Department of Obstetrics and Gynecology, Spitäler Schaffhausen, Schaffhausen, Switzerland.
Department of Obstetrics, University Hospital of Zurich, Zürich, Switzerland.
Arch Gynecol Obstet. 2022 Dec;306(6):1923-1928. doi: 10.1007/s00404-022-06489-1. Epub 2022 Mar 4.
To find a method that could improve the accuracy of fHC evaluation at term.
This retrospective cohort study was based on data from the University Hospital of Zürich (USZ). Study population included singleton fetuses and newborns at term between 2015 and 2017. Fetal biometry was performed within 1 week prior to delivery. Study data consisted of two cohorts with 200 ultrasound measurements each: 200 performed by an expert, 200 by residents. fHC were compared with the newborn's head circumference (nHC). fHC was estimated using two methods: (1) fHC based on sonographically estimated frontooccipital diameter (FOD) and biparietal diameter (BPD). (2) Expected FOD was calculated as a fixed mean FOD/BPD relation, derived from biometry standards as the 50th percentile. If BPD was < 99 mm, FOD was calculated according to the formula BPD × 1.268557, If BPD was ≥ 99 mm, FOD was calculated according to the formula BPD × 1.20641443.
fHC was underestimated compared with nHC in the expert group: percentage error (PE = - 3.68%, SD = 2.79), as well as in the group of residents (PE = - 3.78%, SD = 3.20) using method 1. fHC measurement was significantly more accurate using method 2. In the expert group PE = - 1.17%, SD = 3.08, in the group of residents PE = - 0.95%, SD = 3.33. Bland-Altman analysis showed limits of agreement (LOA) between - 2.41338 and 0.5537828 cm for fHC.
Accuracy of fHC estimation could be improved by extrapolation of FOD when real-time FOD cannot be measured.
寻找一种能够提高足月时胎儿头围（fetal head circumference，fHC）评估准确性的方法。
本回顾性队列研究基于苏黎世大学医院（University Hospital of Zürich，USZ）的数据。研究人群包括 2015 年至 2017 年间足月的单胎胎儿和新生儿。胎儿生物测量在分娩前 1 周内进行。研究数据包括两个队列，每个队列有 200 次超声测量：由专家进行的 200 次测量，由住院医师进行的 200 次测量。fHC 与新生儿头围（nHC）进行比较。fHC 采用两种方法进行估计：（1）基于超声估计的额枕径（frontooccipital diameter，FOD）和双顶间径（biparietal diameter，BPD）的 fHC。（2）预期 FOD 是根据作为第 50 百分位数的生物测量标准得出的固定平均 FOD/BPD 关系计算得出。如果 BPD<99mm，则根据公式 BPD×1.268557 计算 FOD；如果 BPD≥99mm，则根据公式 BPD×1.20641443 计算 FOD。
与专家组的 nHC 相比，使用方法 1 时，fHC 低估了 nHC（百分比误差[percentage error，PE] =-3.68%，标准差[standard deviation，SD]=2.79%），在住院医师组中也是如此（PE=-3.78%，SD=3.20%）。使用方法 2 时，fHC 测量更准确。在专家组中，PE=-1.17%，SD=3.08%，在住院医师组中，PE=-0.95%，SD=3.33%。Bland-Altman 分析显示 fHC 的 LOA 为-2.41338 至 0.5537828cm。
通过实时无法测量 FOD 时的 FOD 外推，可以提高 fHC 估计的准确性。
