Postdoctoral fellow at the Population Studies Center, University of Pennsylvania, Philadelphia, PA, USA.
Int Perspect Sex Reprod Health. 2020 Mar 3;46:9-19. doi: 10.1363/46e8420.
No studies using longitudinal contraceptive histories have investigated whether having an unintended birth (i.e., one resulting from an unintended pregnancy) is associated with change in contraceptive behavior, including in Colombia and Peru, where levels of unintended fertility remain high.
Monthly reproductive history calendar data from the 2010 Colombia and 2012 Peru Demographic and Health Surveys were used to study contraceptive behavior among 13,373 and 7,425 women, respectively. Transition matrices and hazard models were utilized to identify associations between prepregnancy and postpartum contraceptive methods used, and to assess how these relationships differed between women who reported an unintended birth and those with an intended birth.
Women who had been using a traditional, barrier or (in Colombia) short-acting hormonal method before pregnancy were more likely to choose a more effective method postpartum, than to use no method, if their birth had been unintended rather than intended (relative risk ratios, 1.2-1.3 in Colombia; 1.6 in Peru). Compared with their counterparts whose birth had been intended, women with an unintended birth who had been utilizing the most effective methods used in the country (IUD or implant in Colombia, pill or injectable in Peru) were less likely to resume using them postpartum than to use no method (0.7 in Colombia; 0.8 in Peru).
Unintended birth is associated with change in contraceptive behavior. Efforts to understand postpartum contraceptive choices of women who have had an unintended birth should take into account contraceptive behavior at more than one point in women's reproductive lives.
没有使用纵向避孕史的研究调查过意外怀孕（即由非意愿妊娠导致的怀孕）是否与避孕行为的改变有关，包括在哥伦比亚和秘鲁，这两个国家的意外生育率仍然很高。
使用 2010 年哥伦比亚和 2012 年秘鲁的人口与健康调查的每月生殖史日历数据，分别研究了 13373 名和 7425 名妇女的避孕行为。利用转移矩阵和风险模型来确定怀孕前和产后使用的避孕方法之间的关联，并评估这些关系在报告意外怀孕和计划内怀孕的妇女之间有何不同。
与计划内怀孕的妇女相比，在怀孕前使用传统的、屏障式或（在哥伦比亚）短效激素避孕方法的妇女，如果她们的分娩是意外的而不是计划内的，那么在产后更有可能选择更有效的避孕方法，而不是不使用任何方法（相对风险比，哥伦比亚为 1.2-1.3；秘鲁为 1.6）。与分娩计划内的妇女相比，意外分娩的妇女如果在该国使用最有效的方法（哥伦比亚的宫内节育器或植入物，秘鲁的药丸或注射剂），那么她们在产后更有可能继续使用这些方法，而不是不使用任何方法（哥伦比亚为 0.7；秘鲁为 0.8）。
意外怀孕与避孕行为的改变有关。理解意外怀孕妇女产后避孕选择的努力应该考虑到妇女生殖生活中不止一个时间点的避孕行为。
