Search

Objective: To determine sonographic findings in Down syndrome fetuses in the third trimester. Methods: Down syndrome fetuses who had third-trimester ultrasound examinations between 25 and 41 weeks’ gestation were matched for gestational age with three controls each. Fetal structural anomalies, Down syndrome dysmorphology markers (abnormal facial profile, sandal gap, tongue thrusting, clinodactyly, or hypoplastic middle phalanx of the fifth finger), and abnormal long-bone biometry (femur, humerus, tibia, and fibula; femur length to biparietal diameter ratio; and femur length to abdominal circumference ratio were abstracted from the ultrasound reports. The fetal face, hands, feet, profile, and cardiac outflow tracts are routinely evaluated in our center. Results: Seventeen fetuses with Down syndrome who had third-trimester ultrasound evaluations were identified. Anomalies included cardiac defects (five), tongue thrusting (three), clinodactyly (three), abnormal profile (three), sandal gap (two), and duodenal atresia (two). Of the 17 fetuses, at least one long-bone abnormality was found in 13, at least one structural or biometric anomaly was found in 15, and at least two abnormal findings existed in 11. Abnormal ultrasound findings, including structural anomalies, short bones, and Down syndrome dysmorphology markers, were more common in cases than in matched controls. Conclusion: At least one abnormal ultrasound finding was present in 15 of 17 fetuses, and abnormal bone measurements or ratios were discovered in 13 of 17. Abnormal long-bone biometry at third-trimester ultrasound should raise the suspicion of fetal Down syndrome.

Objective: To determine the utilization rate of second-trimester genetic sonogram and its role in influencing the decision for amniocentesis in women at increased risk for fetal trisomy 21. Methods: From November 1, 1993, to December 31, 1996, a second-trimester genetic sonogram or only genetic amniocentesis (as a first choice) were offered to pregnant women referred to our institution who were at increased risk for fetal trisomy 21. Results: During the study period, 2089 women were referred to our unit for genetic prenatal diagnosis; of these, 1426 (68%) chose only genetic amniocentesis, and 663 (32%) chose a genetic sonogram as their first option. The yearly utilization rates of genetic sonogram were two of 477 or 0.4% for 1993, 82 of 495 or 16.6% for 1994, 251 of 523 or 48.0% for 1995, and 328 of 594 or 55.2% for 1996. Adjusting for potential confounders, multivariable logistic regression analysis showed that the most important factors associated with the women's decision to undergo genetic amniocentesis were three or more ultrasound markers present (relative risk [RR] 189.5, 95% confidence interval [CI] 37.1, 980.0), two ultrasound markers present (RR 47.2, 95% CI 9.8, 267.8), one ultrasound marker present (RR 12.7, 95% CI 5.5, 29.7), and abnormal serum biochemistry (RR 3.0, 95% CI 1.0, 8.9). Conclusion: The increasing utilization trend, in conjunction with the fact that an abnormal sonogram was the most influential factor in women's decision to undergo genetic amniocentesis, suggests that genetic sonogram services for detection of trisomy 21 should be added to the armamentarium of all prenatal diagnostic centers.

Objective To investigate which second-trimester ultrasound markers for aneuploidy are the most diagnostically efficient in detecting fetal trisomy 21. Methods All second-trimester genetic sonograms performed since November 1,1992 for women at increased risk for fetal trisomy 21 were analyzed retrospectively. Statistical analysis included descriptive statistics, the test of proportions, and univariate and multivariable logistic regression analysis using trisomy 21 as the dependent variable and ten aneuploidy ultrasound markers as independent variables. Results There were 581 normal fetuses, 23 with trisomy 21 and four with other chromosomal abnormalities. When one or more abnormal ultrasound markers were present, the sensitivity and false-positive rate for trisomy 21 were 87% and 13.4%, respectively. After adjusting for confounders, multivariate logistic regression analysis showed the best combination of ultrasound markers for detecting trisomy 21 to be nuchal fold thickening (relative risk [RR] 85.5; 95% confidence interval [CI] 20.4,357.7), pyelectasis (RR 25.2; 95% CI 6.7, 95.0), and short humerus (RR 20.4; 95% CI 4.5, 92.1). The model combining these three ultrasound markers yielded a sensitivity of 87% and a false-positive rate of 6.7%. Conclusion By using only three ultrasound markers (combination of nuchal fold thickening, pyelectasis, and short humerus) the false-positive rate is decreased from 13.4% to 6.7% without any compromise in the sensitivity (87%). The clinical usefulness of evaluating the various second- trimester ultrasound markers needs to be evaluated in prospective studies.

Objective To establish the efficacy of second-trimester fetal long-bone biometry (femur, humerus, tibia, and fibula length) in detecting trisomy 21 and to generate tables for adjusting the risk of trisomy 21 according to long-bone biometry. Methods Four long bones—femur, humerus, tibia, and fibula—were measured ultrasonically in singleton fetuses before genetic amniocentesis. Fetuses with normal karyotypes were used to derive regression equations describing predicted lengths on the basis of the biparietal diameter measurement. The efficacy of each abnormally short bone, alone and in combination, was determined in 22 fetuses with trisomy 21 encountered during the study period. After the sensitivity and specificity of long-bone biometry were established, appropriate tables were generated by Bayes' theorem to adjust the risk of trisomy 21 in the second trimester depending on long-bone biometry. Results Of 515 patients between 14 and 23 weeks' gestation, 493 had normal fetal karyotypes and 22 had trisomy 21. The sensitivity of an abnormal ultrasound, as defined by the presence of one or more short bones, was 63.6% and the specificity was 78.5%. According to Bayes' theorem, genetic amniocentesis may not be recommended for women less than 40 years old in the presence of normal long-bone biometry (ie, all four bones normal). Conclusion Second-trimester fetal long-bone biometry is useful in detecting trisomy 21 and may be used to adjust the a priori risk of both high- and low-risk women for trisomy 21 and, therefore, the need for genetic amniocentesis.

Objective To use a meta-analysis of all published randomized trials to determine whether the use of continuous electronic fetal heart rate monitoring (EFM) as the main method of intrapartum fetal surveillance is associated with improved pregnancy outcome compared to intermittent auscultation. Data Sources We used the MEDLINE data base and reference lists of articles to identify all published randomized trials of EFM versus intermittent auscultation. Methods of Study Selection A total of nine randomized trials published in peer-review journals were identified. The selection criterion was the use of EFM or intermittent auscultation as the main intrapartum fetal surveillance technique. Data Extraction and Synthesis A total of 18,561 patients were included in the nine published randomized trials, 9398 in the EFM group and 9163 in the auscultation group. Measures of pregnancy outcome included cesarean delivery, cesarean for suspected fetal distress, overall use of forceps or vacuum, use of forceps or vacuum for suspected fetal distress, overall perinatal mortality, and perinatal mortality due to fetal hypoxia (intrapartum or early neonatal death) attributable to the method of intrapartum monitoring. The metaanalysis showed that the patients monitored electronically had a significantly higher overall cesarean rate (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.17–2.01), higher cesarean rate for fetal distress (OR 2.55, 95% CI 1.81–3.53), overall increased use of forceps or vacuum (OR 1.23, 95% CI 1.02–1.49), increased use of forceps or vacuum for suspected fetal distress (OR 2.50, 95% CI 1.97–3.18), and decreased perinatal mortality due to fetal hypoxia (OR 0.41, 95% CI 0.17–0.98). Conclusion Electronic fetal monitoring is associated with increased rates of surgical intervention and decreased perinatal mortality due to fetal hypoxia.

OBJECTIVE: To estimate the value of second-trimester genetic sonography in detecting fetal Down syndrome in patients with advanced maternal age (at least 35 years) and normal triple screen. METHODS: Since July 1999, a prospective collection and recording of all individual triple screen risks for fetal Down syndrome was initiated for all patients with advanced maternal age presenting in our ultrasound unit for second-trimester genetic sonography. Genetic sonography evaluated the presence or absence of multiple aneuploidy markers. Outcome information included the results of genetic amniocentesis, if performed, and the results of pediatric assessment and follow-up after birth. RESULTS: By June 2001, 959 patients with advanced maternal age and normal triple screen were identified. Outcome information was obtained in 768 patients. The median risk for fetal Down syndrome based on maternal age was 1:213 (range 1:37–1:274). The median risk for fetal Down syndrome based on triple screen results was 1:1069 (range 1:275–1:40,000). A total of 673 patients had normal genetic sonography, and none (0%) had Down syndrome; 95 had one or more aneuploidy markers present, and four (4.2%) had fetuses with Down syndrome. The triple screen risks for these four fetuses ranged from 1:319 to 1:833. CONCLUSION: This study suggests that patients with advanced maternal age and normal genetic sonography carried very little risk for Down syndrome. The use of genetic sonography may increase the detection rate of fetal Down syndrome in this group of pregnant women.

Transabdominal ultrasonography in obese pregnant women is often unsatisfactory because of the poor transmission of ultrasound through a thickened abdominal wall. We report our experience with the placement of a transvaginal probe in the umbilicus to improve resolution in obese pregnant patients. The technique, which involves filling the umbilicus with ultrasound transmission gel and inserting the transvaginal probe into the umbilicus, was applied in 25 consecutive obese patients who had unsatisfactory fetal imaging by the standard transabdominal approach. The most frequent reason for incomplete fetal survey by the standard transabdominal approach was unsatisfactory imaging of the fetal heart (19 of 25 cases, 76%). The transumbilical approach resulted in improved resolution and satisfactory cardiac examination in 18 of these 19 cases (95%). In two cases, color and pulsed Doppler interrogation of intrafetal vessels become possible. A complete fetal survey was accomplished in 96% of the cases.

Although cervical cerclage is widely used to prevent preterm birth in women with a history of preterm birth during the second trimester, its use is controversial and has not been supported by several randomized trials. This randomized controlled trial investigated the effectiveness of cerclage to prevent recurrent preterm birth in women with short cervix. Singleton women with a history of spontaneous preterm birth before 34 weeks' gestation and a mid-trimester cervical length less than 25 mm were randomly assigned to either cerclage (n = 148) or no cerclage (n = 153). Cervical length was considered to be a surrogate for cervical competence. The interaction between cerclage efficacy and cervical length was compared for cervical length strata of < 15 mm and 15 to 24 mm. The primary outcome of preterm birth less than 35 weeks' gestation was observed in 32% of women assigned to cerclage and 42% in the no-cerclage group (P = 0.09). Previable birth less than 24 weeks occurred less frequently in the women treated with cerclage than in those who were not (6.1% vs. 14%; P = 0.03). The rates of perinatal death were also significantly less with cerclage (8.8% vs. 16%; P = 0.046). In stratified analysis, comparison of cervical length strata showed that cerclage provided a significant benefit in the less than 15 mm stratum (P = 0.03) but not in the 15 to 24 mm stratum. These findings show that cerclage reduces previable birth and perinatal mortality in women with a history of spontaneous preterm birth at less than 34 weeks' gestation and a cervical length less than 25 mm, but does not prevent birth before a gestational age of 35 weeks unless the cervical length is less than 15 mm.

Objective To compare pregnancy outcomes in women at risk for pregnancy loss treated with elective versus ultrasound-indicated placement of cerclage. Methods A retrospective cohort study was performed on two groups of patients with singleton gestations. The first group consisted of women at risk for pregnancy loss who were treated with an elective cerclage, while the second group was managed conservatively and followed with serial transvaginal cervical sonography and transfundal pressure. An emergency cerclage was placed in women in the second group when the endocervical canal length shortened to < 20 mm, either spontaneously or in response to transfundal pressure. The two groups were compared with respect to maternal demographics, obstetric and gynecological history, and gestational age, both at time of cerclage placement and delivery. Results A total of 138 patients were identified. Eighty-one patients were treated with an elective cerclage and 57 with an ultrasound-indicated cerclage. Patients treated with elective cerclages were older (32 versus 27 years, p = 0.0003), more commonly white (56.8% versus 38.6%, p = 0.0380), less commonly nulliparous (23.5% versus 43.9%, p = 0.0063), and more often private patients (92.6% versus 28.1%, p < 0.0001). A history of previous treatment with cerclage (45.7% versus 10.5%, odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1–0.4) and one prior midtrimester loss (53.1% versus 33.3%, OR 0.4, 95% CI 0.2–0.9) were also more common in the elective versus ultrasound-indicated cerclage group. However, there was no difference in the rates of previous preterm delivery, two midtrimester losses, two terminations of pregnancy, in utero diethylstilbestrol exposure, uterine anomalies, history of cone biopsy or parity. As expected, gestational age at placement of cerclage was significantly earlier in the elective group (13.0 versus 20.0 weeks, p < 0.0001). The median (range) gestational age at delivery (37 (15–41) versus 37 (17–41) weeks, p = 0.90), the number of early (< 25 weeks) losses (9.9% versus 8.8%, OR 1.6, 95% CI 0.3–7.9), and preterm deliveries (< 37 weeks) (35.8% versus 36.8%, OR 1.1, 95% CI 0.4–3.2) were similar in the elective and ultrasound-indicated cerclage patients, respectively. Conclusion In patients at risk for pregnancy loss, placement of cervical cerclages in response to ultrasono-graphically detected shortening of the endocervical canal length is a medically acceptable alternative to the use of elective cerclage. Copyright © 1998 International Society of Ultrasound in Obstetrics and Gynecology

Background: Reported cases of uterine rupture diagnosed by ultrasound have shown fetal membranes ballooning through uterine rupture sites, or adjacent areas of hemorrhage. Case: A 27-year-old gravida 3, para 2 had open fetal surgery to repair a fetal myelomeningocele at 28 weeks’ gestation. Her postoperative course was complicated by threatened preterm labor and anhydramnios. At 33 weeks’ gestation, with maternal symptoms of bowel obstruction, ultrasound showed a fetal leg and section of umbilical cord protruding through the uterine wall. Conclusion: Even in the presence of anhydramnios, uterine wall rupture was identified, because ultrasound evaluation of the uterine wall showed prolapsed fetal parts and umbilical cord. Persistent anhydramnios after open fetal surgery should prompt a search for uterine rupture.

Objective: To compare the outcome of women with a history of midtrimester loss (MTL) when managed with elective cerclage (EC) versus serial cervical sonography (CS). Methods: Over a 7-year period, we identified 199 women with a prior MTL carrying singleton gestations. We compared pregnancy outcomes between 114 women managed with serial CS between 15 and 24 weeks of gestation and 85 women who received EC. In the group who were followed with serial CS, a rescue cerclage or restricted physical activity as the only treatment was considered when the cervical length shortened to 2.0 cm or less. Values were reported as median (range). Results: Results are reported in the following table. Elective cerclage (N = 85) Cervical sonography (N = 114) Cerclage rate 100% 35% Gestational age (GA) at delivery (weeks) 37 (23–41) 38 (18–42) GA less than 37 weeks 44.1% 25.4% ( P = 0.009) GA less than 33 weeks 21.0% 17.5% Preoperative cervical length — 0.88 (0.0–2.0) Conclusion: Women with prior midtrimester loss managed with serial cervical sonography have equal or better perinatal outcomes with lower utilization of cerclage than those treated with elective cerclage.

Objective: To determine whether there is a gestational age cutoff at the time of diagnosis of AEDV of the umbilical artery Doppler waveform that is associated with nearly zero perinatal survival. Methods: Over an 8-year period we identified and compared the outcomes of pregnancies in which AEDV of the umbilical artery Doppler waveform was detected between 19–24 and 25–28 weeks of gestation. All fetuses had normal structure and karyotypes. Small for gestational age (SGA) was defined as less than the 10th percentile for gestational age based on Brenner’s curve. Values are reported in median (range). Results: There were no survivors among the 27 cases identified at 19–24 weeks of gestation: 5 terminations for severe-SGA fetus (birth weight 336 [130–430] grams), 3 terminations for severe preeclampsia and SGA fetus, 12 fetal deaths, 7 neonatal deaths, and 10 cases (46%) of pregnancy-induced hypertension/preeclampsia (PIH/PE). All 8 cases detected at 25–28 weeks of gestation resulted in neonatal survival at discharge (P

Sonographic techniques have been developed to study the biometry and behavior of the cervix during pregnancy which have led to a better understanding of the pathogenesis of pregnancy loss and preterm birth. Nomograms have been developed for singleton and twin gestations, and associations between cervical sonographic characteristics and various adverse pregnancy outcomes have been observed. The new concept of 'relative' cervical incompetence suggests that the cervix may be an independent contributor to preterm birth. The incorporation of cervical sonography in management schemes for the prevention of pregnancy loss or preterm delivery has the potential to impact favorably on perinatal outcome.