Timing of Sexual Intercourse in Relation to Ovulation. Effects on the Probability of Conception, Survival of the Pregnancy, and Sex of the Baby

@article{Wilcox1995TimingOS,
  title={Timing of Sexual Intercourse in Relation to Ovulation. Effects on the Probability of Conception, Survival of the Pregnancy, and Sex of the Baby},
  author={Allen J. Wilcox and Clarice R. Weinberg and Donna D. Baird},
  journal={The New England Journal of Medicine},
  year={1995},
  volume={333},
  pages={1517-1521}
}
Background The timing of sexual intercourse in relation to ovulation strongly influences the chance of conception, although the actual number of fertile days in a woman's menstrual cycle is uncertain. The timing of intercourse may also be associated with the sex of the baby. Methods We recruited 221 healthy women who were planning to become pregnant. At the same time the women stopped using birth-control methods, they began collecting daily urine specimens and keeping daily records of whether… Expand
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TLDR
To maximize the likelihood of conception, intercourse should occur on days with optimal mucus quality, as observed in vaginal discharge, regardless of the exact timing relative to ovulation. Expand
Likelihood of conception with a single act of intercourse: providing benchmark rates for assessment of post-coital contraceptives.
TLDR
It is found that the possibility of late ovulation produces a persistent risk of pregnancy even into the sixth week of the cycle, and post-coital contraceptives may be indicated even when intercourse has occurred late in the cycle. Expand
Day-specific probabilities of clinical pregnancy based on two studies with imperfect measures of ovulation.
TLDR
Methods that anticipate ovulation by several days (such as the assessment of cervical mucus) would be particularly useful for couples who want to time their intercourse either to avoid or facilitate conception. Expand
Female gender pre-selection by maternal diet in combination with timing of sexual intercourse--a prospective study.
TLDR
It is concluded that the combination of maternal diet with timing of intercourse well before ovulation is capable of increasing the probability of conceiving a girl. Expand
Sex ratio associated with timing of insemination and length of the follicular phase in planned and unplanned pregnancies during use of natural family planning.
TLDR
The study suggests that manipulation of the timing of insemination during the cycle cannot be used to affect the sex of offspring. Expand
Peri-implantation intercourse lowers fecundability.
TLDR
Intercourse during the peri-implantation window may be detrimental to natural fertility and methods that allow couples to time intercourse to the fertile window may decrease time to pregnancy by not only increasing the probability of fertilization but also decreasing the probabilities of failed implantation. Expand
Conception probabilities at different days of menstrual cycle in Chinese women.
TLDR
Conception probabilities among Chinese women are different from those in the literature, and calculation of the efficacy of emergency contraception with low-dose mifepristone with the present conception probabilities showed higher efficacy. Expand
Contraceptive failure related to estimated cycle day of conception relative to the start of the last bleeding episode.
TLDR
It is possible that women using hormonal contraceptives may have a higher risk of pregnancy if they ovulate sooner after the onset of bleeding when using 21/7 hormonal contraceptives than after onset of menses when not using hormonal contraception. Expand
Peri-implantation intercourse does not lower fecundability.
TLDR
The current balance of evidence does not support a recommendation for avoiding intercourse in the peri-implantation period among couples trying to conceive. Expand
The role of matching menstrual data with hormonal measurements in evaluating effectiveness of postcoital contraception.
TLDR
Hormonal studies suggest that methods based on pregnancy risk calculated by cycle day do not faithfully reflect the real exposure, and the aim of this study was to improve the accuracy of calculations by evaluating the hormonal status on the day of contraceptive treatment. Expand
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