Jamieson-Grigg Chloe, Kalinowski Pawel, Tong Stephen, Turner Esther, Banting Sarah A, Walker Susan P, MacDonald Teresa M
Department of Obstetrics, Gynaecology and Newborn Health, University of Melbourne, Melbourne, VIC, Australia.
Translational Neurodegeneration Group, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia.
BMC Med. 2025 May 28;23(1):298. doi: 10.1186/s12916-025-04117-8.
Undetected fetal growth restriction is a major risk factor for stillbirth. Detecting small babies is a cornerstone of obstetric care, but we fail to detect most uteroplacental insufficiency impairing fetal growth, and most small fetuses. Slowing fetal growth is thought to flag fetal growth restriction, but uncertainty about what constitutes poor growth has hindered clinical translation. We aim to validate slowing fetal growth velocity as a measurable risk factor for adverse pregnancy outcomes, and to better define growth velocity assessment to aid clinical interpretation.
We performed a retrospective cohort study of ultrasound and birth outcome data. All patients with singleton pregnancies and at least two ultrasound fetal size assessments between 18 and 39 weeks, from January 2009 to May 2022, were included. Universal third trimester ultrasound is not performed at our institution; hence, all pregnancies were referred for at least one scan. Primary outcomes were perinatal mortality (stillbirth or neonatal death) and a composite of adverse perinatal outcomes. Fetal growth velocity was calculated between first and last scans, standardized as exact estimated fetal weight (EFW) z-score change per week.
Among 24,395 pregnancies, most first scans were routine mid-trimester ultrasounds (median 20 weeks), with a median 12 weeks between first and last scans. Each z-score/week reduction in EFW growth rate increased perinatal mortality 23-fold (odds ratio (OR) (95% confidence interval (CI)) = 23.25 (7.03-66.45), p < 10), and adverse perinatal outcome 17-fold (OR (95% CI) = 17.54 (12.93-23.84), p < 10). Slowing fetal growth as EFW z-score change/week was associated with adverse perinatal outcome even among those with fetal size considered normal (Hadlock EFW ≥ 10th centile) at last scan, and when confined to term births (OR (95% CI) = 2.35 (1.66-3.33), p < 10; OR (95% CI) = 3.17 (2.10-4.76), p < 10, respectively). A growth rate cut-off of - 0.13 EFW z-scores/week was identified as optimal for perinatal mortality by Youden Index. Growth slower than this was associated with sixfold increased odds of perinatal death (OR (95% CI) = 6.40 (3.91-10.30), p < 10).
Slowing fetal growth velocity identifies pregnancies at increased risk of poor outcomes. A slowing growth rate < - 0.13 z-scores/week may represent a pragmatic clinical threshold. Fetal growth rate between scans could be incorporated into ultrasound reporting to better identify fetuses at risk.
未被检测出的胎儿生长受限是死产的主要危险因素。检测出胎儿较小是产科护理的基石，但我们未能检测出大多数损害胎儿生长的子宫胎盘功能不全情况以及大多数较小的胎儿。胎儿生长放缓被认为是胎儿生长受限的标志，但对于何为生长不良尚无定论，这阻碍了其临床应用。我们旨在验证胎儿生长速度放缓作为不良妊娠结局的可测量风险因素，并更好地定义生长速度评估方法以辅助临床解读。
我们对超声和出生结局数据进行了一项回顾性队列研究。纳入了2009年1月至2022年5月间所有单胎妊娠且在18至39周期间至少有两次超声胎儿大小评估的患者。我们机构不进行常规的孕晚期超声检查；因此，所有妊娠均至少转诊进行了一次扫描。主要结局是围产期死亡率（死产或新生儿死亡）以及不良围产期结局的综合指标。在首次和末次扫描之间计算胎儿生长速度，并标准化为每周精确估计胎儿体重（EFW）z评分的变化。
在24395例妊娠中，大多数首次扫描是常规的孕中期超声检查（中位时间为20周），首次和末次扫描之间的中位间隔时间为12周。EFW生长率每降低一个z评分/周，围产期死亡率增加23倍（优势比（OR）（95%置信区间（CI））=23.25（7.03 - 66.45），p < 0.001），不良围产期结局增加17倍（OR（95% CI）=17.54（12.93 - 23.84），p < 0.001）。即使在末次扫描时胎儿大小被认为正常（Hadlock EFW≥第10百分位数）的人群中，以及仅限于足月分娩的人群中，以EFW z评分变化/周表示的胎儿生长放缓与不良围产期结局相关（OR（95% CI）分别为2.35（1.66 - 3.33），p < 0.001；OR（95% CI）为3.17（2.10 - 4.76），p < 0.001）。通过约登指数确定，每周-0.13 EFW z评分的生长率截断值对于围产期死亡率而言是最优的。生长速度慢于该值与围产期死亡几率增加6倍相关（OR（95% CI）=6.40（3.91 - 10.30），p < 0.001）。
胎儿生长速度放缓可识别出不良结局风险增加的妊娠。生长速度放缓< -0.13 z评分/周可能代表一个实用的临床阈值。两次扫描之间的胎儿生长速度可纳入超声报告中，以更好地识别有风险的胎儿。
