Harlap S, Shiono P H, Ramcharan S
Int J Epidemiol. 1980 Mar;9(1):49-56. doi: 10.1093/ije/9.1.49.
Spontaneous losses between the 5th and 27th weeks of pregnancy were measured in a prospective study of 32 123 women whose contraceptive history around the time of conception was known. Diaphragm use prior to conception was associated with a significant reduction in second-trimester losses, after taking into account the effects of age, parity, race, marital status, alcohol use, and previous spontaneous or induced abortions. Women who used oral contraceptives and stopped them more than one month prior to their LMP experienced a deficit of first-trimester losses but conceptions occurring immediately after stopping the pill were followed by a small but nonsignificant increase in spontaneous abortions. After oral contraceptive failures there was an increase in first-trimester losses, but no change in the incidence of second-trimester ones. IUD failures were followed by a significant two-fold increase in the risk of both first and second-trimester losses: no differences were detected between the different brands.
在一项对32123名妇女的前瞻性研究中，测量了妊娠第5周至第27周的自然流产情况，这些妇女受孕时的避孕史已知。在考虑了年龄、产次、种族、婚姻状况、饮酒情况以及既往自然流产或人工流产的影响后，受孕前使用隔膜与孕中期流产显著减少有关。在末次月经前一个多月停用口服避孕药的妇女，孕早期流产有所减少，但停药后立即受孕的妇女，自然流产有小幅但不显著的增加。口服避孕药失败后，孕早期流产增加，但孕中期流产发生率没有变化。宫内节育器失败后，孕早期和孕中期流产风险显著增加两倍：不同品牌之间未发现差异。
