Abstract：
Second-trimester ultrasound is the standard technique for fetal anatomy evaluation in the United States despite international guidelines and literature that suggest that first-trimester timing may be superior in patients with obesity. First-trimester imaging performs well in cohorts of participants with obesity.
Our aim was to compare the completion rate of a first-trimester fetal anatomy ultrasound scan with that of a second-trimester fetal anatomy ultrasound scan among pregnant people with a body mass index ≥35 kg/m2.
This randomized controlled trial enrolled participants with a body mass index ≥35 kg/m2 with a singleton gestation and who presented before 14+0/7 weeks of gestation. Participants were randomized to receive an ultrasound assessment of anatomy at either 12+0/7 to 13+6/7 weeks or at 18+0/7 to 22+6/7 weeks. The primary outcome was completion rate (percentage of scans that optimally imaged all the required fetal structures). Secondary outcomes included the necessity of a transvaginal approach, completion rates for each individual view, number of anomalies identified and missed in each group, scan duration, and patient perspectives. A 1-year pilot sample was analyzed using Bayesian methods for the primary outcome with a neutral prior and frequentist analyses for the remaining outcomes.
A total of 128 participants were enrolled, and 1 withdrew consent; 62 subjects underwent a first-trimester ultrasound scan and 62 underwent a second-trimester ultrasound scan. A total of 2 participants did not attend the research visits, and 1 sought termination of pregnancy. In the first-trimester group, 66% (41/62) of ultrasound scans were completed in comparison with 53% (33/62) in the second-trimester ultrasound group (Bayesian relative risk, 1.20; 95% credible interval, 0.91-1.73). When compared with a second-trimester scan plus a follow-up ultrasound, a first-trimester ultrasound plus a second-trimester ultrasound was equally successful in completing the anatomy views (76%). First-trimester anatomy ultrasound scans required a transvaginal approach in 63% (39/62) of cases and had a longer duration than a second-trimester ultrasound scan. No anomalies were missed in either group. First-trimester ultrasound participants who responded to a survey described that they were very satisfied with the technique.
In pregnant subjects with a body mass index ≥35 kg/m2, a single first-trimester anatomy ultrasound scan was more likely to obtain all the recommended anatomic views than a single second-trimester ultrasound scan. An evaluation of anatomy at 12+0/7 to 13+6/7 weeks\' gestation plus an evaluation at 18+0/7 to 22+6/7 led to complete anatomic evaluation 4 weeks earlier than 2 second trimester scans. Assessment of ultrasound duration in a clinical setting is needed to ensure feasibility outside of a research setting.
Our aim was to compare the completion rate of a first-trimester fetal anatomy ultrasound scan with that of a second-trimester fetal anatomy ultrasound scan among pregnant people with a body mass index ≥35 kg/m2.
This randomized controlled trial enrolled participants with a body mass index ≥35 kg/m2 with a singleton gestation and who presented before 14+0/7 weeks of gestation. Participants were randomized to receive an ultrasound assessment of anatomy at either 12+0/7 to 13+6/7 weeks or at 18+0/7 to 22+6/7 weeks. The primary outcome was completion rate (percentage of scans that optimally imaged all the required fetal structures). Secondary outcomes included the necessity of a transvaginal approach, completion rates for each individual view, number of anomalies identified and missed in each group, scan duration, and patient perspectives. A 1-year pilot sample was analyzed using Bayesian methods for the primary outcome with a neutral prior and frequentist analyses for the remaining outcomes.
A total of 128 participants were enrolled, and 1 withdrew consent; 62 subjects underwent a first-trimester ultrasound scan and 62 underwent a second-trimester ultrasound scan. A total of 2 participants did not attend the research visits, and 1 sought termination of pregnancy. In the first-trimester group, 66% (41/62) of ultrasound scans were completed in comparison with 53% (33/62) in the second-trimester ultrasound group (Bayesian relative risk, 1.20; 95% credible interval, 0.91-1.73). When compared with a second-trimester scan plus a follow-up ultrasound, a first-trimester ultrasound plus a second-trimester ultrasound was equally successful in completing the anatomy views (76%). First-trimester anatomy ultrasound scans required a transvaginal approach in 63% (39/62) of cases and had a longer duration than a second-trimester ultrasound scan. No anomalies were missed in either group. First-trimester ultrasound participants who responded to a survey described that they were very satisfied with the technique.
In pregnant subjects with a body mass index ≥35 kg/m2, a single first-trimester anatomy ultrasound scan was more likely to obtain all the recommended anatomic views than a single second-trimester ultrasound scan. An evaluation of anatomy at 12+0/7 to 13+6/7 weeks\' gestation plus an evaluation at 18+0/7 to 22+6/7 led to complete anatomic evaluation 4 weeks earlier than 2 second trimester scans. Assessment of ultrasound duration in a clinical setting is needed to ensure feasibility outside of a research setting.
摘要：
目的：在美国，妊娠中期超声是胎儿解剖评估的标准技术，尽管国际指南和文献表明，肥胖患者的妊娠早期时间可能更优越。在肥胖参与者的队列中，孕早期成像表现良好。我们的目的是比较体重指数（BMI）≥35kg/m2的孕妇的早孕期胎儿解剖与孕中期胎儿解剖超声的完成率。
方法：这项随机对照试验招募了BMI≥35kg/m2且单胎妊娠的参与者，在妊娠140/7周之前出现。参与者在120/7至136/7周随机接受解剖超声评估，或在180/7到226/7周。主要结果是完成率（最佳成像所有所需胎儿结构的扫描百分比）。次要结果包括经阴道入路的必要性，每个视图的完成率，每组识别和遗漏的异常数量，扫描持续时间,和病人的观点。使用贝叶斯方法分析了为期一年的试点样本，以中性先验，以及对其余结果的频繁分析。
结果：共有128名参与者注册，1撤回同意；62例受试者接受了妊娠早期超声检查，62例接受了妊娠中期超声检查；2例未参加研究访问，1人寻求终止妊娠。在孕早期组，66％（41/62）的超声检查完成，而中期妊娠超声组的53％（33/62）（贝叶斯相对风险（RR）1.20，95％可信区间0.91-1.73）。与孕中期扫描加一次超声随访相比，妊娠早期超声加妊娠中期超声在完成解剖方面同样成功(76%).与妊娠中期超声相比，妊娠早期解剖超声在63％（39/62）的病例中需要经阴道入路，并且持续时间更长。两组均未发现异常。对一项调查做出回应的孕早期超声参与者表示，他们对这项技术非常满意。
结论：BMI>35的妊娠受试者，与单一的孕中期超声相比，单一的孕早期解剖超声更有可能获得所有推荐的解剖视图。120/7至136/7周的解剖学评估，再加上在180/7~226/7进行的评估,比2次妊娠中期扫描提前4周完成了评估.需要评估临床环境中的超声持续时间以确保研究环境之外的可行性。
方法：这项随机对照试验招募了BMI≥35kg/m2且单胎妊娠的参与者，在妊娠140/7周之前出现。参与者在120/7至136/7周随机接受解剖超声评估，或在180/7到226/7周。主要结果是完成率（最佳成像所有所需胎儿结构的扫描百分比）。次要结果包括经阴道入路的必要性，每个视图的完成率，每组识别和遗漏的异常数量，扫描持续时间,和病人的观点。使用贝叶斯方法分析了为期一年的试点样本，以中性先验，以及对其余结果的频繁分析。
结果：共有128名参与者注册，1撤回同意；62例受试者接受了妊娠早期超声检查，62例接受了妊娠中期超声检查；2例未参加研究访问，1人寻求终止妊娠。在孕早期组，66％（41/62）的超声检查完成，而中期妊娠超声组的53％（33/62）（贝叶斯相对风险（RR）1.20，95％可信区间0.91-1.73）。与孕中期扫描加一次超声随访相比，妊娠早期超声加妊娠中期超声在完成解剖方面同样成功(76%).与妊娠中期超声相比，妊娠早期解剖超声在63％（39/62）的病例中需要经阴道入路，并且持续时间更长。两组均未发现异常。对一项调查做出回应的孕早期超声参与者表示，他们对这项技术非常满意。
结论：BMI>35的妊娠受试者，与单一的孕中期超声相比，单一的孕早期解剖超声更有可能获得所有推荐的解剖视图。120/7至136/7周的解剖学评估，再加上在180/7~226/7进行的评估,比2次妊娠中期扫描提前4周完成了评估.需要评估临床环境中的超声持续时间以确保研究环境之外的可行性。
