EP19.05: The dynamic changes in upper and lower uterine segment in 3rd stage of labour and blood loss during 3rd stage of labour

Abstract

The myometrial contraction is an important mechanism to reduce blood loss in 3rd and 4th stage of labour. In this study we evaluated the effect of the dynamic changes in different uterine segments on blood loss in the 3rd stage of labour. In a cohort study anterior (AUS) and posterior upper (PUS) and lower (ALS), (PLS) uterine myometrium thickness were measured in the mid region of the upper and lower uterine segments at one minute time intervals by ultrasound in the 3rd stage of labour in 80 term pregnancies and the thickness changes was compared with the amount of blood loss during 3rd stage of labour. The mean gestational age was 39.17 +/- 0.79 weeks. The mean duration of 3rd stage was 5.65 +/- 2.23 minutes. The mean blood loss in 3rd stage of labour was 371.03 +/- 659.84. The mean hemoglobin concentration was 12.32 +/- 0.97 g/dl and 10.98 +/- 1.44 g/dl before and after delivery respectively. In nulliparas the amount of blood loss in the 3rd stage of labour was significantly more than multiparas (P=0.01). The mean myometrial thickness in AUS increased linearly while in ALS decreased linearly during the process of placental expulsion. There was no significant difference in AUS, PUS, ALS and PLS dynamic changes between nulliparas and multiparas. There was no linear correlation between dynamic changes in different uterine segments and blood loss in the 3rd stage of labour. (AUS: R=0.13, P=0.23, PUS: R=0.03, P=0.73, ALS: R=0.01, P=0.92,PLS: R=0.14, P=0.23) There was a linear increase in AUS thickness and a linear decrease in ALS in 3rd stage of labour which enhanced placental expulsion but had no linear correlation with amount of blood loss.