Icahn School of Medicine at Mount Sinai, NY, NY, USA.
Icahn School of Medicine at Mount Sinai, NY, NY, USA.
Eur J Obstet Gynecol Reprod Biol. 2024 Oct;301:77-81. doi: 10.1016/j.ejogrb.2024.08.001. Epub 2024 Aug 3.
Cell-free fetal DNA (cffDNA) screening is routinely performed in pregnancy. Abnormal fetal fraction has been associated with adverse pregnancy outcomes, including hypertensive disorders of pregnancy, which are associated with severe maternal and neonatal morbidity and mortality.
This study examined whether abnormal fetal fraction, defined in this study as fetal fraction either <6 or >15 on the basis of restricted-cubic-spline-plot within our study population, was associated with HDP in a retrospective sample, as well as whether fetal fraction improves the prediction of hypertensive disorders of pregnancy (HDP). We hypothesized that abnormal fetal fraction would be associated with HDP and that adding fetal fraction to a model would significantly improve its strength to predict HDP.
This was a retrospective cohort study of 729 patients delivering singleton, non-anomalous pregnancies with conclusive cffDNA screening. The primary outcome was HDP. Logistic regression models tested associations between fetal fraction and HDP. We evaluated the impact of including fetal fraction on the prediction of hypertensive disorders of pregnancy (HDP) by comparing the area under the receiver operating characteristic (ROC) curve (AUC) between predictive models with and without fetal fraction.
Among the study sample, there was an HDP rate of 11.5 %. Abnormal fetal fraction was defined as <6 % percentile and >15 %, HDP incidence was significantly higher in patients with fetal fraction <6 % compared to patients with fetal fraction in normal range (fetal fraction 6-15 %) (19.5 % vs 10.7 %, p = 0.006 on post hoc comparison). Model 1 had one predictor (fetal fraction) with an AUC of 0.59, Model 2 had three predictors (BMI, nulliparity, history of HDP) with an AUC of 0.71, and Model 3 had four predictors (BMI, nulliparity, history of HDP, and fetal fraction) with an AUC of 0.73. Models 2 and 3 were not significantly different (p = 0.18).
More patients who developed HDP had low fetal fraction and fewer patients who developed HDP had high fetal fraction compared to those patients who did not develop HDP. Based on results from multivariable regression models, we cannot conclude that fetal fraction improves HDP prediction. However, developing standardized values for abnormal fetal fraction may be clinically useful.
游离胎儿 DNA（cffDNA）筛查在妊娠中常规进行。异常胎儿比例与不良妊娠结局相关，包括妊娠高血压疾病，这与严重的母婴发病率和死亡率相关。
本研究在回顾性样本中检查了异常胎儿比例（本研究中定义为根据我们研究人群中的受限立方样条图，胎儿比例<6 或>15）是否与 HDP 相关，以及胎儿比例是否改善妊娠高血压疾病（HDP）的预测。我们假设异常胎儿比例与 HDP 相关，并且将胎儿比例添加到模型中会显著提高其预测 HDP 的强度。
这是一项回顾性队列研究，纳入了 729 名分娩单胎、非异常妊娠且 cffDNA 筛查结果明确的患者。主要结局是 HDP。逻辑回归模型测试了胎儿比例与 HDP 之间的关联。我们通过比较有无胎儿比例的预测模型之间接受者操作特征（ROC）曲线下面积（AUC），评估了包括胎儿比例对妊娠高血压疾病（HDP）预测的影响。
在研究样本中，HDP 发生率为 11.5%。异常胎儿比例定义为<6%百分位数和>15%，与胎儿比例在正常范围内（胎儿比例 6-15%）的患者相比，胎儿比例<6%的患者 HDP 发生率显著更高（19.5%比 10.7%，p=0.006 事后比较）。模型 1 有一个预测因子（胎儿比例），AUC 为 0.59，模型 2 有三个预测因子（BMI、初产妇、HDP 史），AUC 为 0.71，模型 3 有四个预测因子（BMI、初产妇、HDP 史和胎儿比例），AUC 为 0.73。模型 2 和模型 3 之间无显著差异（p=0.18）。
与未发生 HDP 的患者相比，发生 HDP 的患者中更多的患者胎儿比例较低，而发生 HDP 的患者中胎儿比例较高的患者较少。基于多变量回归模型的结果，我们不能得出胎儿比例可改善 HDP 预测的结论。然而，为异常胎儿比例制定标准化值可能具有临床意义。
