ArticleContraception2015
Benchmark pregnancy rates and the assessment of post-coital contraceptives: an update.
Article in Contraception, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
18 citing papers in PubMed, 41 citations in OpenAlex.
- Estimating emergency contraception efficacy with levonorgestrel and copper intrauterine devices.Contraception · 2025Trial
- Rates of pregnancy among levonorgestrel and copper intrauterine emergency contraception initiators: Implications for backup contraception recommendations.Contraception · 2021Trial
- Human stem cell-based embryo models: innovation, ethics, and policy.Human reproduction (Oxford, England) · 2026Article
- What to expect when you want to be expecting: time-to-pregnancy expectations and anticipated worry and help-seeking among a nationally representative survey of women in Uganda.Reproductive health · 2025Article
- Strategies for self-management of painful intercourse among female pregnancy planners.The journal of sexual medicine · 2025Article
- Maximizing the effectiveness of 1.5 mg levonorgestrel for emergency contraception: The case for precoital use.Contraception: X · 2024Article
- The role of legal medicine professionals in preventing pregnancy and sexually transmitted infections among female victims of sexual assault.Forensic science, medicine, and pathology · 2023Review
- High incidence of sexual dysfunction and timed intercourse was found only in infertile males who with known impairment of sperm quality for a long period: evidence from a hospital-based cross-sectional study.Reproductive biology and endocrinology : RB&E · 2022Article
- Reducing the Prevalence of Alcohol-Exposed Pregnancies in the United States: A Simulation Modeling Study.Medical decision making : an international journal of the Society for Medical Decision Making · 2022Article
- Hexavalent sperm-binding IgG antibody released from vaginal film for development of potent on-demand nonhormonal female contraception.Proceedings of the National Academy of Sciences of the United States of America · 2021Article
- Engineering sperm-binding IgG antibodies for the development of an effective nonhormonal female contraception.Science translational medicine · 2021Article
- Perceived likelihood of becoming pregnant and contraceptive use: Findings from population-based surveys in Côte d'Ivoire, Nigeria, and Rajasthan, India.Contraception · 2021Article
- Contraceptive Needs Among Women Recently Incarcerated at a Rural Appalachian Jail.Women's health reports (New Rochelle, N.Y.) · 2021Article
- Engineering tetravalent IgGs with enhanced agglutination potencies for trapping vigorously motile sperm in mucin matrix.Acta biomaterialia · 2020Article
- Shifts in Female Facial Attractiveness during Pregnancy.International journal of environmental research and public health · 2020Article
- Simplifying contraception requirements for iPLEDGE: A decision analysis.Journal of the American Academy of Dermatology · 2020Article
- Hormonal Contraceptives, Female Sexual Dysfunction, and Managing Strategies: A Review.Journal of clinical medicine · 2019Review
- Population, Reproductive, and Sexual Health: Data Are Essential Where Disciplines Meet and Ideologies Conflict.Frontiers in public health · 2016Article
Corrections and comments
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Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
objectiveIn 2001, we provided benchmark estimates of probability of pregnancy given a single act of intercourse. Those calculations assumed that intercourse and ovulation are independent. Subsequent research has shown that this assumption is not valid. We provide here an update of previous benchmark estimates. STUDY
designWe reanalyze earlier data from two North Carolina studies that collected daily urine samples and recorded daily intercourse for multiple menstrual cycles. One study comprised 68 sexually active women with either an intrauterine device or tubal ligation. The second was of 221 women who planned to become pregnant and had discontinued use of any birth control at enrollment. Participants had no known fertility problems. New statistical analyses were based on Monte Carlo simulations and Bayesian methods.
resultsThe probability that a single act of intercourse occurs within a woman's fertile window is 25%, compared with 20% in previous calculations. The probability of pregnancy with intercourse on a given menstrual cycle day is correspondingly higher than previously estimated, with the largest increases occurring on menstrual days 12-22. These increases are, however, fairly small (for example, the peak chance of conception on menstrual day 13 increased from 8.6% to 9.7%).
conclusionsPrevious benchmark rates of pregnancy with one act of intercourse were moderately underestimated due to a mistaken assumption about the independence of intercourse and ovulation. IMPLICATIONS STATEMENT: The chance of pregnancy with a single act of unprotected intercourse is greater than previously estimated. Previous benchmarks may underestimate the efficacy of post-coital contraception.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.