The influence of gestational age and smoking habits on the risk of subsequent preterm deliveries
The influence of gestational age and smoking habits on the risk of subsequent preterm deliveries
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DOI：
10.1056/nejm199909233411303
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发表时间：
1999-09-23
影响因子：
158.5
通讯作者：
Harlow, BL
中科院分区：
文献类型：
--
作者：
Cnattingius, S;Granath, F;Harlow, BL
背景既往早产和母亲吸烟与早产风险增加有关。目前尚不清楚早产时的胎龄是否与连续早产的胎龄相关，也不知道吸烟习惯的变化是否会影响随后早产的风险。方法我们研究了1983至1993年间瑞典243,858名妇女的吸烟习惯、既往极早产或中早产(分别在32周前和32至36周)与随后极早产或中早产的风险之间的关系。结果有过早产经历的妇女与有过早产经历的妇女相比，再次妊娠时发生重度或中度早产的优势比分别为12.4(95%可信区间，9.1~17.0)和7.1(95%可信区间，6.0~8.4)。在有过中度早产经历的女性中，相应的优势比分别为2.3(95%可信区间，1.9至3.0)和5.9(95%可信区间，5.5至6.3)。与不吸烟者相比，每天吸烟1至9支的女性和每天吸烟10支或更多的女性再次早产的优势比分别为1.4(95%可信区间1.1至1.7)和1.6(95%可信区间1.3至2.0)。中度早产的相应优势比为1.3(95%可信区间为1.2至1.4)和1.5(95%可信区间为1.4至1.6)。在两次妊娠之间戒烟的妇女患极早产或中度早产的风险不会增加，而在第二次怀孕时开始吸烟的妇女与继续吸烟者的风险相同。结论连续妊娠中发生极早产的风险主要在有过早产经历的妇女中增加。吸烟习惯的改变也会影响早产的风险。(N Engl J Med 1999；341：943-8)(C)1999年，马萨诸塞州医学会。
Background Previous preterm delivery and maternal smoking are associated with increased risks of preterm delivery. It is not known whether gestational age at the time of a preterm delivery is correlated with gestational age in successive preterm deliveries and whether changes in smoking habits influence the subsequent risk of preterm delivery.Methods We studied the associations among smoking habits, previous very preterm or moderately preterm delivery (before 32 weeks and at 32 to 36 weeks, respectively), and the risk of a subsequent very preterm or moderately preterm delivery in a population-based cohort of 243,858 women in Sweden between 1983 and 1993. The results were adjusted for covariates known to be associated with preterm delivery.Results The odds ratios for very or moderately preterm delivery in a subsequent pregnancy among women with a previous very preterm delivery, as compared with women who had a previous term delivery, were 12.4 (95 percent confidence interval, 9.1 to 17.0) and 7.1 (95 percent confidence interval, 6.0 to 8.4), respectively. Among women with a previous moderately preterm delivery, the corresponding odds ratios were 2.3 (95 percent confidence interval, 1.9 to 3.0) and 5.9 (95 percent confidence interval, 5.5 to 6.3), respectively. The odds ratios for a very preterm second delivery among the women who smoked 1 to 9 cigarettes per day and those who smoked 10 or more cigarettes per day, as compared with nonsmokers, were 1.4 (95 percent confidence interval, 1.1 to 1.7) and 1.6 (95 percent confidence interval, 1.3 to 2.0), respectively. The corresponding odds ratios for moderate preterm delivery were 1.3 (95 percent confidence interval, 1.2 to 1.4) and 1.5 (95 percent confidence interval, 1.4 to 1.6). The women who quit smoking between pregnancies were not at increased risk for very or moderately preterm delivery, whereas the women who started to smoke in the second pregnancy had the same risk as those who continued to smoke.Conclusions The risk of a very preterm delivery in successive pregnancies is increased primarily among women with a previous very preterm delivery. Changes in smoking habits influence the risk of preterm delivery as well. (N Engl J Med 1999;341: 943-8.) (C) 1999, Massachusetts Medical Society.