Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
Labor is the normal process of coordinated, effective involuntary uterine contractions that lead to progressive cervical effacement and dilatation and descent and delivery of the newborn and placenta. Near its termination, labor may be augmented by voluntary bearing-down efforts to assist in delivery of the conceptus. False labor is characterized by irregular (both in interval and duration), brief contractions without fundal dominance, cervical change, or a lower station of the fetal vertex or breech. Dilatation of the cervix is the diameter of the cervical os expressed in centimenters (0–10). . | 6 COURSE AND CONDUCT OF LABOR AND DELIVERY Labor is the normal process of coordinated effective involuntary uterine contractions that lead to progressive cervical effacement and dilatation and descent and delivery of the newborn and placenta. Near its termination labor may be augmented by voluntary bearing-down efforts to assist in delivery of the conceptus. False labor is characterized by irregular both in interval and duration brief contractions without fundal dominance cervical change or a lower station of the fetal vertex or breech. Dilatation of the cervix is the diameter of the cervical os expressed in centimenters 0-10 . Effacement is cervical thinning that occurs before and especially during first stage labor. Effacement of the cervix is expressed as a percentage of cervical length normally 2.5 cm Figs. 6-1 6-2 . An uneffaced cervix is 0 one about 0.25 in length is 100 effaced. Effacement and dilatation are caused by retraction takeup of the cervix toward the uterine corpus not by pressure of the presenting part. The initiation of labor in the human is poorly understood. Labor can be triggered by one or more significant endocrine or physical changes for example abdominal trauma. The onset of labor can occur at any time after well-established pregnancy but the likelihood increases as term is approached. Labor can be induced or stimulated augmented by oxytocic agents e.g. oxytocin or prostaglandin E2 Fig. 6-3 . In 10 of gravidas thefetal membranes rupture before the onset of labor. This reduces the capacity of the uterus thickens the uterine wall and increases uterine irritability. Labor usually follows. At term 90 will be in labor within 24 h after membrane rupture. If labor does not begin in 24 h the case must be considered complicated by prolonged rupture of the membranes. Immediately before or early in labor a small amount of red-tinged mucus may be passed bloody show or mucous plug . This is a collection of thick cervical mucus often mixed with blood and
