5 cm between 15 and 24 weeks' gestation and < or =2.0 cm between 25 and 28 weeks' gestation were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth

We describe a case of hepatic hemangioendothelioma that was first suspected based on prenatal sonographic findings at 19 weeks' menstrual age. At 16 weeks, the patient presented with a markedly elevated maternal serum alpha-fetoprotein level. Serial sonographic examinations revealed that the fetus had cardiomegaly, hepatomegaly with a hepatic mass and dilated intrahepatic vessels, a single umbilical artery, and a placental chorioangioma. Arteriovenous shunting within the hepatic mass was seen using color Doppler and pulsed Doppler sonography. An enlarged artery arising from the abdominal aorta supplying the mass was demonstrated. Postnatal physical examination and radiologic studies supported the diagnosis of hepatic hemangioendothelioma. The evolution in the sonographic appearance of this hepatic lesion in utero over a 17-week period is described

OBJECTIVE: This study was undertaken to compare various ultrasonographic cervical parameters with respect to ability to predict spontaneous preterm birth in twin gestations. STUDY DESIGN: This prospective study involved 131 women carrying twins who were longitudinally evaluated on 524 occasions between 15 and 28 weeks' gestation with transvaginal cervical ultrasonography and transfundal pressure. The following cervical parameters were obtained: funnel width and length, cervical length, percentage of funneling, and cervical index. Receiver operating characteristic curve analysis was used to determine the ultrasonographic cervical parameter evaluated at 15 to 20 weeks' gestation, 21 to 24 weeks' gestation, and 25 to 28 weeks' gestation that were best for prediction of spontaneous preterm birth at <28 weeks' gestation, <30 weeks' gestation, <32 weeks' gestation, and <34 weeks' gestation. RESULTS: The median gestational age at delivery was 36 weeks' gestation (range, 21-41 weeks' gestation). Receiver operating characteristic curve analysis indicted that a cervical length of < or =2.0 cm, regardless of gestational age category at cervical measurement, was at least as good as other ultrasonographic cervical parameters at predicting spontaneous preterm birth. Between 15 and 20 weeks' gestation a cervical length cutoff value of < or =2.0 cm had specificities of 97%, 98%, 99%, and 100% and negative predictive values of 99%, 98%, 95%, and 89% for delivery at <28, <30, <32, and <34 weeks' gestation, respectively. The positive predictive values for delivery at <32 and <34 weeks' gestation were 80% and 100%, respectively. Between 21 and 24 weeks' gestation a cervical length of < or =2.0 cm had specificities of 84%, 84%, 85%, and 86% and negative predictive values of 99%, 99%, 94%, and 87% for delivery at <28, <30, <32, and <34 weeks' gestation, respectively. Between 25 and 28 weeks' gestation cervical length had excellent negative predictive values of 99%, 98%, 95%, and 93% for delivery at <28, <30, <32, and <34 weeks' gestation, respectively. CONCLUSIONS: In twin gestations a cervical length of < or =2.0 cm measured between 15 and 28 weeks' gestation was at least as good as other ultrasonographic cervical parameters at predicting spontaneous preterm birth. The high specificities indicate that cervical length was better at predicting the absence than the presence of various degrees of spontaneous prematurity

OBJECTIVE:The objective of this study was to conduct an economic evaluation of routine prenatal carrier testing for fragile X syndrome. METHODS:This economic analysis was conducted from the societal perspective. A cost-benefit equation was developed based on the premise that the cost of routinely offering prenatal carrier testing for fragile X syndrome should be at least equal to, or less than, the cost of the current practice of not offering such testing. Sensitivity analyses included key assumptions regarding therapeutic abortion rates (50-100%) and patient screening acceptance rates (50-80%). RESULTS:A policy of routinely offering prenatal carrier testing for fragile X syndrome may be beneficial only if the cost per screening test is less than $120 during the first year of the screening program, or less than $240 when the program reaches its full maturity. Given the current cost per screening test of $250, prenatal screening for carrier status for fragile X syndrome carries the potential for annual losses of approximately $10 to $195 million in the United States. In addition, approximately 46-115 fetal lives may be lost due to invasive genetic procedures. CONCLUSIONS:Prenatal screening for fragile X syndrome may be economically beneficial only if the cost of the prenatal screening test for carrier identification is considerably less than the current cost.

OBJECTIVE:The purpose of this study was to determine whether elevated levels of umbilical vein IL-6 would be a better marker for early neonatal sepsis than the clinical signs of maternal chorioamnionitis. METHODS:Patients delivering preterm because of spontaneous preterm labor or premature rupture of the membranes were evaluated for clinical signs of chorioamnionitis, which was defined as a temperature of > or =100.4 degrees F along with > or =2 of the following: significant maternal tachycardia (> or = 120 bpm), fetal tachycardia (> or =160 bpm), purulent discharge, uterine tenderness, and leukocytosis (WBC > or =18,000 cells/mm3). Umbilical vein blood was assayed for interleukin-6. An elevated interleukin-6 level was determined to be 25 pg/mL. Infants were evaluated for evidence of early neonatal sepsis. The abilities of clinical chorioamnionitis and interleukin-6 levels > or =25 pg/mL to predict early neonatal sepsis were compared. RESULTS:There were 28 patients delivering 14 (50%) neonates with evidence for early neonatal sepsis. The incidence of suspected neonatal sepsis in women with and without clinical chorioamnionitis was 6/10 (60%) vs. 8/18 (44.4%), P = 0.43. Using receiver operator characteristic curves, the best cutoff for interleukin-6 was found to be 25 pg/mL. The compared sensitivity, specificity, and positive and negative predictive values of clinical chorioamnionitis vs. interleukin-6 levels > or =25 pg/mL for predicting early neonatal sepsis were 42.9% vs. 92.9%, 71.4% vs. 92.9%, 60% vs. 92.9%, and 55.6% vs. 92.9%, respectively. CONCLUSIONS:Elevated umbilical vein levels of interleukin-6 predict those preterm infants with early sepsis better than the presence of clinical chorioamnionitis.

OBJECTIVE:The objective was to perform a systematic review of prospective randomized trials evaluating the efficacy of oral tocolytics in the prevention of recurrent preterm labor and its associated complications. METHODS:A MEDLINE search of English language articles published since 1966 was performed to identify studies of maintenance oral tocolytic therapy. Studies were included in the review which: 1) randomized patients to an oral tocolytic after stabilization with parenteral therapy; 2) reported results for either a placebo or a control group; and 3) included patients with intact membranes only. These studies were analyzed for nine outcomes, including incidence of preterm delivery, incidence of recurrent preterm labor, latency from treatment to delivery, gestational age, birthweight, admission to an intensive care nursery (ICN), incidence of respiratory distress syndrome (RDS), incidence of intraventricular hemorrhage (IVH), and perinatal mortality. RESULTS:Seven studies met the inclusion criteria, four of which used oral terbutaline for the treatment arm (two had a control group, and two had a placebo group), and one used oral ritodrine (with a placebo group). Of the remaining two, one used oral ritodrine and oral magnesium chloride (with a control group), and the other used oral terbutaline and oral magnesium chloride (with a placebo group). The results of the individual studies suggest that there was no beneficial effect of oral tocolytic therapy on the incidence of preterm delivery (odds ratio (OR) range: 0.7-2.0), incidence of preterm labor recurrence (OR range: 0.6-3.2), ICN admission (OR range: 1.3-2.0), incidence of RDS (OR range 0.1-4.3), incidence of IVH (OR range 0.3-2.0), perinatal mortality (OR range: 1.6-4.3), or gestational age at delivery. CONCLUSIONS:We concluded that a meta-analysis based on the available studies is not possible due to the fact that there is little that these seven studies have in common with respect to treatment comparisons. In addition, inconsistent definitions of outcome variables makes pooling this data inappropriate and invalid. Therefore, well-designed, large, randomized trials are needed to evaluate the efficacy of oral tocolytics in improving perinatal outcome.

OBJECTIVE:To compare the accuracy of three different sonographic circumference measurement techniques in predicting birth weight in term fetuses, using a standard equation for estimating fetal weight. METHODS:Fifty-three singleton, term fetuses were examined sonographically within 24 hours of scheduled elective cesarean delivery. The biparietal diameter (BPD) and femur length (FL) were measured using standard techniques, and head circumference (HC) and abdominal circumference (AC) were measured using three separate circumference measurement techniques (Two-diameter, ellipse, and trace). With the use of each circumference method, estimated fetal weights were determined for each fetus according to a weight-estimation formula incorporating BPD, HC, AC, and FL. The accuracy of the formula using each circumference measurement technique for predicting actual birth weight was calculated. RESULTS:The mean (+/- standard deviation [SD]) gestational age was 38.1 +/- 0.9 weeks and the mean actual birth weight was 3536 +/- 472 g. The two-diameter and ellipse circumference measurements allowed more accurate birth weight prediction than did the trace method, with mean (+/- SD) percent deviations from the actual birth weight of -0.5 +/- 7.8%, 1.9 +/- 8.0%, and 8.2 +/- 11.6% (P < .05), respectively. The trace method was the least accurate, with a mean birth weight overestimation of 266 g and measurements within 10% of the actual birth weight only 49.1% of the time. The two-diameter and ellipse method yielded predicted birth weights within 10% of actual birth weights in 77.4 and 79.2% of cases, respectively. CONCLUSION/CONCLUSIONS:Two-diameter and ellipse circumference measurement techniques are similarly accurate in predicting birth weight and both are significantly better than the trace technique.

OBJECTIVE:To compare the efficacy and cost effectiveness of different screening programs for fetal Down syndrome (DS). METHODS:Screening tools evaluated included maternal age, triple screening (TS), and ultrasound (U/S) for fetal markers of DS. Sensitivities used were TS: 55% <35 years, 80% > or = 35 years; U/S: 70%. Average regional fees used were TS: $80, U/S: $200, amniocentesis (AM): $1,000. Five screening programs were evaluated: 1) <35 years, no screening; > or = 35 years, AM; 2) <35 years, TS with AM for screen-positive subjects; > or = 35 years, AM; 3) all patients, TS with AM for screen-positive subjects; 4) <35 years, TS followed by U/S for screen-positive women, AM for women with fetal markers of DS on U/S; > or = 35 years TS with AM for screen-positive subjects; 5) all women, TS followed by U/S for screen-positive women, AM for women with fetal markers of DS on U/S. The sensitivity, total cost, cost/case DS detected (Cost/DS), AM losses, and residual risk (RR, undetected DS fetuses/women not receiving AM) were calculated for each screening program. Population analysis was performed using 1988 IL delivery statistics. RESULTS:It was estimated that 260 cases of DS would occur in the population of 167,654 women (8.4% > or = 35 years at delivery). Sensitivity for programs 1-5 was 30, 69, 62, 51, and 36 percent, respectively, and cost/DS was 181,000, 203,000, 162,000, 151,000, and 194,000 dollars, respectively. CONCLUSIONS:DS screening incorporating TS in all patients with program #4 and without program #3 selective U/S in women <35 years yield the best combination of sensitivity and cost effectiveness while minimizing the number of AM-related losses.