Ray Joel G, Bartsch Emily, Park Alison L, Shah Prakesh S, Dzakpasu Susie
Affiliations: Departments of Medicine and of Obstetrics and Gynecology (Ray), St. Michael's Hospital, University of Toronto; University of Toronto (Bartsch); Institute for Clinical Evaluative Sciences (Park); Department of Paediatrics (Shah), Mount Sinai Hospital, University of Toronto; Toronto, Ont.; Maternal, Child and Youth Health Unit (Dzakpasu), Public Health Agency of Canada, Ottawa, Ont.
CMAJ Open. 2017 Jun 23;5(2):E508-E516. doi: 10.9778/cmajo.20160092.
Hypertensive disorders, especially preeclampsia, are the leading reason for provider-initiated preterm birth. We estimated how universal acetylsalicylic acid (ASA) prophylaxis might reduce rates of provider-initiated preterm birth associated with preeclampsia and intrauterine growth restriction, which are related conditions.
We performed a cohort study of singleton hospital births in 2013 in Canada, excluding Quebec. We estimated the proportion of term births and provider-initiated preterm births affected by preeclampsia and/or intrauterine growth restriction, and the corresponding mean maternal and newborn hospital length of stay. We projected the potential number of cases reduced and corresponding hospital length of stay if ASA prophylaxis lowered cases of preeclampsia and intrauterine growth restriction by a relative risk reduction (RRR) of 10% (lowest) or 53% (highest), as suggested by randomized clinical trials.
Of the 269 303 singleton live births and stillbirths in our cohort, 4495 (1.7%) were provider-initiated preterm births. Of the 4495, 1512 (33.6%) had a diagnosis of preeclampsia and/or intrauterine growth restriction. The mean maternal length of stay was 2.0 (95% confidence interval [CI] 2.0-2.0) days among term births unaffected by either condition and 7.3 (95% CI 6.1-8.6) days among provider-initiated preterm births with both conditions. The corresponding values for mean newborn length of stay were 1.9 (95% CI 1.8-1.9) days and 21.8 (95% CI 17.4-26.2) days. If ASA conferred a 53% RRR against preeclampsia and/or intrauterine growth restriction, 3365 maternal and 11 591 newborn days in hospital would be averted. If ASA conferred a 10% RRR, 635 maternal and 2187 newborn days in hospital would be averted.
A universal ASA prophylaxis strategy could substantially reduce the burden of long maternal and newborn hospital stays associated with provider-initiated preterm birth. However, until there is compelling evidence that administration of ASA to all, or most, pregnant women reduces the risk of preeclampsia and/or intrauterine growth restriction, clinicians should continue to follow current clinical practice guidelines.
高血压疾病，尤其是先兆子痫，是医疗人员引发早产的主要原因。我们评估了普遍使用乙酰水杨酸（ASA）预防性治疗可能如何降低与先兆子痫和宫内生长受限相关的医疗人员引发的早产发生率，这两种情况是相关联的病症。
我们对2013年加拿大（不包括魁北克省）单胎医院分娩进行了一项队列研究。我们估计了足月分娩以及受先兆子痫和/或宫内生长受限影响的医疗人员引发的早产的比例，以及相应的产妇和新生儿平均住院天数。我们预测了如果ASA预防性治疗按照随机临床试验所建议的相对风险降低（RRR）10%（最低）或53%（最高）来降低先兆子痫和宫内生长受限的病例数，潜在可减少的病例数以及相应的住院天数。
在我们队列中的269303例单胎活产和死产中，4495例（1.7%）是医疗人员引发的早产。在这4495例中，1512例（33.6%）被诊断为先兆子痫和/或宫内生长受限。在未受这两种情况影响的足月分娩中，产妇平均住院天数为2.0（95%置信区间[CI] 2.0 - 2.0）天，而在同时患有这两种情况的医疗人员引发的早产中，产妇平均住院天数为7.3（95% CI 6.1 - 8.6）天。新生儿平均住院天数的相应值分别为1.9（95% CI 1.8 - 1.9）天和21.8（95% CI 17.4 - 26.2）天。如果ASA对先兆子痫和/或宫内生长受限的RRR为53%，可避免3365个产妇住院日和11591个新生儿住院日。如果ASA的RRR为10%，可避免635个产妇住院日和2187个新生儿住院日。
普遍的ASA预防性治疗策略可大幅减轻与医疗人员引发的早产相关的产妇和新生儿长期住院负担。然而，在有确凿证据表明对所有或大多数孕妇使用ASA可降低先兆子痫和/或宫内生长受限的风险之前，临床医生应继续遵循当前的临床实践指南。
