孕16-36周MRI胎盘体积及胎盘-胎儿体积比的正常参考范围：前瞻性研究
本研究为单中心前瞻性研究，纳入247例健康单胎孕妇的265个MRI数据集，建立孕16-36周胎盘体积（PV）和胎盘-胎儿体积比（PFR）的MRI正常百分位曲线。PV从16周均值149 cm³增至36周890 cm³，PFR从1.22降至0.31，提示PFR随孕周进展生理性下降。这些基准可能有助于检测胎盘功能障碍和描述胎儿生长受限。
要点
- 孕16-36周PV和PFR的MRI正常百分位曲线可用于评估胎盘生长。
- PFR随孕周进展生理性下降，从16周1.22降至36周0.31。
- PV增长呈对数回归模型，PFR变化呈二次项模型。
核心结论
- 研究建立了孕16-36周基于MRI的PV和PFR正常百分位曲线，证实PFR随孕周进展生理性下降。
研究设计与样本
- 单中心前瞻性研究，纳入247例健康低风险单胎孕妇的265个MRI数据集，孕周16-36周。
- MRI采用标准化协议，使用三维成像软件分割胎盘和胎儿体积。
- 胎儿平均体积来自同一队列先前发表的基于MRI的正常数据集。
诊断标准与关键数值
- PV均值从16周149 cm³增至36周890 cm³，增长函数为PV(GA)=(911.3×ln(GA))-2375.7，GA单位为周。
- PFR均值从16周1.22降至36周0.31，关系模型为PFR(GA)=4.03-(0.215×GA)+(0.00313×GA²)，GA单位为周。
- 生成了PV和PFR的百分位曲线。
临床应用与阅片要点
- 可将PV和PFR的MRI百分位曲线用于日常阅片，辅助识别胎盘功能障碍和胎儿生长受限。
- 注意本研究基于健康低风险单胎人群，应用于病理妊娠和多胎妊娠需进一步验证。
局限性
- 单中心研究，样本来自健康低风险单胎孕妇，结论外推至病理妊娠和多胎妊娠需进一步验证。
- 胎儿平均体积来自同一队列先前发表的数据集，非同步测量。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
英文原文（摘要）· 点击展开
OBJECTIVE: The placenta plays a crucial role in fetal development, yet normal placental volumetric growth trajectories remain poorly characterized, as most studies focus on pathological pregnancies or limited gestational-age (GA) ranges. We aimed to establish magnetic reference imaging (MRI)-based normative reference curves for placental volume (PV) and the placental-to-fetal-volume ratio (PFR) between 16 and 36 weeks' gestation.
METHODS: This single-center, prospective study conducted as part of the 'LUMIERE on the Fetus' project included healthy pregnant women with a low-risk, singleton, 16-36-week fetus evaluated between December 2021 and June 2022. Additional participants with MRI data available at 16 weeks were recruited between January 2023 and October 2025. MRI was performed using a standardized protocol, and placental and fetal volumes were segmented using three-dimensional imaging software. Mean fetal body volume across 16-36 weeks was derived from our previously published normative MRI-based dataset obtained from the same cohort. Mean PV and PFR were calculated for each week of gestation. PV growth across gestation was modeled using logarithmic regression, while PFR growth was modeled using a quadratic term, and percentile curves were generated.
RESULTS: The study cohort comprised 265 MRI datasets from 247 healthy pregnant women with a singleton fetus. Mean PV increased from 149 cm3 at 16 weeks to 890 cm3 at 36 weeks, following the function: PV(GA) = (911.3 × ln(GA)) - 2375.7, where GA is in weeks. Over the same period, fetal body volume increased 22-fold, leading to a progressive decline in PFR. Specifically, mean PFR decreased from 1.22 at 16 weeks to 0.31 at 36 weeks, confirming its downward trajectory as fetal growth progresses. The relationship between PFR and GA was modeled using the quadratic function: PFR(GA) = 4.03 - (0.215 × GA) + (0.00313 × GA2), where GA is in weeks.
CONCLUSION: This study establishes MRI-based normative percentile curves for PV and PFR, from 16 to 36 weeks' gestation, confirming the physiological decline in PFR with advancing gestation. These benchmarks may aid in detecting placental dysfunction and characterizing fetal growth restriction. Further validation is needed in pathological and multiple pregnancies. © 2026 International Society of Ultrasound in Obstetrics and Gynecology.
引用
- Bouachba A, Bartin R, Virfollet J, et al. Normative ranges of MRI-based placental volume and placental-to-fetal-volume ratio at 16-36 weeks: prospective study. Ultrasound Obstet Gynecol. 2026. PMID: 41987663. doi:10.1002/uog.70226
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。