分娩

分娩与助产

第一产程
第一产程所需时间最长（通常初产妇需要约16个小时，经产妇约8个小时）。在这个产程里，可以开始感受到分娩阵痛，随后阵痛频率渐渐地变快，疼痛强度逐渐地增强。这种一再重现的阵痛由子宫肌节律性收缩所引起。
起初，子宫肌收缩持续约30秒，15-20分钟重复出现。随着分娩进程的发展，子宫肌松弛的时间缩短到3-4分钟，而收缩时间持续60秒或更久。为分娩已经做过各种适当练习准备的产妇通过身体放松和调节呼吸能够减轻身体疲劳，而不是象未经训练的产妇那样挣扎着强忍身体的痛楚。
产妇经历这个产程，可以扩张子宫颈口，直到能够让胎儿头颅通过、娩出到阴道的那种程度。一旦完成了这个过程，分娩的第一产程便宣告结束，而实际的分娩也就迫近了。
临盆时，子宫收缩持续约1分钟，每隔约5分钟重现，这就是向医院紧急进发的充足理由。分娩即将到来的另外征象是在子宫与阴道之间作为屏障作用的宫颈粘液栓（会沾染上淡淡的血迹）被排除（在中国，此为“见红”——译者注）。还有另外的征象是羊膜囊的破裂（通常称为破水），此时会从阴道流出清亮的水状液体。

Birth

Labor and Delivery

The First Stage of Labor
The first stage of labor takes the longest time. (In general, about 16 hours for women delivering their first baby and about 8 hours for the others.) During this period, labor pains begin to be felt and slowly become more frequent and more intense. These recurring pains are caused by rhythmic muscular contractions of the uterus followed by complete relaxation.
At first, the contractions last about 30 seconds and occur about every 15 to 20 minutes. As labor progresses, the periods of relaxation shrink to about 3 to 4 minutes while the contractions last 60 seconds or more. A woman who has prepared herself for childbirth by appropriate exercises can ease much of the physical strain by relaxing and breathing in certain ways which support rather than fight the process taking place inside her body.
This process is aimed at dilating the cervix to the point where the baby's head can pass through it into the vagina. Once this is accomplished, the first stage of labor has come to an end and the actual birth is near.
Labor contractions lasting close to a minute and which recur about every five minutes are reason enough to proceed to the hospital. Another sign that birth is at hand is the expulsion of the cervical mucous plug which acts as a barrier between vagina and uterus. (It will be flecked with some light red blood.) Still another sign is the rupture of the membranes of the amniotic sac (commonly called bag of waters). This rupture will produce a flow of clear, water like fluid from the vagina.