Farsetti Daniele, Barbieri Moira, Magni Elena, Zamagni Giulia, Monasta Lorenzo, Maso Gianpaolo, Vasapollo Barbara, Pometti Francesca, Ferrazzi Enrico Maria, Lees Christoph, Valensise Herbert, Stampalija Tamara
Department of Surgical Sciences, University of Rome Tor Vergata, Rome, Italy; Department of Obstetrics and Gynecology, Policlinico Casilino, Rome, Italy.
Unit of Obstetrics, Division of Obstetrics and Gynecology, Department of Woman, Child, and Newborn, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
Am J Obstet Gynecol. 2025 Jul;233(1):66.e1-66.e14. doi: 10.1016/j.ajog.2025.01.001. Epub 2025 Jan 4.
Identifying fetal growth restriction and distinguishing it from a constitutionally small fetus can be challenging. The umbilical vein blood flow is a surrogate parameter of the amount of oxygen and nutrients delivered to the fetus, providing valuable insights about the function of the placenta. Nevertheless, currently, this parameter is not used in the diagnosis and management of fetal growth restriction.
To evaluate the umbilical vein blood flow and fetal growth velocity in small for gestational age fetuses and in fetal growth restriction, and to evaluate their capacity to predict adverse perinatal outcome and iatrogenic preterm birth. Secondly, to assess the correlation between umbilical vein blood flow and fetal growth velocity.
This was a prospective multicentric observational cohort study of women with a diagnosis of small for gestational age or fetal growth restriction in which fetal biometry and Doppler assessment, including umbilical vein blood flow measurement, were performed. The fetal growth velocity was derived from the difference between the estimated fetal weight calculated in 2 consecutive sonographic evaluations. The pregnancies were followed until delivery. Between-group differences were evaluated, and Pearson or Spearman correlation coefficients were reported to assess the relationship between variables of interest. Optimal cutoffs on the resulting receiver operating characteristic curve were determined and used to predict the outcomes of interest. Simple and multiple logistic regression models were estimated using umbilical vein blood flow and fetal growth velocity to predict adverse perinatal outcomes and iatrogenic preterm birth.
The study population included 64 small for gestational age and 58 growth restricted fetuses. When compared to reference ranges, small for gestational age fetuses had significantly lower fetal growth velocity and umbilical vein blood flow (P<.001). When compared to small for gestational age, fetuses with growth restriction had lower umbilical vein blood flow (P<.001), umbilical vein blood flow corrected for estimated fetal weight and abdominal circumference (P<.01 and P<.001), and fetal growth velocity (P<.001). Fetal growth velocity was positively correlated with umbilical vein blood flow (r=0.46, P<.001). The multivariable logistic regression analyses showed that, after adjusting for diagnosis of fetal growth restriction, umbilical vein blood flow ≤0.65 multiple of the median (adjusted odds ratio [aOR] 3.5; 95% confidence interval [CI] 1.0-11.8) and fetal growth velocity ≤0.63 multiple of the median (adjusted odds ratio 3.0, 95% CI 1.2-7.9) were associated with adverse perinatal outcome. Furthermore, when accounting for fetal growth restriction diagnosis, umbilical vein blood flow ≤0.60 multiple of the median (adjusted odds ratio 5.2, 95% CI 1.7-15.9), and fetal growth velocity ≤0.63 multiple of the median (adjusted odds ratio 3.6, 95% CI 1.1-12.6) were significant predictors of iatrogenic preterm birth.
Umbilical vein blood flow could play a role to identify fetuses with fetal growth restriction and to predict fetal growth at the subsequent biometric evaluation. We found a significant correlation between umbilical vein blood flow and fetal growth. Umbilical vein blood flow and fetal growth velocity are independent predictors of iatrogenic preterm birth and adverse perinatal outcome in a population of small fetuses, regardless of the Delphi consensus criteria. These results support future study on the predictive value of this parameter in fetuses with a suspected fetal growth restriction.
识别胎儿生长受限并将其与体质性小胎儿区分开来可能具有挑战性。脐静脉血流是输送给胎儿的氧气和营养物质数量的替代参数，能为胎盘功能提供有价值的见解。然而，目前该参数未用于胎儿生长受限的诊断和管理。
评估小于胎龄胎儿和胎儿生长受限中的脐静脉血流及胎儿生长速度，并评估它们预测不良围产期结局和医源性早产的能力。其次，评估脐静脉血流与胎儿生长速度之间的相关性。
这是一项前瞻性多中心观察性队列研究，研究对象为诊断为小于胎龄或胎儿生长受限的女性，对其进行胎儿生物测量和多普勒评估，包括脐静脉血流测量。胎儿生长速度源自连续两次超声评估计算出的估计胎儿体重之差。对这些妊娠进行随访直至分娩。评估组间差异，并报告Pearson或Spearman相关系数以评估感兴趣变量之间的关系。确定所得受试者工作特征曲线上的最佳截断值，并用于预测感兴趣的结局。使用脐静脉血流和胎儿生长速度估计简单和多元逻辑回归模型，以预测不良围产期结局和医源性早产。
研究人群包括64例小于胎龄胎儿和58例生长受限胎儿。与参考范围相比，小于胎龄胎儿的胎儿生长速度和脐静脉血流显著更低（P<0.001）。与小于胎龄胎儿相比，生长受限胎儿的脐静脉血流更低（P<0.001），校正估计胎儿体重和腹围后的脐静脉血流更低（P<0.01和P<0.001），胎儿生长速度也更低（P<0.001）。胎儿生长速度与脐静脉血流呈正相关（r = 0.46，P<0.001）。多变量逻辑回归分析显示，在调整胎儿生长受限诊断后，脐静脉血流≤中位数的0.65倍（调整优势比[aOR] 3.5；95%置信区间[CI] 1.0 - 11.8）和胎儿生长速度≤中位数的0.63倍（调整优势比3.0，95% CI 1.2 - 7.9）与不良围产期结局相关。此外，在考虑胎儿生长受限诊断时，脐静脉血流≤中位数的0.60倍（调整优势比5.2，95% CI 1.7 - 15.9）和胎儿生长速度≤中位数的0.63倍（调整优势比3.6，95% CI 1.1 - 12.6）是医源性早产的显著预测因素。
脐静脉血流在识别胎儿生长受限胎儿及预测后续生物测量评估中的胎儿生长方面可能发挥作用。我们发现脐静脉血流与胎儿生长之间存在显著相关性。无论德尔菲共识标准如何，在小胎儿群体中，脐静脉血流和胎儿生长速度是医源性早产和不良围产期结局的独立预测因素。这些结果支持未来对该参数在疑似胎儿生长受限胎儿中的预测价值进行研究。
