Although the cesarean section rate has increased steadily for the past 12 years, further increase seems unlikely since the indications for performing the operation are already broadly defined. Most of the earlier indications will remain unchanged (eg, the presence of placenta previa and cephalopelvic disproportion). The trend toward vaginal delivery in perhaps 30% to 40% of breech births will probably have no material effect on the number of cesarean sections performed, and the present use of cesarean section for multiple pregnancy will probably continue. The two conditions under which cesarean section rates might become significantly lower are (1) automatic repeat cesarean section (which now accounts for more than 25% of all cesarean sections), a procedure which will probably decline as increasing numbers of such women have vaginal deliveries, and (2) a redefinition of the present midforceps classification, which will permit some of the easy midforceps deliveries from a low level to be performed without the legally abhorrent stigma of mid-forceps delivery. The value of prophylactic antibiotics for women predisposed to infection has now been proved, and further placebo studies to demonstrate this are not warranted. In the past, "type and match 2 units" was a routine prelude to cesarean section, and for every unit of blood transfused to cesarean section patients, some 25 units were cross-matched and held in (unnecessary) readiness. This formula is gradually giving way to type and screen, eliminating countless crossmatches. Because of possible harmful fetal effects, preoperative fluid loading, a necessary part of conduction anesthesia, is changing from the customary 5% glucose to the use of fluids containing no glucose. It has been suggested that conduction anesthesia may not offer unlimited time for cesarean section, as used to be thought. Apgar scores are lower if the time from uterine incision to delivery is longer than three minutes, a diminution that may be a function of the anesthesia or may reflect difficulty in delivery. Cesarean section mortality is much lower than it was in former years, but one may expect from one to two deaths per 1,000 operations. Overall, the maternal mortality from cesarean section per se is probably from three to five times higher than that of vaginal delivery (in one series, 11.5 times higher than vaginal delivery). The incidence of mild, transient respiratory signs in the newborn is higher after cesarean than after vaginal delivery, and the incidence of respiratory distress syndrome is also slightly higher.(ABSTRACT TRUNCATED AT 400 WORDS)
尽管剖宫产率在过去12年中稳步上升,但由于手术指征已被广泛界定,进一步上升似乎不太可能。大多数早期指征将保持不变(例如,前置胎盘和头盆不称的存在)。大约30%至40%的臀位分娩采用阴道分娩的趋势可能对剖宫产的数量没有实质性影响,目前剖宫产用于多胎妊娠的情况可能会继续。剖宫产率可能显著降低的两种情况是:(1)选择性再次剖宫产(目前占所有剖宫产的25%以上),随着越来越多此类女性进行阴道分娩,这一手术可能会减少;(2)对目前低位产钳分类进行重新定义,这将允许一些低位的容易的产钳分娩在没有低位产钳分娩那种法律上令人厌恶的污名的情况下进行。预防性抗生素对易感染女性的价值现已得到证实,进一步进行安慰剂研究来证明这一点是没有必要的。过去,“血型鉴定并备血2单位”是剖宫产的常规前奏,对于每给剖宫产患者输注1单位血液,大约有25单位进行交叉配血并(不必要地)备用。这种方式正逐渐被血型鉴定和筛查所取代,从而消除了无数次交叉配血。由于可能对胎儿产生有害影响,术前补液(传导麻醉的必要部分)正从常规的5%葡萄糖改为使用不含葡萄糖的液体。有人提出,传导麻醉可能不像过去认为的那样能为剖宫产提供无限的时间。如果从子宫切开到分娩的时间超过三分钟,阿氏评分会更低,这种降低可能是麻醉的作用,也可能反映出分娩困难。剖宫产死亡率比过去几年低得多,但每1000例手术可能会有1至2例死亡。总体而言,剖宫产本身导致的孕产妇死亡率可能比阴道分娩高3至5倍(在一个系列中,比阴道分娩高11.5倍)。剖宫产术后新生儿出现轻度、短暂呼吸体征的发生率高于阴道分娩,呼吸窘迫综合征的发生率也略高。(摘要截选至400字)