{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T07:07:04Z","timestamp":1775718424317,"version":"3.50.1"},"reference-count":37,"publisher":"Wiley","issue":"7","license":[{"start":{"date-parts":[[2024,12,26]],"date-time":"2024-12-26T00:00:00Z","timestamp":1735171200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2024,12,26]],"date-time":"2024-12-26T00:00:00Z","timestamp":1735171200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Andrology"],"published-print":{"date-parts":[[2025,10]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Accurately judging the efficacy of contraceptives is vital for preventing unintended pregnancy. The Pearl index and life table analysis describe female contraceptive performance. However, they are not ideal for quantifying male contraceptive efficacy given differences between male and female methods. In particular, male contraceptives like condoms are used \u201con demand\u201d rather than long\u2010term like female contraceptives. Additionally, the number of episodes of sexual intercourse, a key determinant of risk, is not considered. Lastly, men can father concurrent pregnancies in more than one woman. For these reasons, a male\u2010specific measure may provide a more accurate measure of male contraceptive efficacy.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objectives and Methods<\/jats:title>\n                    <jats:p>As each episode of heterosexual intercourse within a fertile couple is associated with an approximately 3% risk of pregnancy, the chance of an unintended pregnancy with a given number of episodes of sexual intercourse can be modeled with and without contraceptives of various effectiveness.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Such modeling demonstrates that unintended pregnancy is strongly associated with both the number of episodes of sexual intercourse and the efficacy of the method. Based on these models, I propose a novel metric for male contraceptive efficacy called the Probability of Pregnancy\n                      <jats:sub>100<\/jats:sub>\n                      , defined as the percent chance of an unintended pregnancy occurring with 100 episodes of intercourse. Probability of Pregnancy\n                      <jats:sub>100<\/jats:sub>\n                      should be easy for men to understand and is applicable to men with multiple sexual partners or men using \u201con\u2010demand\u201d contraceptives.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion and conclusions<\/jats:title>\n                    <jats:p>\n                      The prevention of unintended pregnancy by a male contraceptive is strongly influenced by both method efficacy and sexual frequency. Probability of Pregnancy\n                      <jats:sub>100<\/jats:sub>\n                      may offer a better measure of male contraceptive efficacy compared to the Pearl index and life table analysis as it takes sexual frequency into account; however, Probability of Pregnancy\n                      <jats:sub>100<\/jats:sub>\n                      will need to be tested prospectively in male contraceptive studies alongside the Pearl index and life table analysis to determine its utility compared to these existing measures of contraceptive efficacy.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/andr.13831","type":"journal-article","created":{"date-parts":[[2024,12,27]],"date-time":"2024-12-27T01:04:50Z","timestamp":1735261490000},"page":"1980-1986","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The probability of pregnancy in 100 episodes of sexual intercourse: A measure of male contraceptive performance"],"prefix":"10.1111","volume":"13","author":[{"given":"John K.","family":"Amory","sequence":"first","affiliation":[{"name":"Department of Medicine University of Washington  Seattle Washington USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,12,26]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(01)18648-4"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.2307\/2060159"},{"key":"e_1_2_9_4_1","first-page":"558","article-title":"A guide to interpreting contraceptive efficacy studies","volume":"76","author":"Trussell J","year":"1990","journal-title":"Obstetric Gynecol"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/sim.4780100206"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.contraception.2023.110140"},{"key":"e_1_2_9_7_1","unstructured":"U.S. Food and Drug Administration.Center for Drug Evaluation and Research. Establishing effectiveness and safety for hormonal drug products intended to prevent pregnancy: guidance for industry (draft).2019. Accessed November 12 2024. Available from:https:\/\/www.fda.gov\/regulatory\u2010information\/search\u2010fda\u2010guidance\u2010documents\/establishing\u2010effectiveness\u2010and\u2010safety\u2010hormonal\u2010drug\u2010products\u2010intended\u2010prevent\u2010pregnancy\u2010guidance"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1080\/09540121.2012.668285"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1363\/psrh.12017"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/0029\u20107844(96)00246\u20103"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2013.02.040"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph17144985"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1093\/biostatistics\/kxq006"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0015-0282(16)33908-5"},{"key":"e_1_2_9_15_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199512073332301"},{"key":"e_1_2_9_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/s0010\u20107824(01)00191\u20103"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.contraception.2015.01.002"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.fertnstert.2012.10.031"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.29063\/ajrh2017\/v21i3.7"},{"key":"e_1_2_9_20_1","volume-title":"Basic and Clinical Biostatistics","author":"White S"},{"key":"e_1_2_9_21_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000123246.11511.e4"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41574\u2010018\u20100111\u20104"},{"key":"e_1_2_9_23_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmjgh\u20102021\u2010007151"},{"key":"e_1_2_9_24_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMsa1506575"},{"key":"e_1_2_9_25_1","doi-asserted-by":"publisher","DOI":"10.1002\/j.1939\u20104640.2005.tb01077.x"},{"key":"e_1_2_9_26_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deu259"},{"key":"e_1_2_9_27_1","first-page":"2011","article-title":"Current contraceptive use and variation by selected characteristics among women aged 15\u201344: United States, 2011\u20102013","volume":"86","author":"Daniels K","year":"2015","journal-title":"Natl Health Stat Rep"},{"key":"e_1_2_9_28_1","doi-asserted-by":"publisher","DOI":"10.1001\/jama.1956.02970090081016"},{"key":"e_1_2_9_29_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0015-0282(16)58144-8"},{"key":"e_1_2_9_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/s0015\u20100282(02)04694\u20100"},{"key":"e_1_2_9_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.contraception.2010.03.011"},{"key":"e_1_2_9_32_1","doi-asserted-by":"publisher","DOI":"10.2307\/3097748"},{"key":"e_1_2_9_33_1","doi-asserted-by":"publisher","DOI":"10.21037\/tau.2016.08.20"},{"key":"e_1_2_9_34_1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/deaa156"},{"key":"e_1_2_9_35_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa003005"},{"key":"e_1_2_9_36_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4302-5114-9_2"},{"key":"e_1_2_9_37_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10508\u2010017\u20100953\u20101"},{"key":"e_1_2_9_38_1","doi-asserted-by":"publisher","DOI":"10.1080\/01621459.1976.10480949"}],"container-title":["Andrology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/andr.13831","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/andr.13831","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/andr.13831","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T06:33:59Z","timestamp":1775716439000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/andr.13831"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,12,26]]},"references-count":37,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2025,10]]}},"alternative-id":["10.1111\/andr.13831"],"URL":"https:\/\/doi.org\/10.1111\/andr.13831","archive":["Portico"],"relation":{},"ISSN":["2047-2919","2047-2927"],"issn-type":[{"value":"2047-2919","type":"print"},{"value":"2047-2927","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,12,26]]},"assertion":[{"value":"2024-11-26","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-12-16","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-12-26","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}