Emam Doaa, Corbella Giulia, Poziello Caterina, Fabozzo Simona, Farina Antonio, Candiani Massimo, Kagan Karl Oliver, Cavoretto Paolo Ivo
Department of Obstetrics and Gynaecology, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy.
Department of Gynecology and Obstetrics, University Hospitals Tanta, Tanta, Egypt.
Arch Gynecol Obstet. 2025 Sep 8. doi: 10.1007/s00404-025-08172-7.
Recommendations regarding the use of third-trimester ultrasound lack universal consensus. Yet, there is evidence which supports its value in assessing fetal growth, fetal well-being, and a number of pregnancy-related complications. This literature review evaluates the available scientific evidence regarding its applications, usefulness, and the timing of the third-trimester scan in a low-risk population.
A literature search (PubMed, Embase, Scopus; until April 1st, 2025) identified English-language studies dealing with third-trimester ultrasound screening, its aims, and its best timing. International and national guidelines were reviewed to assess the current recommendations. Large, high-quality studies were then used to evaluate the completeness of the current recommendations and to analyze additional parameters that could be considered when assessing the usefulness of a third-trimester ultrasound screening.
Six international and national sets of guidelines regarding the third-trimester ultrasound were analyzed, showing wide variability in recommendations. While all six support its use, mainly for fetal growth, amniotic fluid, and placental assessment, only ISUOG and SIEOG specify the gestational age at which it should be performed (32-36 weeks). Fetal biometry and anatomy are universally suggested, while recommendations for Doppler studies, biophysical profile, and cervical length are inconsistent. Newer applications, such as pre-eclampsia screening and prediction of labor onset and intrapartum complications, are not yet included. Recent major studies in low-risk populations suggest 36-week gestation as the optimal screening time.
There is a broad recognition of third-trimester ultrasound being useful for fetal monitoring, but consensus is lacking regarding its routine use in low-risk populations, its outcomes and timing. Major evidence supports ultrasound screening at 36-week gestation in low-risk pregnancies to predict fetal growth restriction, macrosomia, structural anomalies, complications due to placental abnormalities, pre-eclampsia and onset of labor. When preceded by effective risk stratification done earlier in pregnancy, this strategy may enhance pregnancy management potentially improving maternal-fetal outcomes.
关于孕晚期超声检查的使用建议尚未达成普遍共识。然而，有证据支持其在评估胎儿生长、胎儿健康状况以及一些与妊娠相关并发症方面的价值。本综述评估了关于其在低风险人群中的应用、实用性以及孕晚期超声检查时机的现有科学证据。
进行文献检索（截至2025年4月1日的PubMed、Embase、Scopus），以识别涉及孕晚期超声筛查、其目的及最佳时机的英文研究。查阅国际和国家指南以评估当前建议。然后使用大型高质量研究来评估当前建议的完整性，并分析在评估孕晚期超声筛查的实用性时可考虑的其他参数。
分析了六套关于孕晚期超声的国际和国家指南，结果显示建议存在很大差异。虽然所有六套指南都支持使用孕晚期超声，主要用于评估胎儿生长、羊水和胎盘情况，但只有国际妇产科超声学会（ISUOG）和西班牙妇产科和产科学会（SIEOG）明确规定了进行检查的孕周（32 - 36周）。普遍建议进行胎儿生物测量和解剖学检查，而关于多普勒研究、生物物理评分和宫颈长度的建议则不一致。子痫前期筛查以及分娩发动和产时并发症预测等新应用尚未纳入其中。近期在低风险人群中的主要研究表明，妊娠36周是最佳筛查时间。
人们普遍认识到孕晚期超声对胎儿监测有用，但对于其在低风险人群中的常规使用、结果及检查时机缺乏共识。主要证据支持在低风险妊娠中于妊娠36周进行超声筛查，以预测胎儿生长受限、巨大儿、结构异常、胎盘异常引起的并发症、子痫前期和分娩发动。若在妊娠早期进行有效的风险分层后实施该策略，可能会改善妊娠管理，潜在地改善母胎结局。
