Adashek J A, Peaceman A M, Lopez-Zeno J A, Minogue J P, Socol M L
Department of Obstetrics and Gynecology, Northwestern University Medical School, Chicago, Illinois.
Am J Obstet Gynecol. 1993 Oct;169(4):936-40. doi: 10.1016/0002-9378(93)90030-m.
Our purpose was to determine factors contributing to the increased use of cesarean section in patients > or = 35 years old.
Data were collected prospectively on nulliparous patients in spontaneous labor with term, singleton pregnancies and vertex presentations. Criteria for the diagnosis of labor were standardized: regular, painful uterine contractions at least once every 5 minutes in the presence of either complete cervical effacement or spontaneous rupture of membranes. The labors of women > or = 35 years old (n = 74) were compared with those of women 20 to 29 years old (n = 275).
The cesarean section rate was significantly greater for patients > or = 35 years old (21.6% vs 10.2%, odds ratio 2.4, 95% confidence interval 1.2 to 5.1). Mean birth weights were similar in the two groups, but when birth weight was > or = 3600 gm patients > or = 35 years old were more likely to be delivered by cesarean section (36.7% vs 12.2%, odds ratio 4.0, 95% confidence interval 1.4 to 11.9). There were no differences between the two age groups in physician factors that could explain the disparate rates of cesarean delivery. Indeed, of patients delivered vaginally the older parturients received oxytocin for longer duration (6.4 +/- 2.6 vs 5.0 +/- 3.1 hours, p < 0.05) and at higher maximum doses (12.4 +/- 6.1 vs 9.8 +/- 6.2 mU, p < 0.05). After controlling for potentially confounding variables with multiple logistic regression analysis, maternal age (R = 0.125, p < 0.005), birth weight (R = 0.196, p < 0.001), the need for oxytocin (R = 0.210, p < 0.001), and epidural anesthesia (R = 0.195, p < 0.001) were found to be independently associated with the increased rate of cesarean section.
We could not identify any controllable physician factors affecting the rate of cesarean section in patients > or = 35 years old. The increased oxytocin requirements and the incidence of dystocia with birth weight > or = 3600 gm suggest that maternal and fetal characteristics contribute to the increased frequency of cesarean section in older parturients.
我们的目的是确定导致35岁及以上患者剖宫产使用率增加的因素。
前瞻性收集未产妇自然分娩、足月、单胎妊娠且为头先露的数据。分娩诊断标准标准化：在宫颈完全消失或胎膜自然破裂的情况下，每5分钟至少有一次规律、疼痛的子宫收缩。将35岁及以上女性（n = 74）的分娩情况与20至29岁女性（n = 275）的进行比较。
35岁及以上患者的剖宫产率显著更高（21.6%对10.2%，优势比2.4，95%置信区间1.2至5.1）。两组的平均出生体重相似，但当出生体重≥3600克时，35岁及以上患者更有可能通过剖宫产分娩（36.7%对12.2%，优势比4.0，95%置信区间1.4至11.9）。在可能解释剖宫产率差异的医生因素方面，两个年龄组之间没有差异。实际上，在阴道分娩的患者中，年龄较大的产妇使用缩宫素的时间更长（6.4±2.6对5.0±3.1小时，p<0.05），最大剂量更高（12.4±6.1对9.8±6.2 mU，p<0.05）。通过多因素逻辑回归分析控制潜在的混杂变量后，发现产妇年龄（R = 0.125，p<0.005）、出生体重（R = 0.196，p<0.001）、使用缩宫素的必要性（R = 0.210，p<0.001）和硬膜外麻醉（R = 0.195，p<0.001）与剖宫产率增加独立相关。
我们无法确定任何影响35岁及以上患者剖宫产率的可控医生因素。缩宫素需求增加以及出生体重≥3600克时难产发生率表明，母体和胎儿特征导致老年产妇剖宫产频率增加。
