Vaughan Barbara, Trussell James, Kost Kathryn, Singh Susheela, Jones Rachel
Guttmacher Institute, New York, NY 10038, USA.
Contraception. 2008 Oct;78(4):271-83. doi: 10.1016/j.contraception.2008.05.007. Epub 2008 Jul 24.
Discontinuation of contraceptive use that is not immediately followed by resumption of use of another method while a woman is at risk is a common cause of unintended pregnancy.
We provide new estimates of discontinuation for the pill, injectable, male condom, withdrawal and fertility-awareness-based methods, and identify socioeconomic characteristics associated with discontinuation for the pill, male condom and withdrawal. We provide new estimates of resumption of use by prior method used and identify socioeconomic characteristics associated with resumption of use. Estimates are obtained using the 2002 National Survey of Family Growth, supplemented by the 2001 Abortion Patient Survey to correct for underreporting of abortion.
The fraction of method use segments discontinued for method-related reasons within 1 year was highest for the male condom (57%), withdrawal (54%) and fertility-awareness-based methods (53%), and lowest for the pill (33%), with the injectable in-between (44%). However, contraception was abandoned altogether in only 25% of cases. The probability of resuming use of a contraceptive was 72% in the initial month of exposure to the risk of an unintended pregnancy; this rose to 76% by the third month.
The risk of discontinuation of use of reversible methods of contraception for method-related reasons, including a change of method, is very high, but fortunately the risk of abandoning use of contraception altogether is far lower, and most spells of exposure to risk of an unintended pregnancy following discontinuation are protected from the start by a switch to another method.
在女性仍有怀孕风险时,停止使用一种避孕方法后未立即恢复使用另一种方法是意外怀孕的常见原因。
我们提供了关于口服避孕药、注射剂、男用避孕套、体外射精和基于生育意识的避孕方法停用情况的新估计,并确定了与口服避孕药、男用避孕套和体外射精停用相关的社会经济特征。我们提供了按先前使用方法划分的恢复使用情况的新估计,并确定了与恢复使用相关的社会经济特征。估计数据来自2002年全国家庭成长调查,并辅以2001年堕胎患者调查以纠正堕胎报告不足的问题。
在1年内因方法相关原因停用的避孕方法使用阶段比例,男用避孕套最高(57%),体外射精(54%)和基于生育意识的避孕方法(53%)次之,口服避孕药最低(33%),注射剂居中(44%)。然而,只有25%的情况是完全放弃避孕。在面临意外怀孕风险的最初一个月内,恢复使用避孕方法的概率为72%;到第三个月时升至76%。
因方法相关原因(包括更换方法)停用可逆性避孕方法的风险非常高,但幸运的是,完全放弃使用避孕方法的风险要低得多,而且大多数停用后面临意外怀孕风险的阶段从一开始就通过更换为另一种方法得到了保护。