[Observation of course of placental separation by continuous dynamic ultrasonography during third stage of labor].
OBJECTIVE
To investigate the physiologic course of third stage of labor, and to judge the optimal time of natural placental separation permitted.


METHODS
To observe and record the course of third stage of labor by continuous dynamic ultrasonography and to estimate the total amount of blood loss from placental separation within two hours after delivery by the method of weighing lost blood.


RESULTS
Third stage of labor can be divided into four phases: the latent phase (4.37 +/- 3.78) min, the contraction phase (1.48 +/- 0.97) min, the detachment phase (0.50 +/- 0.00) min, and the expulsion phase (0.62 +/- 2.23) min. In 85% of the puerperas the third stage of labor takes about 10 minutes (average 6.94 minutes). The amount of postpartum hemorrhage and the risk of the patient increased prominently if the time of stage of labor was longer than 10 minutes (P < 0.01).


CONCLUSIONS
The third stage of labor must be limited in 10 minutes to prevent postpartum hemorrhage.
Cai
Xiang-ying
XY
Department of Obsterics and Gynecology, Wuxi, Fourth People's Hospital, Jiangsu Province, Wuxi 214062, China.
He
Cheng-zhang
CZ
Feng
Pei-zhen
PZ
Lu
Ying-hua
YH
Wang
Xi-mei
XM
Wang
Yuan
Y
Huang
Wen-qin
WQ
D000328:Adult; D036861:Delivery, Obstetric / Q000379:methods; D005260:Female; D006801:Humans; D007749:Labor Stage, Third / Q000502:physiology*; D010920:Placenta / Q000000981:diagnostic imaging* / Q000502:physiology; D006473:Postpartum Hemorrhage / Q000517:prevention & control; D011247:Pregnancy; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color; D016216:Ultrasonography, Prenatal; D014599:Uterus / Q000000981:diagnostic imaging / Q000502:physiology