Rolnik D L, O'Gorman N, Fiolna M, van den Boom D, Nicolaides K H, Poon L C
Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
Ultrasound Obstet Gynecol. 2015 Jan;45(1):106-11. doi: 10.1002/uog.14671. Epub 2014 Dec 4.
To examine whether maternal plasma concentrations of total cell-free (cf)DNA and fetal fraction at 11-13 and 20-24 weeks' gestation in pregnancies that subsequently develop pre-eclampsia (PE) are different from those without this complication.
Total cfDNA and fetal fraction were measured in 20 cases of early PE requiring delivery at < 34 weeks, in 20 cases of late PE with delivery at ≥ 34 weeks and in 200 normotensive controls, at 11-13 and 20-24 weeks' gestation. Total cfDNA and fetal fraction measured at 11-13 weeks were converted to multiples of the median (MoM), corrected for maternal characteristics and gestational age. The distributions of total cfDNA and fetal fraction at 20-24 weeks were expressed as MoM of values at 11-13 weeks. The Mann-Whitney U-test was used to determine the significance of differences in the median values in each outcome group relative to that in the controls.
In the early-PE group at 11-13 weeks, compared with controls, there was a significant increase in median total cfDNA (2104 genome equivalents (GE)/mL vs 1590 GE/mL) and a decrease in median fetal fraction (6.8% vs 8.7%). In the late-PE group at 20-24 weeks, compared with controls, there was a significant decrease in median fetal fraction (8.2% vs 9.6%). These significant differences between groups were not observed when the values were converted to MoM.
Measurements of total cfDNA and fetal fraction in maternal plasma at 11-13 and 20-24 weeks are not predictive of PE.
研究随后发生子痫前期（PE）的孕妇在妊娠11 - 13周和20 - 24周时母体血浆中总游离（cf）DNA浓度及胎儿游离DNA比例是否与未发生该并发症的孕妇不同。
对20例在<34周时因早期PE需要分娩的孕妇、20例在≥34周时因晚期PE分娩的孕妇以及200例血压正常的对照组孕妇，在妊娠11 - 13周和20 - 24周时测量总cfDNA和胎儿游离DNA比例。将11 - 13周时测量的总cfDNA和胎儿游离DNA比例转换为中位数倍数（MoM），并根据母体特征和孕周进行校正。20 - 24周时总cfDNA和胎儿游离DNA比例的分布表示为11 - 13周时数值的MoM。采用曼-惠特尼U检验确定各结局组中位数与对照组中位数差异的显著性。
在11 - 13周的早期PE组中，与对照组相比，总cfDNA中位数显著升高（2104基因组当量（GE）/mL对1590 GE/mL），胎儿游离DNA比例中位数降低（6.8%对8.7%）。在20 - 24周的晚期PE组中，与对照组相比，胎儿游离DNA比例中位数显著降低（8.2%对9.6%）。当将这些数值转换为MoM时，未观察到组间的这些显著差异。
在妊娠11 - 13周和20 - 24周时测量母体血浆中的总cfDNA和胎儿游离DNA比例不能预测PE。
