cervical dilatation การใช้

Harvey Karman in the United States refined the technique in the early 1970s with the development of the Karman cannula, a soft, flexible cannula that avoided the need for initial cervical dilatation and so reduced the risks of puncturing the uterus.
Three randomized, controlled trials showed that early initiation of epidural analgesia ( cervical dilatation, < 4 cm ) does not increase the rate of cesarean delivery among women with spontaneous or induced labour, as compared with early initiation of analgesia with parenteral opioids.
Such a device was soon developed ( commercially known as the PartoSure test ) and was initially evaluated in a multicenter, multinational pilot study, that included 101 consecutively recruited pregnant women with singleton pregnancies who presented with symptoms of preterm labor, clinically intact amniotic membranes, and minimal cervical dilatation.