Department of Obstetrics and Gynecology, Süleyman Demirel University Faculty of Medicine, Isparta, Turkey.
Obstetrics and Gynecology Clinic, Buca Women's and Children's Diseases Hospital, Izmir, Turkey.
Gynecol Obstet Invest. 2021;86(1-2):94-99. doi: 10.1159/000512749. Epub 2021 Jan 20.
Fractional thigh volume (TVol) and fractional arm volume (AVol) measurements by three-dimensional (3D) ultrasound can reveal valuable information on fetal soft tissue development. However, it is not clear whether TVol or AVol provides better estimates of fetal body proportion and adiposity, independent of routine two-dimensional (2D) ultrasound biometry. The primary objective of the current study was to determine the correlations between fractional limb volumes (FLVs) and neonatal anthropometric parameters.
In this cross-sectional study, fetal FLVs were obtained within 24 h before term delivery from 40 medically and obstetrically uncomplicated pregnancies scheduled for elective cesarean section. TVol and AVol were determined using offline software. Postnatal morphometric data including birth weight; crown-heel, arm, and leg lengths; head, abdominal, mid-thigh, and mid-arm circumferences; and anterior thigh, biceps, and subscapular skinfold thicknesses were obtained. Pearson and partial correlation analyses were used to determine the relationships across antenatal volume calculations and neonatal indices. Correlation coefficients (r) were calculated.
Mean maternal age, BMI, and parity were 29.1 ± 5.4 years, 29.7 ± 3.5 kg/m2, and 1.0 ± 1.3, respectively. AVol showed moderate correlations with most of the neonatal parameters, including mid-thigh circumference (r = 0.683), mid-arm circumference (r = 0.627), birth weight (r = 0.583), head circumference (HC, r = 0.560), and abdominal circumference (r = 0.542). However, TVol was weakly related to only some of the indices. After controlling for gestational age, maternal age, BMI, parity, and 2D ultrasound biometry, TVol was no longer associated with any of the parameters, while AVol was independently correlated with mid-thigh (r = 0.724) and mid-arm circumference (r = 0.560), birth weight (r = 0.502), ponderal index (r = 0.402), HC (r = 0.382), biceps (r = 0.384), and subscapular skinfold thickness (r = 0.350).
The current design includes limited number of pregnancies with only scheduled cesarean deliveries. Neonatal percent body fat was not calculated, and air-displacement plethysmography was not used to assess neonatal body composition. The study population was Caucasian with a relatively high maternal BMI, which may limit extrapolation of the results to other settings.
AVoL measurements by 3D ultrasound before delivery are significantly correlated with most of the neonatal morphometric indices, independent of maternal characteristics and 2D biometric parameters. AVol may have advantages over TVol for assessing limb soft tissue development in term fetuses. Future research can focus on feasibility and predictive ability of AVol measurements in prospective studies that include serial biometry over time.
通过三维（3D）超声测量胎儿的大腿体积（TVol）和手臂体积（AVol）可以提供有价值的胎儿软组织发育信息。然而，目前尚不清楚 TVol 或 AVol 能否更好地估计胎儿的身体比例和肥胖程度，而不受常规二维（2D）超声生物测量的影响。本研究的主要目的是确定胎儿四肢体积（FLV）与新生儿人体测量参数之间的相关性。
在这项横断面研究中，在计划择期剖宫产的 40 例医学和产科上无并发症的妊娠中，在分娩前 24 小时内通过离线软件获得胎儿的 FLV。测量 TVol 和 AVol。获取出生后形态学数据，包括出生体重；头臀长、手臂和腿长；头、腹、大腿和上臂围；前大腿、肱二头肌和肩胛下皮褶厚度。采用 Pearson 和偏相关分析来确定产前体积计算和新生儿指数之间的关系。计算相关系数（r）。
平均母亲年龄、BMI 和产次分别为 29.1±5.4 岁、29.7±3.5kg/m2 和 1.0±1.3。AVol 与大多数新生儿参数呈中度相关，包括大腿围（r=0.683）、上臂围（r=0.627）、出生体重（r=0.583）、头围（HC，r=0.560）和腹围（r=0.542）。然而，TVol 仅与部分指数呈弱相关。在校正胎龄、母亲年龄、BMI、产次和 2D 超声生物测量后，TVol 与任何参数均无相关性，而 AVol 与大腿围（r=0.724）和上臂围（r=0.560）、出生体重（r=0.502）、体重指数（r=0.402）、HC（r=0.382）、肱二头肌（r=0.384）和肩胛下皮褶厚度（r=0.350）独立相关。
目前的设计包括仅计划剖宫产的有限数量的妊娠。未计算新生儿体脂百分比，也未使用空气置换体描仪评估新生儿的身体成分。研究人群为白种人，母亲 BMI 相对较高，这可能限制了结果在其他环境中的推广。
分娩前通过 3D 超声测量 AVoL 与大多数新生儿形态学指数显著相关，不受母亲特征和 2D 生物测量参数的影响。在评估足月胎儿四肢软组织发育方面，AVol 可能优于 TVol。未来的研究可以集中在包括随时间进行多次生物测量的前瞻性研究中，对 AVoL 测量的可行性和预测能力进行研究。
