母体特征联合宫颈长度在预测双胎妊娠自发早产中的作用

Objective: The purpose of this study was to examine the value of combining maternal characteristics and measurement of cervical length at 22 to 24 weeks in the prediction of spontaneous early preterm delivery. Study design: Cervical length was measured by transvaginal sonography at 22 to 24 weeks in 1163 twin pregnancies attending for routine antenatal care. Logistic regression analysis was used to examine the effect of maternal demographic characteristics and cervical length on the risk of spontaneous early preterm delivery. Results: The rate of spontaneous delivery before 32 weeks was 6.5% . The rate of early delivery was inversely related to cervical length,and for a false-positive rate of 10% , the detection rate of early delivery was 65.3% . The respective detection rate for maternal characteristics and obstetric history was 26.4% . Logistic regression analysis demonstrated that the only significant independent predictor of spontaneous early delivery was cervical length. Conclusion: In twins, the prediction of spontaneous early preterm delivery by measurement of cervical length at 22 to 24 weeks is not improved by maternal characteristics.

在未经选择的低危人群中联合母体因素和子宫动脉多普勒测速法建立先兆子痫预测模型

Objective: The purpose of this study was to develop a predictive model for preeclampsia. Study design: This was a prospective screening study for preeclampsia using uterine artery Doppler ultrasound in unselected low-risk singleton pregnancies at community hospitals in the UK (n = 32,157). Logistic regression models were developed and their predictive ability assessed using the area under the receiver operator curve (AROC). Results: Six hundred twelve (2.0% ) women developed preeclampsia, and 144 (0.5% ) required early delivery (< 34 weeks). A model using both maternal and ultrasound factors had an AROC of 0.798, which was higher than ultrasound alone (0.729, P < .0001) or maternal factors alone (0.712, P < .0001). In early onset disease, the AROC of ultrasound alone (0.922) was not significantly improved by adding maternal predictors (0.945, P = .27). In contrast, late onset disease was better predicted by the combined model (AROC 0.798) than ultrasound alone (AROC 0.729, P < .0001) or maternal factors alone (AROC 0.712, P < .0001). Conclusion: The combination of uterine artery Doppler ultrasound and maternal factors provided the

孕11～13^(+6)周胎儿13-三体的超声筛查

Objective: The purpose of this study was to examine the sonographic features of trisomy 13 at 11 to 13+ 6 weeks of gestation. Study design: This was a retrospective study that examined the features of trisomy 13 at the ultrasound scan at 11 to 13+ 6 weeks of gestation, which in our center is performed for the measurement of crown-rump length, nuchal translucency thickness, and fetal heart rate and the examination for major defects. Results: In the 181 fetuses with trisomy 13, there were holoprosencephaly, exomphalos, and/or megacystis in 92 fetuses (50.2% ), fetal heart rate above the 95th percentile in 129 fetuses (71.3% )- , and nuchal translucency above the 95th percentile in 141 fetuses (77.9% ). There was no significant association between nuchal translucency and fetal heart rate, and it was estimated that inclusion of fetal heart rate in nuchal translucency screening can improve the detection rate of trisomy 13 by approximately 5% . Conclusion: At the 11 to 13+ 6- week scan, the measurement of fetal nuchal translucency and fetal heart rate and fetal examination for holoprosencephaly, exomphalos, and megacystis can identify >90% of fetuses with trisomy 13.

对30564例孕妇在妊娠早期行21-三体综合征筛查的前瞻性研究

Objective: This study was undertaken to evaluate the performance of a 1- stop clinic for first- trimester assessment of risk (OSCAR)for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) thickness, and maternal serum- free β - human chorionic gonadotrophin (hCG) and pregnancy- associated plasma protein- A (PAPP- A). Study design: OSCAR was carried out in 30,564 pregnancies at 11 to 13+ 6 weeks. Patient- specific risks for trisomy 21 and detection and falsepositive rates were calculated. Results: The median maternal age was 34 (range 15- 49) years. Chromosomal abnormalities were identified in 330 pregnancies, including 196 cases of trisomy 21. The estimated risk for trisomy 21 was 1 in 300 or greater in 7.5% of the normal pregnancies, in 93.4% of those with trisomy 21 and in 88.8% of those with other chromosomal defects. Conclusion: The most effective method of screening for chromosomal defects is by first- trimester fetal NT and maternal serum biochemistry.

妊娠早期鼻骨测量用于21-三体筛查

Objective: This study was undertaken to investigate the impact of incorporating assessment of the nasal bone into first-trimester combined screening by fetal nuchal translucency(NT) thickness and maternal serum biochemistry. Study design: In this prospective combined screening study for trisomy 21, the fetal nasal bone was also examined and classified as present or absent. A multivariate approach was used to calculate patient-specific risks for trisomy 21 and the detection rate(DR) and false-positive rate(FPR) were estimated. We examined 2 screening strategies; first, integrated first-trimester screening in all patients and second, first-stage screening of all patients using fetal NT and maternal serum free fl-hCG and PAPP-A, followed by second-stage assessment of nasal bone only in those with an intermediate risk of 1 in 101 to 1 in 1000 after the firststage. Results: The nasal bone was absent in 113(0.6%) of the 20,165 chromosomally or phenotypically normal fetuses and in 87(62.1%) of the 140 fetuses with trisomy 21. With combined first-trimester NT and serum screening, the DR of 90%was achieved at a FPR of 5%. Inclusion of the nasal bone, either in all cases or in about 10%of the total in the 2-stage approach, halved the FPR to 2.5%. Conclusion: Inclusion of the nasal bone in first-trimester combined screening for trisomy 21 achieves a DR of 90%for a FPR of 2.5%.

18号染色体三体的胎心超声检查法

Background: Previously reported pathological series suggest that cardiac malformations are universal in trisomy 18. We examined our experience of fetal echocardiography in trisomy 18 for comparison. Methods: Of 255 fetuses with trisomy 18 detected in our centre between January 1999 and June 2004, 174 were evaluated using fetal echocardiography. Our results were compared to four previous echocardiographic and four autopsy series, comprising 89 and 110 patients, respectively. Results: Of these 174 fetuses, 114 were examined between 10 and 14 weeks gestation and the remainder between 15 and 33 weeks. An increased nuchal translucency measurement was the reason for referral inmost of the early cases and extracardiac anomalies in the remainder. Images were non-diagnostic in 12 cases (7% ), all examined at < 15 weeks gestation. Abnormal cardiac findings were detected in 118 of the remaining 162 fetuses (73% ), including 15 with functional anomalies. The various heart malformations included ventricular septal defects, tetralogy of Fallot, left heart disease, and atrioventricular septal defects. In all series used for comparison, a similar diversity of disease was seen. In pathological series of trisomy 18, structural heart malformations were found in all cases, but some had lesions which would not be detectable echocardiographically in the fetus. Conclusion: Abnormal cardiac findings are detectable echocardiographically in the majority of cases of trisomy 18 examined during fetal life, but not in all. A wide spectrum of heart defects is seen. Diagnosis of heart malformations can be made reliably, even in the first trimester at the time of nuchal translucency measurement.

胎儿颈项透明层厚度测量和快速非整倍体筛查行早期产前染色体异常诊断的观察性研究

Objective: To investigate an approach for the analysis of samples obtained in screening for trisomy 21 that retains the advantages of quantitative fluorescent polymerase chain reaction (qf- PCR) over full karyotyping and maximises the detection of clinically significant abnormalities. Design: Observational study. Setting: Tertiary referral centre. Subjects: 17 446 pregnancies, from which chorionic villous samples had been taken after assessment of risk for trisomy 21 by measurement of fetal nuchal translucency (NT) thickness at 11 to 13th weeks of gestation. Interventions: Analysis of chorionic villous samples by full karyotyping and by qf- PCR for chromosomes 13, 18, 21, X, and Y. Main outcome measure: Detection of clinically significant chromosomal abnormalities. Results: The fetal karyotype was normal in 15 548 (89.1% ) cases and abnormal in 1898 (10.9% ) cases, including 1722 with a likely clinically significant adverse outcome. Karyotyping all cases would lead to the diagnosis of all clinically significant abnormalities, and a policy of relying entirely on qf- PCR would lead to the diagnosis of 97.9% of abnormalities. An alternative strategy where by qf- PCR is the main method of analysis and full karyotyping is reserved for those cases with a minimum fetal NT thickness of 4 mm would require full karyotyping in 10.1% of the cases, would identify 99.0% of the significant abnormalities, and would cost 60% less than full karyotyping for all. Conclusions: In the diagnosis of chromosomal abnormalities after first trimester screening for trisomy 21, a policy of qf- PCR for all samples and karyotyping only if the fetal NT thickness is increased would reduce the economic costs, provide rapid delivery of results, and identify 99% of the clinically significant chromosomal abnormalities.