Okuyama Ayumi, Hasegawa Junichi, Seo Kohei, Izdebski Tatsuya, Goto Minako, Sekizawa Akihiko, Ichizuka Kiyotake
Department of Obstetrics and Gynecology, Showa University Northern Yokohama Hospital, Yokohama 224-8503, Japan.
Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo 142-0064, Japan.
Diagnostics (Basel). 2024 Jul 11;14(14):1490. doi: 10.3390/diagnostics14141490.
This study aimed to clarify the relationship between fluctuations in uterine stiffness during the third stage of labor and blood loss upon placenta delivery using shear wave elastography.
This prospective cohort study enrolled consecutive singleton pregnant women above 37 weeks of gestation who delivered infants transvaginally at a single perinatal center. Shear wave velocities (SWV) were continuously measured during the third stage of transvaginal labor using transabdominal ultrasound and these values were compared between groups with large (≥500 g) and small amounts of bleeding during this stage.
In total, 8 cases of large bleeding and 47 cases of small bleeding were compared. The large amount of bleeding group had a significantly lower median of minimum SWV values (0.97 [0.52-1.01] m/s than the small amount of bleeding group (1.25 [1.04-1.48] m/s = 0.02). However, no significant differences were observed between the two groups in terms of median, mean, and maximum SWV values. The time from delivery of the infant to placental delivery was significantly longer in the large amount of bleeding group (median time: 370.5 s vs. 274 s, < 0.05).
Ultrasound quantification of uterine stiffness using shear wave elastography demonstrated that uterine contractions may influence the biological hemostasis of the uterus during the third stage of labor. Baseline uterine stiffness was weak and a longer duration of placental separation might be associated with cases of large amounts of bleeding during this stage.
本研究旨在利用剪切波弹性成像技术阐明分娩第三产程中子宫硬度波动与胎盘娩出时失血之间的关系。
这项前瞻性队列研究纳入了在单一围产期中心经阴道分娩的连续单胎妊娠且孕周超过37周的孕妇。在经阴道分娩的第三产程中，使用经腹超声连续测量剪切波速度（SWV），并比较该阶段出血量多（≥500 g）和出血量少的两组之间的这些值。
总共比较了8例大出血病例和47例小出血病例。大出血组的最小SWV值中位数（0.97 [0.52 - 1.01] m/s）显著低于小出血组（1.25 [1.04 - 1.48] m/s， = 0.02）。然而，两组在SWV值的中位数、平均值和最大值方面未观察到显著差异。大出血组从婴儿娩出到胎盘娩出的时间明显更长（中位数时间：370.5秒对274秒，< 0.05）。
使用剪切波弹性成像技术对子宫硬度进行超声定量分析表明，子宫收缩可能会影响分娩第三产程中子宫的生理性止血。基线子宫硬度较弱且胎盘分离时间较长可能与该阶段的大量出血病例有关。
