Silver Robert M, Ahrens Katherine, Wong Luchin F, Perkins Neil J, Galai Noya, Lesher Laurie L, Faraggi David, Wactawski-Wende Jean, Townsend Janet M, Lynch Anne M, Mumford Sunni L, Sjaarda Lindsey, Schisterman Enrique F
Departments of Obstetrics and Gynecology, University of Utah Health Sciences Center and Intermountain Health Care, Salt Lake City, Utah, and University of Colorado, Aurora, Colorado; the Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland; the Department of Statistics, University of Haifa, Mt. Carmel, Haifa, Israel; the Department of Social and Preventive Medicine, University at Buffalo, Buffalo, New York; the Department of Family, Community and Rural Health, Commonwealth Medical College, Scranton, Pennsylvania.
Obstet Gynecol. 2015 Apr;125(4):876-884. doi: 10.1097/AOG.0000000000000736.
To evaluate the association between low-dose aspirin initiated before conception and the risk of preterm birth.
This was a secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial. Women with a history of pregnancy loss (original stratum: one loss less than 20 weeks of gestation during the previous year; expanded stratum: one or two losses with no restrictions on timing or gestational age of the losses) were randomized to either daily low-dose aspirin (81 mg, n=615) and folic acid or folic acid alone (placebo; n=613). Preterm birth was compared between groups using intent-to-treat analysis.
Preterm birth rates were 4.1% (22/535 low-dose aspirin) and 5.7% (31/543 placebo) (relative risk [RR] 0.72, 95% confidence interval [CI] 0.42-1.23); spontaneous preterm birth rates were 1.1% (6/535 low-dose aspirin) and 2.2% (12/543 placebo) (RR 0.51, 95% CI 0.19-1.34); medically indicated preterm birth rates were 2.6% (14/535 low-dose aspirin) and 2.9% (16/543 placebo) (RR 0.89, 95% CI 0.44-1.80). After restriction to confirmed pregnancies using inverse probability weighting, preterm birth rates were 5.7% and 9.0% (RR 0.63, 95% CI 0.37-1.09) and spontaneous preterm birth rates were 1.4% and 3.2% (RR 0.44, 95% CI 0.17-1.18). In confirmed pregnancies in the original stratum, preterm birth occurred in 3.8% and 9.7% of the low-dose aspirin and placebo groups, respectively (RR 0.39, 95% CI 0.16-0.94).
Preconception low-dose aspirin was not significantly associated with the overall rate of preterm birth. Although the study was underpowered for this secondary analysis, numeric trends in favor of benefit, particularly in the women with a recent, single early pregnancy loss, warrant further investigation.
ClinicalTrials.gov, www.clinicaltrials.gov, NCT00467363.
评估孕前开始使用低剂量阿司匹林与早产风险之间的关联。
这是一项对阿司匹林在妊娠与生殖中的作用试验的二次分析。有流产史的女性（原始分层：前一年有一次妊娠20周前的流产；扩展分层：有一或两次流产，对流产时间或孕周无限制）被随机分为每日服用低剂量阿司匹林（81毫克，n = 615）加叶酸组或仅服用叶酸组（安慰剂；n = 613）。使用意向性分析比较两组间的早产情况。
早产率在低剂量阿司匹林组为4.1%（22/535），安慰剂组为5.7%（31/543）（相对风险[RR] 0.72，95%置信区间[CI] 0.42 - 1.23）；自发早产率在低剂量阿司匹林组为1.1%（6/535），安慰剂组为2.2%（12/543）（RR 0.51，95% CI 0.19 - 1.34）；医学指征性早产率在低剂量阿司匹林组为2.6%（14/535），安慰剂组为2.9%（16/543）（RR 0.89，95% CI 0.44 - 1.80）。使用逆概率加权法限制为确诊妊娠后，早产率分别为5.7%和9.0%（RR 0.63，95% CI 0.37 - 1.09），自发早产率分别为1.4%和3.2%（RR 0.44，95% CI 0.17 - 1.18）。在原始分层的确诊妊娠中，低剂量阿司匹林组和安慰剂组的早产发生率分别为3.8%和9.7%（RR 0.39，95% CI 0.16 - 0.94）。
孕前低剂量阿司匹林与早产总发生率无显著关联。尽管该研究对此次二次分析的效能不足，但数值趋势显示可能有益，尤其是对于近期有单次早期妊娠流产的女性，值得进一步研究。
ClinicalTrials.gov，www.clinicaltrials.gov，NCT00467363
