Fitiri M, Papavasileiou D, Mesaric V, Syngelaki A, Akolekar R, Nicolaides K H
Fetal Medicine Research Institute, King's College Hospital, London, UK.
Fetal Medicine Unit, Medway Maritime Hospital, Gillingham, UK.
Ultrasound Obstet Gynecol. 2025 Feb;65(2):154-162. doi: 10.1002/uog.29139. Epub 2024 Dec 2.
First, to report the incidence of non-cephalic presentation at a routine 36-week ultrasound scan, the uptake and success of external cephalic version (ECV) and the incidence of spontaneous rotation from non-cephalic to cephalic presentation. Second, to determine the maternal and pregnancy characteristics that provide a significant contribution to the prediction of non-cephalic presentation at the 36-week scan, successful ECV from non-cephalic to cephalic presentation and spontaneous rotation from non-cephalic to cephalic presentation.
This was a retrospective analysis of prospectively collected data from 107 875 women with a singleton pregnancy who had undergone a routine ultrasound scan at 35 + 0 to 36 + 6 weeks' gestation. Patients with breech or transverse/oblique presentation were divided into two groups: those scheduled for elective Cesarean section for a fetal or maternal indication other than abnormal presentation, and those that would potentially require ECV. The latter group was reassessed after 1-2 weeks and, if the abnormal presentation persisted, the parents were offered ECV or elective Cesarean section at 38-40 weeks' gestation. Multivariable logistic regression analysis was carried out to determine which maternal and pregnancy characteristics provided a significant contribution in the prediction of non-cephalic presentation at the 36-week scan, successful ECV from non-cephalic to cephalic presentation and spontaneous rotation from non-cephalic to cephalic presentation.
At the 36-week scan, fetal presentation was cephalic in 101 664 (94.2%) pregnancies and either breech, transverse or oblique in 6211 (5.8%). In 0.3% of cases with cephalic presentation at the 36-week scan, there was subsequent spontaneous rotation to non-cephalic presentation, and in half of these, the diagnosis was made during labor or at birth. ECV was attempted in 1584/6211 (25.5%) pregnancies with non-cephalic presentation at the 36-week scan and was successful in only 44.1% of cases. In the remaining 74.5% of cases, ECV was not attempted because of any of the following reasons: ECV was declined; Cesarean section was planned for a reason other than abnormal presentation; ECV was planned for the subsequent 1-2 weeks but, in the meantime, there was spontaneous rotation to cephalic presentation; or there was spontaneous onset of labor or rupture of membranes before planned ECV. In 5513/6211 (88.8%) pregnancies with non-cephalic presentation at the 36-week scan, ECV was not attempted or was unsuccessful, and in 37.7% of these, there was subsequent spontaneous rotation to cephalic presentation. Among the 6211 pregnancies with non-cephalic presentation at the 36-week scan, the presentation at birth was cephalic in 43.8%; in 74.8%, this was due to spontaneous rotation, and in 25.2%, it was due to successful ECV. Multivariable analysis demonstrated that the likelihood of non-cephalic presentation at the 36-week scan, that of successful ECV and that of spontaneous rotation from non-cephalic to cephalic presentation was affected by several maternal and pregnancy characteristics, but the predictive performance for these events was poor, with the area under the receiver-operating-characteristics curve ranging from 0.608 to 0.717 and the detection rate at a 10% false-positive rate ranging from 19.0% to 33.7%.
Routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation could improve pregnancy outcome by substantially reducing the risk of unexpected abnormal presentation in labor. However, an additional ultrasound scan for fetal presentation should be considered in all women when they present in labor. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
第一，报告在孕36周常规超声检查时非头位的发生率、外倒转术（ECV）的接受率及成功率，以及非头位自发转为头位的发生率。第二，确定对预测孕36周超声检查时非头位、非头位成功转为头位的ECV以及非头位自发转为头位有显著贡献的母体和妊娠特征。
这是一项对107875名单胎妊娠女性前瞻性收集数据的回顾性分析，这些女性在妊娠35⁺⁰至36⁺⁶周时接受了常规超声检查。臀位或横位/斜位的患者分为两组：因胎儿或母体指征（而非胎位异常）计划择期剖宫产的患者，以及可能需要ECV的患者。后一组在1 - 2周后重新评估，如果异常胎位持续存在，在妊娠38 - 40周时为其父母提供ECV或择期剖宫产。进行多变量逻辑回归分析，以确定哪些母体和妊娠特征对预测孕36周超声检查时的非头位、非头位成功转为头位的ECV以及非头位自发转为头位有显著贡献。
在孕36周超声检查时，101664例（94.2%）妊娠为头位，6211例（5.8%）为臀位、横位或斜位。在孕36周超声检查时为头位的病例中，0.3%随后自发转为非头位，其中一半在分娩期间或出生时确诊。在孕36周超声检查时为非头位的1584/6211例（25.5%）妊娠中尝试了ECV，仅44.1%的病例成功。在其余74.5%的病例中，未尝试ECV的原因如下：拒绝ECV；因胎位异常以外的原因计划剖宫产；计划在随后1 - 2周进行ECV，但在此期间自发转为头位；或在计划的ECV前自发临产或胎膜破裂。在孕36周超声检查时为非头位的5513/6211例（88.8%）妊娠中，未尝试ECV或ECV未成功，其中37.7%随后自发转为头位。在孕36周超声检查时为非头位的6211例妊娠中，43.8%出生时为头位；其中74.8%是由于自发转位，25.2%是由于ECV成功。多变量分析表明，孕36周超声检查时非头位、ECV成功以及非头位自发转为头位的可能性受多种母体和妊娠特征影响，但对这些事件的预测性能较差，受试者操作特征曲线下面积为0.608至0.717，假阳性率为10%时的检测率为19.0%至33.7%。
在妊娠35⁺⁰至36⁺⁶周进行常规超声检查可通过大幅降低分娩时意外异常胎位的风险来改善妊娠结局。然而，所有临产女性均应考虑额外进行一次胎儿胎位超声检查。© 2024作者。《妇产科超声》由约翰·威利父子有限公司代表国际妇产科超声学会出版。
