Dept. Clinical Sciences Sacco, Obstet Gynecol, Buzzi Children's Hospital, University of Milan, Italy.
Placenta. 2011 Jul;32(7):487-92. doi: 10.1016/j.placenta.2011.04.004. Epub 2011 Apr 30.
The aim of this study was to assess and compare uterine artery (UtA) blood flow volume in pregnant patients with an abnormal uterine Doppler pulsatility index (PI) who delivered fetuses with an appropriate weight for gestational age (AGA) or with intrauterine growth restricted (IUGR). We prospectively recruited singleton pregnancies with abnormal uterine arteries P.I. between 18 and 38 weeks of gestation regardless of estimated fetal weight (EFW). Vessel diameter and blood flow velocity were measured along the UtA upstream to the vessel bifurcation in both the right and left UtAs. Uterine blood flow volumes measured in these pregnancies were compared to historical Control-pregnancies. Forty-three patients delivered at term a normal weight newborn (AGA-pregnancies). Thirty patients delivered growth restricted newborns at 32 weeks (i.r. 29-36w) with a median weight of 1160 gr (i.r. 1000-2065 gr) (IUGR-pregnancies). At mid-gestation (18 + 0 - 25 + 6 weeks + days of gestation) a significantly lower uterine blood flow volume per unit weight was observed between the two study groups and compared to controls: 142 ml/min/kg in IUGR-pregnancies, 217 ml/min/kg in AGA-pregnancies and 538 ml/min/kg in Control-pregnancies. These striking differences in blood flow volume were already present at mid-gestation, at a time when EFW was still normal. In late gestation (27 + 0 - 37 + 6 weeks + days of gestation), pregnancies with an abnormal uterine P.I. showed persistently low UtA flow (<50% of controls) even when corrected for fetal weight: 81 ml/min/kg in IUGR-pregnancies, 105 ml/min/kg in AGA-pregnancies, and 193 ml/min/kg in Control-pregnancies; p < 0.0001. Our findings are consistent with other recent studies regarding the association between reduced uterine blood flow volume and fetal growth restriction. However, the study brings new insight into the finding of abnormal uterine P.I. in normally grown fetuses typically dismissed as "falsely abnormal" or "false positive" findings. Our study suggests that blood flow volume measurement may serve as a new tool to assess this group of patients and possibly those with ischemic placental diseases that may provide some basis for therapeutic interventions.
本研究旨在评估和比较子宫动脉（UtA）血流容积在伴有异常子宫多普勒搏动指数（PI）的妊娠患者中的表现，这些患者所分娩的胎儿体重为适于胎龄（AGA）或存在宫内生长受限（IUGR）。我们前瞻性招募了 18 至 38 孕周伴有异常子宫动脉 PI 的单胎妊娠患者，而不考虑估计胎儿体重（EFW）。在右和左 UtA 中沿着 UtA 上游到血管分叉处测量血管直径和血流速度。将这些妊娠中的子宫血流容积与历史对照妊娠进行比较。43 例足月分娩体重正常的新生儿（AGA 妊娠）。30 例在 32 周（i.r. 29-36w）分娩体重受限的新生儿，中位体重为 1160 克（i.r. 1000-2065 克）（IUGR 妊娠）。在中期妊娠（18 + 0 - 25 + 6 周+天），两个研究组与对照组相比，单位体重的子宫血流容积明显较低：IUGR 妊娠为 142ml/min/kg，AGA 妊娠为 217ml/min/kg，对照组为 538ml/min/kg。这些血流容积的显著差异在中期妊娠时已经存在，此时 EFW 仍然正常。在晚期妊娠（27 + 0 - 37 + 6 周+天），伴有异常子宫 PI 的妊娠即使校正胎儿体重后，UtA 血流仍持续较低（<50%的对照组）：IUGR 妊娠为 81ml/min/kg，AGA 妊娠为 105ml/min/kg，对照组为 193ml/min/kg；p<0.0001。我们的发现与其他关于子宫血流容积减少与胎儿生长受限之间关联的近期研究一致。然而，本研究为异常子宫 PI 在通常生长的胎儿中发现的异常提供了新的见解，这些胎儿通常被认为是“假性异常”或“假阳性”发现。我们的研究表明，血流容积测量可能成为评估这组患者的新工具，也可能为可能存在缺血性胎盘疾病的患者提供一些治疗干预的依据。
