Likelihood of conception with a single act of intercourse: providing benchmark rates for assessment of post-coital contraceptives
Likelihood of conception with a single act of intercourse: providing benchmark rates for assessment of post-coital contraceptives
复制标题
DOI：
10.1016/s0010-7824(01)00191-3
复制
发表时间：
2001-04-01
期刊：
影响因子：
2.9
通讯作者：
Baird, DD
中科院分区：
文献类型：
--
作者：
Wilcox, AJ;Dunson, DB;Baird, DD
紧急性交后避孕药可有效降低怀孕风险，但其有效程度仍不确定。疗效的测量取决于未治疗的妊娠率，而妊娠率无法直接测量。我们使用一项对221名试图怀孕的妇女进行的前瞻性研究的数据，间接估计了这种怀孕率。我们先前估计了与排卵相关的性交行为怀孕的概率。在这篇文章中，我们将这些数据扩展到估计怀孕的概率相对于性交在一个给定的周期日（从以前的月经开始计数）。在评估性交后避孕药的有效性时，其他方法没有纳入关于排卵变异性的准确信息。我们发现，晚排卵的可能性产生了持续的怀孕风险，甚至进入周期的第六周。即使在周期的后期发生性交，也可能需要性交后避孕。(C)2001 Elsevier Science Inc. All rights reserved.
Emergency post-coital contraceptives effectively reduce the risk of pregnancy, but their degree of efficacy remains uncertain. Measurement of efficacy depends on the pregnancy rate without treatment, which cannot be measured directly. We provide indirect estimates of such pregnancy rates, using data from a prospective study of 221 women who were attempting to conceive. We previously estimated the probability of pregnancy with an act of intercourse relative to ovulation. In this article, we extend these data to estimate the probability of pregnancy relative to intercourse on a given cycle day (counting from onset of previous menses). In assessing the efficacy of post-coital contraceptives, other approaches have not incorporated accurate information on the variability of ovulation. We find that the possibility of late ovulation produces a persistent risk of pregnancy even into the sixth week of the cycle. Post-coital contraceptives may be indicated even when intercourse has: occurred late in the cycle. (C) 2001 Elsevier Science Inc. All rights reserved.